PRIME MEDICAL SERVICES INC /TX/
10-K, 1998-03-31
MISC HEALTH & ALLIED SERVICES, NEC
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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                    FORM 10-K

              [X] Annual Report Pursuant to Section 13 or 15(d) of
                       the Securities Exchange Act of 1934
                   For the fiscal year ended December 31, 1997

            [ ] Transition Report Pursuant to Section 13 or 15(d) of
                       the Securities Exchange Act of 1934
                         For the transition period from
                                       to

                         Commission File Number: 0-22392


                          PRIME MEDICAL SERVICES, INC.
             (Exact name of registrant as specified in its charter)

                 DELAWARE                                         74-2652727
      (State or other jurisdiction of                          (I.R.S. Employer
       incorporation or organization)                        Identification No.)

               1301 Capital of Texas Highway, Austin, Texas 78746
               (Address of principal executive offices) (Zip Code)

                                 (512) 328-2892
              (Registrant's telephone number, including area code)

     Check whether the issuer (1) has filed all reports  required to be filed by
Section 13 or 15(d) of the Securities  Exchange Act of 1934 during the preceding
12 months (or for such shorter  period that the  registrant was required to file
such reports), and (2) has been subject to such filing requirements for the past
90 days. YES X NO

         Check if there is no  disclosure  of  delinquent  filers in response to
Item 405 of  Regulation  S-K contained in this form,  and no disclosure  will be
contained,  to the best of the  registrant's  knowledge,  in definitive proxy or
information statements incorporated by reference in Part III of the Form 10-K or
any amendment to this Form 10-K.

         State  the  aggregate   market  value  of  the  voting  stock  held  by
non-affiliates  computed by  reference to the price at which the stock was sold,
or the average bid and asked prices of such stock, as of a specified date within
60 days prior to the date of filing.
             Aggregate Market Value at March 20, 1998: $228,150,000

Indicate the number of shares  outstanding  of each of the  issuer's  classes of
common equity, as of the latest practicable date.
                                                 Number of Shares Outstanding at
          Title of Each Class                            March 20, 1998
          -------------------                            --------------
      Common Stock, $.01 par value                         19,314,267

                       DOCUMENTS INCORPORATED BY REFERENCE
         Selected portions of the Registrant's definitive proxy material for the
1998 annual meeting of shareholders  are incorporated by reference into Part III
of the Form 10-K.

                                        

<PAGE>



                          PRIME MEDICAL SERVICES, INC.

                           ANNUAL REPORT ON FORM 10-K

                      FOR THE YEAR ENDED DECEMBER 31, 1997


                                     PART I

ITEM 1.           BUSINESS.

         Prime Medical Services,  Inc., a Delaware  corporation  ("Prime" or the
"Company"),  is the  largest  provider  of  lithotripsy  services  in the United
States.  Lithotripsy  is a  non-invasive  procedure  for the treatment of kidney
stones, typically performed on an outpatient basis, that eliminates the need for
lengthy hospital stays and extensive  recovery periods  associated with surgery.
The  Company  has 61  lithotripters  of which 54 are  mobile and seven are fixed
site. The Company's  lithotripters  performed approximately 36,000 procedures in
the United States in 1997 through its network of approximately 450 hospitals and
surgery  centers in 34 states.  In addition,  the Company has over 270 contracts
with managed care organizations.

         Lithotripters  fragment  kidney stones by use of  extracorporeal  shock
wave lithotripsy.  The Company provides services related to the operation of the
lithotripters,  including  scheduling,  staffing,  training,  quality assurance,
maintenance,  regulatory  compliance and contracting with payors,  hospitals and
surgery  centers.  Medical  care is rendered  by the  urologists  utilizing  the
lithotripters. Management believes that the Company has collected the industry's
largest  and  most  comprehensive  lithotripsy  database,   containing  detailed
treatment and outcomes data on over 120,000 lithotripsy procedures.  The Company
and its  associated  urologists  utilize this database in seeking to provide the
highest quality of lithotripsy services as efficiently as possible.

         From 1992 through 1997, the Company completed 12 acquisitions involving
57 lithotripter  operations and internally developed four new operations.  Since
1992,  the Company  has  substantially  divested  its  original  non-lithotripsy
businesses.

Lithotripsy Industry Overview

         Kidney stones  develop from crystals made up primarily of calcium which
separate from urine and build up on the inner surfaces of the kidney.  The exact
cause of kidney stone formation is unclear,  and there is no known  preventative
cure in the vast  majority of cases.  Approximately  25% of all kidney stones do
not pass  spontaneously  and therefore  require  medical or surgical  treatment.
Kidney stone treatments used by urologists  include  lithotripsy,  drug therapy,
endoscopic extraction or open surgery. While the nature and location of a kidney
stone impacts the choice of treatment,  the Company believes the majority of all
kidney stones that require treatment are treated with lithotripsy  because it is
non-invasive,  typically  requires no general  anesthesia,  and rarely  requires
hospital stays. After  fragmentation by lithotripsy,  the resulting kidney stone
fragments pass out of the body naturally. Recovery from the procedure is usually
a matter of hours.

         Kidney stone disease is most  prevalent in the southern  United States.
Men are  afflicted  with kidney  stones more than twice as  frequently as women,
with the highest incidence occurring in men

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<PAGE>



45 to 64 years of age.

Kidney Stone Treatment Methods

     A number of kidney stone  treatments  are used by  urologists  ranging from
non-invasive  procedures,  such as drug  therapy  or  lithotripsy,  to  invasive
procedures, such as endoscopic extraction or open surgery. The type of treatment
a  urologist  chooses  depends  on a  number  of  factors,  such as the size and
chemical  make-up of the stone,  the stone's  location in the urinary system and
whether  the  stone is  contributing  to  other  urinary  complications  such as
blockage or infection.

     Certain  types of less common kidney stones may be dissolved by drugs which
allow normal passage from the urinary system. Stones located in certain areas of
the urinary tract may be extracted  endoscopically.  These  procedures  commonly
require  general or local  anesthesia  and can injure the involved  areas of the
urinary  tract.  Frequently,  kidney  stones  are  located  where  they  are not
accessible by an endoscopic procedure.  Prior to the development of lithotripsy,
stones  lodged in the upper  urinary tract were often treated by open surgery or
percutaneous stone removal,  both major operations requiring an incision to gain
access to the stone. After such procedures, the patient typically spends several
days in the hospital  followed by a convalescence  period of three to six weeks.
As the  technology  for treating  kidney stones has  improved,  there has been a
shift from more expensive and  complicated  invasive  procedures to safer,  more
cost efficient and less painful non-invasive procedures, such as lithotripsy.

Extracorporeal Shock Wave Lithotripsy

     General.  The lithotripter  has  dramatically  changed the course of kidney
stone disease treatment since lithotripsy is normally performed on an outpatient
basis, often without general anesthesia. Recovery times are generally only a few
hours,  and most patients can return to work the next day. There are three basic
types of lithotripsy treatment currently available:  electromagnetic,  spark-gap
and  piezoelectric.  A decision regarding which type is used in any instance may
depend on several factors, among which are the treating physician's preferences,
treatment times, stone location, and anesthesia considerations.  The Company has
40  electromagnetic  machines,  20  spark-gap  machines  and  one  piezoelectric
machine.

     Electromagnetic    Technology.    Most   new   lithotripters   utilize   an
electromagnetic  shock wave  component  that  eliminates the need for disposable
electrodes. The use of lithotripters employing electromagnetic technology allows
for more  precise  focusing  of shock wave  energy and more  predictable  energy
delivery than other  lithotripsy  technologies,  which  eliminates  the need for
anesthesia  in most  cases.  Utilization  of systems  employing  electromagnetic
technology  usually results in  fragmentation  of the kidney stone in between 60
and 90 minutes.

     Spark Gap Technology. With these lithotripsy systems, shock waves generated
by a disposable  high-voltage  spark  electrode  are focused on a kidney  stone.
Utilization  of  systems  employing  spark gap  technology  usually  results  in
fragmentation of the kidney stone in less than 60 minutes.  The use of spark-gap
technology  often  requires  the  administration  of  sedatives  or  intravenous
anesthesia care and in some cases requires general anesthesia.

     Piezoelectric  Technology.  Lithotripters applying piezoelectric technology
focus shock waves on the kidney stone using a linear array of ceramic  elements.
This  technology  has  not  been  widely  adopted,  and  there  are  only  a few
lithotripters utilizing piezoelectric technology operating in the United States.

                                        2

<PAGE>




Other Lines of Business

     In September  1997, the Company,  through its acquisition of a 75% interest
in AK Associates,  L.L.C.  ("AK"),  began providing  manufacturing  services and
installation,  upgrade,  refurbishment and repair of major medical equipment for
mobile  medical  services  providers.  The  Company  paid $4.8  million for this
interest,  plus an earn-out of up to $1.1  million.  The  remaining 25% of AK is
owned  by  certain  members  of AK  management.  The  Company  did  not  receive
significant revenues from AK during 1997.

     In October 1997, the Company began providing thermotherapy services for the
treatment of benign  prostatic  hyperplasia  ("BPH").  BPH is the  non-cancerous
enlargement  of  the  prostate,   a  condition   common  in  men  over  age  60.
Thermotherapy uses microwaves to apply heat to the prostate, resulting in relief
of the  symptoms  of BPH without  damaging  surrounding  tissues.  Thermotherapy
relieves the symptoms of BPH without incurring the risks of complications  often
associated with surgery and more invasive  procedures.  The Company operates one
mobile  thermotherapy  device servicing hospitals and surgery centers in eastern
North  Carolina,  and has  been  granted  an  unrestricted  license  to  provide
thermotherapy  services with a second mobile system in southern California.  The
Company intends to evaluate the success of its thermotherapy  operations and may
expand such  operations in the future.  The Company did not receive  significant
revenues from this activity during 1997.

     Prime  Cardiac   Rehabilitation   Services,   Inc.  ("Prime  Cardiac"),   a
wholly-owned subsidiary of the Company, provides non-medical management services
for six cardiac rehabilitation centers,  pursuant to agreements with physicians,
clinics and hospitals ("Medical Providers"). The Medical Providers have absolute
authority  over the medical  services  provided at the centers,  fees charged to
patients and the collection practices of the facility.  Prime Cardiac's fees are
generally  based  on  collected  revenues  of  the  centers.   The  Company  has
substantially  reduced its cardiac  rehabilitation  business over the last three
years,  which accounted for less than 1% of the Company's total revenues for the
year ended December 31, 1997.

Potential Liabilities-Insurance

         All medical  procedures  performed  in  connection  with the  Company's
business  activities  are  conducted  directly by, or under the  supervision  of
physicians,  who are not employees of the Company.  The Company does not provide
medical services to any patients. However, patients being treated at health care
facilities at which the Company provides its non-medical services could suffer a
medical emergency  resulting in serious injury or death, which could subject the
Company to the risk of lawsuits seeking substantial damages.

         The Company  currently  maintains  general and  professional  liability
insurance with a total limit of $1,000,000 per loss event and $3,000,000  policy
aggregate  and an umbrella  excess limit of  $10,000,000,  with a deductible  of
$25,000 per occurrence.  In addition, the Company requires medical professionals
who utilize its services to maintain  professional  liability insurance.  All of
these insurance policies are subject to annual renewal by the insurer.  If these
policies  were to be canceled or not  renewed,  or failed to provide  sufficient
coverage  for  the  Company's  liabilities,  the  Company  might  be  forced  to
self-insure against the potential  liabilities referred to above. In that event,
a single  incident  might  result  in an award of  damages  which  might  have a
material adverse effect on the operations of the Company.

                                        3

<PAGE>




Government Regulation and Supervision

         The  Company is subject to  extensive  regulation  by both the  federal
government  and the  states in which the  Company  conducts  its  business.  The
Company is subject to Section  1128B of the Social  Security  Act (known as "the
Illegal  Remuneration  Statute"),  which imposes civil and criminal sanctions on
persons  who  solicit,  offer,  receive  or pay any  remuneration,  directly  or
indirectly,  for  referring,  or  arranging  for the  referral of, a patient for
treatment that is paid for in whole or in part by Medicare,  Medicaid or similar
government  programs.  The federal  government  has published  regulations  that
provide  exceptions  or a  "safe  harbor"  for  certain  business  transactions.
Transactions  that are  structured  within  the safe  harbors  are deemed not to
violate the Illegal Remuneration  Statute.  Transactions that do not satisfy all
elements  of a relevant  safe  harbor do not  necessarily  violate  the  Illegal
Remuneration  Statute,  but may be subject to greater  scrutiny  by  enforcement
agencies.  The  arrangements  between the Company and the partnerships and other
entities in which it owns an  indirect  interest  and through  which the Company
provides most of its lithotripsy  services (and the  corresponding  arrangements
between such partnerships and other entities and the treating physicians who own
interests  therein  and  who  use  the  lithotripsy  facilities  owned  by  such
partnerships  and other  entities)  could  potentially  be questioned  under the
illegal remuneration prohibition and may not fall within the protection afforded
by these safe harbors. Many states also have laws similar to the Federal Illegal
Remuneration Statute.  While failure to fall within the safe harbors may subject
the Company to scrutiny  under the Illegal  Remuneration  Statute,  such failure
does  not   constitute  a  violation  of  the  Illegal   Remuneration   Statute.
Nevertheless,  these illegal  remuneration  laws,  as applied to activities  and
relationships  similar to those of the Company,  have been  subjected to limited
judicial  and  regulatory  interpretation,  and the Company has not  obtained or
applied  for any  opinion  of any  regulatory  or  judicial  authority  that its
business  operations  and  affiliations  are  in  compliance  with  these  laws.
Therefore,  no  assurances  can be given that the Company's  activities  will be
found to be in compliance with these laws if scrutinized by such authorities.

         In addition to the Illegal  Remuneration  Statute,  Section 1877 of the
Social  Security Act ("Stark II") imposes  certain  restrictions  upon referring
physicians  and  providers  of  certain  designated  health  services  under the
Medicare,  Medicaid and Champus  Programs  ("Government  Programs").  Subject to
certain exceptions, Stark II provides that if a physician (or a family member of
a physician) has a financial  relationship with an entity: (i) the physician may
not make a referral  to the  entity  for the  furnishing  of  designated  health
services reimbursable under the Government Programs; and (ii) the entity may not
bill Government Programs, any individual or any third-party payor for designated
health services furnished pursuant to a prohibited referral under the Government
Programs. The prohibitions of Stark II only apply to the treatment of Government
Program   patients,   and  have  no  application   to  services   performed  for
non-government  program patients.  Entities and physicians  committing an act in
violation of Stark II will be required to refund amounts  collected in violation
of the statute and also are subject to civil money  penalties and exclusion from
the  Government  Programs.  Urologists  are  investors in 43 of the Company's 61
lithotripsy operations,  and the two Company affiliates engaged in thermotherapy
services have  referring  physicians-  investors  (the Company  lithotripsy  and
thermotherapy  affiliates  with referring  physicians-investors  are referred to
herein as the "Company Physician Entities").

         Many key terms in Stark II are not  adequately  defined and the statute
is silent  regarding its application to vendors,  such as the Company  Physician
Entities,  contracting "under  arrangements" with hospitals for the provision of
outpatient  services.  Since the passage of Stark II, the  Company,  interpreted
Stark II  consistently  with the informal view of the General Counsel for Health
and

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Human  Services,  and concluded  that the statute did not apply to its method of
conducting  business.  Based upon a  reasonable  interpretation  of Stark II, by
referring  a patient to a hospital  furnishing  the  outpatient  lithotripsy  or
thermotherapy services "under arrangements" with the Company Physician Entities,
a physician  investor in a Company  Physician Entity is not making a referral to
an entity (the hospital) in which they have an ownership interest.

         On  January  9,  1998,  the  federal   government   published  proposed
regulations  under Stark II (the "Proposed  Stark  Regulations").  By clarifying
certain  ambiguities and defining  certain  statutory  terms, the Proposed Stark
Regulations   and   accompanying   commentary   apply  the  physician   referral
prohibitions  of  Stark  II to  the  Company  Physician  Entities'  practice  of
contracting  "under  arrangements"  with  hospitals for treatment and billing of
Government Program patients. Only hospitals can bill the Government Programs for
lithotripsy and thermotherapy services; thus contracting under arrangements with
hospitals was the way the Company Physician Entities  economically  participated
in the treatment of  Government  Program  patients.  Absent a  restructuring  of
traditional operations, to comply with the government's  interpretation of Stark
II, the  physician-  investors  will be  prohibited  from  referring  Government
Program  patients  to the  hospitals  contracting  with  the  Company  Physician
Entities.  The Company cannot  predict when final Stark II  regulations  will be
issued  or  the  substance  of  the  final  regulations,  but  the  interpretive
provisions  of the  Proposed  Stark  Regulations  may be viewed  as the  federal
government's  interim  enforcement  position until final regulations are issued.
Restructuring  traditional  operations  may reduce  Company  revenues  and limit
future  growth by (i)  reducing  or  eliminating  revenues  attributable  to the
treatment of Government Program patients by the Company Physician Entities, (ii)
reducing  revenues  from the  treatment  of  non-government  patients by Company
Physician Entities due to physician,  hospital and third-party payor anxiety and
concern created by Stark II, (iii) requiring the Company  Physician  Entities to
restructure  their  operations  to comply  with Stark II, (iv)  restricting  the
acquisition or development of additional lithotripsy or thermotherapy operations
that  will  both  treat   Government   Program   patients  and  have   referring
physician-investors,  (v) impairing the Company's  relationship  with urologists
and (vi) otherwise materially adversely impacting the Company.

         Many states  currently  have laws  similar to Stark II that  restrict a
physician with a financial  relationship with an entity from referring  patients
to that entity.  Often these laws contain statutory exceptions for circumstances
where the referring  physician,  or a member of his practice group, treats their
own patients.  States also commonly  require  physicians to disclose to patients
their financial  relationship with an entity. The Company believes that it is in
material   compliance   with  these  state  laws.   Nevertheless,   these  state
self-referral laws, as applied to activities and relationships  similar to those
of  the  Company,  have  been  subjected  to  limited  judicial  and  regulatory
interpretation,  and the Company has not  obtained or applied for any opinion of
any  regulatory  or  judicial   authority  that  its  business   operations  and
affiliations are in compliance with these laws. Therefore,  no assurances can be
given that the Company's activities will be found to be in compliance with these
laws if scrutinized by such authorities.

         In  addition,  upon  the  occurrence  of  changes  in the law  that may
adversely affect  operations,  the Company is required to purchase the interests
of  physician-investors  for certain of the Company  Physician  Entities.  These
mandatory purchase  obligations require the payment by the Company of a multiple
of earnings  similar to  multiples  used by the Company in pricing the  original
acquisition of such interests. To the extent the Company is required to purchase
such  interests,  such  purchases  might cause a default  under the terms of the
Company's  senior  credit  facility,  impair  the  Company's  relationship  with
urologists  and  otherwise  have a  material  adverse  impact  on  the  Company.
Regulatory  developments,  such as Stark II, might also dictate that the Company
purchase all the

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interests of its physician-investors, regardless of any contractual requirements
to do so,  or  substantially  alter its  business  and  operations  to remain in
compliance with applicable laws. Accordingly, there can be no assurance that the
Company will not be required to change its business  practices or its investment
relationships with urologists or that the Company will not experience a material
adverse  effect  as a  result  of any  challenge  made  by a  federal  or  state
regulatory   agency.   In   addition,   there   can   be   no   assurance   that
physician-investors who, voluntarily or otherwise,  divest of their interests in
Company  Physician  Entities will continue to refer patients at the same rate or
at all.

         Some states require  approval,  usually in the form of a certificate of
need  ("CON"),  prior to the  purchase of major  medical  equipment  exceeding a
predesignated  capital expenditure  threshold or for the commencement of certain
clinical health services.  Such approval is generally based upon the anticipated
utilization  of the  service  and the  projected  need  for the  service  in the
relevant geographical area of the state where the service is to be provided. CON
laws  differ in many  respects,  and not every  state's  CON law  applies to the
Company.  Most of the  Company's  operations  originated in states which did not
require a CON for  lithotripsy  services,  and the Company has obtained a CON in
states  where  one  is  required.  Some  states  also  require  registration  of
lithotripters  with the state agency  which  administers  its CON program.  Such
registration  is  not  subject  to  any  required  approval,  but  rather  is an
administrative  matter  imposed so that the state will be aware of all  existing
clinical health  services.  The Company  registers in those states which require
these filings.

         All states in which the Company  operates  require  registration of the
fluoroscopic  x-ray tubes which are utilized to locate the kidney stones treated
with the Company's lithotripters.  The registration  requirements are imposed in
order to facilitate periodic inspection of the fluoroscopic tubes.

         Some states have  regulations  that require  facilities  such as mobile
lithotripters  to be licensed and to have  appropriate  emergency care resources
and qualified staff meeting the stated educational and experience criteria.  The
Company's lithotripsy equipment is subject to regulation by the U.S. Food & Drug
Administration,  and the motor  vehicles  utilized to  transport  the  Company's
mobile  lithotripsy  equipment  are  subject  to safety  regulation  by the U.S.
Department of  Transportation  and the states in which the Company  conducts its
mobile  lithotripsy  business.  The  Company  believes  that  it is in  material
compliance with these regulations.

         Except as  provided  herein,  the  Company  believes it complies in all
material  respects  with the  foregoing  laws  and  regulations,  and all  other
applicable  regulatory  requirements;  however,  these laws are complex and have
been broadly construed by courts and enforcement agencies. Thus, there can be no
assurance  that the Company will not be required to change its  practices or its
relationships  with  treating  physicians  who  are  investors  in  the  Company
Physician  Entities,  or that the Company will not experience  material  adverse
effects as a result of any investigations or enforcement actions by a federal or
state regulatory  agency.  Further,  the Company  acknowledges that the Proposed
Stark Regulations apply the physician  referral  prohibitions of Stark II to the
Company  Physician  Entities'  practice of contracting  under  arrangements with
hospitals for the treatment and billing of  Government  Program  patients.  As a
consequence,  the Company Physician  Entities will have to restructure or modify
their  business  practices  in order to  comply  with the  Stark II  statute  as
interpreted by the Proposed Stark Regulations.

         A number of proposals  for  healthcare  reform have been made in recent
years,  some of which have included  radical  changes in the healthcare  system.
Healthcare  reform  could  result  in  material  changes  in the  financing  and
regulation of the healthcare business, and the Company is unable to

                                        6

<PAGE>



predict the effect of such  changes on its future  operations.  It is  uncertain
what legislation on healthcare reform, if any, will ultimately be implemented or
whether other changes in the  administration  or  interpretation of governmental
healthcare programs will occur. There can be no assurance that future healthcare
legislation  or  other  changes  in  the  administration  or  interpretation  of
governmental  healthcare programs will not have a material adverse effect on the
results of operations of the Company.

Equipment

         The Company  purchases its  lithotripter  equipment and  maintenance is
generally  provided pursuant to service contracts with the manufacturer or local
service  companies.  The cost of a new  lithotripter  ranges  from  $600,000  to
$1,200,000.  For mobile lithotripsy,  the Company either purchases or leases the
tractor,  usually for a term up to five years,  and  purchases  the trailer or a
self contained coach.

Employees

         As of March 15, 1998, the Company employed  approximately 330 full-time
employees and approximately 20 part-time employees.

Competition

         The market to provide  lithotripsy  services is highly  fragmented  and
competitive.  The Company  competes  with other private  facilities  and medical
centers  that  offer  lithotripsy  services  and  with  hospitals,  clinics  and
individual medical  practitioners that offer conventional  medical treatment for
kidney stones.  Certain of the Company's current and potential  competitors have
substantially  greater financial resources than the Company and may compete with
the Company for  acquisitions  and development of operations in markets targeted
by the Company. A decrease in the purchase price of lithotripters as a result of
the  development  of less  expensive  lithotripsy  equipment  could decrease the
Company's  competitive  advantage.  Most of the Company's  lithotripsy  services
agreements  have matured past their initial terms and are now in annual  renewal
terms  or  are  on a  month-to-month  basis.  Another  significant  provider  of
lithotripsy services is also a manufacturer of lithotripsy equipment,  which may
create different  incentives for such provider in pricing lithotripsy  services.
Moreover,  while the  Company  believes  that  lithotripsy  has  emerged  as the
superior  treatment  for  kidney  stone  disease,   the  Company  competes  with
alternative kidney stone disease treatments.

ITEM 2.           PROPERTIES.

         The Company's principal executive office is located in Austin, Texas in
an office building owned by American  Physicians  Services Group,  Inc. ("APS").
The Company  pays APS  approximately  $8,000 per month,  which  includes  rental
payment for  approximately  5,600  square feet of office  space,  reception  and
telephone services, and certain other services and facilities.  The office space
lease expires in December, 1998.

         The Company leases  approximately 11,000 square feet of office space in
Fayetteville,  NC under two leases  expiring in 2001. The current  monthly lease
amount is approximately $10,000.


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         The Company leases  approximately  24,000 square feet of  manufacturing
and office space in Mokena,  Illinois  under a lease which expires in 2000.  The
current monthly lease amount is approximately $12,000.

ITEM 3.           LEGAL PROCEEDINGS.

         From time to time,  the Company  may be named as a party to  litigation
proceedings incidental to its business. The Company does not believe the outcome
of any such  litigation  is  likely  to have a  material  adverse  effect on its
business, financial condition or results of operations.

ITEM 4.           SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

         NONE.


                                                      PART II

ITEM 5.           MARKET FOR REGISTRANT'S COMMON STOCK AND RELATED
                  STOCK HOLDER MATTERS.

         The following  table sets forth the high and low closing prices for the
Company's  common  stock  in the  over-the-counter  market  as  reported  by the
National  Association of Securities Dealers,  Inc., Automated Quotations System,
for the years ended December 31, 1997 and 1996 (NASDAQ Symbol "PMSI").

         Year Ended December 31, 1997        High                      Low

                  First Quarter              $12.38                  $ 9.75
                  Second Quarter              11.81                    8.94
                  Third Quarter               14.75                   10.25
                  Fourth Quarter              14.69                   11.75

         Year Ended December 31, 1996         High                      Low

                  First Quarter              $13.31                  $ 6.75
                  Second Quarter              20.38                   13.06
                  Third Quarter               17.25                   11.00
                  Fourth Quarter              13.75                   10.00

     On March 20, 1998, the Company had  approximately  800 holders of record of
its common stock.

         The Company has not  declared  any cash  dividends  on its common stock
during the last two years and has no present  intention  of  declaring  any cash
dividends in the foreseeable  future. In addition,  the Company is not permitted
by its current credit facility to declare or make any payments for dividends. It
is the  present  policy of the Board of  Directors  to retain  all  earnings  to
provide  funds for the growth of the  Company.  The  declaration  and payment of
dividends in the future will be determined by the Board of Directors  based upon
the  Company's  earnings,  financial  condition,   capital  requirements,   loan
covenants and such other factors as the Board of Directors may deem

                                        8

<PAGE>



relevant.

ITEM 6.  SELECTED FINANCIAL DATA.

($ in thousands, except per share data)
<TABLE>
<S>                                    <C>            <C>            <C>            <C>            <C>    
                                                            Years Ended December 31,
                                         1997          1996            1995          1994          1993
                                         ----          ----            ----          ----          ----

Revenues:

  Lithotripsy                          $ 93,113       $ 71,602       $ 22,153       $ 14,843       $  7,309

  Other                                   2,866            802          1,042          9,925         13,259
                                       --------       --------       --------      ---------       --------

  Total                                $ 95,979       $ 72,404       $ 23,195       $ 24,768       $ 20,568
                                       ========       ========       ========       ========       ========

Income:

  Net income                           $ 14,856       $   8,961      $  7,204       $  4,504       $  2,539
                                       ========       =========      ========       ========       ========

Diluted earnings per share:
  Net income                             $ 0.76          $ 0.49        $ 0.48         $ 0.31         $ 0.21
                                         ======          ======        ======         ======         ======

Dividends per share                       None           None           None          None            None

Total assets                           $225,826       $202,534       $ 77,627       $ 53,861       $ 38,678
                                       ========       ========       ========       ========       ========

Long-term obligations                  $ 71,198       $ 70,910       $ 22,323       $ 12,734       $  2,675
                                       ========       ========       ========       ========       ========

</TABLE>

ITEM 7.           MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                  CONDITION AND RESULTS OF OPERATIONS.

Forward Looking Statements

         The  statements  contained  in this  Report  on Form  10-K that are not
purely historical are  forward-looking  statements within the meaning of Section
27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act
of 1934,  including  statements  regarding  the  Company's  expectation,  hopes,
intentions or strategies  regarding the future.  Readers  should not place undue
reliance on forward-looking  statements. All forward-looking statements included
in this document are based on  information  available to the Company on the date
hereof, and the Company assumes no obligation to update any such forward-looking
statements.  It is important to note that the  Company's  actual  results  could
differ materially from those in such forward-looking  statements. In addition to
any risks and uncertainties specifically identified in the text surrounding such
forward- looking statements,  the reader should consult the Company's reports on
Form 10-Q and other filings under the  Securities Act of 1933 and the Securities
Exchange  Act of 1934,  for factors  that could cause  actual  results to differ
materially from those presented.

         The forward-looking statements included herein are necessarily based on
various  assumptions  and estimates and are inherently  subject to various risks
and  uncertainties,  including risks and uncertainties  relating to the possible
invalidity of the underlying  assumptions and estimates and possible  changes or
developments  in  social,  economic,   business,  industry,  market,  legal  and
regulatory circumstances and conditions and actions taken or omitted to be taken
by third parties,

                                        9

<PAGE>



including   customers,   suppliers,   business   partners  and  competitors  and
legislative,   judicial  and  other  governmental   authorities  and  officials.
Assumptions  related to the foregoing involve  judgements with respect to, among
other things,  future  economic,  competitive  and market  conditions and future
business  decisions,  all of  which  are  difficult  or  impossible  to  predict
accurately and many of which are beyond the control of the Company.  Any of such
assumptions  could be inaccurate and  therefore,  there can be no assurance that
the  forward-looking  statements  included  in this  Report on Form 10-K will be
prove to be accurate.

Year ended December 31, 1997 compared to the year ended December 31, 1996

     For the year ended December 31, 1997, total revenues increased  $23,575,000
(33%)  as  compared  to the same  period  in 1996.  Revenues  from  lithotripter
operations increased by $21,511,000 primarily due to the acquisitions of (i) one
lithotripter  entity that owned or managed 31 lithotripters  throughout the U.S.
effective May 1996,  (ii)  additional  interests in 10  partnerships  in January
1997,  (iii) one company that owned two  lithotripters  effective  June 1997 and
(iv) a 38.25% interest in a lithotripter unit effective May 1997.  Revenues from
manufacturing  were  $2,358,000,  related  to the  acquisition  of  the  trailer
manufacturer  in September 1, 1997.  Revenues  from  cardiac  centers  decreased
$323,000 primarily due to the one sold cardiac center.

     For the  year  ended  December  31,  1997,  costs  and  expenses (excluding
depreciation  and  amortization) increased  from  34% to 35%  of  revenues,  and
increased  $8,486,000  (34%) in absolute  terms,  compared to the same period in
1996.  Costs of  services  associated  with  lithotripter  operations  increased
$5,459,000 (27%) in absolute terms primarily due to the  acquisitions  discussed
above,  and decreased from 28% to 27% of  lithotripter  revenues.  Expenses from
manufacturing were $1,743,000.  Cost of services associated with cardiac centers
decreased  $322,000  (51%)  primarily  due to the  sale of one  cardiac  center.
Corporate expenses were 6% of revenues for both years as the Company was able to
successfully grow without  proportionately  adding overhead.  Corporate expenses
increased  $1,438,000 (34%) primarily due to the additional  corporate  expenses
associated with the acquisitions discussed above.

     For the year ended December 31, 1997, other deductions decreased $1,592,000
primarily due to $3,535,000 in debt issuance and canceled  stock  offering costs
in 1996, compared to only $360,000 which were recorded in 1997, partially offset
by an increase in  interest  expense of  $1,500,000  due to  borrowings  in 1997
related to the acquisitions discussed above.

     Minority interest in consolidated income increased $5,498,000 primarily due
to the  other  ownership  interest  associated  with 21  partnerships  in  which
Lithotripters,  Inc.  holds a controlling  interest.  The Company  concluded the
Lithotripters, Inc. acquisition effective May 1, 1996.

     Provision  for income  taxes  increased  $3,799,000  due to the increase in
income before income taxes,  partially offset by the Company fully utilizing its
net  operating  loss and  other  carryforwards  in  1997,  which  resulted  in a
reduction in the beginning of year valuation allowance of $2,399,000.

Year ended December 31, 1996 compared to the year ended December 31, 1995

     Total revenues increased  $49,209,000 (212%) as compared to the same period
in  1995.  Revenues  from  lithotripter   operations  increased  by  $49,449,000
primarily  due to the  acquisitions  of (i) an entity  that  owned or managed 31
lithotripters  effective  May 1, 1996 (ii) an entity that owned or managed eight
lithotripters  effective  October 1, 1995, and (iii) a 70% interest in an entity
that operated one  lithotripter,  as of July 1, 1995.  In addition,  the Company
acquired a 32.5%  interest in an entity that operated one  lithotripter  in June
1995. Revenues from cardiac centers decreased

                                       10

<PAGE>



$240,000 primarily due to four discontinued/sold cardiac centers.

     Costs and expenses (excluding depreciation and amortization) decreased from
43% to 34% of revenues,  but  increased  $14,742,000  (147%) in absolute  terms,
compared  to the  same  period  in  1995.  Costs  of  services  associated  with
lithotripter  operations increased $13,943,000 (233%) in absolute terms and from
27% to 28% of lithotripter revenues primarily due to the acquisitions  discussed
above. Cost of services associated with cardiac centers decreased $873,000 (58%)
primarily due to four  discontinued/sold  cardiac  centers.  Corporate  expenses
decreased  from 11% to 6% of revenues  as the  Company was able to  successfully
grow without  proportionately  adding  overhead.  Corporate  expenses  increased
$1,672,000 (65%) primarily due to the additional  corporate expenses  associated
with the acquisition  discussed above and the management incentive plans tied to
the performance of the Company.

     Other deductions increased $8,251,000 primarily due to (i) the write-off of
$2,735,000  in fees paid to lenders to obtain  financing,  and  $800,000 in fees
associated  with a proposed  stock offering that was canceled in August 1996 and
(ii) an increase in interest  expense of $4,746,000  due to $74.0 million in new
borrowings  in  1996  primarily  for the  acquisition  of  Lithotripters,  Inc.,
effective May 1, 1996.

     Minority interest in consolidated  income increased  $18,122,000  primarily
due to the other  ownership  interest  associated  with 21 partnerships in which
Lithotripters,  Inc.  holds a controlling  interest.  The Company  concluded the
acquisition of Lithotripters, Inc. effective May 1, 1996.

Liquidity and Capital Resources

     Cash was  $23,770,000 and $20,096,000 at December 31, 1997 and December 31,
1996,  respectively.  Cash provided by operations was  $51,693,000  for the year
ended  December 31, 1997 and  $41,602,000  for the year ended December 31, 1996.
The Company's  subsidiaries  generally  distribute  all of their  available cash
quarterly,  after establishing  reserves for estimated capital  expenditures and
working  capital.  For the years ended December 31, 1997 and 1996, the Company's
subsidiaries  distributed  cash of  approximately  $28,667,000 and  $13,440,000,
respectively, to minority interest holders.

     Cash used by investing  activities for the year ended December 31, 1997 was
$22,949,000  primarily  due to  $20,217,000  associated  with  acquisitions  and
$4,546,000 for the purchase of equipment and leasehold  improvements,  partially
offset by $1,690,000 in distributions  from investments.  Cash used by investing
activities for the year ended December 31, 1996 was $71,770,000 primarily due to
expenditures of $70,129,000  associated with acquisitions  including  $3,387,000
for  deferred  payments,  and  $2,526,000  for the  purchase  of  equipment  and
leasehold improvements. This was partially offset by $1,257,000 in distributions
from investments.

     Cash used in financing  activities for the year ended December 31, 1997 was
$25,070,000, primarily due to distributions to minority interests of $28,667,000
offset by net borrowings of $873,000,  and contributions  received from minority
interests of  $2,381,000.  Cash  provided by financing  activities  for the year
ended December 31, 1996 was $45,572,000,  which was primarily due to $58,649,000
in net borrowings under credit facilities,  partially offset by distributions to
minority interests of $13,440,000.

     The Company's existing credit facility is comprised of two term loans and a
revolving line of credit. The term loans bear interest at the rate of LIBOR plus
two percent to three percent,  payable monthly,  and require quarterly or annual
principal  payments.  At December 31, 1997,  approximately  $39 million was owed
under the term loan which matures in April 2001, and  approximately  $40 million
was owed under the term loan which matures in April 2003.  The revolving line of
credit  has a  borrowing  limit of $50.0  million  none of  which  was  drawn at
December 31, 1997.

     On March 27,  1998,  the Company  completed  an offering of $100 million of
senior  subordinated notes due 2008 (the  "Notes")  to  qualified  institutional
buyers. The net proceeds from the offering

                                       11

<PAGE>



of  approximately  $96  million  will  be  used to  repay  all  outstanding
indebtedness  under the Company's bank  facility,  with the remainder to be used
for general corporate purposes, including acquisitions.  In connection herewith,
the Company will take a charge to earnings of approximately $3.8 million for 
debt issuance costs associated with the Notes.

     The  Company  is  currently  evaluating  its  alternatives  in light of the
Proposed Stark Regulations.  While the Company believes the changing  regulatory
environment  may benefit the Company by  creating  new  lithotripsy  acquisition
opportunities,  the Company is reevaluating  its historical  model for providing
lithotripsy  and  thermotherapy   services  through   operations  which  include
physician- investors and has delayed the organization of physician  partnerships
that were in various stages of development.

     The Company  intends to increase the number of its  lithotripsy  operations
primarily through acquisitions.  The Company believes that the fragmented nature
of the lithotripsy  industry,  combined with operational  challenges  created by
increasing regulatory and business complexities, including Stark II, the Illegal
Remuneration   Statute  and  similar  state  laws,   will  provide   significant
lithotripsy acquisition opportunities.  Where appropriate, the Company will seek
to  increase  its  ownership  interest  in  current  lithotripsy  operations  by
purchasing  interests of urologists and other investors who desire to divest due
to  concerns  over  regulatory  issues,  a desire  to  realize a return on their
investment or  retirement.  The Company  intends to fund the purchase  price for
future  acquisitions using borrowings under its senior credit facility, proceeds
from the offering of the Notes and cash flow from operations.  In addition,  the
Company  may  use  shares  of  its  common  stock  in  such  acquisitions  where
appropriate.

     The Company has announced a stock repurchase program of up to $15.0 million
of common stock.  From time to time, the Company may purchase  additional shares
of its common stock where, in the judgment of management,  market  valuations of
its stock do not accurately  reflect the Company's past and projected results of
operations. The Company intends to fund any such purchases using available cash,
cash flow from operations and borrowings under its senior credit facility.

     The Company's ability to make scheduled payments of principal of, or to pay
the interest on, or to refinance,  its indebtedness,  or to fund planned capital
expenditures will depend on its future performance,  which, to a certain extent,
is subject to general economic, financial, competitive,  legislative, regulatory
and other  factors that are beyond its control.  Based upon the current level of
operations and anticipated cost savings and revenue growth,  management believes
that cash flow from  operations  and available  cash,  together  with  available
borrowings  under its  senior  credit  facility,  will be  adequate  to meet the
Company's future  liquidity needs for at least the next several years.  However,
there can be no assurance that the Company's  business will generate  sufficient
cash flow  from  operations,  that  anticipated  revenue  growth  and  operating
improvements  will be realized or that future borrowings will be available under
the senior  credit  facility  in an amount  sufficient  to enable the Company to
service its indebtedness or to fund its other liquidity needs.

Impact of Inflation

     The assets of the Company are not affected by inflation because the Company
is not required

                                       12

<PAGE>



to make large investments in fixed assets.  However,  the rate of inflation will
affect  certain of the Company's  expenses,  such as employee  compensation  and
benefits.

New Accounting Pronouncements

     In June 1997, the FASB issued FASB No. 131,  Disclosures  about Segments of
an Enterprise  and Related  Information,  which the Company is required to adopt
for annual  periods  beginning  after  December  15,  1997 and  interim  periods
beginning in fiscal year 1999.  SFAS No. 131  establishes  standards for the way
that public  companies  report  information  about operating  segments in annual
financial  statements and requires that those companies report information about
segments in interim  financial  reports issued to shareholders.  The Company has
not yet completed its analysis of this statement and the impact on its financial
statements.

Year 2000 Compliance

     The Company is aware of the issues  associated with the programming code in
existing  computer systems as the year 2000 approaches.  The "year 2000 problem"
is pervasive and complex as virtually every computer  operation will be affected
in some way by the  rollover  of the two digit  year  value to 00.  The issue is
whether computer systems will properly recognize date sensitive information when
the  year  changes  to  2000.  Systems  that  do  not  properly  recognize  such
information could generate erroneous data or cause a system to fail. The Company
does not  anticipate  that it will incur  significant  operating  expenses or be
required to invest  heavily in  computer  systems  improvements  to be year 2000
compliant.  However,  significant  uncertainty  exists  concerning the potential
costs  and  effects  associated  with any year  2000  compliance.  Any year 2000
compliance  problem of either the Company or its vendors,  third party payors or
customers  could  have a  material  adverse  effect on the  Company's  business,
results of operations, financial condition and prospects.

ITEM 7.A          QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET
                  RISK.

         Not required for 1997.

ITEM 8.           FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA.

         The  information  required  by this item is  contained  in  Appendix  A
attached hereto.

ITEM 9.           CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON
                  ACCOUNTING AND FINANCIAL DISCLOSURE.

         NONE.


                                    PART III

ITEM 10.          DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT.

     The information  required by this item is contained in the definitive proxy
material of the Company to be filed in connection  with its 1998 annual  meeting
of shareholders,  except for the information regarding executive officers of the
Company which is provided below. The information required by this item contained
in such definitive proxy material is incorporated herein by reference.




                                       13

<PAGE>



                  EXECUTIVE OFFICERS OF THE REGISTRANT.

     As of March 20, 1998, the executive officers of the Company are as follows:

     Name                   Age             Position

Kenneth S. Shifrin           48        Chairman of the Board

Joseph Jenkins, M.D., J.D.   50        President, Chief Executive Officer
                                          and Director

Michael Madler               39        Senior  Vice President - Operations

Dan Myers, M.D.              49        Senior Vice President - Development

Stan Johnson                 44        Vice President

Cheryl L. Williams           46        Chief Financial Officer, Vice
                                          President-Finance, and Secretary

The foregoing  does not include  positions  held in the Company's  subsidiaries.
Officers  are  elected  for annual  periods.  There are no family  relationships
between any of the executive officers and/or directors of the Company.

     Mr.  Shifrin  has been  Chairman of the Board and a director of the Company
since October 1989. In addition,  Mr.  Shifrin has served in various  capacities
with APS since February  1985, and is currently  Chairman of the Board and Chief
Executive Officer of APS.

     Dr. Jenkins has been President and Chief  Executive  Officer and a director
of the Company since April 1996.  From May 1990 until December 1991, Dr. Jenkins
was a Vice President of Lithotripters,  Inc. Since January 1992, Dr. Jenkins has
been President of Lithotripters, Inc. Dr. Jenkins is a board certified urologist
and is a founding  member,  a past  president  and  currently  a director of the
American Lithotripsy Society.

     Mr.  Madler has been Sr. Vice  President--Operations  of the Company  since
August   1996.   From  July  1993  to  August   1996,   Mr.   Madler   was  Vice
President--Operations of the Company.  Previously, Mr. Madler was Vice President
of Operations of American Health Services Corp., a diagnostic  imaging  company,
from July 1991 to June 1993.  He was  employed by the Company from 1985 to 1991,
most recently as its Vice President of Operations.

     Dr.  Myers has been Sr. Vice  President--Development  of the Company  since
August 1996. Dr. Myers is a board  certified  urologist and was a Vice President
of Lithotripters, Inc. from January 1990 until it was acquired by the Company in
April 1996.

     Mr.  Johnson has been a Vice  President of the Company and President of Sun
Medical  Technologies,  Inc. ("Sun"), a wholly-owned  subsidiary of the Company,
since November 1995.  Mr.  Johnson was the Chief  Financial  Officer of Sun from
1990 to 1995.

                                       14

<PAGE>




     Ms. Williams has been Chief Financial Officer, Vice  President--Finance and
Secretary of the Company  since  October 1989.  Ms.  Williams was  Controller of
Fairchild  Aircraft  Corporation  from August 1988 to October 1989. From 1985 to
1988, Ms. Williams served as the Chief Financial Officer of APS Systems, Inc., a
wholly-owned subsidiary of APS.

ITEM 11.          EXECUTIVE COMPENSATION.

     The information  required by this item is contained in the definitive proxy
statement of the Company to be filed in connection  with its 1998 annual meeting
of shareholders, which information is incorporated herein by reference.

ITEM 12.          SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND
                  MANAGEMENT.

     The information  required by this item is contained in the definitive proxy
statement of the Company to be filed in connection  with its 1998 annual meeting
of shareholders, which information is incorporated herein by reference.

ITEM 13.          CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS.

     The information  required by this item is contained in the definitive proxy
statement of the Company to be filed in connection  with its 1998 annual meeting
of shareholders, which information is incorporated herein by reference.


                                     PART IV

ITEM 14.          EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON
                  FORM 8-K.

(a)  1.  Financial Statements.

     The  information  required by this item is contained in Appendix A attached
hereto.

     2.  Financial Statement Schedules.

     NONE

All other schedules are omitted as the required  information is presented in the
Consolidated Financial Statements and related notes.

(b) Reports on Form 8-K.

         None.


                                       15

<PAGE>



(c)  Exhibits. (1)

     3.1     Certificate of Incorporation of the Company. (2)

     3.2     Bylaws of the Company. (2)

     4.1     Specimen of Common Stock Certificate. (2)

     10.1*   Prime Medical Services, Inc. 1993 Stock Option Plan. (3)

     10.2*   First Amendment to the Prime Medical Services, Inc. 1993 Stock 
             Option Plan. (12)

     10.3*   Second Amendment to the Prime Medical Services, Inc. 1993 Stock 
             Option  Plan. (12)

     10.4    Rights Agreement dated October 18, 1993 between the Company and
             American Stock Transfer and Trust Company. (3)

     10.5    Form of Indemnification Agreement dated October 11, 1993 between
             the Company and certain of its officers and directors. (3)

     10.6    Partnership Agreement of Metro Atlanta Stonebusters, G.P. (5)

     10.7    Management Agreement dated July 28, 1994 between the Alabama Renal
             Stone Institute, Inc. and Alabama Kidney Stone Foundation, Inc. (6)

     10.8    Asset Purchase Agreement, dated August 30, 1994, between Prime
             Lithotripter Operations, Inc. and Alabama Lithotripsy Joint 
             Venture. (7)

     10.9    Asset Purchase Agreement, dated August 30, 1994, between Prime
             Lithotripter Operations, Inc. and Baptist Medical Center - 
             Montclair. (7)

     10.10   Promissory Note, dated August 30, 1994, issued by Prime 
             Lithotripter Operations, Inc. to Baptist Medical Center - 
             Montclair.  (7)

     10.11   Management Agreement, dated August 30, 1994, between Prime 
             Lithotripter Operations, Inc. and Alabama Lithotripsy Associates, 
             Inc.  (7)

     10.12   Security Agreement dated August 30, 1994, between Prime 
             Lithotripter Operations, Inc. and Baptist Medical Center - 
             Montclair.  (7)

     10.13   Amended and Restated Joint Venture Agreement dated April, 1989, 
             between Prime Diagnostic Imaging Services, Inc. and The Shasta 
             Diagnostic Imaging Medical Group. (4)



                                       16

<PAGE>



     10.14  Loan Agreement dated November 28, 1994 between Prime Medical 
            Services, Inc., The First National Bank of Boston, NationsBank of 
            Texas, N.A. and The First National Bank of Boston, as agent.  (8)

     10.15  First Amendment to Loan Agreement dated August 17, 1995 between 
            Prime Medical Services, Inc. and The First National Bank of Boston, 
            as agent. (9)

     10.16  Amended and Restated Loan Agreement dated April 26, 1996 between 
            Prime Medical Services, Inc., The First National Bank of Boston, 
            NationsBank of Texas, N.A. and The First National Bank of Boston, 
            as agent. (11)

     10.17  Second Amended and Restated Loan Agreement between Prime Medical
            Services, Inc., The First National Bank of Boston, N.A. and 
            NationsBank of Texas, N.A., as agent. (12)

     10.18  Revolving Credit Note, dated March 31, 1997 in the amount of
            $14,111,111.11 issued by the Company to NationsBank of Texas, N.A. 
            as agent. (12)

     10.19  Revolving Credit Note, dated March 31, 1997 in the amount of
            $13,888,888.89 issued by the Company to The First National Bank of 
            Boston as agent. (12)

     10.20  Revolving  Credit  Note,  dated March 31, 1997 in the amount of 
            $8,333,333.33 issued by the Company to Bank One, Texas, N.A. 
            as agent. (12)

     10.21  Revolving Credit Note, dated March 31, 1997 in the amount of
            $6,666,666.67 issued by the Company to Imperial Bank as agent. (12)

     10.22  Revolving Credit Note, dated March 31, 1997 in the amount of
            $7,000,000.00 issued by the Company to The Sumitomo Bank, Limited as
            agent. (12)

     10.23  Term Note A, dated March 31, 1997 in the amount of $12,500,000.00 
            issued by the Company to NationsBank of Texas, N.A. as agent. (12)

     10.24  Term Note A,  dated  March 31,  1997 in the amount of $12,500,000.00
            issued  by the  Company  to The First National Bank of Boston as 
            agent. (12)

     10.25  Term Note A, dated March 31, 1997 in the amount of $7,500,000.00 
            issued by the Company to Bank One, Texas, N.A. as agent. (12)

     10.26  Term Note A, dated March 31, 1997 in the amount of $7,500,000.00 
            issued by the Company to Imperial Bank as agent. (12)

                                       17

<PAGE>



     10.27   Term Note A, dated March 31, 1997 in the amount of $5,000,000.00 
             issued by the Company to The Sumitomo Bank, Limited as agent. (12)

     10.28   Term Note B, dated March 31, 1997 in the amount of $10,000,000.00 
             issued by the Company to NationsBank of Texas, N.A. as agent. (12)

     10.29   Term Note B, dated March 31, 1997 in the amount of $5,000,000.00 
             issued by the Company to Crescent/MACH Partners, L.P. as agent.(12)

     10.30   Term Note B,  dated  March 31,  1997 in the amount of $5,000,000.00
             issued by the Company to Merrill Lynch Senior Floating Rate Fund, 
             Inc. as agent. (12)

     10.31   Term Note B,  dated  March 31,  1997 in the amount of $5,000,000.00
             issued  by  the  Company  to  Pilgrim America Prime Rate Trust as 
             agent. (12)

     10.32   Term Note B, dated March 31, 1997 in the amount of $5,000,000.00 
             issued by the Company to ING Capital Senior Secured High Income 
             Fund, L.P. as agent. (12)

     10.33   Term Note B, dated March 31, 1997 in the amount of $5,000,000.00 
             issued by the Company to Van Kampen American Capital Prime Rate 
             Income as agent. (12)

     10.34   Term Note B, dated March 31, 1997 in the amount of $5,000,000.00 
             issued by the Company to Paribas Capital Funding LLC as agent. (12)

     10.35   Operating Agreement for Southern California Stone Center, L.L.C.(9)

     10.36   Lease Agreement dated July 1, 1995 between Kidney Stone Center of 
             South Florida, L.C. and Madorsky and Pinon Kidney Stone Center of 
             South Florida, P.A. (9)

     10.37*  Employment Agreement dated October 27, 1995 between Prime Medical
             Services, Inc. and Stan D. Johnson. (9)

     10.38*  Employment Agreement dated May 1, 1996 between Prime Medical 
             Services, Inc. and Joseph Jenkins, M.D., J.D. (11)

     10.39*  Employment Agreement dated April 1, 1997 between Prime Medical
             Services, Inc. and William Walsh. (12)

     10.40*  Employment Agreement dated October 8, 1997 between Prime Medical
             Services, Inc. and Robert Bachman. (12)


                                       18

<PAGE>



     10.41* Employment Agreement dated October 8, 1997 between Prime Medical
            Services, Inc. and Larry Sodomire. (12)

     10.42  Stock Purchase Agreement dated April 26, 1996 between Prime Medical
            Services, Inc.; Lithotripters, Inc.; William R. Jordan, M.D.; 
            Franklin S. Clark, M.D.; Dan A. Myers, M.D.; Thomas B. Mobley, M.D.;
            Thomas R. Jordan; Anthony E. Rand; Estate of H. Edward Rietze, III;
            Phillip J. Gallina; Joseph Jenkins, M.D.; William B. Grine, M.D.; 
            and W. Alan Terry. (10)

     10.43  Registration Rights Agreement dated April 26, 1996 between Prime 
            Medical Services, Inc.; Lithotripters, Inc.; William R. Jordan, 
            M.D.; Franklin S. Clark, M.D.; Dan A. Myers, M.D.; Thomas B. Mobley,
            M.D.; Thomas R. Jordan; Anthony E. Rand; Estate of H. Edward Rietze,
            III; Phillip J. Gallina; Joseph Jenkins, M.D.; William B. Grine, 
            M.D.; and W. Alan Terry. (10)

     10.44  Partnership Interest Purchase Agreement dated May 1, 1997 among 
            Prime Lithotripter Operations,  Inc., Tenn-Ga Stone Group Two, L.P.,
            NGST, Inc. and all the shareholders of NGST, Inc. (12)

     10.45  Stock Purchase Agreement dated June 1, 1997 between Sun Medical
            Technologies, Inc. and Executive Medical Enterprises, Inc. (12)

     10.46  Contribution Agreement dated October 8, 1997 between Prime Medical
            Services, Inc. and AK Associates. (12)

     10.47  Limited Partnership Agreement of Pacific Medical Limited 
            Partnership. (12)

     10.48  Limited Partnership Agreement of California I Prostatherapy Limited
            Partnership. (12)

     10.49  Limited Partnership Agreement of Great Lakes Lithotripsy Limited
            Partnership. (12)

     10.50  Limited Partnership Agreement of Texas Lithotripsy Limited 
            Partnership VI, L.P. (12)

     10.51  Limited Partnership Agreement of North Carolina Prostatherapy 
            Limited Partnership I. (12)

     21.1   List of subsidiaries of the Company.  (12)

     23.1   Independent Auditors' Consent of KPMG Peat Marwick LLP.   (12)

     27     Financial Data Schedule (12)
 --------------

     *   Executive compensation plans and arrangements.



                                       19

<PAGE>



     (1) The exhibits listed above will be furnished to any security holder upon
written request for such exhibit to Cheryl L. Williams,  Prime Medical Services,
Inc.,  1301 Capital of Texas  Highway,  Suite C-300,  Austin,  Texas 78746.  The
Securities and Exchange Commission (the "SEC") maintains a website that contains
reports,  proxy  and  information  statements  and other  information  regarding
registrants that file electronically with the SEC at "http://www.sec.gov".

     (2)  Filed  as an  Exhibit  to  the  Registration  Statement  on  Form  S-4
(Registration No. 33-56900) of the Company and incorporated herein by reference.

     (3) Filed as an Exhibit to the  Current  Report on Form 8-K of the  Company
dated October 18, 1993 and incorporated herein by reference.

     (4) Filed as an  Exhibit  to the  Annual  Report on Form 10-K of Old Prime,
Commission  File  Number  0-9963,  for the  year  ended  December  31,  1992 and
incorporated herein by reference.

     (5) Filed as an Exhibit to the Current Report on Form 8-K dated May 5, 1994
of the Company and incorporated herein by reference.

     (6) Filed as an  Exhibit to the  Current  Report on Form 8-K dated July 28,
1994 of the Company and incorporated herein by reference.

     (7) Filed as an Exhibit to the Current  Report on Form 8-K dated  September
13, 1994 of the Company and incorporated herein by reference.

     (8) Filed as an Exhibit to the  Annual  Report on Form 10-K of the  Company
for the year ended December 31, 1994.

     (9) Filed as an Exhibit to the  Annual  Report on Form 10-K of the  Company
for the year ended December 31, 1995.

     (10) Filed as an Exhibit to the Current  Report on Form 8-K dated April 26,
1996 of the Company and incorporated herein by reference.

     (11) Filed as an Exhibit to the Annual  Report on Form 10-K of the  Company
for the year ended December 31, 1996.

     (12)         Filed herewith.

                                       20

<PAGE>



                                   SIGNATURES

     Pursuant  to the  requirements  of  Section  13 or 15(d) of the  Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.

                                        PRIME MEDICAL SERVICES, INC.



                                         By /s/ Joseph Jenkins, M.D., J.D.
                                            ------------------------------
                                         Joseph Jenkins, M.D., J.D., President,
                                         Chief Executive Officer and Director

                                         Date:  March 30, 1998

     Pursuant to the  requirements of the Securities  Exchange Act of 1934, this
report has been signed by the following  persons on behalf of the registrant and
in the capacities and on the dates indicated.



By: /s/ Kenneth S. Shifrin
    -----------------------
    Kenneth S. Shifrin
    Chairman of the Board

Date:  March 30, 1998


By: /s/ Cheryl L. Williams
    -----------------------
    Cheryl L. Williams
    Vice President of Finance, Secretary
    and Chief Financial Officer (Principal
    Financial and Accounting Officer)

Date:  March 30, 1998


By: /s/ Joseph Jenkins
    -------------------
    Joseph Jenkins, M.D., President,
    Chief Executive Officer and Director

Date:  March 30, 1998





                                       21

<PAGE>



By: /s/ Paul R. Butrus
    ------------------
     Paul R. Butrus, Director

Date:  March 30, 1998


By: /s/ William E. Foree
    --------------------
    William E. Foree, M.D., Director

Date:  March 30, 1998


By: /s/ Irwin Katz
    ---------------
    Irwin Katz, Director

Date:  March 30, 1998


By: /s/ John McEntire
    -----------------
     John McEntire, Director

Date:   March 30, 1998


By: /s/ William A. Searles
    ----------------------
    William A. Searles, Director

Date:  March 30, 1998


By: /s/ Michael Spalding
    ---------------------
    Michael Spalding, M.D., Director

Date:  March 30, 1998





                                       22

<PAGE>








                                   APPENDIX A

                                      INDEX
                                                                        Page


Independent Auditors' Report                                             A-2

Consolidated Financial Statements:
     Consolidated Statements of Income 
          for the years ended December 31, 1997, 1996 and 1995.          A-3

     Consolidated Balance Sheets at December 31, 1997 and 1996.          A-4

     Consolidated Statements of Stockholders' Equity 
          for the years ended December 31, 1997, 1996 and 1995.          A-6

     Consolidated Statements of Cash Flows 
          for the years ended December 31, 1997, 1996 and 1995.          A-7

     Notes to Consolidated Financial Statements.                         A-11








                                       A-1

<PAGE>



                          Independent Auditors' Report




The Board of Directors and Shareholders
Prime Medical Services, Inc.:

We  have  audited  the  accompanying  consolidated financial statements of Prime
Medical   Services,   Inc.  and  subsidiaries   ("Company")  as  listed  in  the
accompanying   index.   These   consolidated   financial   statements   are  the
responsibility of the Company's management.  Our responsibility is to express an
opinion on these  consolidated  financial  statements based on our audits.

We  conducted  our  audits  in  accordance  with  generally   accepted  auditing
standards.  Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements.  An audit also includes
assessing the  accounting  principles  used and  significant  estimates  made by
management,  as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the consolidated  financial statements referred to above present
fairly,  in all  material  respects,  the  financial  position of Prime  Medical
Services,  Inc. and  subsidiaries at December 31, 1997 and 1996, and the results
of their operations and their cash flows for each of the years in the three-year
period ended December 31, 1997, in conformity with generally accepted accounting
principles.  


/s/ KPMG Peat Marwick, LLP
- --------------------------
Austin, Texas
February 27, 1998, except Note N,
  to which the date is March 27, 1998










                                       A-2

<PAGE>



                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                        CONSOLIDATED STATEMENTS OF INCOME

($ in thousands, except per share data)      Years Ended December 31,
                                         1997           1996            1995
                                         ----           ----            ----
Fee Revenue:
   Lithotripsy:
         Fee revenues                  $84,537         $65,138          $19,306
         Management fees                 6,237           4,698            1,617
         Equity income                   2,339           1,766            1,230
                                      --------       ---------       ----------
                                        93,113          71,602           22,153

   Manufacturing                         2,358              --               --
   Cardiac                                 479             802            1,042
   Other                                    29              --               --
                                      --------     -----------     ------------
         Total fee revenue              95,979          72,404           23,195
                                      --------     -----------     ------------

   Cost of services and general and
       administrative expenses
         Lithotripsy                    25,381          19,922            5,979
         Manufacturing                   1,743              --               --
         Cardiac                           310             632            1,505
         Other                             168              --               --
         Corporate                       5,683           4,245            2,573
                                      --------       ---------       ----------
                                        33,285          24,799           10,057

    Depreciation and amortization        9,911           8,422            3,195
                                      --------       ---------       ----------
         Total operating expenses       43,196          33,221           13,252
                                       -------       ---------        ---------

Operating income                        52,783          39,183            9,943

Other income (deductions):
     Interest and dividends                740             459              152
     Interest expense                   (7,477)         (5,977)         ( 1,231)
     Loan fees and stock offering costs   (360)         (3,535)             --
     Other, net                              6             370              647
                                    ----------     -----------      ------------

                                        (7,091)         (8,683)         (   432)
                                     ---------     -----------       -----------
Income before provision for income taxes
     and minority interest              45,692          30,500            9,511

Minority interest in 
     consolidated income                25,041          19,543            1,421

Provision for income taxes               5,795           1,996              886
                                      --------      ----------       -----------

Net income                             $14,856       $   8,961        $   7,204
                                     =========       =========        ==========

Basic earnings per share:
     Net income                          $0.77           $0.51            $0.51
                                         =====           =====            =====

     Weighted average shares 
          outstanding                   19,275          17,633           14,226
                                        ======          ======           ======

Diluted earnings per share:
     Net income                          $0.76           $0.49            $0.48
                                         =====           =====            =====

     Weighted average shares 
          outstanding                   19,461          18,638           15,350
                                        ======          ======           ======

          See accompanying notes to consolidated financial statements.
                                       A-3

                                                            A-3

<PAGE>




                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                           CONSOLIDATED BALANCE SHEETS


($ in thousands)


                                                         December 31,
                                                       1997              1996
                                                     --------          --------

ASSETS

Current assets:
     Cash                                            $ 23,770          $ 20,096
     Accounts receivable, less allowance
       for doubtful accounts of $811 in 1997
       and $335 in 1996                                19,387            16,346
     Other receivables                                  1,103             1,842
     Deferred income taxes                              1,506               948
     Prepaid expenses and other current assets          1,776               841
                                                    ---------        ----------

          Total current assets                         47,542            40,073
                                                     --------          --------

Property and equipment:
     Equipment, furniture and fixtures                 32,673            28,318
     Leasehold improvements                               531               113
                                                    ---------         ---------

                                                       33,204            28,431
Less accumulated depreciation and
     amortization                                     (13,497)           (8,089)
                                                     --------          --------

     Property and equipment, net                       19,707            20,342
                                                     --------           -------


Other investments                                      12,305             8,100
Goodwill, at cost, net of amortization                143,823           131,415
Other noncurrent assets                                 2,449             2,604
                                                    ---------         ---------

                                                     $225,826          $202,534
                                                     ========          ========







                                                                   (continued)
          See accompanying notes to consolidated financial statements.
                                       A-4

                                                            

<PAGE>



                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                     CONSOLIDATED BALANCE SHEETS (continued)


($ in thousands)

                                                         December 31,
                                                      1997              1996
                                                  ----------        -----------
LIABILITIES:

Current Liabilities:

  Current portion of long-term debt                $  11,138          $ 10,522
  Accounts payable                                     5,386             4,451
  Accrued expenses                                    20,859            16,582
                                                   ----------         ---------

     Total current liabilities                        37,383            31,555

Long-term debt, net of current portion                71,198            70,910
Deferred income taxes                                  5,809             4,907
                                                  -----------        ----------

     Total liabilities                               114,390           107,372

Minority interest                                     19,372            18,735

STOCKHOLDERS' EQUITY:

Preferred stock, $.01 par value,
  1,000,000 shares authorized;
  none outstanding                                      --                 --
Common stock, $.01 par value,
  40,000,000 shares authorized;
  19,306,267 issued in 1997 and
  19,078,933 issued in 1996                              193               191
Capital in excess of par value                        84,050            83,271
Accumulated earnings (deficit)                         7,821           ( 7,035)
                                                  -----------        -----------

     Total stockholders' equity                       92,064            76,427
                                                   ----------        ----------

                                                   $ 225,826          $202,534
                                                   =========          ========












          See accompanying notes to consolidated financial statements.
                                       A-5

                                                            

<PAGE>



                          PRIME MEDICAL SERVICES, INC.
                 CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
              For the years ended December 31, 1997, 1996 and 1995

($ in thousands, except share data)
<TABLE>

<S>                          <C>           <C>           <C>           <C>        <C>     <C>        <C>            <C>

                                 Issued     Capital in   Accumulated
                              Common Stock   Excess of    Earnings       Treasury Stock               Reciprocal
                                Shares        Amount     Par Value     (Deficit)  Shares    Amount   Stockholdings    Total
                             -------------- ----------   ------------  --------- -------- ---------- -------------  ---------

Balance, January 1, 1995        14,594,663       $146        $58,631   ($23,200)   30,000     ($101)     ( $1,055)  $ 34,421

  Net income for the year              --         --             --       7,204       --        --            --       7,204
  Exercise of stock options        135,000          1             69        --        --        --            --          70
  Reclassification of
    reciprocal stockholdings           --         --             --         --        --        --          1,055      1,055
                             -------------- ----------  -------------  --------- --------  --------- -------------  ---------
Balance, December 31, 1995      14,729,663        147         58,700   ( 15,996)   30,000      (101)          --      42,750

  Net income for the year              --         --             --       8,961       --        --            --       8,961
  Issuance of stock              1,636,364         17         14,903        --        --        --            --      14,920
  Exercise of stock options
      including tax benefit of
      $130 on non-qualifying
      exercises                    477,666          5            488        --        --        --            --         493
  Debt converted to stock          921,415          9          5,241        --        --        --            --       5,250
  Exercise of warrants           1,343,825         13          4,040        --        --        --            --       4,053
  Retirement of treasury
      stock                  (      30,000)       --       (     101)       --    (30,000)      101           --         --
                             -------------- ----------     ----------  --------- ---------  -------- -------------  --------
Balance, December 31, 1996      19,078,933        191          83,271  (  7,035)      --        --            --      76,427

  Net income for the year              --         --             --      14,856       --        --            --      14,856

  Exercise of stock options
      including tax benefit of
      $438 on non-qualifying
      exercises                    227,334          2            779        --        --        --            --         781
                             -------------- ----------     ----------  --------- ---------  -------- ------------- ---------

Balance, December 31, 1997      19,306,267     $  193      $  84,050   $  7,821       --    $   --   $        --   $  92,064
                             ============== ==========     ==========  ========= =========  ======== ============= =========

</TABLE>

          See accompanying notes to consolidated financial statements.
                                       A-6

                                                                   

<PAGE>




                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                      CONSOLIDATED STATEMENTS OF CASH FLOWS
<TABLE>
<S>                                                <C>               <C>            <C>    

($ in thousands)
                                                      Years Ended December 31,
                                                     1997              1996           1995
                                                     ----              ----           ----

CASH FLOWS FROM OPERATING ACTIVITIES:
  Fee and other revenue collected                  $90,924           $ 72,452       $ 21,640
  Cash paid to employees, suppliers
      of goods and others                          (31,685)           (25,190)       ( 9,094)
  Interest received                                    739                459            157
  Interest paid                                    ( 7,521)           ( 5,104)       ( 1,275)
  Taxes paid                                       (   764)           ( 1,015)       (   530)
                                                   --------          ---------      ---------

      Net cash provided by operating activities     51,693             41,602         10,898
                                                   --------          ---------      ---------

CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchase of lithotripter entities                (20,217)           (66,742)       (15,033)
  Proceeds from sale of investment in American
                Physicians Service Group, Inc. stock   --                 --           2,753
  Purchases of equipment and leasehold
       improvements                                ( 4,546)           ( 2,526)      (    473)
  Deferred payments on lithotripter entities           --             ( 3,387)           --
  Proceeds from sales of equipment                      30                  6             21
  Investments                                        1,690              1,257            864
  Other                                                 94           (    378)      (      6)
                                                   --------          ---------      ---------

       Net cash used by investing activities       (22,949)           (71,770)      ( 11,874)
                                                   --------          ---------      ---------

CASH FLOWS FROM FINANCING ACTIVITIES:
  Payments on notes payable & capital  leases,
       exclusive of interest                       (50,328)           (15,351)       ( 9,588)
  Borrowings on notes payable                       51,201             74,000         14,284
  Distributions to minority interest               (28,667)           (13,440)       ( 1,644)
  Contributions by minority interest                 2,381                --             --
  Exercise of stock options                            343                363             70
  Other                                                --                 --          (  366)
                                                   --------          ---------      ---------

      Net cash provided by (used in) 
          financing activities                     (25,070)            45,572          2,756
                                                   --------          ---------      ---------

NET INCREASE IN CASH AND CASH
    EQUIVALENTS                                      3,674             15,404          1,780

Cash and cash equivalents, beginning of period      20,096              4,692          2,912
                                                   --------          ---------      ---------


Cash and cash equivalents, end of period           $23,770           $ 20,096       $  4,692
                                                   ========          =========      =========
</TABLE>

          See accompanying notes to consolidated financial statements.
                                       A-7





<PAGE>




                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                CONSOLIDATED STATEMENTS OF CASH FLOWS (continued)

($ in thousands)
<TABLE>
<S>                                                <C>                <C>            <C>    


                                                             Years Ended December 31,
                                                      1997              1996             1995
                                                      ----              ----             ----

Reconciliation of net income to net
 cash provided by operating activities
  Net income                                       $ 14,856           $ 8,961        $   7,204
  Adjustments to reconcile net
    income to cash provided by
    operating activities:
       Minority interest in consolidated income      25,041            19,543            1,421
       Depreciation and amortization                  9,911             8,422            3,195
       Provision for uncollectible accounts             427               319              771
       Equity in earnings of affiliates              (2,342)          ( 1,773)          (1,234)
       Gain on sale of investment in American
              Physicians Service Group, Inc. stock      --                 --            ( 559)
       Provision for deferred income taxes               68               974              193
       Writeoff of loan fees                            --                696              --
       Other                                          1,162                --             (226)
       Changes in operating  assets and  liabilities,
          net of effect of purchase transactions:
           Accounts receivable                       (3,156)            1,284           (  541)
           Other receivables                            754               472            2,197
           Other current assets                        (602)              529             (447)
           Accounts payable                             934               452           (1,224)
           Accrued expenses                           4,640             1,723              148
                                                   --------         ---------      -----------

        Total adjustments                            36,837            32,641            3,694
                                                   --------          --------       ----------

        Net cash provided by operating activities  $ 51,693          $ 41,602         $ 10,898
                                                   ========          ========         ========



</TABLE>











          See accompanying notes to consolidated financial statements.
                                       A-8


<PAGE>



                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                CONSOLIDATED STATEMENTS OF CASH FLOWS (continued)

($ in thousands)
<TABLE>
<S>                                                <C>               <C>                  <C>    

                                                              Years Ended December 31,
                                                       1997              1996             1995
                                                       ----              ----             ----

SUPPLEMENTAL INFORMATION OF
  NON-CASH INVESTING AND
  FINANCING ACTIVITIES:

In   1997,  the  Company  acquired  (1)  
additional  ownership  interests  in  10
partnerships  (2) a 38.25% general  
partnership  interest in a lithotripter
operation  (3) 100% of the  stock of a  
lithotripter  operator  and (4) 75% equity  
interest  in  a  trailer  manufacturer.   
These  transactions  are discussed  
further in Notes C and D. The acquired assets
and  liabilities  were as follows:

           Current assets decreased by             $    9,532
           Noncurrent assets increased by               4,041
           Goodwill increased by                       15,836
           Current liabilities increased by             1,343
           Noncurrent liabilities increased            10,000
           Minority interest decreased by                 998

At December 31, 1997, the Company had accrued
distributions payable to minority interests.  The
effect of this transaction was as follows:

           Current liabilities increased by             8,655
           Minority interest decreased by               8,655

In 1996, the Company acquired (1) 
100% of the outstanding stock of a
corporation which operated 31 
lithotripters and (2) increased ownership
in two partnerships, in which the Company
is the managing general partner. These 
transactions are discussed further in 
Note D. The acquired assets
and liabilities were as follows:

           Current assets increased by                               $19,032
           Noncurrent assets increased by                             12,630
           Goodwill increased by                                      82,297
           Current liabilities increased by                           13,110
           Noncurrent liabilities increased by                        69,712
           Minority interest increased by                             16,218
           Stockholders' equity                                       14,919

</TABLE>

          See accompanying notes to consolidated financial statements.
                                       A-9



<PAGE>



                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                CONSOLIDATED STATEMENTS OF CASH FLOWS (continued)

($ in thousands)
<TABLE>
<S>                                                <C>               <C>            <C>    

                                                             Years Ended December 31,
                                                      1997              1996          1995
                                                      ----              ----          ----

In 1996, several holders of notes
issued by the Company elected to convert 
the outstanding balances of the notes 
into 921,000 shares of the Company stock.
In addition, certain holders of warrants 
exercised their warrants and the Company 
issued 1,344,000 shares of the Company's 
stock to the warrant holders. The effect
of these transactions were as follows:

           Current assets increased by                                  1,749
           Current liabilities decreased by                             4,062
           Noncurrent liabilities decreased by                          3,493
           Stockholders' equity increased by                            9,304

At December 31, 1996, the Company had accrued
distributions payable to minority interests. The
effect of this transaction was as follows:

           Current liabilities increased by                            10,705
           Minority interest decreased by                              10,705

In 1995, the Company acquired (1) 100% of
the outstanding stock of a corporation
which owned or managed eight lithotripter
operations and (2) 70% interest in a 
lithotripter operation. These transactions 
are discussed further in Note D. The
acquired assets and liabilities were as follows:

           Current assets decreased by                                              $   9,905
           Noncurrent assets increased by                                               2,491
           Goodwill increased by                                                       19,553
           Current liabilities increased by                                             7,249
           Noncurrent liabilities increased by                                          4,890

In 1995, the Company retired a note payable
to American Physicians Service Group, Inc.
("APS"). This note was retired by the Company
transferring to APS shares of stock of APS
that the Company owned. The effect of this
transaction is as follows:

           Current assets decreased by                                                     3
           Investment in APS decreased by                                                301
           Notes payable decreased by                                                    297
           Stockholders' equity                                                            7
</TABLE>

          See accompanying notes to consolidated financial statements.
                                      A-10


<PAGE>


                                             
                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

A.       ORGANIZATION AND OPERATION OF THE COMPANY

         Prime Medical Services, Inc. ("Prime"), through its direct and indirect
         wholly-owned subsidiaries,  provides non-medical management services to
         lithotripsy,  prostatherapy,  and cardiac  rehabilitation  centers. 
         References to the Company are to Prime and its controlled and 
         affiliated entities.  The Company also manufactures trailers for  major
         medical equipment manufacturers and mobile medical  service  providers.
         The Company operates lithotripters in 34 states.

B.       SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

         Consolidation

         The  consolidated  financial  statements  include  the  accounts of 
         Prime,  its wholly-owned  subsidiaries,  entities more than 50% owned
         and  partnerships  where Prime  has  control,  even  though  its
         ownership  is less  than  50%.  Investments  in  entities  in which the
         Company's  investment is less than 50% ownership,  and the Company does
         not control,  are  accounted  for by the equity  method if ownership is
         between 20% - 50%, or by the cost method if ownership is less than 20%.
         Through  December  31,  1997,  the Company had  recognized  $466,000 in
         undistributed  earnings using the equity method. This amount represents
         undistributed  earnings  from  entities,  in which the Company  owns 50
         percent or less, and does not exhibit control.  All  significant 
         intercompany  accounts  and  transactions  have  been eliminated.

         Cash Equivalents

         The Company  considers  as cash  equivalents  demand  deposits  and all
         short-term  investments  with an original  maturity of three  months or
         less.

         Property and Equipment

         Property  and  equipment  are  stated at cost.  Major  betterments  are
         capitalized  while  normal  maintenance  and  repairs  are  charged  to
         operations.  Depreciation is computed by the straight-line method using
         estimated useful lives of five to ten years. Leasehold improvements are
         generally amortized over ten years or the term of the lease,  whichever
         is shorter. When assets are sold or retired, the corresponding cost and
         accumulated  depreciation or amortization  are removed from the related
         accounts and any gain or loss is credited or charged to operations.

         





                                      A-11

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





B.       SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, continued

        
         Intangible Assets

         The Company  records as goodwill the excess of the purchase  price over
         the fair value of the net assets associated with acquired  businesses.
         Goodwill is amortized over a period not to exceed forty years using the
         straight-line basis.  Accumulated amortization at December 31, 1997 and
         1996 is $9,745,000 and $5,798,000,  respectively.  Goodwill is reviewed
         for impairment whenever events or changes in  circumstances   indicate
         that  the  carrying  amount  may  not  be recoverable.  If the sum of 
         the expected future undiscounted cash flows is less than the carrying 
         amount of the goodwill,  a loss is recognized for the  difference  
         between the fair value and  carrying  value of the goodwill.

         Revenue Recognition

         Revenues generated from management services are recognized as they are 
         earned.

         The Company's lithotripsy fee revenues are based upon fees charged for
         services to hospitals, commercial insurance carriers, state and
         federal health care agencies, and individuals, net of contractual fee
         reductions. 

         Revenues  for the  manufacture  of trailers  are  recognized  using the
         percentage of completion method.

         At December 31, 1997,  approximately 15% of accounts  receivable relate
         to units operating in Texas, 11% relate to units located in California,
         11% relate to  operations  located in North  Carolina  and 9% relate to
         units located in Louisiana.

         Reciprocal Stockholdings

         The  Company  had   accounted   for  its   investment  in  its  largest
         shareholder's  common stock on the equity basis prior to 1995 (see Note
         C). The  Company's  investment  was reduced for the  Company's pro rata
         interest in the common stock of the Company owned by such  shareholder.
         This  reduction  was  reflected in an  offsetting  charge to reciprocal
         stockholdings.   When  the  Company's   investment  dropped  below  5%
         in 1995, reciprocal stockholdings were eliminated.


                                      A-12

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





B.       SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, continued

         Income Tax

         Deferred tax assets and  liabilities  are recognized for the future tax
         consequences   attributable   to  differences   between  the  financial
         statement carrying amounts of existing assets and liabilities and their
         respective tax bases and operating  loss and tax credit  carryforwards.
         Deferred  tax assets and  liabilities  are measured  using  enacted tax
         rates  expected to apply to taxable  income in the years in which those
         temporary  differences  are expected to be  recovered  or settled.  The
         effect on deferred tax assets and  liabilities of a change in tax rates
         is recognized in income in the period that includes the enactment date.

         Long-Lived Assets

         Long-lived  assets  are  reviewed  for  impairment  whenever  events or
         changes in  circumstances  indicate that the carrying amount may not be
         recoverable.  If the sum of the expected future undiscounted cash flows
         is less than the carrying amount of the asset, a loss is recognized, 
         for the difference  between the fair value and carrying value of the
         asset.

         Accounts Receivable

         Accounts receivable are recorded based on revenues,  less allowance for
         doubtful accounts and contractual adjustments.

         Stock-Based Compensation

         The Financial  Accounting Standards Board issued Statement of Financial
         Accounting  Standards No. 123, Accounting for Stock-Based  Compensation
         ("Statement  123"), in October 1995 for  implementation in fiscal years
         beginning  after  December 15,  1995.  Statement  123 became  effective
         beginning with the Company's  first quarter of fiscal year 1996 and did
         not have a  material  effect on the  Company's  financial  position  or
         results of  operations.  Upon  adoption of  Statement  123, the Company
         continued to measure  compensation expense for its stock-based employee
         compensation  plans using the intrinsic value method  prescribed by APB
         Opinion No. 25,  Accounting for Stock Issued to Employees.  The Company
         provides  proforma  disclosures of net income and earnings per share as
         if the fair  value-based  method  prescribed  by Statement 123 had been
         applied in measuring compensation expense. (See Note J).






                                      A-13

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





B.       SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, continued

         Debt Issuance Costs

         The Company expenses debt issuance costs as incurred.

         Estimates Used to Prepare Financial Statements

         Management  uses  estimates  and  assumptions  in  preparing  financial
         statements in accordance with generally accepted accounting principles.
         Those estimates and assumptions  affect the reported  amounts of assets
         and liabilities,  the disclosure of contingent  assets and liabilities,
         and the reported revenues and expenses.  Actual results could vary from
         the estimates that were assumed in preparing the financial statements.

         Reclassification

         Certain  reclassifications  have  been  made to  amounts  presented  in
         previous years to be consistent with the 1997 presentation.

         Earnings Per Share

         Statement of Financial  Accounting  Standards  No. 128,  "Earnings  per
         Share",   specifies  new   measurement,   presentation  and  disclosure
         requirements  for  earnings  per share and is  required  to be  applied
         retroactively  upon initial adoption.  The Company has adopted SFAS No.
         128 effective  with the release of December 31, 1997 earnings data, and
         accordingly,  has restated herein all previously  reported earnings per
         share data.  Basic earnings per share is based on the weighted  average
         shares  outstanding  without any dilutive effects  considered.  Diluted
         earnings per share  reflects  dilution from all  contingently  issuable
         shares,  including  options and convertible  debt. A reconciliation  of
         such earnings per share data is as follows:



                                      A-14

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





B.   SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, continued

     ($ in thousands, except per share data)

               1997
                                                        Per Share
                                      Income    Shares   Amounts
     Basic EPS
     Net Income.....................    $14,856   19,275 $   0.77
                                                         ========

     Effect of dilutive securities:
     Options      .                                  186
                                       --------      ---
     Diluted EPS....................    $14,856   19,461 $   0.76
                                        =======   ====== ========


               1996
                                                        Per Share
                                      Income    Shares   Amounts
     Basic EPS
     Net Income.....................    $ 8,961   17,633 $   0.51
                                                         ========

     Effect of dilutive securities:
     Warrants.......................                 400
     Convertible Debt...............        101      224
     Options      .                                  381
                                       --------      ---
     Diluted EPS....................     $9,062   18,638 $   0.49
                                         ======   ====== ========

               1995
                                                        Per Share
                                      Income    Shares   Amounts
     Basic EPS
     Net Income.....................    $ 7,204   14,226 $   0.51
                                                         ========

     Effect of dilutive securities:
     Warrants.......................                 402
     Convertible Debt...............         97      209
     Options      .                                  513
                                       --------      ---
     Diluted EPS....................     $7,301   15,350 $   0.48
                                         ======   ====== ========


        Unexercised  employee stock options to purchase  841,000 and 706,000 
        shares of Prime common stock as of December  31,  1997 and 1996,  
        respectively,  were not  included  in the  computations  of diluted  EPS
        because the options exercise prices were greater than the average market
        price of Prime's common stock during the respective periods.

                                      A-15

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





C.   INVESTMENTS

        Tenn-Ga

        In May 1997, the Company acquired a 38.25% general partner interest in a
        partnership  that provides mobile  lithotripsy  service in Tennessee and
        Georgia.  The purchase price was cash of $3,470,000.  This investment is
        accounted for using the equity method.

        Southern California

        Effective  June 1, 1995,  the  Company  acquired a 32.5%  interest  in a
        limited  liability  company that operates a fixed site lithotripter near
        Los Angeles,  California.  This  investment  is accounted  for using the
        equity method.

        Texas, Ohio & Louisiana Partnerships

        In December  1994,  the Company  acquired  all of the common stock of 
        three  corporations.  Each  corporation  is the  general  partner  and 
        holds an approximate  20%  interest  in a limited  partnership  which  
        operates  a mobile lithotripter. Texas ESWL/Laser Lithotripter, Ltd.
        operates a mobile lithotripter in Texas,  Oklahoma and  Arkansas.  Ohio 
        Mobile  Lithotripter,  Ltd.  operates a mobile lithotripter in Ohio. 
        Arklatx Mobile Lithotripter, L.P. operates a mobile lithotripter  in  
        Louisiana.  This  investment is accounted for using the equity method.

        American Physicians Service Group, Inc.

        At December 31, 1997 and 1996, the Company owned 50,000 shares of common
        stock, representing approximately 1%, of the outstanding common stock of
        American  Physicians Service Group, Inc. (APS). APS owned  approximately
        16% of the outstanding  common stock of the Company at December 31, 1997
        and 1996.  The  Company's  pro rata interest in its own shares of common
        stock  had  been   included  in   stockholders'   equity  as  reciprocal
        stockholdings prior to 1995. (See Note B).  Two of the  Company's  eight
        board members are also on the board of APS.

        The Company  occupies  approximately  5,600  square feet of office space
        owned by APS. The Company also shares  certain  personnel  with APS. The
        monthly rent and personnel cost is approximately $8,000.

D.       ACQUISITIONS

         Effective September 1, 1997, the Company acquired a 75% equity interest
         in AK Associates,  LLC ("AK"),  which provides  installation,  upgrade,
         manufacturing,  refurbishment  and repair  services  for major  medical
         equipment  manufacturers  and mobile  medical  service  providers.  The
         purchase price was $4,761,000 in cash with contingent  consideration up
         to another  $1,050,000  being  payable  based upon certain  performance
         criteria being met by AK during 1998.  This  transaction  was accounted
         for using the purchase method of accounting.

                                      A-16

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





D.       ACQUISITIONS, continued

         Effective  June 1,  1997,  the  Company  acquired  100% of the stock of
         Executive  Medical  Enterprises,  Inc.  ("EME"),  which  operated three
         lithotripters in California,  Oregon and Washington. The purchase price
         was  $1,339,000 in cash and potential  contingent  consideration  based
         upon the  performance of these  operations  during 1998, 1999 and 2000.
         The  transaction  was  accounted  for  using  the  purchase  method  of
         accounting.

         In   January 1997, the Company purchased  additional  ownership  
         interests in 10 partnerships,  which  the  Company  controls.  The  
         purchase  price for the additional  ownership interests was $10,510,000
         in cash. These transactions were accounted for using the purchase 
         method of accounting.

         Unaudited proforma combined income data for the years ended December 
         31,  1997  and  1996  of the  Company  and  the  acquisitions
         discussed  above assuming all were effective January 1, 1996 is as
         follows:
         ($ in thousands except per share data)
                                                1997           1996
                                             --------        -------

                  Total revenues             $100,228        $81,143
                  Total expenses               84,941         71,080
                                             --------       --------
                    Net income               $ 15,287        $10,063
                                             ========        =======

                  Diluted earnings per share    $0.79          $0.54
                                                =====          =====

         Effective May 1, 1996, the Company acquired 100% of the common stock of
         Lithotripters,  Inc. ("Litho"). Litho operated 31 lithotripters serving
         approximately  200  locations  in 19  states.  The  purchase  price was
         $86,500,000  consisting of $71,600,000 cash and 1,636,000 shares of the
         Company's  common stock valued at  $14,900,000.  This  transaction  was
         accounted for using the purchase method of accounting.

         Effective  November  1,  1996,  the  Company  increased  its  ownership
         interest in two partnerships that operate lithotripters in Arkansas and
         South Carolina.  The Company  acquired an additional  12.0% interest in
         Fayetteville  Lithotripters  Limited  Partnership - Arkansas I and 2.7%
         interest in  Fayetteville  Lithotripters  Limited  Partnership  - South
         Carolina II, which the Company manages as General Partner. The purchase
         price was $1,291,000 in cash. This  transaction was accounted for using
         the purchase method of accounting.

         Unaudited proforma combined income data for the years ended December 
         31,  1996  and  1995  of the  Company  and  the  acquisitions
         discussed  immediately above assuming both were effective January 1,
         1995 is as follows:



                                      A-17

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





         D.       ACQUISITIONS, continued

                  ($ in thousands except per share data)

                                                   1996             1995
                                                  ------          -------

                  Total revenues                  $92,499         $82,934
                  Total expenses                   82,684          74,409
                                                  -------         -------

                    Net income                    $ 9,815        $  8,525
                                                  =======        ========

                  Diluted earnings per share      $  0.51        $   0.50
                                                  =======        ========

         Effective October 1, 1995, the Company acquired 100% of the outstanding
         stock of Sun Medical  Technologies,  Inc.  ("Sun").  Sun operates eight
         lithotripters  serving  clients in California,  Arizona,  Montana, New
         Mexico,  Washington  and Wyoming.  The purchase  price was  $16,150,000
         consisting of cash of $9,438,000,  deferred payments payable in January
         1996 of  $2,687,000,  notes  payable of  $4,025,000,  and  warrants  to
         purchase  200,000  shares of the Company's  common stock.  The exercise
         price of the warrants  represented  the market  price of the  Company's
         common stock at the date the warrants were issued. The notes payable of
         $4,025,000 were convertible into 672,000 shares of the Company's common
         stock. These noteholders elected to convert the outstanding balances of
         their notes into the  Company's  stock in 1996.  This  acquisition  was
         accounted for using the purchase method of accounting.

         Effective  July 1, 1995 the Company  acquired an undivided 70% interest
         in a fixed site lithotripter  located in Fort Lauderdale,  Florida. The
         purchase  price was  $5,550,000  consisting of cash of  $3,885,000  and
         notes  payable of  $1,665,000, which could be converted into 326,000 
         shares of the Company's common stock. The noteholder elected to convert
         the outstanding balance of such note into the Company's stock in 1996.
         The acquisition was accounted for using the purchase method of 
         accounting.

         


                                      A-18

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





E.       FAIR VALUE OF FINANCIAL INSTRUMENTS

         Statement of Financial  Accounting Standards No. 107, Disclosures About
         Fair Value of Financial Instruments  (Statement 107), requires that the
         Company disclose estimated fair values for its financial instruments as
         of December 31, 1997 and 1996.  The carrying amounts and fair values of
         the Company's financial instruments are as follows:
<TABLE>
           <S>                                         <C>           <C>        <C>         <C>   

                                                                   1997                    1996
                                                        ----------------------  -------------------------
                                                       Carrying       Fair      Carrying     Fair
           ($ in Thousands)                             Amount        Value      Amount      Value
                                                        ------        -----      ------      -----
              Financial assets:
           Cash                                         $23,770       $23,770   $20,096     $20,096
           Accounts receivable                           19,387        19,387    16,346      16,346
           Other receivables                              1,103         1,103     1,842       1,842
           Investment in American
               Physicians Service Group, Inc.               173           356       173         325

              Financial liabilities:
           Debt                                          82,336        82,336    81,432      81,432
           Accounts payable                               5,386         5,386     4,451       4,451
</TABLE>

           The  following  methods and assumptions were  used  by the  Company
           in estimating its fair value disclosures for financial instruments.

           Cash

           The carrying  amounts for cash  approximate  fair value  because they
           mature in less than 90 days and do not present  unanticipated  credit
           concerns.

           Accounts Receivable and Other Receivables

           The carrying value of these  receivables  approximates the fair value
           due to their short-term nature and historical collectibility.

           Investment in American Physicians Service Group, Inc.

           The fair value of the stock is based on the last  trade  value at the
           end of the year.

           Debt

           The carrying value of debt approximates fair value since the majority
           is primarily floating rate debt based on current market rates.



                                      A-19

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





E.         FAIR VALUE OF FINANCIAL INSTRUMENTS, continued

           Accounts Payable

           The carrying value of the payables approximates fair value due to the
           short-term nature of the obligation.

           Limitations

          Fair value estimates are made at a specific point in time,  based
          on relevant market  information  and  information  about the financial
          instrument.  Fair value  estimates  are based on  existing  on-balance
          sheet financial  instruments  without attempting to estimate the value
          of anticipated future business and the value of assets and liabilities
          that  are not  considered  financial  instruments.  Other  significant
          assets and  liabilities  that are not considered  financial  assets or
          liabilities include the deferred tax assets and liabilities,  property
          and equipment,  equity  investment in  partnerships,  goodwill,  other
          noncurrent  assets  and  accrued  expenses.   In  addition,   the  tax
          ramifications  related to the realization of the unrealized  gains and
          losses can have a significant  effect on fair value estimates and have
          not been considered in the aforementioned estimates.

F.       ACCRUED EXPENSES

         Accrued expenses consist of the following:

                                                  December 31,      December 31,
                                                     1997              1996
         ($ in Thousands)

         Legal fees                                 $ 634             $ 452
         Accrued group insurance costs                228               164
         Compensation and payroll
           related expense                          1,787             1,502
         Taxes, other than income taxes               439               334
         Accrued interest                             984             1,028
         Provision for closed centers                 159               163
         Income taxes payable                       4,229               761
         Dividends payable to minority interest     8,655            10,705
         Deferred payments for acquisitions         1,339               --
         Other                                      2,405             1,473
                                                  -------           -------
                                                  $20,859           $16,582
                                                  =======           =======


                                      A-20

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





G.       INDEBTEDNESS

         Long-term debt, other than bank debt, are as follows:

         ($ in thousands) 

         Interest                        December 31,
           Rates      Maturities       1997        1996
         --------     ----------     -------     ------

         None         2000 - 2006    $   161     $  241
         6%               --              --        984
         11.5%           1998              6         12
                                     -------    -------

                                         167      1,237
         Less current portion of
          long-term debt                   6      1,100
                                     -------     ------

                                     $   161     $  137
                                     =======     ======

       The non-interest bearing notes totaling $161,000 are unsecured. The 11.5%
       note is secured by computer equipment.

       Long-term bank notes payable are as follows:

       ($ in thousands)

       Interest                         December 31,
         Rates         Maturities      1997       1996
       --------        ----------    -------     ------

       60-day LIBOR
         plus 2 1/2%    1998-2003    $79,000     $76,750
       Prime            1998-2001      2,969       3,245
       Prime + 1%         1998           200         200
                                     -------     -------
                                      82,169      80,195
       Less current portion of
             long-term bank debt      11,132       9,422
                                     -------     -------
                                     $71,037     $70,773
                                     =======     =======

       During 1997,  the Company  increased  its bank  facility with Bank Boston
       from $90 million to $135 million. The facility consists of three separate
       loans:  (1) a $45 million term loan bearing an interest  rate of LIBOR +2
       to 3%, payable quarterly, with quarterly principal payments,  maturing in
       April 2001, (2) a $40 million term loan bearing an interest rate of LIBOR
       +2 to 3%, payable quarterly, with annual principal payments,  maturing in
       April  2003,  and (3) a $50 million  revolving  credit  facility  bearing
       interest of LIBOR +2 to 3%, maturing in April 2001. At December 31, 1997,
       the entire $50 million revolving credit facility was undrawn. At December
       31, 1997,


                                      A-21

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





G.     INDEBTEDNESS, continued

     interest on the  Company's  bank  facility was 8.6%.  The bank  facility is
collateralized  by the  assets  of  the  Company,  including  the  stock  of its
subsidiaries. (See Note N)

       The stated  principal  repayments for all indebtedness as of December 31,
1997 are payable as follows:
                                                       ($ in thousands) 
                           1998                              $11,138
                           1999                               13,134
                           2000                               13,706
                           2001                                7,426
                           2002                                  800
                           Thereafter                         36,132

H.       COSTS OF SERVICES AND GENERAL AND ADMINISTRATIVE EXPENSES

         Costs of services and general and  administrative  expenses  consist of
the following:

                                           Years Ended December 31,      
                                             1997        1996      1995
                                          ----------  ---------  ---------

            ($ in thousands)

            Salaries, wages and benefits     $15,779   $11,953   $ 4,027
            Other costs of services            7,569     6,878     3,412
            General and administrative         3,595     1,941       718
            Legal and professional             2,064     1,315       659
            Manufacturing costs                1,394      --         --
            Other                              2,884     2,712     1,241
                                           ---------   -------   -------
                                             $33,285   $24,799   $10,057
                                           =========   =======   =======

I.       COMMITMENTS AND CONTINGENCIES

         At  December  31,  1997,   minimum  annual  rental   commitments  under
         non-cancelable  operating leases for equipment and office space,  which
         may contain renewal and escalation clauses through 2001, are:
         
                             ($ in thousands)

                    1998             $ 439
                    1999               365
                    2000               309
                    2001                 2
                    

                                      A-22

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





I.         COMMITMENTS AND CONTINGENCIES

           Rent  expense  for  equipment  and office  space for the years  ended
           December 31, 1997, 1996 and 1995 are $568,000, $360,000, and 
           $239,000, respectively.

           The  Company  sponsors  a  partially,   self-insured   group  medical
           insurance  plan. The plan is designed to provide a specified level of
           coverage,  with stop-loss coverage provided by a commercial  insurer.
           The Company's maximum claim exposure is limited to $35,000 per person
           per policy year. At December 31, 1997,  the Company had 172 employees
           enrolled in the plan. The plan provides non-contributory coverage for
           employees and  contributory  coverage for  dependents.  The Company's
           contributions  totaled  $351,000  in  1997,  $224,000  in  1996,  and
           $150,000 in 1995.

J.         COMMON STOCK OPTIONS

           1993 Stock Option Plan:

           The  Company has elected to follow  Accounting  Principles  Board
           Opinion No. 25, "Accounting for Stock Issued to Employees" ("APB 25")
           and related Interpretations  in  accounting  for its  employee  stock
           options.  The Company provides proforma disclosures of net income and
           earnings per share as if the fair-value based method prescribed by
           Statement 123 had been applied in measuring compensation expense.
           Under APB 25, because the exercise  price of the  Company's  employee
           stock options equals the market price of the underlying  stock on the
           date of grant, no compensation expense is recognized.

           On October 12, 1993,  the Company  adopted the 1993 Stock Option Plan
           which  authorizes the grant of up to 2,000,000  shares to certain key
           employees,  directors,  and  consultants and advisors to the Company.
           Options  granted  under the 1993 Stock  Option  Plan shall  terminate
           no later than ten years from the date the option is  granted, unless 
           the option terminates sooner by reason of termination of employment,
           disability or death.

           In June 1997,  the  Company  adopted an  amendment  to the 1993 Stock
           Option Plan that raised the number of shares to be issued by 500,000.

           A  summary  of the  Company's  stock  option  activity,  and  related
           information for the years ended December 31, follows:






                                      A-23

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





J.         COMMON STOCK OPTIONS, continued
<TABLE>
<S>                             <C>        <C>                <C>       <C>               <C>      <C>

                                           1997                        1996                        1995
                                ---------------------------   --------------------------  --------------------

                                Options    Weighted-Average   Options   Weighted-Average  Options  Weighted-Average
                                 (000)      Exercise Price     (000)     Exercise Price    (000)    Exercise Price
Outstanding - beginning
    of year                       1,228         $8.99             975        $1.31          1,055        $0.98
Granted                             428         11.94             730        13.87             55         5.58
Exercised                          (227)         1.51            (477)        0.52           (135)        0.52
Forfeited                           (35)        12.19             (--)         --             (--)         --
                                 ------                       -------

Outstanding-end of year           1,394        $11.04           1,228        $8.99            975        $1.31
                                 ======                       =======                     =======

Exercisable at end of year          466        $ 8.21             422        $2.03            816        $0.75

Weighted-average fair
     value of options granted
     during the year              $5.21         --              $6.13          --           $2.07         --

</TABLE>

           The following table summarizes the Company's  outstanding  options at
December 31, 1997:
<TABLE>
          <S>                         <C>        <C>              <C>           <C>            <C>    
                                                    Outstanding options         Exercisable options
                                                 -------------------------      ----------------------
                                                   Average        Weighted                     Weighted
                                                  Remaining        Average                      Average
                                      Options    Contractual      Exercise      Options        Exercise
           Range of Exercise Prices   (000)         Life           Price         (000)          Price
           ------------------------   ------     -----------      ---------     -------        --------

           $  0.25 - $  4.12             223       2.0 years       $  1.39          195         $ 1.10
           $  4.13 - $  8.25              37       3.9 years       $  5.75           10         $ 5.99
           $  8.26 - $12.37              292       2.3 years       $ 10.55            5         $ 8.94
           $12.38 - $16.50               842       3.9 years       $ 14.04          256         $13.72
                                      ------                                    -------

           Total                       1,394                                        466
                                     =======                                    =======
</TABLE>

           Pro forma information  regarding net income and earnings per share is
           required by Statement 123, and has been  determined as if the Company
           had  accounted  for its employee  stock  options under the fair value
           method  of that  Statement.  The fair  value for  these  options  was
           estimated at the date of grant using a Black-  Scholes option pricing
           model with the following weighted-average assumptions for 1995, 1996,
           and 1997

                                      A-24

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





J.         COMMON STOCK OPTIONS, continued

           respectively:  risk-free  interest  rates  of 5.7%,  6.2%  and  6.2%;
           dividend yields of 0%, 0% and 0%; volatility  factors of the expected
           market price of the Company's common stock of .38, .53 and .46; and a
           weighted-average expected life of the option of 4 years.

           The  Black-Scholes  option  valuation  model was developed for use in
           estimating  the fair  value of traded  options  which have no vesting
           restrictions  and  are  fully  transferable.   In  addition,   option
           valuation models require the input of highly  subjective  assumptions
           including the expected stock price volatility.  Because the Company's
           employee stock options have characteristics  significantly  different
           from those of traded  options,  and because changes in the subjective
           input assumptions can materially  affect the fair value estimate,  in
           management's  opinion, the existing models do not necessarily provide
           a reliable  single  measure of the fair value of its  employee  stock
           options.

           For purposes of pro forma  disclosures,  the estimated  fair value of
           the options is amortized to expense over the options' vesting period.
           The Company's pro forma information  follows (in thousands except for
           earnings per share information):

                                            1997           1996         1995
                                           -------       -------       ------

                  Pro forma net income     $12,448       $ 8,109       $7,197
                  Pro forma earnings
                    per share
                      Basic                  $0.65         $0.46        $0.51
                      Diluted                $0.64         $0.44        $0.47

          Statement 123 calls for a prospective application of compensation 
          relating to the grant of stock options and, consequently pro-forma 
          financial information may not be indicative of future amounts until
          the new rules are applied to all outstanding nonvested awards.

K.       OTHER INCOME (EXPENSE)

         Included in other, net in the consolidated statements of operations are
the following components:

($ in thousands)
                                            Years Ended December 31,
                                      1997           1996         1995
Collections on amounts               -----          -----        -----
     previously written off          $ --           $ 192          --
Gain on sale of investment 
     in American Physicians Service
     Group, Inc. Stock                 --              --          559
Equipment rental                       --              58          --
Other income                             6            120           88
                                     -----          -----        -----
Other, net                           $   6          $ 370        $ 647
                                     =====          =====        =====



                                      A-25

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS







L.       INCOME TAXES

         The  Company files a consolidated tax return  with  its  wholly  owned
         subsidiaries.  A substantial portion of consolidated income is not 
         taxed at the corporate level as it represents income from partnerships.
         Accordingly, only the portion  of  income  from  these  partnerships  
         attributable  to  the  Company's ownership interests is included in
         taxable income in the consolidated tax return and financial statements.
         The minority interest portion of this income is the responsibility of 
         the individual partners.

         Income tax expense consists of the following:
         ($ in thousands)
                                                  Years ended December 31,
                                                 ----------------------------
                                                  1997        1996      1995
                                                 ------      ------    ------
               Federal                           
                  Current                        $4,369      $   97    $ 110
                  Deferred                           68         974      193 
               State                              1,358         925      583
                                                 ------      ------    -----
                                                 $5,795      $1,996    $ 886
                                                 ======      ======    =====

          A reconciliation of expected income tax (computed by applying the 
          United States statutory income tax rate of 35% for 1997 and 34% for  
          1996 and 1995, to earnings before income taxes) to total income
          tax expense in the accompanying consolidated statements of income 
          follows:
          ($ in thousands)                        Years ended December 31,
                                                 ------------------------
                                                  1997        1996      1995
                                                 ------      ------    ------
               Expected federal income tax       $7,228      $3,725    $2,751
               Change in beginning of year
                    valuation allowance          (2,399)     (3,093)   (2,091)
               State taxes                        1,358         925       583
               Other                             (  392)        439    (  357) 
                                                 ------      ------    ------
                                                 $5,795      $1,996    $  886
                                                 ======      ======    ======
        
         The tax effects of temporary  differences that give rise to significant
         portions of the deferred tax assets and  deferred  tax  liabilities  at
         December 31, 1997 and 1996 are presented below.
         ($ in thousands)
                                                  1997             1996
                                                 -----           ------
         Deferred tax assets:
           Accounts receivable,
             principally due to allowance
             for doubtful accounts               $ 266           $  114
           AMT credit carryforwards                --               249
           Net operating loss carryforwards        --               944
           Investment tax credit carryforwards     --             1,200
           Accrued expenses deductible
             for tax purposes when paid          1,240              834
           Property and equipment,
             principally due to
             differences in depreciation           --               656
           Other                                   932              829
                                                 -----           ------
             Total gross deferred tax assets     2,438            4,826
             Less valuation allowance              --            (2,399)
                                                 -----           ------
             Net deferred tax assets             2,438            2,427
                                                 -----           ------
         Deferred tax liabilities:
           Property and equipment,
             principally due to
             differences in depreciation       (  583)              --
           Investments in affiliated
             entities, principally due to
             undistributed income              (2,807)           (2,860)
           Intangible assets, principally
             due to differences in
             amortization periods for tax
             purposes                          (2,419)           (1,872)
           IRS Section 481(A) adjustment
             for partnerships acquired         (  -- )           (  175)
                                              -------            ------


                                      A-26

<PAGE>


                  PRIME MEDICAL SERVICES, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS





L.       INCOME TAXES, continued
                                                  1997          1996
           Total gross deferred tax             -------       -------
               liabilities                      ( 5,809)      ( 4,907)
                                                -------       -------
           Net deferred tax liability           ($3,371)      ($2,480)
                                                =======       =======

         The valuation allowance for deferred tax assets as of December 31, 1997
         was $-0-  representing  a  decrease  of  $2,399,000,  primarily  due to
         utilization  of  net  operating  loss   carryforwards.   The  valuation
         allowance for deferred tax assets as of January 1, 1996 was  $5,492,000
         with the  change in the total  valuation  allowance  for the year ended
         December 31, 1996 being a decrease of $3,093,000. The Company  believed
         that the valuation  allowance at December 31, 1996 was necessary due to
         uncertainties  regarding the Company's use of the net operating loss 
         carryforwards and tax credit  carryforwards  which could have become 
         limited in the event  that the Company experienced a greater than 50%
         stock ownership  change in a  three-year  period (as defined in the 
         Internal Revenue Service regulations).
                
         In assessing the realizability of deferred tax assets, management 
         considers whether it is more likely than not that some  portion or all 
         of the deferred tax assets will not be realized.  The ultimate 
         realization of deferred tax assets is dependent upon the  generation of
         future  taxable  income during the periods in which those temporary  
         differences become deductible.  Management  considers the scheduled 
         reversal of deferred tax liabilities, projected future taxable income,
         and tax planning strategies in making this assessment.

         Based upon the level of historical  taxable income and  projections for
         future taxable income over the periods  which the deductible temporary 
         differences reverse, management believes it is more likely than not the
         Company will realize the benefits of these deductible differences,  net
         of the existing  valuation  allowances. 

M.       RELATED PARTY TRANSACTIONS

         See Notes B and C for additional related party  transactions  involving
         investments in affiliates.

N.       SUBSEQUENT EVENT

         On March 27, 1998, the Company completed an offering of $100 million of
         senior   subordinated  notes  due  2008  (the   "Notes")  to  qualified
         institutional   buyers.   The  net   proceeds   from  the  offering  of
         approximately  $96.0  million  will be used to  repay  all  outstanding
         indebtedness under the Company's bank facility, with the remainder  to
         be  used  for  general  corporate  purposes,   including acquisitions.
         In connection herewith, the Company will take a charge to earnings of
         approximately $3.8 million for debt issuance costs associated with the 
         Notes.  (See Note B)

                                      A-27

<PAGE>


<PAGE>
 
                                FIRST AMENDMENT
                                       TO
                             1993 STOCK OPTION PLAN
                                       OF
                          PRIME MEDICAL SERVICES, INC.


     Prime Medical Services, Inc., a Delaware corporation, formerly known as New
PMSI, Inc. (the "Corporation"), hereby adopts this first amendment (this
"Amendment") to its 1993 stock option plan (the "Plan") effective for all
purposes as of June 18, 1997 (the "Effective Date").

                                R E C I T A L S

     WHEREAS, on October 12, 1993 the Corporation adopted the Plan, a copy of
which is attached hereto as Exhibit-A; and

     WHEREAS, pursuant to Section 2.1 of the Plan, subject to certain
adjustments provided for in the Plan, the aggregate number of shares of the
Corporation's stock to be issued pursuant to the exercise of all options granted
under the plan may not exceed two million (2,000,000) shares; and

     WHEREAS, at the annual meeting of the Corporation's shareholders held on
the Effective Date, and in accordance with Section 9 of the Plan (relating to
amendments of the Plan), the shareholders of the Corporation approved an
amendment to the Plan, as contained herein, pursuant to which the aggregate
number of shares of stock that could be issued pursuant
<PAGE>
 
to the exercise of all options granted under the Plan would be increased by five
hundred thousand (500,000) shares.

     NOW, THEREFORE, in consideration of, and pursuant to, the foregoing, the
Corporation hereby adopts this Amendment to the Plan as follows:

     1.  Paragraph 2.1 of the Plan is hereby amended to read in its entirety as
follows:

         2.1. Description of Stock and Maximum Shares Allocated. The Stock which
     Options granted hereunder give a Holder the right to purchase may be
     unissued or reacquired shares of Stock, as the Corporation may, in its sole
     and absolute discretion, from time to time determine.

     Subject to the adjustments provided for in Paragraph 6.7 hereof, the
     aggregate number of shares of Stock to be issued pursuant to the exercise
     of all Options granted hereunder may equal but shall not exceed 2,500,000
     shares of Stock.

     2.  Except as specifically amended hereby, the Plan shall remain in full
force and effect in accordance with its terms.

                                       2
<PAGE>
 
     IN WITNESS WHEREOF, the Corporation, acting by and through its officer
hereunto duly authorized, has executed this Amendment as of the Effective Date.


                                             PRIME MEDICAL SERVICES, INC.


                                             By:/s/ Cheryl L. Williams
                                                ---------------------------
                                                Cheryl L. Williams
                                                Vice President - Finance

                                       3

<PAGE>
 
                                SECOND AMENDMENT
                                       TO
                             1993 STOCK OPTION PLAN
                                       OF
                          PRIME MEDICAL SERVICES, INC.


     Prime Medical Services, Inc., a Delaware corporation, formerly known as New
PMSI, Inc. (the "Corporation"), hereby adopts this second amendment (this
"Amendment") to its 1993 Stock Option Plan (the "Plan") effective for all
purposes as of ___________, 1997 (the "Effective Date").

                                R E C I T A L S

     WHEREAS, on October 12, 1993 the Corporation adopted the Plan, which was
subsequently amended by that certain First Amendment (the "First Amendment")
dated effective June 18, 1997, a copy of which is attached hereto as Exhibit-A;
and

     WHEREAS, the Corporation's Board of Directors have approved an amendment to
the Plan, as contained herein, pursuant to which (i) the Plan may be
administered by either the Board of Directors or a committee of the Board duly
appointed under the terms of the Plan and comprised solely of non-employee
directors, and (ii) the holders of Non-Incentive Options (as defined in the
Plan) may assign or transfer such Options with the approval of the Board of
Directors or its appointed committee; and
<PAGE>
 
     WHEREAS, the Corporation desires to amend and restate the Plan to reflect
the incorporation of the First Amendment and this Amendment, and to delete all
references therein to "New PMSI, Inc." and substitute the Corporation's current
name in place thereof.

     NOW, THEREFORE, in consideration of, and pursuant to, the foregoing, the
Corporation hereby adopts this Amendment to the Plan as follows:

     1.  Section 1.7 of the Plan is hereby amended to read in its entirety as
follows:

               1.7.  "Non-Employee Directors" shall mean directors who meet the
         definition of "Non-Employee Directors" under Rule 16b-3 under the Act.

     2.  Section 3.1 of the Plan is hereby amended to read in its entirety as
follows:

               3.1.  Administrator.  An administrative body designated by the
                     -------------                                           
         Board of Directors shall administer the Plan (the "Administrator").
         The Board of Directors may designate itself as the Administrator or
         appoint two or more Non-Employee Directors to a committee which shall
         serve as the Administrator.

                                       2
<PAGE>
 
     3.  All sections of the Plan (inclusive of section headings) are amended to
replace the term "Committee" or "Committee's" with "Administrator" or
"Administrator's", respectively.

     4.  Section 6.5 of the Plan is hereby amended to delete the second sentence
thereof and to add, in its place, the following sentences:

         Incentive Options shall not be transferable other than by will or the
         laws of descent and distribution. Non-Incentive Options shall not be
         transferable other than by will or the laws or descent and
         distribution, or upon the express prior written consent of the
         Administrator in each instance.

     5.  The Plan is hereby amended to remove all references to "New PMSI, Inc."
and to replace each such reference with "Prime Medical Services, Inc."

     6.  Except as specifically amended hereby, the Plan shall remain in full
force and effect in accordance with its terms.

     7.  The Plan, as amended and restated to reflect the First Amendment and
this Amendment, is attached hereto as Exhibit-B, and is hereby adopted for all
purposes.

                                       3
<PAGE>
 
     IN WITNESS WHEREOF, the Corporation, acting by and through its officer
hereunto duly authorized, has executed this Amendment as of the Effective Date.


                                             PRIME MEDICAL SERVICES, INC.


                                             By: /s/ Cheryl L. Williams
                                                ---------------------------
                                                Cheryl L. Williams
                                                Vice President - Finance

                                       4

<PAGE>
 
                          PRIME MEDICAL SERVICE, INC.

                              AMENDED AND RESTATED

                             1993 STOCK OPTION PLAN


                           Scope and Purpose of Plan
                           -------------------------

     Prime Medical Services, Inc., a Delaware corporation (the "Corporation"),
has adopted this Stock Option Plan (the "Plan") to provide for the granting of:

     (a)   Incentive Options (hereinafter defined) to certain key employees of
           the Corporation, or of its Affiliates (hereinafter defined), and

     (b)   Non-Incentive Options (hereinafter defined) to certain key employees
           and non-employee directors of the Corporation or of its Affiliates.

     The purpose of the Plan is to provide an incentive for Eligible Individuals
(hereinafter defined) to remain in the service of the Corporation or its
Affiliates, to extend to them the opportunity to acquire a proprietary interest
in the Corporation so that they will apply their best efforts for the benefit of
the Corporation, and to aid the Corporation in attracting able persons to enter
the service of the Corporation and its Affiliates.

SECTION 1. Definitions.

     1.1.  "Act" shall mean the Securities Exchange Act of 1934, as amended.

     1.2.  "Affiliates" shall mean (a) any corporation, other than the
Corporation, in an unbroken chain of corporations ending with the Corporation if
each of the corporations, other than the Corporation, owns stock possessing
fifty percent (50%) or more of the total combined voting power of all classes of
stock in one of the other corporations in such chain and (b) any corporation,
other than the Corporation, in an unbroken chain of corporations beginning with
the Corporation if each of the corporations, other than the last corporation in
the unbroken chain, owns stock possessing fifty percent (50%) or more of the
total combined voting power of all classes of stock in one of the other
corporations in such chain.

     1.3.  "Agreement" shall mean the written agreement between the Corporation
and a Holder evidencing the Option granted by the Corporation and the
understanding of the parties with respect thereto.

     1.4.  "Board of Directors" shall mean the board of directors of the
Corporation.

     1.5.  "Code" shall mean the Internal Revenue Code of 1986, as amended.

     1.6.  "Administrator" shall mean the Administrator appointed pursuant to
Section 3.1 to administer the Plan.

     1.7.  "Non-Employee Directors" shall mean directors who meet the definition
of "Non-Employee Directors" under Rule 16b-3 under the Act.

     1.8.  "Effective Date" shall mean the date that PMSI Acquisition
Corporation is merged with and into Prime Medical Services, Inc.
<PAGE>
 
     1.9.  "Eligible Individuals" shall mean (a) key employees, including
officers and directors who are also employees of the Corporation or of any of
its Affiliates, (b) non-employee directors and officers of the Corporation or of
any of its Affiliates and (c) consultants and advisors of the Corporation or of
any of its Affiliates who render bona fide services to the Corporation or to any
of its Affiliates; provided such services must not be in connection with the
offer or sale of securities in a capital-raising transaction.

     1.10. "Fair Market Value" shall mean:

     (a)   If shares of Stock of the same class are listed or admitted to
unlisted trading privileges on any national or regional securities exchange at
the date of determining the Fair Market Value, the last reported sale price on
such exchange on the last business day prior to the date in question; or

     (b)   If shares of Stock of the same class shall not be listed or admitted
to unlisted trading privileges as provided in Subparagraph 1.10(a) and sales
prices therefor in the over-the-counter market shall be reported by the National
Association of Securities Dealers, Inc. Automated Quotations, Inc. ("NASDAQ")
National Market System at the date of determining the Fair Market Value, the
last reported sale price so reported on the last business day prior to the date
in question; or

     (c)   If shares of Stock of the same class shall not be listed or admitted
to unlisted trading privileges as provided in Subparagraph 1.10(a) and sales
prices therefor shall not be reported by the NASDAQ National Market System as
provided in Subparagraph 1.10(b), and bid and asked prices therefor in the over-
the-counter market shall be reported by NASDAQ (or, if not so reported, by the
National Quotation Bureau Incorporated) at the date of determining the Fair
Market Value, the average of the closing bid and asked prices on the last
business day prior to the date in question; and

     (d)   If shares of Stock of the same class shall not be listed or admitted
to unlisted trading privileges as provided in Subparagraph 1.10(a) and sales
prices or bid and asked prices therefor shall not be reported by NASDAQ (or the
National Quotation Bureau Incorporated) as provided in Subparagraph 1.10(b) or
Subparagraph 1.10(c) at the date of determining the Fair Market Value, the value
determined in good faith by the Administrator.

For purposes of valuing Incentive Options, the Fair Market Value of Stock shall
be determined without regard to any restriction other than one which, by its
terms, will never lapse.

     1.11. "Holder" shall mean an Eligible Individual to whom an Option has
been granted.

     1.12. "Incentive Options" shall mean stock options that are intended to
satisfy the requirements of Section 422A of the Code.

     1.13. "Non-Incentive Options" shall mean stock options that do not satisfy
the requirements of Section 422A of the Code.

     1.14. "Options" shall mean either Incentive Options or Non-Incentive
Options, or both.

     1.15. "Stock" shall mean the Corporation's authorized common stock, $.01
par value, together with any other securities with respect to which Options
granted hereunder may become exercisable.

SECTION 2. Stock and Maximum Number of Shares Subject to the Plan.
           ------------------------------------------------------ 

     2.1.  Description of Stock and Maximum Shares Allocated.  The Stock which
           -------------------------------------------------                  
Options granted hereunder give a Holder the right to purchase may be unissued or
reacquired shares of Stock, as the Corporation may, in its sole and absolute
discretion, from time to time determine.
<PAGE>
 
     Subject to the adjustments provided for in Paragraph 6.7 hereof, the
aggregate number of shares of Stock to be issued pursuant to the exercise of all
Options granted hereunder may equal but shall not exceed 2,500,000 shares of
Stock.

     2.2.  Restoration of Unpurchased Shares.  If an Option granted hereunder
           ---------------------------------                                 
expires or terminates for any reason during the term of this Plan and prior to
the exercise of the Option in full, the shares of Stock subject to but not
issued under such Option shall again be available for Option granted hereunder
subsequent thereto.

SECTION 3. Administration of the Plan.
           -------------------------- 

     3.1.  Administrator.  An administrative body designated by the Board of
           -------------                                                    
Directors shall administer the Plan (the "Administrator"). The Board of
Directors may designate itself as the Administrator or appoint two or more Non-
Employee Directors to a committee which shall serve as the Administrator.

     3.2.  Meetings and Actions of Administrator.  The Administrator shall hold
           -------------------------------------                               
its meetings at such times and places as it may determine.  All decisions and
determinations of the Administrator shall be made by the majority vote or
decision of all of its members present at a meeting; provided, however, that any
decision or determination reduced to writing and signed by all of the members of
the Administrator shall be as fully effective as if it had been made at a
meeting duly called and held.  The Administrator may make any rules and
regulations for the conduct of its business that are not inconsistent with the
provisions hereof and with the bylaws of the Corporation as it may deem
advisable.

     3.3.  Administrator's Powers.  Subject to the express provisions hereof,
           ----------------------                                            
the Administrator shall have the authority, in its sole and absolute discretion,
(a) to adopt, amend, and rescind administrative and interpretive rules and
regulations relating to the Plan; (b) to determine the terms and provisions of
the respective Agreements (which need not be identical), including provisions
defining or otherwise relating to (i) subject to Section 6 of the Plan, the term
and the period or periods and extent of exercisability of the Options, (ii) the
extent to which the transferability of shares of Stock issued upon exercise of
Options is restricted, and (iii) the effect of approved leaves of absence
(consistent with any applicable regulations of the Internal Revenue Service);
(c) to accelerate the time of exercisability of any Option that has been
granted; (d) to construe the respective Agreements and the Plan; and (e) to make
all other determinations and perform all other acts necessary or advisable for
administering the Plan, including the delegation of such ministerial acts and
responsibilities as the Administrator deems appropriate.  The Administrator may
correct any defect or supply any omission or reconcile any inconsistency in the
Plan or in any Agreement in the manner and to the extent it shall deem expedient
to carry it into effect, and it shall be the sole and final judge of such
expediency.  The Administrator shall have full discretion to make all
determinations on the matters referred to in this Paragraph 3.3; such
determinations shall be final, binding and conclusive.

SECTION 4. Eligibility and Participation.
           ----------------------------- 

     4.1.  Eligible Individuals.  Options may be granted hereunder only to
           --------------------                                           
persons who are Eligible Individuals at the time of the grant thereof.
Notwithstanding any provision contained herein to the contrary, a person shall
not be eligible to receive an Incentive Option hereunder unless he is an
employee of the Corporation or an Affiliate, nor shall a person be eligible to
receive an Incentive Option hereunder if he, at the time such Option  is
granted, would own (within the meaning of Sections 422A and 425 of the Code)
stock possessing more than ten percent (10%) of the total combined voting power
or value of all classes of stock of the Corporation or of an Affiliate unless at
the time such Incentive Option is granted the exercise price per share of Stock
is at least one hundred and ten percent (110%) of the Fair Market Value of each
share of Stock to which the Incentive Option relates and the Incentive Option is
not exercisable after the expiration of five years from the date it is granted.

     4.2.  No Right to Option.  The adoption of the Plan shall not be deemed to
           ------------------                                                  
give any person a right to be granted an Option.
<PAGE>
 
SECTION 5. Grant of Options and Certain terms of the Agreements.
           ---------------------------------------------------- 

     Subject to the express provisions hereof, the Administrator shall determine
which Eligible Individuals shall be granted Options hereunder from time to time.
In making grants, the Administrator shall take into consideration the
contribution the potential Holder has made or may make to the success of the
Corporation or its Affiliates and such other considerations as the Administrator
may from time to time specify.  The Administrator shall also determine the
number of shares subject to each of such Options, and shall authorize and cause
the Corporation to grant Options in accordance with such determinations.

     The date on which the Administrator completes all action constituting an
offer of an Option to an individual, including the specification of the number
of shares of Stock to be subject to the Option, shall be the date on which the
Option covered by an Agreement is granted, even though certain terms of the
Agreement may not be at such time determined and even though the Agreement may
not be executed until a later time.  In no event, however, shall an Optionee
gain any rights in addition to those specified by the Administrator in its
grant, regardless of the time that may pass between the grant of the Option and
the actual execution of the Agreement by the Corporation and the Optionee.

     Each Option granted hereunder shall be evidenced by an Agreement, executed
by the Corporation and the Eligible Individual to whom the Option is granted,
incorporating such terms as the Administrator shall deem necessary or desirable.
More than one Option may be granted hereunder to the same Eligible Individual
and be outstanding concurrently hereunder.  In the event an Eligible Individual
is granted both one or more Incentive Options and one or more Non-Incentive
Options, such grants shall be evidenced by separate Agreements, one for each of
the Incentive Option grants and one for each of the Non-Incentive Option grants.

     Each Agreement may contain or otherwise provide for conditions giving rise
to the forfeiture of the Stock acquired pursuant to an Option granted hereunder
or otherwise and such restrictions on the transferability of shares of the Stock
acquired pursuant to an Option granted hereunder or otherwise as the
Administrator in its sole and absolute discretion shall deem proper or
advisable.  Such conditions giving rise to forfeiture may include, but need not
be limited to, the requirement that the Holder render substantial services to
the Corporation or its Affiliates for a specified period of time.  Such
restrictions on transferability may include, but need not be limited to, options
and rights of first refusal in favor of the Corporation and shareholders of the
Corporation other than the Holder of such shares of Stock who is a party to the
particular Agreement or a subsequent holder of the shares of Stock who is bound
by such Agreement.  In addition, no Option may be exercisable for a period of
more than ten years from the date the Option is granted.

SECTION 6. Terms and Conditions of Options.
           ------------------------------- 

     All Options granted hereunder shall comply with, be deemed to include, and
shall be subject to the following terms and conditions:

     6.1.  Number of Shares.  Each Agreement shall state the number of shares of
           ----------------                                                     
Stock to which it relates.

     6.2.  Exercise Price.  Each Agreement shall state the exercise price per
           --------------                                                    
share of Stock.  The exercise price per share of Stock subject to an Incentive
Option shall not be less than the greater of (a) the par value per share of the
Stock or (b) 100% of the Fair Market Value per share of the Stock on the date of
the grant of the Option.  The exercise price per share of Stock subject to a
Non-Incentive Option shall be determined by the Administrator upon the granting
of the Non-Incentive Option.

     6.3.  Automatic Options.  Notwithstanding Paragraph 6.2, on the Effective
           -----------------                                                  
Date the persons then holding unexercised options granted pursuant to the 1990
Stock Option Plan and Second Amended and Restated Stock Option Plan of Prime
Medical Services, Inc. ("Prime Plans"), shall automatically be granted Non-
Incentive Options under the Plan covering the same number of shares of Stock, at
the same exercise price and for the same term as set forth in the options
granted to such persons under the Prime Plans.  The grant of such Non-Incentive
Options shall be in cancellation of such options granted to such persons under
the Prime Plans.
<PAGE>
 
     6.4.  Medium and Time of Payment, Method of Exercise, and Withholding
           ---------------------------------------------------------------
Taxes.  The exercise price of an Option shall be payable upon the exercise of
the Option in cash or by certified or cashier's check payable to the order of
the Corporation, or, with the consent of the Administrator, with shares of Stock
of the Corporation owned by the Holder, including a multiple series of exchanges
of such Stock, or with the consent of the Administrator, by a combination of
cash and such shares.  Exercise of an Option shall not be effective until the
Corporation has received written notice of exercise.  Such notice must specify
the number of whole shares to be purchased and be accompanied by payment in full
of the aggregate exercise price of the number of shares purchased.  The
Corporation shall not in any case be required to sell, issue, or deliver a
fractional share of Stock with respect to any Option.

     The Administrator may, in its discretion, require a Holder to pay to the
Corporation at the time of exercise of an Option or portion thereof the amount
that the Corporation deems necessary to satisfy its obligation to withhold
Federal, state or local income or other taxes incurred by reason of the
exercise.  Where the exercise of an Option does not give rise to an obligation
to withhold Federal income or other taxes on the date of exercise, the
Corporation may, in its discretion, require a Holder to place shares of Stock
purchased under the Option in escrow for the benefit of the Corporation until
such time as Federal income or other tax withholding is no longer required with
respect to such shares or until such withholding is required on amounts included
in the gross income of the Holder as a result of the exercise of an Option or
the disposition of shares of Stock acquired pursuant thereto.  At such later
time, the Corporation, in its discretion, may require a Holder to pay to the
Corporation the amount that the Corporation deems necessary to satisfy its
obligation to withhold Federal, state or local income or other taxes incurred by
reason on the exercise of the Option or the disposition of shares of Stock.
Upon receipt of such payment by the Corporation, such shares of Stock shall be
released from escrow to the Holder.

     6.5.  Term, Time of Exercise, and Transferability of Options.  In addition
           ------------------------------------------------------              
to such other terms and conditions as may be included in a particular Agreement
granting an Option, an Option shall be exercisable during a Holder's lifetime
only by the Holder or by the Holder's guardian or legal representative.
Incentive Options shall not be transferable other than by will or the laws of
descent and distribution. Non-Incentive Options shall not be transferable other
than by will or the laws of descent and distribution, or upon the express prior
written consent of the Administrator in each instance.  The provisions of the
remainder of this paragraph shall apply to the extent a Holder's Agreement does
not expressly provide otherwise.  If a Holder ceases to be an Eligible
Individual, the Option shall terminate ninety days after such Holder ceases to
be an Eligible Individual.  Notwithstanding the foregoing, if a Holder ceases to
be an Eligible Individual by reason of (a) disability (as defined in Section
105(d)(4)), or (b) death, then the Holder shall have the right for twelve months
after the date of disability or death to exercise an Option to the extent such
Option is exercisable on the date of his disability.

     That portion of the Option which is not exercisable on the date the Holder
ceases to be an Eligible Individual shall terminate and be forfeited to the
Corporation on the date of such cessation.

     Notwithstanding any other provision of this Plan, no Incentive Option shall
be exercisable after the expiration of ten years from the date it is granted, or
the period specified in Paragraph 4.1, if applicable.  The Administrator shall
have authority to prescribe in any Agreement that the Option evidenced thereby
may be exercised in full or in part as to any number of shares subject thereto
at any time or from time to time during the term of the Option, or in such
installments at such times during said term as the Administrator may prescribe.
Except as provided above and unless otherwise provided in any Agreement, an
Option may be exercised at any time or from time to time during the term of the
Option.  Such exercise may be as to any or all whole (but no fractional) shares
which have become purchasable under the Option.

     Within a reasonable time or such time as may be permitted by law after the
Corporation receives written notice that the Holder has elected to exercise all
or a portion of an Option, such notice to be accompanied by payment in full of
the aggregate Option exercise price of the number of shares of Stock purchased,
the Corporation shall issue and deliver a certificate representing the shares
acquired in consequence of the exercise and any other amounts payable in
consequence of such exercise.  In the event that a Holder exercises both an
Incentive Option, or portion thereof, and a Non-Incentive Stock Option, or a
portion thereof, separate Stock certificates shall be issued, one for the Stock
subject to the Incentive Option and one for the Stock subject to the Non-
Incentive Stock Option.  The number of the shares of Stock transferable due to
an exercise of an Option under this Plan shall not be increased due to the
passage of time, except as may be provided in an Agreement.  However, this
number of such shares of
<PAGE>
 
Stock which are transferable may increase due to the occurrence of certain
events which are fully described in Paragraph 6.7.

     Nothing herein or in any Option granted hereunder shall require the
Corporation to issue any shares upon exercise of any Option if such issuance
would, in the opinion of counsel for the Corporation, constitute a violation of
the Securities Act of 1933, as amended, or any similar or superseding statute or
statutes, or any other applicable statute or regulation, as then in effect.  At
the time of any exercise of an Option, the Corporation may, as a condition
precedent to the exercise of such Option, require from the Holder of the Option
(or in the event of his death, his legal representatives, heirs, legatees, or
distributees) such written representations, if any, concerning his intentions
with regard to the retention or disposition of the shares being acquired by
exercise of such Option and such written covenants and agreements, if any, as to
the manner of disposal of such shares as, in the opinion of counsel to the
Corporation, may be necessary to ensure that any disposition by such Holder (or
in the event of his death, his legal representatives, heirs, legatees, or
distributees), will not involve a violation of the Securities Act of 1933, as
amended, or any similar or superseding statute or statutes, or any other
applicable state or federal statute or regulation, as then in effect.
Certificates for shares of Stock, when issued, may have the following or similar
legend, or statements of other applicable restrictions, endorsed thereon, and
may not be immediately transferable:

     The shares of Stock evidenced by this certificate have been issued to the
     registered owner in reliance upon written representations that these shares
     have been purchased for investment.  These shares have not been registered
     under the Securities Act of 1933, as amended, or any applicable state
     securities laws, in reliance upon an exception from registration.  Without
     such registration, these shares may not be sold, transferred, assigned or
     otherwise disposed of unless, in the opinion of the Corporation and its
     legal counsel, such sale, transfer, assignment or disposition will not be
     in violation of the Securities Act of 1933, as amended, applicable rules
     and regulations of the Securities and Exchange Commission, and any
     applicable state securities laws.

     6.6.  Limitation on Aggregate Value of Shares That May Become First
           -------------------------------------------------------------
Exercisable During Any Calendar Year Under an Incentive Option.  Except as is
- --------------------------------------------------------------               
otherwise provided in the second paragraph of Paragraph 6.7 hereof, with respect
to any Incentive Option granted under this Plan, the sum of:

     (a)  the aggregate Fair Market Value of shares of Stock subject to such
          Incentive Option that first become purchasable in a calendar year
          under such Incentive Option, and

     (b)  the aggregate Fair Market Value of shares of Stock or stock of any
          Affiliate (or a predecessor of the Corporation or an Affiliate)
          subject to any other incentive stock option (within the meaning of
          Section 422A of the Code) of the Corporation or its Affiliates (or a
          predecessor corporation of any such corporation), that first become
          purchasable in a calendar year under such incentive stock option may
          not (with respect to any Holder) exceed $100,000, with such Fair
          Market Value to be determined as of the date the Incentive Option or
          such other incentive stock option is granted.

For purposes of this Paragraph 6.6, "predecessor corporation" means (i) a
corporation that was a party to a transaction described in Section 425(a) of the
Code (or which would be so described if a substitution or assumption under such
section had been effected) with the Corporation, (ii) a corporation which, at
the time the new incentive stock option (within the meaning of Section 422A of
the Code) is granted, is an Affiliate of the Corporation or a predecessor
corporation of any such corporations, or (iii) a predecessor corporation of any
such corporations.

     6.7.  Adjustments Upon Changes in Capitalization.  Notwithstanding any
           ------------------------------------------                      
other provision hereof, in the event of any change in the number of outstanding
shares of Stock effected without receipt of consideration therefor by the
Corporation, by reason of a stock dividend, or split, combination, exchange of
shares or other recapitalization, merger, or otherwise, in which the Corporation
is the surviving corporation (1) the aggregate number and class of the reserved
shares, (2) the number and class of shares subject to each outstanding Option
and (3) the exercise price of each outstanding Option shall be automatically
adjusted to equitably reflect the effect thereon of such change (provided,
however, that any fractional share resulting from such adjustment may be
eliminated).  In the event of a dispute concerning such adjustment, the
Administrator has full discretion to determine the resolution of the dispute.
Such determination shall be final, binding and conclusive.  The number of
reserved shares or the number of shares
<PAGE>
 
subject to any outstanding Option shall be automatically reduced by any fraction
included therein which results from any adjustment made pursuant to this
Paragraph 6.7.

     The following provisions of this Paragraph 6.7 shall apply unless a
Holder's Agreement provides otherwise.  In the event of:

     (a)  a dissolution or liquidation of the Corporation,

     (b)  a merger or consolidation (other than a merger effecting a re-
          incorporation of the Corporation in another state or any other merger
          or a consolidation in which the shareholders of the surviving
          corporation and their proportionate interests therein immediately
          after the merger or consolidation are substantially identical to the
          shareholders of the Corporation and their proportionate interests
          therein immediately prior to the merger or consolidation) in which the
          Corporation is not the surviving corporation (or survives only as a
          subsidiary of another corporation in a transaction in which the
          shareholders of the parent of the Corporation and their proportionate
          interests therein immediately after the transaction are not
          substantially identical to the shareholders of the Corporation and
          their proportionate interests therein immediately prior to the
          transaction; provided, however, that the Administrator may at any time
          prior to such a merger or consolidation provide by resolution that the
          foregoing provisions of this parenthetical shall not apply if a
          majority of the board of directors of such parent immediately after
          the transaction consists of individuals who constituted a majority of
          the Board of Directors immediately prior to the transaction), or

     (c)  a transaction in which any person (other than a shareholder of the
          Corporation that already is the owner of 50% or more of the total
          combined voting power of all classes of the Corporation on the date of
          the Holder's Agreement) becomes the owner of 50% or more of the total
          combined voting power of all classes of stock of the Corporation
          (provided, however, that the Administrator may at any time prior to
          such transaction provide by resolution that this subparagraph (c)
          shall not apply if such acquiring person is a corporation and a
          majority of the board of directors of the acquiring corporation
          immediately after the transaction consists of individuals who
          constituted a majority of the Board of Directors immediately prior to
          the acquisition of such 50% or more total combined voting power)

the Administrator may, at its election, as of the effective time of such
transaction, either (1) change the number and kind of shares of stock (including
substitution of shares of another corporation) and exercise price in the manner
it deems appropriate, provided, however, that in no event may any change be made
under this Paragraph 6.7 which would constitute a "modification" within the
meaning of Section 425(h)(3) of the Code; or (2) purchase the Options from each
Holder by tendering cash equal to the Fair Market Value of the Stock represented
by the Options less the exercise price of the Options specified in each
agreement, without regard to the determination as to the periods and
installments of exercisability made pursuant to a Holder's Agreement if (and
only if) such Options have not at that time expired or been terminated.

     6.8.  Rights as a Shareholder.  A Holder shall have no right as a
           -----------------------                                    
shareholder with respect to any shares covered by his Option until a certificate
representing such shares is issued to him.  No adjustment shall be made for
dividends (ordinary or extraordinary, whether in cash or other property) or
distributions or other rights for which the record date is prior to the date
such certificate is issued, except as provided in Paragraph 6.7 hereof.

     6.9.  Modification, Extension and Renewal of Options.  Subject to the terms
           ----------------------------------------------                       
and conditions of and within the limitations of the Plan, the Administrator may
modify, extend or renew outstanding Options granted under the Plan, or accept
the surrender of Options outstanding hereunder (to the extent not theretofore
exercised) and authorize the granting of new Options hereunder in substitution
therefor (to the extent not theretofore exercised).  The Administrator may not,
however, without the consent of the Holder, modify any outstanding Options so as
to specify a higher or lower exercise price or base amount or accept the
surrender of outstanding Incentive Options and authorize the granting of new
Options in substitution therefor specifying a higher or lower exercise price.
In addition, no modification of an Option granted hereunder shall, without the
consent of the Holder, alter or impair any
<PAGE>
 
rights or obligations under any Option theretofore granted hereunder to such
Holder under the Plan, except as may be necessary, with respect to Incentive
Options, to satisfy the requirements of Section 422A of the Code.

     6.10.  Furnish Information.  Each Holder shall furnish to the Corporation
            -------------------                                               
all information requested by the Corporation to enable it to comply with any
reporting or other requirement imposed upon the Corporation by or under any
applicable statute or regulation.

     6.11.  Obligation to Exercise:  Termination of Employment.  The granting of
            --------------------------------------------------                  
an Option hereunder shall impose no obligation upon the Holder to exercise the
same or any part thereof.  In the event of a Holder's termination of employment
with the Corporation or an Affiliate, the unexercised portion of an Option
granted hereunder shall terminate in accordance with Paragraph 6.5 hereof.

     6.12.  Agreement Provisions.  The Agreements authorized under the Plan
            --------------------                                           
shall contain such provisions in addition to those required by the Plan
(including, without limitation, restrictions or the removal of restrictions upon
the exercise of the Option and the retention or transfer of shares thereby
acquired) as the Administrator shall deem advisable.  Each Agreement shall
identify the Option evidenced thereby as an Incentive Option or a Non-Incentive
Option, as the case may be, and no Agreement shall cover both an Incentive
Option and a Non-Incentive Option.  Each Agreement relating to an Incentive
Option granted hereunder shall contain such limitations and restrictions upon
the exercise of the Incentive Option to which it relates as shall be necessary
for the Incentive Option to which such Agreement relates to constitute an
incentive stock option, as defined in Section 422A of the Code.

SECTION 7.  Remedies.
            -------- 

     7.1.   Attorneys Fees.  The Corporation shall be entitled to recover from a
            --------------                                                      
Holder reasonable attorneys' fees incurred in connection with the enforcement of
the terms and provisions of the Plan and any Agreement whether by an action to
enforce specific performance or for damages for its breach or otherwise.

     7.2.   Specific Performance.  The Corporation shall be entitled to enforce
            --------------------                                               
the terms and provisions of this Paragraph 7, including the remedy of specific
performance, in Travis County, Texas.

SECTION 8.  Duration of Plan.
            ---------------- 

     No Options will be granted herein after the date that is ten years from the
earlier of (a) the date the Plan is accepted by the Board of Directors or (b)
the date the Plan is approved by the stockholders of the Corporation.

SECTION 9.  Amendment of Plan.
            ----------------- 

     The Board of Directors may at any time terminate or from time to time amend
or suspend the Plan; provided, however, that no such amendment shall, without
                     --------  -------                                       
approval of the shareholders of the Corporation, except as provided in Section 7
hereof, (a) increase the aggregate number of shares of Stock as to which Options
may be granted under the Plan; (b) change the minimum Option exercise price; (c)
increase the maximum period during which Options may be exercised; or (d) extend
the effective period of the Plan.  No Option may be granted during any
suspension of the Plan or after the Plan has been terminated and no amendment,
suspension or termination shall, without a Holder's consent, adversely alter or
impair any of the rights or obligations under any Option theretofore granted to
such Holder under the Plan.

SECTION 10. General.
            ------- 

     10.1.  Application of Funds.  The proceeds received by the Corporation from
            --------------------                                                
the sale of shares pursuant to Options shall be used for general corporate
purposes.

     10.2.  Right of the Corporation and Affiliates to Terminate Employment.
            ---------------------------------------------------------------  
Nothing contained in the Plan, or in any Agreement, shall confer upon any Holder
the right to continue in the employ of the Corporation or any Affiliate, or
interfere in any way with the rights of the Corporation or any Affiliate to
terminate his employment any time.
<PAGE>
 
     10.3.  No Liability for Good Faith Determinations.  Neither the members of
            ------------------------------------------                         
the Board of Directors nor any member of the Administrator shall be liable for
any act, omission, or determination taken or made in good faith with respect to
the Plan or any Option granted under it, and members of the Board of Directors
and the Administrator shall be entitled to indemnification and reimbursement by
the Corporation in respect of any claim, loss, damage, or expense (including
attorneys' fees, the costs of settling any suit, provided such settlement is
approved by independent legal counsel selected by the Corporation, and amounts
paid in satisfaction of a judgment, except a judgment based on a finding of bad
faith) arising therefrom to the full extent permitted by law and under any
directors and officers liability or similar insurance coverage that may from
time to time be in effect.

     10.4.  Information Confidential.  As partial consideration for the granting
            ------------------------                                            
of each Option hereunder, the Agreement may, in the Administrator's sole and
absolute discretion, provide that the Holder shall agree with the Corporation
that he will keep confidential all information and knowledge that he has
relating to the manner and amount of his participation in the Plan; provided,
however, that such information may be disclosed as required by law and may be
given in confidence to the Holder's spouse, tax and financial advisors, or to a
financial institution to the extent that such information is necessary to secure
a loan.  In the event any breach of this promise comes to the attention of the
Administrator, it shall take into consideration such breach, in determining
whether to recommend the grant of any future Option to such Holder, as a factor
militating against the advisability of granting any such future Option to such
individual.

     10.5.  Other Benefits.  Participation in the Plan shall not preclude the
            --------------                                                   
Holder from eligibility in any other stock option plan of the Corporation or any
Affiliate or any old age benefit, insurance, pension, profit sharing,
retirement, bonus, or other extra compensation plans which the Corporation or
any Affiliate has adopted, or may, at any time, adopt for the benefit of its
employees.

     10.6.  Execution of Receipts and Releases.  Any payment of cash or any
            ----------------------------------                             
issuance or transfer of shares of Stock to the Holder, or to his legal
representative, heir, legatee, or distributee, in accordance with the provisions
hereof, shall, to the extent thereof, be in full satisfaction of all claims of
such persons hereunder.  The Administrator may require any Holder, legal
representative, heir, legatee, or distributee, as a condition precedent to such
payment, to execute a release and receipt therefor in such form as it shall
determine.

     10.7.  No Guarantee of Interests.  Neither the Administrator nor the
            -------------------------                                    
Corporation guarantees the Stock of the Corporation from loss or depreciation.

     10.8.  Payment of Expenses.  All expenses incident to the administration,
            -------------------                                               
termination, or protection of the Plan, including, but not limited to, legal and
accounting fees, shall be paid by the Corporation or its Affiliates; provided,
however, the Corporation or an Affiliate may recover any and all damages, fees,
expenses, and/or costs arising out of any actions taken by the Corporation to
enforce its rights hereunder.

     10.9.  Corporation Records.  Records of the Corporation or its Affiliates
            -------------------                                               
regarding the Holder's period of employment, termination of employment and the
reason therefor, leaves of absence, re-employment, and other matters shall be
conclusive for all purposes hereunder, unless determined by the Administrator to
be incorrect.

     10.10. Information.  The Corporation and its Affiliates shall, upon
            -----------                                                 
request or as may be specifically required hereunder, furnish or cause to be
furnished, all of the information or documentation which is necessary or
required by the Administrator to perform its duties and functions under the
Plan.

     10.11. No Liability of Corporation.  The Corporation assumes no obligation
            ---------------------------                                        
or responsibility to the Holder or his legal representatives, heirs, legatees,
or distributees for any act of, or failure to act on the part of, the
Administrator.

     10.12. Corporation Action.  Any action required of the Corporation shall
            ------------------                                               
be by resolution of its Board of Directors or by a person authorized to act by
resolution of the Board of Directors.
<PAGE>
 
     10.13.  Severability.  If any provision of this Plan is held to be illegal
             ------------                                                      
or invalid for any reason, the illegality or invalidity shall not affect the
remaining provisions hereof, but such provision shall be fully severable and the
Plan shall be construed and enforced as if the illegal or invalid provision had
never been included herein.

     10.14.  Notices.  Whenever any notice is required or permitted hereunder,
             -------                                                          
such notice must be in writing and personally delivered or sent by mail or by a
nationally recognized courier service.  Any notice required or permitted to be
delivered hereunder shall be deemed to be delivered on the date on which it is
personally delivered, or, if mailed, whether actually received or not, on the
third business day after it is deposited in the United States mail, certified or
registered, postage prepaid, addressed to the person who is to receive it at the
address which such person has previously specified by written notice delivered
in accordance herewith, or, if by courier, twenty-four hours after it is sent,
addressed as described in this Section.  The Corporation or a Holder may change,
at any time and from time to time, by written notice to the other, the address
which it or he had previously specified for receiving notices.  Until changed in
accordance herewith, the Corporation and each Holder shall specify as its and
his address for receiving notices the address set forth in the Agreement
pertaining to the shares to which such notice relates.

     10.15.  Waiver of Notice.  Any person entitled to notice hereunder may
             ----------------                                              
waive such notice.

     10.16.  Successors.  The Plan shall be binding upon the Holder, his legal
             ----------                                                       
representatives, heirs, legatees and distributees upon the Corporation, its
successors, and assigns, and upon the Administrator, and its successors.

     10.17.  Headings.  The titles and headings of Sections and Paragraphs are
             --------                                                         
included for convenience of reference only and are not to be considered in
construction of the provisions hereof.

     10.18.  Governing Law.  All questions arising with respect to the
             -------------                                            
provisions of the Plan shall be determined by application of the laws of the
State of Texas except to the extent Texas law is preempted by federal law.
Questions arising with respect to the provisions of an Agreement that are
matters of contract law shall be governed by the laws of the state specified in
the Agreement, except to the extent preempted by federal law and except to the
extent that Texas corporate law conflicts with the contract law of such state,
in which event Texas corporate law shall govern.  The obligation of the
Corporation to sell and deliver Stock hereunder is subject to applicable laws
and to the approval of any governmental authority required in connection with
the authorization, issuance, sale, or delivery of such Stock.

     10.19.  Word Usage.  Words used in the masculine shall apply to the
             ----------                                                 
feminine where applicable, and wherever the context of the Plan dictates, the
plural shall be read as the singular and the singular as the plural.


     IN WITNESS WHEREOF, Prime Medical Services, Inc. acting by and through its
officer hereunto duly authorized, has executed this Amended and Restated Plan on
the ____ day of _________, 1997.


                                     PRIME MEDICAL SERVICES, INC.


                                     By:/s/ Cheryl L. Williams
                                        -----------------------------------
                                        Cheryl L. Williams
                                        Vice President - Finance

<PAGE>
 
                         PRIME MEDICAL SERVICES, INC.

                          SECOND AMENDED AND RESTATED
                                LOAN AGREEMENT

                          $45,000,000.00 TERM LOAN A
                          $40,000,000.00 TERM LOAN B

                                      AND

                     $50,000,000.00 REVOLVING CREDIT LOAN

                      THE FIRST NATIONAL BANK OF BOSTON,
                            as Administrative Agent

                          NATIONSBANK OF TEXAS, N.A.,
                            as Documentation Agent

                       NATIONSBANC CAPITAL MARKETS, INC.
                             as Syndication Agent

                                      AND

                           THE LENDERS NAMED HEREIN,
                                  as Lenders

                          Dated as of March 31, 1997
<PAGE>
 
                               TABLE OF CONTENTS

                                                                         Page
                                                                         ----
ARTICLE I          DEFINITIONS...........................................  1
     Section 1.1   Amendment and Restatement.............................  1
     Section 1.2   Definitions...........................................  1
     Section 1.3   Other Definitional Provisions......................... 16

ARTICLE II         ADVANCES.............................................. 16
     Section 2.1   Commitments........................................... 16
     Section 2.2   Notes................................................. 17
     Section 2.3   Repayment of Advances................................. 17
     Section 2.4   Interest.............................................. 18
     Section 2.5   Borrowing Procedure................................... 18
     Section 2.6   Continuations; Conversions............................ 19
     Section 2.7   Use of Proceeds....................................... 19
     Section 2.8   Fees.................................................. 20

ARTICLE III        PAYMENTS.............................................. 20
     Section 3.1   Method of Payment..................................... 20
     Section 3.2   Optional Prepayment................................... 20
     Section 3.3   Mandatory Prepayments................................. 21
     Section 3.4   Pro Rata Treatment.................................... 22
     Section 3.5   Non-Receipt of Funds by the Administrative Agent...... 22
     Section 3.6   Withholding Taxes..................................... 22
     Section 3.7   Withholding Tax Exemption............................. 23
     Section 3.8   Computation of Interest............................... 23
     Section 3.9   Order of Application.................................. 23

ARTICLE IV         YIELD PROTECTION AND ILLEGALITY....................... 25
     Section 4.1   Additional Costs...................................... 25
     Section 4.2   Limitation on Eurodollar Advances..................... 26
     Section 4.3   Illegality............................................ 26
     Section 4.4   Treatment of Eurodollar Advances...................... 26
     Section 4.5   Compensation.......................................... 27
     Section 4.6   Capital Adequacy...................................... 27

ARTICLE V          SECURITY.............................................. 28
     Section 5.1   Collateral............................................ 28
     Section 5.2   Setoff................................................ 28
     Section 5.3   Guaranties............................................ 29

ARTICLE VI         CONDITIONS PRECEDENT.................................. 29
     Section 6.1   Initial Advance....................................... 29
     Section 6.2   All Advances.......................................... 30


                                     - i -
<PAGE>
 
ARTICLE VII        REPRESENTATIONS AND WARRANTIES........................ 31
     Section 7.1   Existence............................................. 31
     Section 7.2   Financial Statements.................................. 31
     Section 7.3   Corporate Action:  No Breach.......................... 32
     Section 7.4   Operation of Business................................. 32
     Section 7.5   Litigation and Judgments.............................. 32
     Section 7.6   Rights in Properties; Liens........................... 32
     Section 7.7   Enforceability........................................ 32
     Section 7.8   Approvals............................................. 32
     Section 7.9   Debt.................................................. 33
     Section 7.10  Taxes................................................. 33
     Section 7.11  Use of Proceeds; Margin Securities.................... 33
     Section 7.12  ERISA................................................. 33
     Section 7.13  Disclosure............................................ 33
     Section 7.14  Subsidiaries; Partnerships............................ 33
     Section 7.15  Agreements............................................ 34
     Section 7.16  Compliance with Legal Requirements; Governmental
                   Authorizations........................................ 34
     Section 7.17  Investment Company Act................................ 34
     Section 7.18  Public Utility Holding Company Act.................... 35
     Section 7.19  Environmental Matters................................. 35

ARTICLE VIII       POSITIVE COVENANTS.................................... 35
     Section 8.1   Reporting Requirements................................ 35
     Section 8.2   Maintenance of Existence; Conduct of Business......... 37
     Section 8.3   Maintenance of Properties............................. 37
     Section 8.4   Taxes and Claims...................................... 37
     Section 8.5   Insurance............................................. 38
     Section 8.6   Inspection Rights..................................... 38
     Section 8.7   Keeping Books and Records............................. 38
     Section 8.8   Compliance with Laws.................................. 38
     Section 8.9   Compliance with Agreements............................ 38
     Section 8.10  Further Assurances.................................... 38
     Section 8.11  ERISA................................................. 39
     Section 8.12  Information Relating to Proposed Acquisitions......... 39
     Section 8.13  After-Acquired Subsidiaries........................... 39
     Section 8.14  Syndication Cooperation............................... 39

ARTICLE IX         NEGATIVE COVENANTS.................................... 39
     Section 9.1   Debt.................................................. 39
     Section 9.2   Limitation on Liens................................... 40
     Section 9.3   Mergers, Etc.......................................... 40
     Section 9.4   Restricted Payments................................... 41
     Section 9.5   Investments........................................... 41
     Section 9.6   Limitation on Issuance of Capital Stock............... 41
     Section 9.7   Transactions With Affiliates.......................... 42
     Section 9.8   Disposition of Assets................................. 42
     Section 9.9   Sale and Leaseback.................................... 42
     Section 9.10  Prepayment of Debt.................................... 42
     Section 9.11  Nature of Business.................................... 42


                                    - ii -
<PAGE>
 
     Section 9.12  Environmental Protection.............................. 42
     Section 9.13  Accounting............................................ 42
     Section 9.14  Amendment of Partnership and Management Agreements.... 43

ARTICLE X          FINANCIAL COVENANTS................................... 43
     Section 10.1  Total Debt to EBITDA.................................. 43
     Section 10.2  Interest Coverage Ratio............................... 43
     Section 10.3  Total Debt Service Coverage Ratio..................... 43
     Section 10.4  Consolidated Net Worth................................ 43
     Section 10.5  Minimum EBITDA........................................ 44

ARTICLE XI         DEFAULT............................................... 44
     Section 11.1  Events of Default..................................... 44
     Section 11.2  Remedies.............................................. 46
     Section 11.3  Performance by the Administrative Agent............... 46

ARTICLE XII        THE ADMINISTRATIVE AGENT.............................. 47
     Section 12.1  Appointment, Powers and Immunities.................... 47
     Section 12.2  Rights of Administrative Agent as a Lender............ 48
     Section 12.3  Sharing of Payments, Etc.............................. 48
     Section 12.4  Indemnification....................................... 49
     Section 12.5  Independent Credit Decisions.......................... 49
     Section 12.6  Several Commitments................................... 50
     Section 12.7  Successor Administrative Agent........................ 50
     Section 12.8  Independent Contractor................................ 50

ARTICLE XIII       MISCELLANEOUS......................................... 51
     Section 13.1  Expenses.............................................. 51
     Section 13.2  Indemnification....................................... 51
     Section 13.3  No Duty............................................... 52
     Section 13.4  No Fiduciary Relationship............................. 52
     Section 13.5  No Waiver; Cumulative Remedies........................ 52
     Section 13.6  Successors and Assigns................................ 52
     Section 13.7  Survival.............................................. 54
     Section 13.8  ENTIRE AGREEMENT...................................... 55
     Section 13.9  Amendments, Etc....................................... 55
     Section 13.10 Maximum Interest Rate................................. 55
     Section 13.11 Notices............................................... 56
     Section 13.12 Governing Law......................................... 56
     Section 13.13 Counterparts.......................................... 56
     Section 13.14 Severability.......................................... 56
     Section 13.15 Headings.............................................. 56
     Section 13.16 Construction.......................................... 56
     Section 13.17 Independence of Covenants............................. 56
     Section 13.18 Confidentiality....................................... 56
     Section 13.19 Renewal and Increase.................................. 57
     Section 13.20 Waiver of Jury Trial.................................. 57
     Section 13.21 Choice of Forum; Consent to Service of Process and
                   Jurisdiction.......................................... 57


                                    - iii -
<PAGE>
 
                               INDEX TO EXHIBITS
                               -----------------

EXHIBIT   DESCRIPTION OF EXHIBIT
- -------   ----------------------

A         Advance Request Form
B         Form of Assignment and Acceptance
C         Form of Revolving Credit Note
D         Form of Term Note A
E         Form of Term Note B
F         Perfection Certificate
G         Form of Opinion of Counsel for Borrower and the Guarantors
H         Compliance Certificate


                               INDEX TO SCHEDULES
                               ------------------

SCHEDULE  DESCRIPTION OF SCHEDULE
- --------  -----------------------

1         Commitments
2         Guarantors
3         Partnerships
7.5       Existing Litigation
7.9       Existing Debt
7.14.1    Capitalization of Subsidiaries
7.14.2    Partners
7.15      Agreements
7.16      Governmental Disclosures
7.19      Environmental Matters
9.2       Existing Liens


                                    - iv -
<PAGE>
 
                   SECOND AMENDED AND RESTATED LOAN AGREEMENT

     THIS SECOND AMENDED AND RESTATED LOAN AGREEMENT (the "AGREEMENT"), dated as
of March 31, 1997, is among PRIME MEDICAL SERVICES, INC., a Delaware corporation
("BORROWER"), each of the lenders or other lending institutions which is or
which may from time to time become a signatory hereto or any successor or
assignee thereof (collectively, the "LENDERS" and individually, a "LENDER"), THE
FIRST NATIONAL BANK OF BOSTON ("FNBB"), a national banking association, as
Administrative Agent for itself and the other Lenders (in such capacity,
together with its successors in such capacity, the "ADMINISTRATIVE AGENT") and
NATIONSBANK OF TEXAS, N.A. ("NATIONSBANK"), a national banking association, as
Documentation Agent for itself and the other Lenders (in such capacity, together
with its successors in such capacity, the "DOCUMENTATION AGENT"), and
NATIONSBANC CAPITAL MARKETS, INC., as Syndication Agent (in such capacity,
together with its successors in such capacity, the "SYNDICATION AGENT").

                                R E C I T A L S
                                - - - - - - - -

     1.   Reference is hereby made to that certain Loan Agreement dated as of
November 28, 1994, by and between Borrower, the Banks defined therein, and FNBB,
as Agent for the Banks defined therein as amended by that certain First
Amendment to Loan Agreement dated as of August 17, 1995, as amended by the
Amended and Restated Loan Agreement dated as of April 26, 1996 among FNBB,
NationsBank and FNBB, as Syndication Agent, as amended by the First Amendment to
Amended and Restated Loan Agreement dated as of June 14, 1996 among FNBB,
NationsBank and the other Banks named therein (collectively, the "ORIGINAL
CREDIT AGREEMENT").

     2.   The parties hereto desire to amend the Original Credit Agreement, to
provide for, among other things, (a) an additional $40,000,000.00 term loan, (b)
a $10,000,000.00 increase in the maximum amount  available under the Revolving
Credit Commitment, (c) the addition of certain lenders as parties thereto, and
(d) modification and amendment to certain other provisions therein, subject to
the terms and conditions set forth in this Agreement.

     3.   The Administrative Agent, the Documentation Agent, the Syndication
Agent, the Lenders and Borrower desire and have agreed to amend and restate the
Original Credit Agreement in its entirety as and pursuant to this Agreement.

     NOW THEREFORE, in consideration of the premises and the mutual covenants
herein contained, the parties hereto agree as follows:

                                   ARTICLE I

                                  DEFINITIONS

      SECTION 1.1   AMENDMENT AND RESTATEMENT.  This Agreement is in renewal,
extension, modification, increase and restatement of the Original Credit
Agreement.

      SECTION 1.2   DEFINITIONS.  As used in this Agreement, the following terms
shall have the following meanings:

     "ACQUISITION" means any transaction, or any series of related transactions,
consummated on or after the date hereof, by which Borrower or any Subsidiary
directly or indirectly (a) acquires all or substantially all
<PAGE>
 
of the assets of any Person, whether through purchase of assets, merger, or
otherwise, (b) acquires (in one transaction or as the most recent transaction in
a series of transactions) at least a majority (in number of votes) of the
securities (or similar ownership interests) of any Person, or (c) acquires (in
one transaction or as the most recent transaction in a series of transactions)
at least a majority of the general partnership interests of any Person.

     "ADDITIONAL COSTS" has the meaning specified in SECTION 4.1.

     "ADJUSTED EURODOLLAR RATE" means, for any Eurodollar Advance for any
Interest Period therefor, the rate per annum (rounded upwards, if necessary, to
the nearest 0.01%) determined by the Administrative Agent to be equal to (a) the
Eurodollar Rate for such Eurodollar Advance for such Interest Period divided by
(b) 1.00 minus the Reserve Requirement for such Eurodollar Advance for such
Interest Period.

     "ADMINISTRATIVE AGENT" has the meaning specified in the preamble.

     "ADVANCE" means (a) with respect to the Revolving Credit Commitment, each
advance of funds by the Lenders having a Revolving Credit Commitment, or any of
them, to Borrower pursuant to SECTION 2.5(a), (b) with respect to the Term Loan
A Commitment, each advance by the Lenders having a Term Loan A Commitment, or
any of them, to Borrower pursuant to SECTION 2.5(b), and (c) with respect to the
Term Loan B Commitment, each advance by the Lenders having a Term Loan B
Commitment, or any of them, to Borrower pursuant to SECTION 2.5(b).

     "ADVANCE REQUEST FORM" means a certificate, in substantially the form of
EXHIBIT A, properly completed and signed by Borrower requesting an Advance.

     "AFFILIATE" means, as to any Person, any other Person (a) that directly or
indirectly, through one or more intermediaries, Controls or is Controlled by, or
is under common Control with, such Person, (b) that directly or indirectly
beneficially owns or holds five percent (5%) or more of any class of voting
stock of such Person, or (c) five percent (5%) or more of the voting stock of
which is directly or indirectly beneficially owned or held by the Person in
question; provided, however, in no event shall the Agents or any Lender be
deemed an Affiliate of Borrower or any of its Subsidiaries.

     "AFTER-ACQUIRED SUBSIDIARY" has the meaning specified in SECTION 8.13.

     "AGENTS" means the Administrative Agent, the Documentation Agent and the
Syndication Agent. "AGENT" means any one of the Agents.

     "ALTERNATE BASE RATE" means, at any time,  the greater of (a) the variable
rate of interest established from time to time by the Administrative Agent as
its "BASE RATE" and set by the Administrative Agent as a general reference rate
of interest charged by the Administrative Agent, and (b) the Federal Funds Rate
plus one-half of one percent (.5%).  Borrower acknowledges that the
Administrative Agent may, from time to time, extend credit to other borrowers at
rates of interest varying from, and having no relationship to, such general
reference rate. Each change in the Alternate Base Rate shall become effective
without prior notice to Borrower automatically as of the opening of business on
the date of such change in the Alternate Base Rate.

     "ALTERNATE BASE RATE ADVANCES" means Advances that bear interest at rates
based upon the Alternate Base Rate.

                                       2
<PAGE>
 
     "APPLICABLE LENDING OFFICE" means for each Lender and each Type of Advance,
the lending office of such Lender (or of an Affiliate of such Lender) designated
for such Type of Advance below its name on the signature pages hereof or an
Assignment and Acceptance, or such other office of such Lender (or of an
Affiliate of such Lender) as such Lender may from time to time specify to
Borrower and the Administrative Agent as the office by which its Advances of
such Type are to be made and maintained.

     "APPLICABLE MARGIN" means the interest margin over the Alternate Base Rate
or the Adjusted Eurodollar Rate, as the case may be, that is as follows: (a) for
Advances under the Term Loan B, three percent (3.00%), and (b) for Advances
under the Revolving Credit Commitment and the Term Loan A, (i) from the date
hereof until the delivery of financial statements and a compliance certificate
for the period ending March 31, 1997, as required hereunder, (A) one percent
(1.00%) for Alternate Base Rate Advances, and (B) two and one-half percent
(2.50%) for Eurodollar Advances; and (iii) thereafter, based on the Total Debt
to EBITDA Ratio as of and for the most recent four (4) quarter period ending on
or before the date of determination, the margin set forth opposite such ratio
below:

<TABLE>
<CAPTION>

================================================================================
                                          APPLICABLE MARGIN    APPLICABLE MARGIN
  TOTAL DEBT TO EBITDA RATIO             ALTERNATE BASE RATE       EURODOLLAR
                                              ADVANCES              ADVANCES
- ------------------------------------------------------------------------------- 
<S>                                     <C>                    <C>
 
Less than 2.0 to 1.0                              0.5%               2.00%
- ------------------------------------------------------------------------------- 
Less than 2.50 to 1.0 but greater                0.75%               2.25%
than or equal to 2.0 to 1.0
- ------------------------------------------------------------------------------- 
Less than 3.0 to 1.0 but greater                 1.00%               2.50%
than or equal to 2.50 to 1.0
- ------------------------------------------------------------------------------- 
Greater than or equal to 3.00 to 1.0             1.25%               2.75%
================================================================================
</TABLE>

The Total Debt to EBITDA Ratio shall be determined from the then most current of
either (a) the quarterly or annual financial statements and related compliance
certificate delivered pursuant to SECTION 8.1, or (b) the most recent Advance
Request Form for a Permitted Acquisition, calculating any adjustments to such
ratio necessitated as a result of the Permitted Acquisition for which such
Advance was made.  The adjustment, if any, to the Applicable Margin shall be
effective commencing on the fifth (5th) Business Day after delivery of such
financial statements (and related compliance certificate) or the respective date
of Advance for a Permitted Acquisition, as the case may be.  If Borrower fails
at any time to furnish to the Administrative Agent and the Lenders the financial
statements and related compliance certificate as required to be delivered
pursuant to SECTION 8.1, then the maximum Applicable Margin shall apply until
such time as such financial statements and compliance certificates are so
delivered.

     "APPLICABLE PAYMENT AMOUNT" means, as of any date, an amount equal to (a)
the aggregate amount of Debt of the Companies, as of such date, minus (b) the
product of (i) EBITDA of the Companies, for the four (4) fiscal quarter period
immediately preceding the date of determination, including EBITDA of any Company
acquired by Borrower during that period, and (ii) 2.75; provided that if such
Applicable Payment Amount is less than $0.00, then the Applicable Payment Amount
shall be $0.00.

     "APPLICABLE RATE" means: (a) during any period that an Advance is an
Alternate Base Rate Advance, the Alternate Base Rate plus the Applicable Margin;
and (b) during any period that an Advance is a Eurodollar Advance, the Adjusted
Eurodollar Rate plus the Applicable Margin.

                                       3
<PAGE>
 
     "APPLICABLE UNUSED FEE PERCENTAGE" means  the per annum rate with respect
to the unused portion of the Revolving Credit Commitments as follows: (a) from
the date hereof until delivery of financial statements and a compliance
certificate for the period ending March 31, 1997, as required hereunder,  one-
half of one percent (0.50%); and (b) thereafter, based on the Total Debt to
EBITDA Ratio as of and for the most recent four (4) quarter period ending on or
before the date of determination, the percentage set forth opposite such ratio
below:

================================================================================
                                              APPLICABLE UNUSED
    TOTAL DEBT TO EBITDA RATIO                  FEE PERCENTAGE
- --------------------------------------------------------------------------------
 
Less than 2.5 to 1.0                                0.375%
- --------------------------------------------------------------------------------
Greater than or equal to 2.50 to 1.0                 0.50%
================================================================================

The Applicable Unused Fee Percentage shall be adjusted, if necessary, at the
same time as adjustments to the Applicable Margin.

     "APPROVED FUND" means, with respect to any Lender that is a fund that
invests in loans, any other fund that invests in loans and is managed by the
same investment advisor as such Lender or by an Affiliate of such investment
advisor.

     "ASSIGNEE" has the meaning specified in SECTION 13.6.

     "ASSIGNING LENDER" has the meaning specified in SECTION 13.6.

     "ASSIGNMENT AND ACCEPTANCE" means an assignment and acceptance entered into
by an Assigning Lender and its Assignee and accepted by the Administrative Agent
pursuant to SECTION 13.6, in substantially the form of EXHIBIT B.

     "BASLE ACCORD" means the proposals for risk-based capital framework
described by the Basle Committee on Banking Regulations and Supervisory
Practices in its paper entitled "INTERNATIONAL CONVERGENCE OF CAPITAL
MEASUREMENT AND CAPITAL STANDARDS" dated July 1988, as amended, supplemented and
otherwise modified and in effect from time to time, or any replacement thereof.

     "BORROWER SECURITY AGREEMENT" means the Borrower Security Agreement dated
as of April 26, 1996, executed by Borrower in favor of the Administrative Agent
for the benefit of the Lenders, as the same may be amended, supplemented, or
modified from time to time, including the Consent, Confirmation and Ratification
of Borrower Security Agreement dated the date hereof, which Borrower Security
Agreement is in renewal, amendment, restatement and substitution of that certain
Borrower Security Agreement dated November 28, 1994, executed by Borrower in
favor of the Administrative Agent, for the benefit of the Lenders under the
Original Credit Agreement, as amended pursuant to that First Amendment to
Borrower Security Agreement dated as of August 17, 1995.

     "BUSINESS DAY" means (a) any day on which the Administrative Agent is open
for regular business, and (b) with respect to all borrowings, payments,
Conversions, Continuations, Interest Periods, and notices in connection with
Eurodollar Advances, any day which is a Business Day described in clause (a)
above and which is also a day on which dealings in Dollar deposits are carried
out in the London interbank market.

                                       4
<PAGE>
 
     "CAPITAL LEASE OBLIGATIONS" means, as to any Person, the obligations of
such Person to pay rent or other amounts under a lease of (or other agreement
conveying the right to use) real and/or personal property, which obligations are
required to be classified and accounted for as a capital lease on a balance
sheet of such Person under GAAP.  For purposes of this Agreement, the amount of
such Capital Lease Obligations shall be the capitalized amount thereof, as
determined in accordance with GAAP.

     "CHANGE IN CONTROL" means the individuals who, as of the date of this
Agreement, constitute the members of Borrower's Board of Directors (the
"INCUMBENT BOARD") do not constitute or cease for any reason to constitute at
least fifty percent (50%) of:

          (a)   Borrower's Board of Directors; or

          (b)   The surviving corporation's Board of Directors in the event of 
     any merger or consolidation involving Borrower (if permitted by SECTION
     9.3); or

          (c)   The controlling entity's board of directors, the comparable 
     body if there is no Board of Directors, or voting control if there is no
     comparable body, in the event that the surviving corporation under clause
     (b) above is directly or indirectly controlled by that entity.

Any individual who becomes a member of the Board of Directors or comparable body
or who obtains a voting interest, as applicable under clauses (a), (b), or (c)
above, after the date of this agreement and whose appointment to the Board, or
nomination for election, was approved or ratified by a vote of the individuals
comprising at least fifty (50%) of the Incumbent Board shall be deemed to be a
member of the Incumbent Board.

     "CODE" means the Internal Revenue Code of 1986, as amended, and the
regulations promulgated and rulings issued thereunder.

     "COLLATERAL" has the meaning specified in SECTION 5.1.

     "COMMITMENT" means, as to each Lender as of any date, the aggregate amount
of the Revolving Credit Commitment, the Term Loan A Commitment and the Term Loan
B Commitment of such Lender. "COMMITMENTS" means the aggregate amount of the
Revolving Credit Commitments, the Term Loan A Commitments and the Term Loan B
Commitments of all the Lenders.

     "COMPANIES" means Borrower and its Subsidiaries.

     "CONFIDENTIAL INFORMATION" means any and all information relating to the
Companies, including, without limitation, information relating to each of the
Company's financial condition, business plans, management, earnings, assets,
liabilities, contracts, processes, products, research and development
activities, intellectual property, services, customers, suppliers, marketing and
sales.  In addition, Confidential Information shall include any and all other
information marked or identified in writing by any of the Companies as
"CONFIDENTIAL" or "CONFIDENTIAL INFORMATION" and provided by each of the
Companies or its representatives to any of the Lenders or the Agents or obtained
by the Lenders or the Agents after an inspection pursuant to SECTION 8.6.
Notwithstanding the foregoing, "CONFIDENTIAL INFORMATION" shall not include:

                                       5
<PAGE>
 
          (i)   any information known to an Agent or a Lender prior to 
     disclosure by any of the Companies or its representatives, as documented
     prior to such disclosure in such Agent's or Lender's written records;

          (ii)  any information which an Agent or a Lender demonstrates became
     available to it on a non-confidential basis from a source (other than any
     of the Companies) who is not bound by a confidentiality agreement with, or
     any other contractual, legal or fiduciary obligation of confidentiality to,
     any of the Companies or any other party with respect to such information;

          (iii) any information which an Agent or a Lender demonstrates is or
     becomes generally available to the public other than as a result of a
     disclosure by it in breach of SECTION 13.18; and

          (iv)  any information which an Agent or a Lender demonstrates was
     conceived of or developed by it or any of its employees without access or
     reference, directly or indirectly, to the Confidential Information.

     "CONSOLIDATED NET INCOME" means, for any Person for any period, the amount
which, in conformity with GAAP, would be shown on a consolidated income
statement of such Person as net income for such period, after deduction of any
minority interests.

     "CONSOLIDATED NET WORTH" means, at any particular time, all amounts which,
in conformity with GAAP, would be included as stockholders' equity on a
consolidated balance sheet of the Companies.

     "CONTINUE," "CONTINUATION," and "CONTINUED" refers to the continuation
pursuant to SECTION 2.6 of a Eurodollar Advance from one Interest Period to the
next Interest Period.

     "CONTROL" means the possession, directly or indirectly, of the power to
direct or cause the direction of the management or policies of a Person, whether
through the ownership of voting securities or other ownership interests, by
contract or otherwise.  "CONTROLLING" and "CONTROLLED" have meanings correlative
thereto.

     "CONVERSION" and "CONVERTED" refers to a conversion pursuant to SECTION 2.6
of one Type of Advance into another Type of Advance.

     "DEBT" means as to any Person at any time (without duplication and without
duplication among the Companies): (a) all obligations of such Person for
borrowed money; (b) all obligations of such Person evidenced by bonds, notes,
debentures, or other similar instruments; (c) all obligations of such Person to
pay the deferred purchase price of property or services, except trade accounts
payable of such Person arising in the ordinary course of business that are not
past due by more than ninety (90) days; (d) all Capital Lease Obligations of
such Person; (e) all indebtedness or other obligations of others of the types
described in this definition, if Guaranteed by such Person; (f) all obligations
secured by a Lien existing on property owned by such Person, whether or not the
obligations secured thereby have been assumed by such Person or are non-recourse
to the credit of such Person; (g) all reimbursement obligations of such Person
(whether contingent or otherwise) in respect of letters of credit, Lenders'
acceptances, surety or other bonds and similar instruments; (h) Hedging
Agreements, and (i) all liabilities of such Person in respect of unfunded vested
benefits under any Plan; provided, however, that the term Debt shall not include
endorsements of instruments for deposit or collection in the ordinary course of
business.

                                       6
<PAGE>
 
     "DEFAULT" means an Event of Default or the occurrence of an event or
condition which with the giving of notice or the lapse of time or both would
become an Event of Default.

     "DEFAULTING LENDER" means any Lender that has defaulted on any of its
obligations under this Agreement.

     "DEFAULT RATE" means the lesser of (a) the Maximum Rate, and (b) the sum of
the Alternate Base Rate in effect from day to day plus the Applicable Margin
plus two percent (2%).

     "DOCUMENTATION AGENT" has the meaning specified in the preamble.

     "DOLLARS" and "$" mean lawful money of the United States of America.

     "EBITDA" means, for any Person for any period, Consolidated Net Income of
such Person for such period, determined after deduction of any minority
interests,  plus all amounts deducted therefrom during such period, in
conformity with GAAP, for interest, taxes, depreciation and amortization.

     "ELIGIBLE ASSIGNEE" means any commercial bank, savings and loan
association, savings bank, finance company, insurance company, pension fund,
mutual fund, fund which is regularly engaged in making, purchasing or investing
in loans, or other financial institution (whether a corporation, partnership, or
other entity) approved by the Administrative Agent and, so long as no Default
has occurred and is continuing, Borrower, such approvals not to be unreasonably
withheld.

     "ENVIRONMENTAL LAWS" means any and all federal, state, and local laws,
regulations, and requirements pertaining to health, safety, or the environment,
including, without limitation, the Comprehensive Environmental Response,
Compensation and Liability Act of 1980, 42 U.S.C. (S) 9601 et seq., the Resource
Conservation and Recovery Act of 1976, 42 U.S.C. (S) 6901 et seq., the
Occupational Safety and Health Act, 29 U.S.C. (S) 651 et seq., the Clean Air
Act, 42 U.S.C. (S) 7401 et seq., the Clean Water Act, 33 U.S.C. (S) 1251 et
seq., and the Toxic Substances Control Act, 15 U.S.C. (S) 2601 et seq., as such
laws, regulations, and requirements may be amended or supplemented from time to
time.

     "ENVIRONMENTAL LIABILITIES" means, as to any Person, all liabilities,
obligations, responsibilities, Remedial Actions, losses, damages, punitive
damages, consequential damages, treble damages, costs, and expenses (including,
without limitation, all reasonable fees, disbursements and expenses of counsel,
expert and consulting fees and costs of investigation and feasibility studies),
fines, penalties, sanctions, and interest incurred as a result of any claim or
demand, by any Person, whether based in contract, tort, implied or express
warranty, strict liability, criminal or civil statute, including any
Environmental Law, permit, order or agreement with any Governmental Authority or
other Person, arising from environmental, health or safety conditions or the
Release or threatened Release of a Hazardous Material into the environment,
resulting from the past, present, or future operations of such Person or its
Affiliates.

     "ERISA" means the Employee Retirement Income Security Act of 1974, as
amended from time to time, and the regulations and published interpretations
thereunder.

     "ERISA AFFILIATE" means any corporation or trade or business which is a
member of the same controlled group of corporations (within the meaning of
Section 414(b) of the Code) as Borrower or is under common control (within the
meaning of Section 414(c) of the Code) with Borrower.

                                       7
<PAGE>
 
     "EURODOLLAR ADVANCES" means Advances the interest rates on which are
determined on the basis of the rates referred to in the definition of "ADJUSTED
EURODOLLAR RATE" in this SECTION 1.1.

     "EURODOLLAR RATE" means, for any Eurodollar Advance for any Interest Period
therefor, the rate per annum (rounded upwards, if necessary, to the nearest
1/100 of 1%) appearing on Telerate Page 3750 (or any successor page) as the
London interbank offered rate for deposits in Dollars at approximately 11:00
a.m. (London time) two Business Days prior to the first day of such Interest
Period for a term comparable to such Interest Period.  If for any reason such
rate is not available, the term "EURODOLLAR RATE" shall mean, for any Eurodollar
Advance for any Interest Period therefor, the rate per annum (rounded upwards,
if necessary, to the nearest 1/100 of 1%) appearing on Reuters Screen LIBO Page
as the London interbank offered rate for deposits in Dollars at approximately
11:00 a.m. (London time) two Business Days prior to the first day of such
Interest Period for a term comparable to such Interest Period, provided,
however, if more than one rate is specified on Reuters Screen LIBO Page, the
applicable rate shall be the arithmetic mean of all such rates.

     "EVENT OF DEFAULT" has the meaning specified in SECTION 11.1.

     "EXCESS CASH FLOW" means, for any semi-annual period described in SECTION
3.3(B)(iii), (a) EBITDA, minus (b) total cash income tax expense actually paid
during such period, minus (c) the aggregate amount of any optional prepayments
of the Obligations during such period, minus (d) scheduled principal payments in
respect of all Debt during such period, minus (e) total consolidated interest
expense in respect of all Debt actually paid or that is payable during such
period, minus (f) capital expenditures during such period (provided that such
capital expenditures shall not exceed (x) $4,000,000.00 minus (y) the aggregate
amount of capital expenditures during the two (2) fiscal quarters ending prior
to such semi-annual fiscal period).

     "FEDERAL FUNDS RATE" means, for any day, the rate per annum (rounded
upwards, if necessary, to the nearest 0.01%) equal to the weighted average of
the rates on overnight Federal funds transactions with members of the Federal
Reserve System arranged by Federal funds brokers on such day, as published by
the Federal Reserve Bank of New York on the Business Day next succeeding such
day, provided that (a) if the day for which such rate is to be determined is not
a Business Day, the Federal Funds Rate for such day shall be such rate on such
transactions on the next preceding Business Day as so published on the next
succeeding Business Day, and (b) if such rate is not so published on such next
succeeding Business Day, the Federal Funds Rate for any day shall be the average
rate charged to the Administrative Agent on such day on such transactions as
determined by the Administrative Agent.

     "FNBB" has the meaning specified in the preamble.

     "GAAP" means generally accepted accounting principles, applied on a
consistent basis, as set forth in Opinions of the Accounting Principles Board of
the American Institute of Certified Public Accountants and/or in statements of
the Financial Accounting Standards Board and/or their respective successors and
which are applicable in the circumstances as of the date in question.
Accounting principles are applied on a "CONSISTENT BASIS" when the accounting
principles applied in a current period are comparable in all material respects
to those accounting principles applied in a preceding period, except for changes
required by GAAP.  In the event of a change in GAAP, Administrative Agent and
Borrower will thereafter negotiate in good faith to revise any covenants of this
Agreement affected thereby in order to make such covenants consistent with GAAP
then in effect.

     "GOVERNMENTAL AUTHORITY" means any nation or government, any state or
political subdivision thereof and any entity exercising executive, legislative,
judicial, regulatory, or administrative functions of or pertaining to
government.

                                       8
<PAGE>
 
     "GOVERNMENTAL AUTHORIZATION" shall mean any approval, consent, license,
permit, waiver, or other authorization issued, granted, given, or otherwise made
available by or under the authority of any Governmental Authority or pursuant to
any Legal Requirement.

     "GUARANTEE" by any Person means any obligation, contingent or otherwise, of
such Person directly or indirectly guaranteeing any Debt or other obligation of
any other Person and, without limiting the generality of the foregoing, any
obligation, direct or indirect, contingent or otherwise, of such Person (a) to
purchase or pay (or advance or supply funds for the purchase or payment of) such
Debt or other obligation (whether arising by virtue of partnership arrangements,
by agreement to keep-well, to purchase assets, goods, securities or services, to
take-or-pay, or to maintain financial statement conditions or otherwise), or (b)
entered into for the purpose of assuring in any other manner the obligee of such
Debt or other obligation of the payment thereof or to protect the obligee
against loss in respect thereof (in whole or in part), provided that the term
"GUARANTEE" shall not include endorsements for collection or deposit in the
ordinary course of business.  The term "GUARANTEE" used as a verb has a
corresponding meaning.

     "GUARANTIES" means, collectively, the Guaranty Agreements, each dated as of
April 26, 1996, executed by the Guarantors in favor of the Agents and the
Lenders, as the same may be amended, supplemented or modified from time to time,
including the Consent, Confirmation and Ratification of Guaranty Agreements,
dated the date hereof, which Guaranty Agreements are in renewal, amendment,
substitution and replacement of the Guaranty Agreements executed by the
Guarantors under the Original Credit Agreement in favor of the Agent and the
Lenders under the Original Credit Agreement. "GUARANTY" means any one of the
Guaranties.

     "GUARANTORS" means, collectively, all Wholly-Owned Subsidiaries of
Borrower, now owned or hereafter acquired or formed, including, without
limitation, the Subsidiaries listed on SCHEDULE 2. "GUARANTOR" means any one of
the Guarantors.

     "GUARANTOR SECURITY AGREEMENTS" means the Security Agreements, each dated
as of April 26, 1996, executed by the Guarantors in favor of the Administrative
Agent, for the benefit of the Lenders, as the same may be amended, supplemented
or modified from time to time, including the Consent, Confirmation and
Ratification of Guarantor Security Agreements dated the date hereof, which
Security Agreements are in renewal, amendment, restatement and substitution of
the Security Agreements executed by the Guarantors under the Original Credit
Agreement in favor of the Administrative Agent, for the benefit of the Lenders
under the Original Credit Agreement.  "GUARANTOR SECURITY AGREEMENT" means any
one of the Guarantor Security Agreements.

     "HAZARDOUS MATERIAL" means any substance, product, waste, pollutant,
material, chemical, contaminant, constituent, or other material which is or
becomes listed, regulated, or addressed under any Environmental Law, including,
without limitation, asbestos, petroleum, and polychlorinated biphenyls.

     "HEDGING AGREEMENT" has the meaning specified in SECTION 11.1.

     "INTEREST COVERAGE RATIO" means, as to the Companies for any period, (a)
EBITDA for such period divided by (b) the aggregate amount of consolidated
interest expense for such period, all as determined in accordance with GAAP.

     "INTEREST PERIOD" means, with respect to any Eurodollar Advance, each
period commencing on the date such Advance is made or Converted from an Advance
of another Type or, in the case of each subsequent, successive Interest Period
applicable to a Eurodollar Advance, the last day of the next preceding Interest

                                       9
<PAGE>
 
Period with respect to such Advance, and ending on the numerically corresponding
day in the first (1st), second (2nd), third (3rd) or sixth (6th) calendar month
thereafter, as Borrower may select as provided in SECTION 2.5 or 2.6, except
that each such Interest Period which commences on the last Business Day of a
calendar month (or on any day for which there is no numerically corresponding
day in the appropriate subsequent calendar month) shall end on the last Business
Day of the appropriate subsequent calendar month.  Notwithstanding the
foregoing: (a) each Interest Period which would otherwise end on a day which is
not a Business Day shall end on the next succeeding Business Day (or, if such
succeeding Business Day falls in the next succeeding calendar month, on the next
preceding Business Day); (b) any Interest Period which would otherwise extend
beyond the Termination Date shall end on the Termination Date; (c) no more than
six (6) Interest Periods shall be in effect at the same time; and (d) no
Interest Period shall have a duration of less than one (1) month and, if any
Interest Period would otherwise be a shorter period, such Advances shall not be
available hereunder.

     "ISSUANCE PROCEEDS" means the net proceeds of (i) any sale or issuance of
Borrower's capital stock, or (ii) the incurrence of any Debt of the type
described in SUBSECTIONS (a) and (b) of the definition of Debt, in each case to
the extent permitted hereunder; provided that "ISSUANCE PROCEEDS" shall include
proceeds from the exercise of any warrants issued to Alabama Lithotripsy Joint
Venture to the extent such warrant proceeds are contemporaneously used to pay
outstanding Debt to Alabama Lithotripsy Joint Venture.

     "LEGAL REQUIREMENT" shall mean any federal, state, local, municipal,
foreign, international, multinational, or other administrative order,
constitution, law, ordinance, principle of common law, regulation, statute, or
treaty as in effect on the date hereof.

     "LENDER" and "LENDERS" have the meanings specified in the preamble.

     "LIEN" means any lien, mortgage, security interest, tax lien, financing
statement, pledge, charge, hypothecation, assignment, preference, priority, or
other encumbrance of any kind or nature whatsoever (including, without
limitation, any conditional sale or title retention agreement), whether arising
by contract, operation of law, or otherwise.

     "LITHO" means Lithotripters, Inc., a North Carolina corporation.

     "LOAN DOCUMENTS" means this Agreement, the Notes, the Guaranties, the
Borrower Security Agreement, the Guarantor Security Agreements, the Pledge
Agreements, any Hedging Agreement between Borrower and the Administrative Agent,
and all other instruments, documents, and agreements executed and delivered
pursuant to or in connection with this Agreement, as such instruments,
documents, and agreements may be amended, modified, renewed, extended, or
supplemented from time to time.

     "MATERIAL SUBSIDIARY" means, as of any date, (a) any Subsidiary which,
together with its Subsidiaries, accounts for three percent (3%) or more of the
Company's consolidated gross revenues or assets, or (b) any combination of
Subsidiaries which, together with their Subsidiaries, account for seven percent
(7%) or more of the Company's consolidated gross revenues or assets, in each
case on a consolidated basis (but without elimination of any minority interests)
as of and for the most recent fiscal quarter for which such information is
available.  "MATERIAL SUBSIDIARIES" means all of the Material Subsidiaries.

     "MAXIMUM RATE" means, at any time and with respect to any Lender, the
maximum rate of interest under applicable law that such Lender may charge
Borrower.  The Maximum Rate shall be calculated in a manner that takes into
account any and all fees, payments, and other charges in respect of the Loan
Documents that constitute interest under applicable law.  Each change in any
interest rate provided for herein based upon

                                       10
<PAGE>
 
the Maximum Rate resulting from a change in the Maximum Rate shall take effect
without notice to Borrower at the time of such change in the Maximum Rate.

     "MULTIEMPLOYER PLAN" means a multiemployer plan as defined in Section 3(37)
of ERISA to which contributions have been made by Borrower or any ERISA
Affiliate of Borrower and which is covered by Title IV of ERISA.

     "NATIONSBANK" has the meaning specified in the preamble.

     "NOTES" means the Revolving Credit Notes and the Term Notes.  "NOTE" means
any one of the Notes.

     "OBLIGATED PARTY" means any Person who is or becomes party to any agreement
that guarantees or secures payment and performance of the Obligations or any
part thereof.

     "OBLIGATIONS" means all obligations, indebtedness, and liabilities of
Borrower to the Agents and the Lenders, or any of them, arising pursuant to any
of the Loan Documents, now existing or hereafter arising, whether direct,
indirect, related, unrelated, fixed, contingent, liquidated, unliquidated,
joint, several, or joint and several, and all interest accruing thereon and all
attorneys' fees and other expenses incurred in the enforcement or collection
thereof.

     "ORIGINAL CREDIT AGREEMENT" has the meaning specified in the recitals.

     "PARTNERSHIPS" means the partnerships in which Borrower or any Subsidiary
now owns or hereafter acquires general and/or limited partnership interests and
the other Persons in which Borrower or any Subsidiary now owns or hereafter
acquires ownership interests, including, without limitation, the partnerships
and other Persons listed on SCHEDULE 3.  "PARTNERSHIP" means any one of the
Partnerships.

     "PAYMENT DATE" means (a) with respect to Alternate Base Rate Advances and
the commitment fees payable pursuant to SECTION 2.8(a),  the last Business Day
of each April, July, October and January, commencing April 30, 1997, and (b)
with respect to Eurodollar Advances, the last day of the respect Interest Period
therefor, provided that if any Interest Period is greater than three (3) months,
then accrued interest shall also be due and payable shall also be due and
payable on the date that is three (3) months after the commencement of such
Interest Period.

     "PBGC" means the Pension Benefit Guaranty Corporation or any entity
succeeding to all or any of its functions under ERISA.

     "PERMITTED ACQUISITION" means an Acquisition by Borrower or any of its
Subsidiaries with respect to which each of the following conditions shall have
been satisfied:

          (a)   the Acquisition by Borrower or such Subsidiary is of a business,
     assets or Person (as applicable, the "TARGET") which is engaged in
     substantially the same business as the business conducted by Borrower or
     such Subsidiary on the date hereof, or any other business reasonably
     related thereto;

          (b)   as of the closing of such Acquisition, the Acquisition has been
     approved and recommended by the board of directors or other applicable
     governing body of the Target and the Person from which the Target is to be
     acquired;

                                       11
<PAGE>
 
          (c)   prior to the closing of such acquisition, the Target and the
     Person from which the Target is to be acquired must be Solvent;

          (d)   as of the closing of such Acquisition, after giving effect to 
     such Acquisition, Borrower or the Subsidiary that is the acquiring party
     must be Solvent and the Companies, on a consolidated basis, must be
     Solvent;

          (e)   as of the closing of such Acquisition, after giving effect to 
     such Acquisition, no Default shall exist or occur as a result of, and after
     giving effect to, such Acquisition;

          (f)   the aggregate purchase price with respect to such Acquisition 
     does not exceed five (5) times EBITDA of the Target, subject to adjustments
     acceptable to the Administrative Agent where less than all of the business,
     assets or stock of the Target is acquired, acquired pursuant to the
     Acquisition for the four (4) fiscal quarters ending on the most recently
     ended fiscal period prior to the date of such Acquisition;

          (g)   the aggregate cash consideration for such Acquisition does not
     exceed $10,000,000.00 and the aggregate cash consideration for all
     Acquisitions (other than the Acquisition of additional limited partnership
     interests of the Partnerships in which Litho  is, as of the date hereof,
     the general partner) during the immediately preceding twelve (12) month
     period (including such Acquisition) does not exceed $20,000,000.00;

          (h)   after giving effect to such Acquisition, the aggregate Debt of 
     the Companies (without deduction for any minority interests and including
     any Advances under the Revolving Credit Commitments) does not exceed the
     product of (1) EBITDA of the Companies (including EBITDA for the Target
     acquired pursuant to the Acquisition) for the four (4) fiscal quarters
     ending on the closing of the Acquisition, and (2)(A) on or before December
     31, 1998, 2.75 and (B) thereafter, the ratio set forth in SECTION 10.1
     which is applicable to the period for which such calculation is made;

          (i)   the Administrative Agent shall have received pro forma financial
     statements of the Companies (as if the business, assets or Person acquired
     had been acquired since the first (1st) day of the period for which such
     pro forma financial statements are delivered and had been managed and
     conducted in accordance with the Borrower's standard business practices)
     for the prior four (4) fiscal quarters of Borrower and the Companies;

          (j)   if the Target is to be an After-Acquired Subsidiary, then 
     Borrower shall have complied with the terms and conditions set forth in
     SECTION 8.13; and

          (k)   the Administrative Agent has received a certificate, executed by
     the President or a Vice President of Borrower confirming that all
     representations and warranties set forth in the Loan Documents continue to
     be true and correct in all material respects immediately prior to and after
     giving effect to the Permitted Acquisition and the transactions
     contemplated thereby, and setting forth the calculations supporting
     compliance with the limitations prescribed herein.

     "PERSON" means any individual, corporation, business trust, association,
company, partnership, joint venture, Governmental Authority, or other entity.

     "PLAN" means any employee benefit or other plan established or maintained
by Borrower or any ERISA Affiliate of Borrower and which is covered by Title IV
of ERISA.

                                       12
<PAGE>
 
     "PLEDGE AGREEMENTS" means the Pledge Agreements, each dated as of April 26,
1996, executed by Borrower and each Subsidiary of Borrower that owns general
and/or limited partnership interests in the Partnerships in favor of the
Administrative Agent, for the benefit of the Lenders, as the same may be
amended, supplemented or modified from time to time, including the Consent,
Confirmation and Ratification of Pledge and Security Agreements, dated the date
hereof.  "PLEDGE AGREEMENT" means any one of the Pledge Agreements.

     "PLEDGORS" means each of the pledgors of partnership interests or Assigned
Rights (as defined in the applicable Pledge Agreement) pursuant to a Pledge
Agreement.  "PLEDGOR" means any one of the Pledgors.

     "PRINCIPAL OFFICE" means the principal office of the Administrative Agent,
presently located at 100 Federal Street, Boston, Massachusetts 02110.

     "PROHIBITED TRANSACTION" means any transaction set forth in Section 406 of
ERISA or Section 4975 of the Code.

     "REGULATION D" means Regulation D of the Board of Governors of the Federal
Reserve System as the same may be amended or supplemented from time to time.

     "REGULATORY CHANGE" means, with respect to any Lender, any change after the
date of this Agreement in United States federal, state, or foreign laws or
regulations (including Regulation D) or the adoption or making after such date
of any interpretations, directives, or requests applying to a class of banks
including such Lender of or under any United States federal, state, or foreign
laws or regulations (whether or not having the force of law) by any court or
governmental or monetary authority charged with the interpretation or
administration thereof.

     "RELEASE" means, as to any Person, any release, spill, emission, leaking,
pumping, injection, deposit, disposal, disbursement, leaching, or migration of
Hazardous Materials into the indoor or outdoor environment or into or out of
property owned by such Person, including, without limitation, the movement of
Hazardous Materials through or in the air, soil, surface water, ground water, or
property.

     "REMEDIAL ACTION" means all actions required to (a) clean up, remove,
treat, or otherwise address Hazardous Materials in the indoor or outdoor
environment, (b) prevent the Release or threat of Release or minimize the
further Release of Hazardous Materials so that they do not migrate or endanger
or threaten to endanger public health or welfare or the indoor or outdoor
environment, or (c) perform pre-remedial studies and investigations and post-
remedial monitoring and care.

     "REPORTABLE EVENT" means any of the events set forth in Section 4043 of
ERISA.

     "REQUIRED LENDERS" means, as of any date, any combination of Lenders (other
than any Defaulting Lenders) who collectively hold sixty percent (60%) of the
sum of (a) the Revolving Credit Commitments (other than of any Defaulting
Lenders), or if the Revolving Credit Commitments shall have been terminated,
then of the aggregate unpaid principal amount of the Revolving Credit Notes
(other than of any Defaulting Lenders), (b) the aggregate unpaid principal
amount of the Term Notes A (other than of any Defaulting Lenders) and (c) the
aggregate unpaid principal amount of the Term Notes B (other than of any
Defaulting Lenders).

     "RESERVE REQUIREMENT" means, for any Eurodollar Advance for any Interest
Period therefor, the average rate at which reserves (including any marginal,
supplemental or emergency reserves) are required to

                                       13
<PAGE>
 
be maintained during such Interest Period under Regulation D by each Lender on
its portion of such Advance against "EUROCURRENCY LIABILITIES" as such term is
used in Regulation D. Without limiting the effect of the foregoing, the Reserve
Requirement shall reflect any other reserves required to be maintained by a
Lender by reason of any Regulatory Change against (i) any category of
liabilities which includes deposits by reference to which the Adjusted
Eurodollar Rate is to be determined, or (ii) any category of extensions of
credit or other assets which include Eurodollar Advances.

     "REVOLVING CREDIT COMMITMENT" means, as to each Lender as of any date, the
obligation of such Lender on such date to make Advances hereunder in an
aggregate principal amount at any time outstanding up to but not exceeding the
amount shown on SCHEDULE 1 as its Revolving Credit Commitment, as the same may
be reduced pursuant to SECTION 2.1(c) or terminated pursuant to SECTION 2.1(c)
or SECTION 11.2 and as the same may be increased or decreased from time to time
by further assignment pursuant to SECTION 13.6.  "REVOLVING CREDIT COMMITMENTS"
means the Revolving Credit Commitments of all of the Lenders in the original
aggregate amount of $50,000,000.00.

     "REVOLVING CREDIT LOAN" means all Advances with respect to the Revolving
Credit Commitment, evidenced by the Revolving Credit Notes.

     "REVOLVING CREDIT NOTE" means a revolving credit note executed by Borrower,
substantially in the form of EXHIBIT C, payable to each Lender having a
Revolving Credit Commitment in an amount equal to such Lender's Revolving Credit
Commitment, as the same may be amended, supplemented, modified or restated from
time to time, evidencing the obligation of Borrower to repay the Revolving
Credit Loan, and all renewals, modifications and extensions thereof.  "REVOLVING
CREDIT NOTES" means all of the Revolving Credit Notes of the applicable Lenders.

     "RICO" means the Racketeer Influenced and Corrupt Organization Act of 1970,
as amended from time to time.

     "SOLVENT" means, with respect to any Person, that on the date of
determination (a) the fair market value of its assets is greater than the total
amount of liabilities, including, without limitation, contingent liabilities of
such Person which would be required to be included on the balance sheet of such
Person or disclosed in the financial statements of such Person in accordance
with GAAP, (b) the present fair salable value of the assets of such Person is
not less than the amount that will be required to pay the probable liability of
such Person on its debts as they become absolute and matured, (c) such Person
does not intend to, and does believe that it will, incur debts or liabilities
beyond such Person's ability to pay as such debts and liabilities mature, and
(d) such Person is not engaged in business or transactions, and is not about to
engage in business or transactions, for which its assets would constitute an
unreasonably small capital.

     "SUBSIDIARY" means, with respect to any Person, any corporation,
partnership, association, or other business entity (a) of which securities or
other ownership interests representing more than fifty percent (50%) of the
equity or more than fifty percent (50%) of the ordinary voting power or more
than fifty percent (50%) of the general partnership interests are, at the time
any determination is made, owned, Controlled or held by such Person, or (b) that
is, at the time any determination is made, otherwise Controlled by one or more
Subsidiaries of such Person or by such Person and one or more Subsidiaries of
such Person.

     "SYNDICATION AGENT" has the meaning specified in the preamble.

     "TERMINATION DATE" means 1:00 p.m. Boston, Massachusetts time on (a) with
respect to the Revolving Credit Commitments and the Term Loan A Commitments,
April 30, 2001, and (b) with respect to the

                                       14
<PAGE>
 
Term Loan B Commitments, April 30, 2003, as the case may be, or such earlier
date and time on which the Commitments terminate as provided in this Agreement.

     "TERM LOAN A" means the $45,000,000.00 term loan facility provided to
Borrower by the Lenders hereunder.

     "TERM LOAN A COMMITMENT" means, as to the applicable Lenders as of the date
hereof, the obligation of such Lender on such date to make Advances hereunder in
an aggregate principal amount up to but not exceeding the amount shown on
SCHEDULE 1 hereto as its Term Loan A Commitment, as the same may be increased or
decreased from time to time by further assignment pursuant to SECTION 13.6.
"TERM LOAN A COMMITMENTS" means the Term Loan A Commitments of all of the
applicable Lenders in the original aggregate amount of $45,000,000.00.

     "TERM NOTE A" means a term promissory note executed by Borrower,
substantially in the form of EXHIBIT D, payable to each Lender having a Term
Loan A Commitment in an amount equal to such Lender's Term Loan A Commitment, as
the same may be amended, supplemented, modified or restated from time to time,
evidencing the obligation of Borrower to repay the Term Loan A, and all
renewals, modifications and extensions thereof.  "TERM NOTES A" means all of the
Term Notes A of the applicable Lenders.

     "TERM LOAN B" means the $40,000,000.00 term loan facility provided to
Borrower by the Lenders having a Term Loan B Commitment hereunder.

     "TERM LOAN B COMMITMENT" means, as to each Lender as of any date, the
obligation of such Lender on such date to make Advances hereunder in an
aggregate principal amount up to but not exceeding the amount shown on SCHEDULE
1 hereto as its Term Loan B Commitment, as the same may be increased or
decreased from time to time by further assignment pursuant to SECTION 13.6.
"TERM LOAN B COMMITMENTS" means the Term Loan B Commitments of all of the
Lenders in the original aggregate amount of $40,000,000.00.

     "TERM NOTE B" means a term promissory note executed by Borrower,
substantially in the form of EXHIBIT E, payable to each Lender having a Term
Loan B Commitment in an amount equal to such Lender's Term Loan B Commitment, as
the same may be amended, supplemented, modified or restated from time to time,
evidencing the obligation of Borrower to repay the Term Loan B, and all
renewals, modifications and extensions thereof.  "TERM NOTES B" means all of the
Term Notes B of the Lenders having a Term Loan B Commitment.

     "TERM NOTES" means, collectively, the Term Notes A and the Term Notes B.

     "TOTAL DEBT SERVICE COVERAGE RATIO" means, as to the Companies for any
period, (a) the sum of EBITDA for such period, minus the aggregate amount of
capital expenditures made during such period, divided by (b) the sum of all
principal and interest payments payable during such period in respect of all
Debt of the Companies (without deduction for any minority interests), all as
determined on a rolling four (4) quarter and consolidated basis in accordance
with GAAP.

     "TOTAL DEBT TO EBITDA" means, as of any date, the ratio of (a) the
aggregate amount of Debt of the Companies (without deduction for any minority
interests), as of such date, to (b) EBITDA of the Companies, for the four (4)
fiscal quarter period ending on the date of determination.

     "TYPE" means any type of Advance (i.e., Alternate Base Rate Advance or
Eurodollar Advance).

                                       15
<PAGE>
 
     "UCC" means the Uniform Commercial Code as in effect in the Commonwealth of
Massachusetts or other applicable jurisdiction, as amended.

     "WHOLLY-OWNED SUBSIDIARIES" means, as of any date, all Subsidiaries that
are wholly-owned by Borrower or a wholly-owned Subsidiary of Borrower.  "WHOLLY-
OWNED SUBSIDIARY" means any one of the Wholly-Owned Subsidiaries.

     SECTION 1.3   OTHER DEFINITIONAL PROVISIONS.  All definitions contained in
this Agreement are equally applicable to the singular and plural forms of the
terms defined.  The words "hereof," "herein," and "hereunder" and words of
similar import referring to this Agreement refer to this Agreement as a whole
and not to any particular provision of this Agreement.  Unless otherwise
specified, all ARTICLE, SECTION, EXHIBIT and SCHEDULE references pertain to this
Agreement.  All accounting terms not specifically defined herein shall be
construed in accordance with GAAP.  All financial covenants and related
definitions relating to the Companies shall, unless otherwise indicated, be
determined after deduction of any minority interests, provided that all
references to "DEBT" shall include all Debt without deduction for any minority
interests.  Terms used herein that are defined in the UCC, unless otherwise
defined herein, shall have the meanings specified in the UCC.

                                  ARTICLE II

                                   ADVANCES

     SECTION 2.1   COMMITMENTS.

     (a) REVOLVING CREDIT COMMITMENTS.  Subject to the terms and conditions of
this Agreement, each Lender hereby severally agrees to make one or more Advances
to Borrower from time to time from the date hereof to the Termination Date in an
aggregate principal amount at any time outstanding up to but not exceeding the
amount of such Lender's Revolving Credit Commitment as then in effect.  Subject
to the foregoing limitations, and the other terms and provisions of this
Agreement, Borrower may borrow, repay, and reborrow hereunder the amount of the
Revolving Credit Commitments by means of Eurodollar Advances (or, in the event
Eurodollar Advances are unavailable hereunder, Alternate Base Rate Advances when
required or permitted by ARTICLE IV).

     (b) TERM LOAN A AND TERM LOAN B COMMITMENTS.  Subject to the terms and
conditions of this Agreement, (i) each Lender having a Term Loan A Commitment
hereby severally agrees to make a single Advance to Borrower, on or about the
date of this Agreement, in the amount of such Lender's Term Loan A Commitment,
and (ii) each Lender having a Term Loan B Commitment hereby severally agrees to
make a single Advance to Borrower, on or about March 31, 1997, in the amount of
such Lender's Term Loan B Commitment.  Borrower may not borrow, repay, and
reborrow hereunder any portion of the amount of the Term Loan A or the Term Loan
B.

     (c) OPTIONAL REDUCTION AND TERMINATION OF REVOLVING CREDIT COMMITMENTS.
Borrower shall have the right to terminate in whole or reduce in part the unused
portion of the Revolving Credit Commitments upon at least three (3) Business
Days' prior written notice (which notice shall be irrevocable) to the
Administrative Agent specifying the effective date thereof, whether a
termination or reduction is being made, and the amount of any partial reduction,
provided that each partial reduction shall be in the amount of $1,000,000.00 or
a greater integral multiple thereof and Borrower shall simultaneously prepay the
amount by which the unpaid principal amount of the Revolving Credit Notes
exceeds the Revolving Credit Commitments

                                       16
<PAGE>
 
(after giving effect to such notice) plus accrued and unpaid interest on the
principal amount so prepaid. No portion of the Revolving Credit Commitments may
be reinstated after it has been terminated or reduced.

     SECTION 2.2   NOTES.

     (a)  REVOLVING CREDIT NOTES.  The obligation of Borrower to repay each
Lender for Advances made by such Lender pursuant to such Lender's Revolving
Credit Commitment,  and all interest thereon, shall be evidenced by a Revolving
Credit Note dated the date hereof, executed by Borrower and payable to the order
of such Lender in the original principal amount of such Lender's Revolving
Credit Commitment.

     (b)  TERM NOTES A AND TERM NOTES B.

          (i)   The obligation of Borrower to repay each Lender having a Term 
     Loan A Commitment for Advances made by such Lender pursuant to its Term
     Loan A Commitment, and all interest thereon, shall be evidenced by a Term
     Note A dated the date hereof, executed by Borrower and payable to the order
     of such Lender in the original principal amount of such Lender's Term Loan
     A Commitment.

          (ii)  The obligation of Borrower to repay each Lender having a Term
     Loan B Commitment for Advances made by such Lender pursuant to its Term
     Loan B Commitment, and all interest thereon, shall be evidenced by a Term
     Note B dated the date hereof, executed by Borrower and payable to the order
     of such Lender in the original principal amount of such Lender's Term Loan
     B Commitment.

     SECTION 2.3   REPAYMENT OF ADVANCES.

     (a)  REVOLVING CREDIT NOTES.  Borrower shall repay the outstanding 
principal amount of the Revolving Credit Notes on the Termination Date.

     (b)  TERM NOTES A.  Borrower shall repay the outstanding principal amount 
of the Term Notes A as follows:  (i) in five (5) equal quarterly installments, 
on April 30, 1997, July 31, 1997, October 31, 1997, January 31, 1998, and April
30, 1998, each in the amount of $2,000,000.00; (ii) in four (4) equal quarterly
installments, on July 31, 1998, October 31, 1998, January 31, 1999 and April 30,
1999, each in the amount of $2,500,000.00; and (iii) in eight (8) equal
quarterly installments, on July 31, 1999, October 31, 1999, January 31, 2000,
April 30, 2000, July 31, 2000, October 31, 2000, January 31, 2001 and on the
Termination Date, each in the amount of $3,125,000.00.

     (c)  TERM NOTES B.  Borrower shall repay the outstanding principal amount 
of the Term Notes B as follows: (i) in five (5) installments, on April 30th of 
each year, commencing April 30, 1998, and continuing through April 30, 2002, 
each in the amount of $800,000.00; and (ii) one final installment on the 
Termination Date, in the outstanding unpaid principal amount of the Term Notes
B.

     SECTION 2.4   INTEREST.  The unpaid principal amount of all Advances shall
bear interest at a varying rate per annum equal from day to day to the lesser of
(a) the Maximum Rate, or (b) the Applicable Rate.  If at any time the Applicable
Rate for any Advance shall exceed the Maximum Rate, thereby causing the interest
accruing on such Advance to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate for such Advance shall not reduce the rate of
interest on such Advance below the Maximum Rate until the aggregate amount of
interest accrued on such Advance equals the aggregate amount of interest which
would have accrued on such Advance if the Applicable Rate had at all times been
in effect.  Accrued

                                       17
<PAGE>
 
and unpaid interest on the Advances shall be due and payable on each Payment
Date and on the Termination Date. Notwithstanding the foregoing, any outstanding
principal of any Advance and (to the fullest extent permitted by law) any other
amount payable by Borrower under this Agreement or any other Loan Document that
is not paid in full when due (whether at stated maturity, by acceleration, or
otherwise) shall bear interest at the Default Rate for the period from and
including the due date thereof to but excluding the date the same is paid in
full. Interest payable at the Default Rate shall be payable from time to time on
demand.

     SECTION 2.5   BORROWING PROCEDURE.

     (a)  REVOLVING CREDIT LOAN.  Borrower shall give the Administrative Agent
notice by means of an Advance Request Form of each requested Advance under the
Revolving Credit Commitments hereunder at least two (2) Business Days before the
requested date of each Eurodollar Advance (and at least one (1) Business Day
before the requested date of each Alternate Base Rate Advance), specifying: (a)
the requested date of such Advance (which shall be a Business Day); (b) the
amount of such Advance; and (c) the duration of the Interest Period for such
Advance (if a Eurodollar Advance).  The Administrative Agent at its option may
accept telephonic requests for Advances under the Revolving Credit Commitments,
provided that such acceptance shall not constitute a waiver of the
Administrative Agent's right to delivery of an Advance Request Form in
connection with subsequent Advances under the Revolving Credit Commitments.  Any
telephonic request for an Advance under the Revolving Credit Commitments by
Borrower shall be promptly confirmed by submission of a properly completed
Advance Request Form to the Administrative Agent.  Each Advance under the
Revolving Credit Commitments shall be in a minimum principal amount of
$1,000,000.00 or a greater integral multiple thereof, provided that if such
Advance equals the entire remaining unfunded portion of the Revolving Credit
Commitments, it may be for any amount.  The aggregate principal amount of
Eurodollar Advances having the same Interest Period shall be at least equal to
$2,500,000.00 or a greater integral multiple of $500,000.00.

     (b)  TERM LOANS A AND TERM LOANS B.  Borrower shall give the Administrative
Agent notice by means of an Advance Request Form of the initial Advance under
the Term Loan A and the Term Loan B hereunder at least two (2) Business Days
before the requested date thereof, specifying: (a) the requested date of such
Advance (which shall be a Business Day); (b) the amount of such Advance; and (c)
the duration of the Interest Period for such Advance (if a Eurodollar Advance),
provided that any Advance under the Term Loan B shall be a Eurodollar Advance.

     (c)  GENERALLY.  The Administrative Agent shall notify each Lender of the
contents of each Advance Request Form.  Not later than 11:00 a.m. Boston,
Massachusetts time on the date specified for each Advance hereunder, each Lender
will make available to the Administrative Agent at the Principal Office in
immediately available funds, for the account of Borrower, its pro rata share of
each Advance. After the Administrative Agent's receipt of such funds and subject
to the other terms and conditions of this Agreement, the Administrative Agent
will make each Advance available to Borrower by depositing the same, in
immediately available funds, in a deposit account of Borrower maintained at the
Documentation Agent.  All notices under this SECTION 2.5(C) shall be irrevocable
and shall be given not later than 11:00 a.m. Boston, Massachusetts time on the
day which is not less than the number of Business Days specified above for such
notice.

     SECTION 2.6   CONTINUATIONS; CONVERSIONS.

     (a)  CONTINUATIONS.  Borrower shall have the right to Continue Eurodollar
Advances by giving the Administrative Agent written notice specifying: (i) the
Continuation date; (ii) the amount of the Advance to be Continued; and (iii) the
duration of the Interest Period applicable thereto, which notice shall be

                                       18
<PAGE>
 
irrevocable and must be given by Borrower not later than 11:00 a.m. Boston,
Massachusetts time at least two (2) Business Days before each such Continuation.
The Administrative Agent shall promptly notify each Lender of the contents of
each such notice.  If Borrower shall fail to give the Administrative Agent the
notice as specified above for Continuation of a Eurodollar Advance prior to the
end of the Interest Period applicable thereto, such Eurodollar Advance shall be
automatically Continued for a one (1) month Interest Period.  The existing
Eurodollar Advances under the Original Credit Agreement relating to the Term
Loans thereunder shall be Continued hereunder relating to the Term Loans A.

     (b)  CONVERSIONS.  Borrower shall have the right to Convert an Alternate
Base Rate Advance at any time to a Eurodollar Advance by giving the
Administrative Agent written notice specifying: (i) the Conversion Date; (ii)
the amount of the Advance to be Converted; and (iii) the duration of the
Interest Period applicable thereto, which notice shall be irrevocable and must
be given by Borrower not later than 11:00 a.m. Boston, Massachusetts time at
least two (2) Business Days before each such Conversion.  The Administrative
Agent shall promptly notify each Lender of the contents of each such notice.

     (c)  DEFAULT.  After the occurrence and during the continuance of a 
Default, no outstanding Advances may be Converted into, or Continued as, a
Eurodollar Advance.

     SECTION 2.7   USE OF PROCEEDS.

     (a)  REVOLVING CREDIT LOAN.  The proceeds of Advances under the Revolving
Credit Commitments shall be used by Borrower (i) for working capital in the
ordinary course of business, (ii) to purchase, refurbish or replace equipment to
be utilized in lithotripsy operations, (iii) to finance Permitted Acquisitions,
(iv) to the extent permitted by this Agreement, to repurchase outstanding
capital stock of Borrower, and (v) to make loans or capital contributions to its
Subsidiaries the proceeds of which are used by each such Subsidiary for one or
more of the purposes permitted by SUBSECTIONS (i), (ii), (iii), and (iv) of this
SECTION 2.7(a).

     (b)  TERM LOANS A AND TERM LOANS B.  The proceeds of Advances under the
Term Loan A Commitments were used by Borrower to finance the Acquisition of
Litho, and the proceeds of Advances under the Term Loan B Commitments shall be
used by Borrower to fund other Permitted Acquisitions and for capital
expenditures and other working capital purposes.

     SECTION 2.8  FEES.

     (a)  Borrower hereby agrees to pay to the Administrative Agent, for the
ratable account of each Lender having a Revolving Credit Commitment, a
commitment fee on the daily average unused amount of such Lender's Revolving
Credit Commitment for the period from and including the date of this Agreement
to but excluding the Termination Date, at the per annum rate equal to the
Applicable Unused Fee Percentage based on a 365-day or 366-day year, as the case
may be, and the actual number of days elapsed. Accrued commitment fees shall be
payable in arrears on each Payment Date and on the Termination Date.

     (b)  Borrower hereby agrees to pay to the Agents for their own respective
accounts, the fees agreed to by Borrower and the Agents pursuant to a side
letter agreement with each Agent.

                                       19
<PAGE>
 
                                  ARTICLE III

                                   PAYMENTS

     SECTION 3.1   METHOD OF PAYMENT.  All payments of principal, interest, and
other amounts to be paid by Borrower under this Agreement and the other Loan
Documents shall be paid to the Administrative Agent at the Principal Office for
the account of each Lender's Applicable Lending Office in Dollars and in
immediately available funds, without setoff, deduction, or counterclaim, not
later than 1:00 p.m. Boston, Massachusetts time on the date on which such
payment shall become due (each such payment made after such time on such due
date to be deemed to have been made on the next succeeding Business Day).
Borrower shall, at the time of making each such payment, specify to the
Administrative Agent the sums payable by Borrower under this Agreement and the
other Loan Documents to which such payment is to be applied (and in the event
that Borrower fails to so specify, or if an Event of Default has occurred and is
continuing, the Administrative Agent may apply such payment to the Obligations
in such order and manner as it may elect in its sole discretion, subject to
SECTION 3.4).  Each payment received by the Administrative Agent under this
Agreement or any other Loan Document for the account of a Lender shall be paid
promptly to such Lender, in immediately available funds, for the account of such
Lender's Applicable Lending Office.  Whenever any payment under this Agreement
or any other Loan Document shall be stated to be due on a day that is not a
Business Day, such payment may be made on the next succeeding Business Day, and
such extension of time shall in such case be included in the computation of the
payment of interest and commitment fee, as the case may be.

     SECTION 3.2   OPTIONAL PREPAYMENT.  Borrower may, upon at least three (3)
Business Days' prior notice to the Administrative Agent, prepay the Revolving
Notes and the Term Notes A in whole or in part at any time or from time to time
without premium or penalty but with accrued interest to the date of prepayment
on the amount so prepaid, provided that (a) Eurodollar Advances prepaid on a day
other than the last day of the Interest Period for such Advances shall include
the additional compensation, if any, required by SECTION 4.5, and (b) each
partial prepayment shall be in the amount of the aggregate remaining outstanding
principal amount of the Eurodollar Advances or in the principal amount of
$1,000,000.00 or a greater integral multiple thereof.  All notices under this
SECTION 3.2 shall be irrevocable and must be given by Borrower not later than
11:00 a.m. Boston, Massachusetts time on the day which is not less than the
number of Business Days specified above for such notice.  Optional prepayments
of the Term Notes B must be proposed to be made by Borrower pro rata with the
Term Notes A.  So long as the outstanding principal amount of the Term Notes A
on the date of any proposed prepayment exceeds the pro rata portion of the
proposed prepayment to be applied to the Term Notes A, any Lender holding Term
Notes B may elect to be excluded from the pro rata sharing of any optional
prepayment made by Borrower under this SECTION 3.2, and any such prepayment
shall not reduce the outstanding principal balances of the Term Notes B, but
shall be applied pro rata to the Term Notes A.  Such election shall be made in a
writing signed by each such electing Lender who holds Term Notes B and delivered
to the Administrative Agent before the date fixed for such prepayment.  Optional
prepayments shall be applied to the applicable Notes as set forth in SECTION
3.9.

     SECTION 3.3   MANDATORY PREPAYMENTS.

     (a)  REVOLVING CREDIT NOTES.

          (i)   ASSET SALES.  Immediately upon the receipt of the proceeds
     thereof, Borrower shall prepay the Revolving Credit Notes in an amount
     equal to the net proceeds of any sale, liquidation or disposition of any
     assets of any Company (other than the Partnerships or the assets of the
     Partnerships), where such net proceeds exceed $100,000.00.

                                       20
<PAGE>
 
          (ii)  SALE OR ISSUANCE OF CAPITAL STOCK OR DEBT.  Immediately upon the
     receipt of the proceeds thereof, Borrower shall prepay the Revolving Credit
     Notes in an amount equal to fifty percent (50%) of any Issuance Proceeds.

          (iii) AMERICAN PHYSICIANS SERVICE GROUP.  Immediately upon the
     receipt of the proceeds of any disposition of the stock of American
     Physicians Service Group, Inc. held by any Company, Borrower shall prepay
     the Revolving Credit Notes in an amount equal to excess of (A) the net
     proceeds of any disposition, over (B) an amount equal to two dollars
     ($2.00) per share sold or disposed.

          (iv)  APPLICATION OF MANDATORY PREPAYMENTS.  Any such mandatory
     prepayments of the Revolving Credit Notes shall be applied to the Revolving
     Credit Notes on a pro rata basis based upon the outstanding principal
     balances of such Notes as of the date of payment.  Any such prepayments
     shall not reduce the Revolving Credit Commitments.

     (b)  TERM NOTES.

          (i)   ASSET SALES BY PARTNERSHIPS.  Immediately upon the receipt of 
     the proceeds thereof, Borrower shall prepay the Term Notes in an amount
     equal to the net proceeds of any sale, liquidation or disposition of any
     Partnership or of any assets of any Partnership; provided that such net
     proceeds shall be limited to Borrower's or its Wholly-Owned Subsidiary's
     pro rata portion of such net proceeds; and provided further that Borrower
     shall not be required to prepay the Term Notes to the extent that the net
     proceeds of any sale, liquidation or disposition of any assets of any
     Partnership are used by such Partnership to replace such assets with assets
     of similar character within ninety (90) days of such sale, liquidation or
     disposition.

          (ii)  SALE OR ISSUANCE OF CAPITAL STOCK OR DEBT.  Immediately upon the
     receipt of the proceeds thereof, Borrower shall prepay the Term Notes in an
     amount equal to the lesser of (A) fifty percent (50%) of any Issuance
     Proceeds, and (B) the Applicable Payment Amount.

          (iii) EXCESS CASH FLOW.  Borrower shall prepay the Term Notes on each
     April 15 and August 15, commencing April 15, 1997 in amount equal to the
     lesser of (A) seventy-five percent (75%) of Excess Cash Flow for, in the
     case of the payment due each April 15, the period from the preceding July 1
     though December 31, and in the case of the payment due each August 15, the
     period from the preceding January 1 through June 30, fiscal quarter, and
     (B) the Applicable Payment Amount.

          (iv)  APPLICATION OF MANDATORY PREPAYMENTS.  Subject to SECTION
     3.9(a)(iv) below, any mandatory prepayments of the Term Notes shall be
     applied to the Term Notes on a pro rata basis based upon the aggregate
     outstanding principal balances of such Notes owing to each Lender as of the
     date of payment.

     SECTION 3.4   PRO RATA TREATMENT.  Except to the extent otherwise provided
herein: (a) the making and Continuation of Advances under the Revolving Credit
Commitment and the Term Loan A shall be made pro rata among the Lenders
according to the amounts of their respective Revolving Credit Commitments or
Term Loan A Commitments, as the case may be; (b) the making and Continuation of
Advances under the Term Loan B shall be made pro rata among the Lenders
according to the amounts of their respective Term Loan B Commitments; (c) each
termination or reduction of the Revolving Credit Commitments under SECTION
2.1(c) or otherwise shall be applied to the Revolving Credit Commitments of the
Lenders pro rata,

                                       21
<PAGE>
 
according to their respective unused Revolving Credit Commitments; and (d) each
payment and prepayment of principal of or interest on Advances by Borrower shall
be made to the Administrative Agent for the account of the applicable Lenders in
accordance with SECTION 3.9.

     SECTION 3.5   NON-RECEIPT OF FUNDS BY THE ADMINISTRATIVE AGENT.  Unless
the Administrative Agent shall have been notified by a Lender or Borrower (the
"PAYOR") prior to the date on which such Lender is to make payment to the
Administrative Agent of the proceeds of an Advance to be made by it hereunder or
Borrower is to make a payment to the Administrative Agent for the account of one
or more of the Lenders, as the case may be (such payment being herein called the
"REQUIRED PAYMENT"), which notice shall be effective upon receipt, that the
Payor does not intend to make the Required Payment to the Administrative Agent,
the Administrative Agent may assume that the Required Payment has been made and
may, in reliance upon such assumption (but shall not be required to), make the
amount thereof available to the intended recipient on such date and, if the
Payor has not in fact made the Required Payment to the Administrative Agent, the
recipient of such payment shall, on demand, return to the Administrative Agent
the amount made available to it together with interest thereon in respect of the
period commencing on the date such amount was so made available by the
Administrative Agent until the date the Administrative Agent recovers such
amount at a rate per annum equal to the Federal Funds Rate for such period.

     SECTION 3.6   WITHHOLDING TAXES.  All payments by Borrower of principal of
and interest on the Advances and of all fees and other amounts payable under any
Loan Document are payable without deduction for or on account of any present or
future taxes, duties or other charges levied or imposed by the United States of
America or by the government of any jurisdiction outside the United States of
America or by any political subdivision or taxing authority of or in any of the
foregoing through withholding or deduction with respect to any such payments.
If any such taxes, duties or other charges are so levied or imposed, Borrower
will pay additional interest or will make additional payments in such amounts so
that every net payment of principal of and interest on the Advances and of all
other amounts payable by any of them under any Loan Document, after withholding
or deduction for or on account of any such present or future taxes, duties or
other charges, will not be less than the amount provided for herein or therein,
provided that Borrower shall have no obligation to pay such additional amounts
to any Lender to the extent that such taxes, duties, or other charges are levied
or imposed by reason of the failure of such Lender to comply with the provisions
of SECTION 3.7.  Borrower shall furnish promptly to the Administrative Agent for
distribution to each affected Lender, as the case may be, official receipts
evidencing any such withholding or reduction.

     SECTION 3.7   WITHHOLDING TAX EXEMPTION.  Each Lender that is not
incorporated under the laws of the United States of America or a state thereof
agrees that it will deliver to Borrower and the Administrative Agent two (2)
duly completed copies of United States Internal Revenue Service Form 1001 or
4224, certifying in either case that such Lender is entitled to receive payments
from Borrower under any Loan Document, without deduction or withholding of any
United States federal income taxes or (b) if such Lender is claiming exemption
from United States withholding tax under Section 871(h) or 881(c) of the Code
with respect to payments of "portfolio interest," a Form W-8, or any successor
form prescribed by the Internal Revenue Service, and a certificate representing
that such Lender is not a bank for purposes of Section 881(c) of the Code, is
not a 10-percent shareholder (within the meaning of Section 871(h)(3)(B) of the
Code) of the Borrower and is not a controlled foreign corporation related to the
Borrower (within the meaning of section 864(d)(4) of the Code).  Each Lender
which so delivers a W-8, Form 1001 or 4224 further undertakes to deliver to
Borrower and the Administrative Agent two (2) additional copies of such form (or
a successor form) on or before the date such form expires or becomes obsolete or
after the occurrence of any event requiring a change in the most recent form so
delivered by it, and such amendments thereto or extensions or renewals thereof
as may be reasonably requested by Borrower or the Administrative Agent, in each
case certifying that such Lender is entitled to receive payments from Borrower
under any Loan Document without

                                       22
<PAGE>
 
deduction or withholding of any United States federal income taxes, unless an
event (including without limitation any change in treaty, law or regulation) has
occurred prior to the date on which any such delivery would otherwise be
required which renders all such forms inapplicable or which would prevent such
Lender from duly completing and delivering any such form with respect to it and
such Lender advises Borrower and the Administrative Agent that it is not capable
of receiving such payments without any deduction or withholding of United States
federal income tax.

     SECTION 3.8   COMPUTATION OF INTEREST.  Interest on the Eurodollar
Advances shall be computed on the basis of a year of 360 days.  Interest on
Alternate Base Rate Advances and all other amounts payable by Borrower hereunder
shall be computed on the basis of a year of 365 or 366 days, as the case may be.

     SECTION 3.9   ORDER OF APPLICATION.

     (a)  NO DEFAULT. Prior to the occurrence of an Event of Default:

          (i)   any voluntary payment may (except as otherwise provided herein)
     be applied, at the option of Borrower, to either the Revolving Notes or the
     Term Notes;

          (ii)  any payment (whether voluntary or mandatory) of the Revolving
     Notes shall be applied to the Revolving Notes on a pro rata basis based
     upon the outstanding principal balances of the Revolving Notes as of the
     date of payment;

          (iii) any voluntary or mandatory payment of the Term Notes A,
     together with any portion of any voluntary or mandatory prepayment of the
     Term Notes B to the extent the Lenders having Term Loan B Commitments elect
     not to share in the prepayment shall be applied to the Term Notes A on a
     pro rata basis based upon the outstanding principal balances of the Term
     Notes A as of the date of payment, and (x) voluntary prepayments shall be
     applied to reduce the payments required by SECTION 2.3(b) on a pro rata
     basis, and (y) mandatory prepayments shall be applied to reduce the
     payments required by SECTION 2.3(b) in the inverse order of maturity;

          (iv)  so long as the outstanding principal amount of the Term Notes A
     on the date of any proposed voluntary or mandatory prepayment exceeds the
     pro rata portion of the proposed voluntary or mandatory prepayment to be
     applied to the Term Notes A, then any Lender having Term Notes B may elect
     to be excluded from the pro rata sharing of any voluntary or mandatory
     prepayment made by Borrower hereunder, any such prepayment shall not reduce
     the outstanding principal balances of the Term Notes B, but shall be
     applied pro rata to the Term Notes A.  Such election shall be made in
     writing signed by each such electing Lender who holds Term Notes B and
     delivered to the Administrative Agent before the date fixed for such
     prepayment.

          (v)   any voluntary or mandatory payment of the Term Notes B shall be
     applied to the Term Notes B on a pro rata basis (provided that to the
     extent that any Lenders having Term Loan B Commitments elect not to share
     in any voluntary or mandatory prepayment, the prepayments which would have
     otherwise been payable to them shall be applied to the Term Notes A as set
     forth in SECTION 3.9(iii) and (iv) above), based upon the outstanding
     principal balances of the Term Notes B as of the date of payment, and such
     voluntary prepayments shall be applied to reduce the payments required by
     SECTION 2.3(c) on a pro rata basis, and any mandatory payment of the Term
     Notes B shall be applied to reduce the payments required by SECTION 2.3(c),
     in the inverse order of maturity.

                                       23
<PAGE>
 
     (b)  AFTER DEFAULT.  After the occurrence and during the continuance of an
Event of Default, any payment or proceeds of Collateral shall be applied shall
be applied in the following order:  (i) to all fees and expenses for which
Agents or Lenders have not been paid or reimbursed in accordance with the Loan
Documents (and if such payment is less than all unpaid or unreimbursed fees and
expenses, then the payment shall be paid against unpaid and unreimbursed fees
and expenses in the order of incurrence or due date); (ii) to accrued interest
on the Revolving Notes and the Term Notes on a pro rata basis, based upon the
outstanding principal balances of such Notes as of the date of payment; and
(iii) to the principal of the Revolving Notes and the Term Notes on a pro rata
basis, based upon the outstanding principal balances of such Notes as of the
date of payment, and any such prepayments of the Term Notes shall be applied to
reduce the payments required by SECTION 2.3(b) and SECTION 2.3(c), respectively,
in such order as shall be determined by the Administrative Agent in its sole
discretion.

     (c)  APPLICATION TO ADVANCES.  Subject to the foregoing, and so long as no
Event of Default has occurred and is continuing, payments of principal of any
Note shall be applied to such outstanding Alternate Base Rate Advances and
Eurodollar Advances under such Note as Borrower shall select; provided, however,
that Borrower shall select Alternate Base Rate Advances and Eurodollar Advances
to be repaid in a manner designated to minimize the funding loss required to be
paid pursuant to SECTION 4.5, if any, resulting from such payment; and provided
further that if Borrower shall fail to select the Alternate Base Rate Advances
and Eurodollar Advances to which such payments are to be applied, or if an Event
of Default has occurred and is continuing at the time of such payment, then the
Administrative Agent shall be entitled to apply the payment to such Advances in
the manner in which it shall deem appropriate in its sole discretion.

                                  ARTICLE IV

                        YIELD PROTECTION AND ILLEGALITY

     SECTION 4.1   ADDITIONAL COSTS.

     (a)  Borrower hereby agrees to pay directly to each Lender from time to 
time such amounts as such Lender may determine to be necessary to compensate it
for any costs incurred by such Lender which such Lender determines are
attributable to its making or maintaining any Eurodollar Advances hereunder or
its obligation to make any of such Advances hereunder, or any reduction in any
amount receivable by such Lender hereunder in respect of any such Advances or
such obligation (such increases in costs and reductions in amounts receivable
being herein called "ADDITIONAL COSTS"), resulting from any Regulatory Change
which:

          (i)   changes the basis of taxation of any amounts payable to such 
     Lender under this Agreement or its Notes in respect of any of such Advances
     (other than (1) taxes imposed on the overall net income of such Lender or
     its Applicable Lending Office for any of such Advances, (2) franchise or
     similar taxes of such Lender, and (3) amounts withheld pursuant to the last
     sentence of SECTION 3.7);

          (ii)  imposes or modifies any reserve, special deposit, minimum 
     capital, capital ratio, or similar requirement relating to any extensions
     of credit or other assets of, or any deposits with or other liabilities or
     commitments of, such Lender; or

          (iii) imposes any other Additional Cost affecting this Agreement or 
     the Notes or any of such extensions, of credit or liabilities or 
     commitments.

                                       24
<PAGE>
 
Each Lender will notify Borrower of any event occurring after the date of this
Agreement which will entitle such Lender to compensation pursuant to this
SECTION 4.1(a) as promptly as practicable after it obtains knowledge thereof and
determines to request such compensation, and will designate a different
Applicable Lending Office for the Advances affected by such event if such
designation will avoid the need for, or reduce the amount of, such compensation
and will not, in the sole opinion of such Lender, violate any law, rule, or
regulation or be in any way disadvantageous to such Lender, provided that such
Lender shall have no obligation to so designate an Applicable Lending Office
located outside the United States of America.  Each Lender will furnish Borrower
with a certificate setting forth the basis and the amount of each request of
such Lender for compensation under this SECTION 4.1(a). If any Lender requests
compensation from Borrower under this SECTION 4.1(a), Borrower may, by notice to
such Lender (with a copy to the Administrative Agent) suspend the obligation of
such Lender to make or Continue making Eurodollar Advances until the Regulatory
Change giving rise to such request ceases to be in effect (in which case such
Lender's Eurodollar Advances shall be Converted to Alternate Base Rate Advances
in accordance with the provisions of SECTION 4.4).

     (b)  Without limiting the effect of the foregoing provisions of this 
SECTION 4.1, in the event that, by reason of any Regulatory Change, any Lender
either (i) incurs Additional Costs based on or measured by the excess above a
specified level of the amount of a category of deposits or other liabilities of
such Lender which includes deposits by reference to which the interest rate on
Eurodollar Advances is determined as provided in this Agreement or a category of
extensions of credit or other assets of such Lender which includes Eurodollar
Advances or (ii) becomes subject to restrictions on the amount of such a
category of liabilities or assets which it may hold, then, if such Lender so
elects by notice to Borrower (with a copy to the Administrative Agent), the
obligation of such Lender to make or Continue making Eurodollar Advances
hereunder shall be suspended until such Regulatory Change ceases to be in effect
(in which case such Lender's Eurodollar Advances shall be Converted to Alternate
Base Rate Advances in accordance with the provisions of SECTION 4.4).

     (c)  Determinations and allocations by any Lender for purposes of this
SECTION 4.1 of the effect of any Regulatory Change on its costs of maintaining
its obligations to make Advances or of making or maintaining Advances or on
amounts receivable by it in respect of Advances, and of the additional amounts
required to compensate such Lender in respect of any Additional Costs, shall be
conclusive, absent manifest error and provided that such determinations and
allocations are made on a reasonable basis.

     SECTION 4.2   LIMITATION ON EURODOLLAR ADVANCES.  Anything herein to the
contrary notwithstanding, if with respect to any Eurodollar Advance for any
Interest Period therefor:

     (a)  The Administrative Agent determines (which determination shall be
conclusive absent manifest error) that quotations of interest rates for the
relevant deposits referred to in the definition of "EURODOLLAR RATE" in SECTION
1.1 are not being provided in the relative amounts or for the relative
maturities for purposes of determining the rate of interest for such Advances as
provided in this Agreement; or

     (b)  The Required Lenders determine (which determination shall be
conclusive absent manifest error) and notify the Administrative Agent that the
rate of interest referred to in the definition of "EURODOLLAR RATE" in SECTION
1.1 on the basis of which the rate of interest for such Advances for such
Interest Period is to be determined do not accurately reflect the cost to the
Lenders of making or maintaining such Advances for such Interest Period;

then the Administrative Agent shall give Borrower prompt notice thereof
specifying the relevant amounts or periods, and so long as such condition
remains in effect, the Lenders shall be under no obligation to make or Continue
additional Eurodollar Advances and Borrower shall, on the last day(s) of the
then-current Interest

                                       25
<PAGE>
 
Period(s) for the outstanding Eurodollar Advances, prepay such Eurodollar
Advances or Convert them to Alternate Base Rate Advances in accordance with
SECTION 4.4.

     SECTION 4.3   ILLEGALITY.  Notwithstanding any other provision of this
Agreement, in the event that it becomes unlawful for any Lender or its
Applicable Lending Office to (a) honor its obligation to make Eurodollar
Advances hereunder, or (b) maintain Eurodollar Advances hereunder, then such
Lender shall promptly notify Borrower (with a copy to the Administrative Agent)
thereof and such Lender's obligation to make or maintain Eurodollar Advances
shall be suspended until such time as such Lender may again make and maintain
Eurodollar Advances (in which case such Lender's Eurodollar Advances shall be
Converted to Alternate Base Rate Advances in accordance with the provisions of
SECTION 4.4).

     SECTION 4.4   TREATMENT OF EURODOLLAR ADVANCES.  If the Eurodollar
Advances of any Lender are to be Converted pursuant to SECTION 4.1, 4.2 or 4.3,
such Lender's Eurodollar Advances shall be automatically Converted into
Alternate Base Rate Advances on the last day(s) of the then current Interest
Period(s) for the Eurodollar Advances (or, in the case of a Conversion required
by SECTION 4.1(b) or 4.3(b), on such earlier date as such Lender may specify to
Borrower with a copy to the Administrative Agent) and, unless and until such
Lender gives notice as provided below that the circumstances specified in
SECTION 4.1, 4.2 or 4.3 which gave rise to such Conversion no longer exist:

     (a)  To the extent that such Lender's Eurodollar Advances have been so
Converted, all payments and prepayments of principal which would otherwise be
applied to such Lender's Eurodollar Advances shall be applied instead to its
Alternate Base Rate Advances; and

     (b)  All Advances which would otherwise be made or Continued by such Lender
as Eurodollar Advances shall be made as or Converted into Alternate Base Rate
Advances.

If such Lender gives notice to Borrower (with a copy to the Administrative
Agent) that the circumstances specified in SECTION 4.1, 4.2 or SECTION 4.3 which
gave rise to the Conversion of such Lender's Eurodollar Advances pursuant to
this SECTION 4.4 no longer exist (which such Lender agrees to do promptly upon
such circumstances ceasing to exist) at a time when Advances are outstanding,
such Lender's Alternate Base Rate Advances shall be automatically Converted, on
the first day(s) of the next succeeding Interest Period(s) for such outstanding
Eurodollar Advances to the extent necessary so that, after giving effect
thereto, all Eurodollar Advances held by the Lenders holding the same are held
pro rata (as to principal amounts and Interest Periods) in accordance with their
respective Commitments.

     SECTION 4.5   COMPENSATION.  Borrower shall pay to the Administrative
Agent, for the account of each Lender, upon the request of such Lender through
the Administrative Agent, such amount or amounts as shall be sufficient (in the
reasonable opinion of such Lender) to compensate it for any loss, cost, or
expense incurred by it as a result of:

     (a)  Any payment, prepayment or Conversion of a Eurodollar Advance for any
reason (including, without limitation, the acceleration of the outstanding
Advances pursuant to SECTION 11.2) on a date other than the last day of an
Interest Period for such Advance; or

     (b)  Any failure by Borrower for any reason (including, without limitation,
the failure of any conditions precedent specified in ARTICLE VI to be satisfied)
to borrow or prepay a Eurodollar Advance on the date for such borrowing or
prepayment, specified in the relevant notice of borrowing or prepayment under
this Agreement.

                                       26
<PAGE>
 
Such compensation shall not exceed the excess, if any, of (i) the amount of
interest which otherwise would have accrued on the principal amount so paid or
not borrowed for the period from the date of such payment or failure to borrow
to the last day of the Interest Period for such Advance (or, in the case of a
failure to borrow, the Interest Period for such Advance which would have
commenced on the date specified for such borrowing) at the applicable rate of
interest for such Advance provided for herein over (ii) the interest component
of the amount such Lender would have bid in the London interbank market for
Dollar deposits of leading banks and amounts comparable to such principal amount
and with maturities comparable to such period.

     SECTION 4.6   CAPITAL ADEQUACY.  If after the date hereof, any Lender
shall have determined that the adoption or implementation of any applicable law,
rule, or regulation regarding capital adequacy (including, without limitation,
any law, rule, or regulation implementing the Basle Accord), or any change
therein, or any change in the interpretation or administration thereof by any
central bank or other Governmental Authority charged with the interpretation or
administration thereof, or compliance by such Lender (or its parent) with any
guideline, request, or directive regarding capital adequacy (whether or not
having the force of law) of any central bank or other Governmental Authority
(including, without limitation, any guideline or other requirement implementing
the Basle Accord), has or would have the effect of reducing the rate of return
on such Lender's (or its parent's) capital as a consequence of its obligations
hereunder or the transactions contemplated hereby to a level below that which
such Lender (or its parent) could have achieved but for such adoption,
implementation, change or compliance (taking into consideration such Lender's
policies with respect to capital adequacy) by an amount deemed by such Lender to
be material, then from time to time, within ten (10) Business Days after demand
by such Lender (with a copy to the Administrative Agent), which demand shall be
delivered by such Lender to Borrower as promptly as practicable after such
Lender obtains knowledge of such reduction in its rate of return, Borrower shall
pay to such Lender such additional amount or amounts as will compensate such
Lender (or its parent) for such reduction.  A certificate of such Lender
claiming compensation under this SECTION and setting forth the additional amount
or amounts to be paid to it hereunder shall be conclusive, absent manifest error
and provided that the determination thereof is made on a reasonable basis.  In
determining such amount or amounts, such Lender may use any reasonable averaging
and attribution methods.

                                   ARTICLE V

                                   SECURITY

     SECTION 5.1   COLLATERAL.  To secure the full and complete payment and
performance of the Obligations, Borrower shall execute and deliver or cause to
be executed and delivered the documents described below covering the property
and collateral described therein (which, together with any other property and
collateral which may now or hereafter secure the Obligations or any part
thereof, is sometimes herein called the "COLLATERAL"):

     (a)  Borrower shall execute and deliver to the Administrative Agent, for
the benefit of the Lenders, the First Amendment to the Borrower Security
Agreement.

     (b)  The Guarantors shall execute and deliver to the Administrative Agent,
for the benefit of the Lenders, the First Amendment to the Guarantor Security
Agreements.

     (c) Pledgors shall execute and deliver to the Administrative Agent, for
the benefit of the Lenders, the First Amendment to the Pledge Agreements.

                                       27
<PAGE>
 
     (d)  Borrower shall execute and cause to be executed such further documents
and instruments, including without limitation, Uniform Commercial Code financing
statements, as the Administrative Agent and the Documentation Agent, in their
sole discretion, deem necessary or desirable to evidence and perfect the
Administrative Agent's liens and security interests in the Collateral.

     SECTION 5.2   SETOFF.  If an Event of Default shall have occurred and is
continuing, each Lender is hereby authorized at any time and from time to time,
without notice to Borrower (any such notice being hereby expressly waived by
Borrower), to set off and apply any and all deposits (general or special, time
or demand, provisional or final) at any time held and other indebtedness at any
time owing by such Lender to or for the credit or the account of Borrower
against any and all of the obligations of Borrower now or hereafter existing
under this Agreement, such Lender's Notes, or any other Loan Document,
irrespective of whether or not the Administrative Agent or such Lender shall
have made any demand under this Agreement or such Lender's Notes or such other
Loan Document and although such obligations may be unmatured.  Each Lender
agrees promptly to notify Borrower (with a copy to the Administrative Agent)
after any such setoff and application, provided that the failure to give such
notice shall not affect the validity of such setoff and application.  The rights
and remedies of each Lender hereunder are in addition to other rights and
remedies (including, without limitation, other rights of setoff) which such
Lender may have.

     SECTION 5.3   GUARANTIES.  Each Guarantor shall unconditionally and
irrevocably confirm its guaranty of the payment and performance of the
Obligations by execution and delivery of the First Amendment to the Guaranties.

                                  ARTICLE VI

                             CONDITIONS PRECEDENT

     SECTION 6.1   INITIAL ADVANCE.  The obligation of each Lender to make its
initial Advance is subject to the condition precedent that the Documentation
Agent shall have received on or before the day of such Advance all of the
following, each dated (unless otherwise indicated) the date hereof, in form and
substance satisfactory to the Documentation Agent:

     (a)  RESOLUTIONS.  Resolutions of the Boards of Directors of Borrower and
each Guarantor certified by the Secretary or an Assistant Secretary of each of
them which authorize the execution, delivery, and performance by such Company of
this Agreement and/or the other Loan Documents to which such Company is or is to
be a party;

     (b)  INCUMBENCY CERTIFICATE.  A certificate of incumbency certified by the
Secretary or an Assistant Secretary of Borrower and each Guarantor certifying
the names of the officers of each such Company, authorized to sign this
Agreement and each of the other Loan Documents to which each such Company is or
is to be a party (including the certificates contemplated herein) together with
specimen signatures of such officers;

     (c)  ARTICLES OF INCORPORATION.  The articles of incorporation of Borrower
and Litho certified, in the case of Borrower, by the Secretary of State of
Delaware, and, in the case of Litho, by the Secretary or an Assistant Secretary
of such Company;

     (d)  BYLAWS.  The bylaws of Borrower and Litho certified by the Secretary 
or an Assistant Secretary of each such Company;

                                       28
<PAGE>
 
     (e)  GOVERNMENTAL CERTIFICATES.  Certificates of the appropriate government
officials of the state of incorporation of Borrower and Litho as to the
existence and good standing of each of them;

     (f)  NOTES.  The Notes executed by Borrower;

     (g)  BORROWER SECURITY AGREEMENT.  The Consent, Confirmation and
Ratification of Borrower Security Agreement executed by Borrower;

     (h)  GUARANTIES.  The Consent, Confirmation and Ratification of Guaranty
Agreement executed by the Guarantors;

     (i)  GUARANTOR SECURITY AGREEMENT.  The Consent, Confirmation and
Ratification of Guarantor Security Agreements executed by the Guarantors;

     (j)  PLEDGE AGREEMENTS.  The Consent, Confirmation and Ratification of
Pledge and Security Agreements executed by the Pledgors;

     (k)  FINANCING STATEMENTS.  Uniform Commercial Code financing statements
executed by Borrower and each Guarantor and covering the Collateral;

     (l)  STOCK CERTIFICATES.  Stock certificates evidencing all stock pledged
pursuant to the Borrower Security Agreement and each Guarantor Security
Agreement, as applicable, together with stock powers duly executed in blank;

     (m)  CERTIFICATES OF TITLE.  Original certificates of title, together with
executed applications for title, for all vehicles used in connection with the
transportation of lithotripters pledged pursuant to the Borrower Security
Agreement and the Guarantor Security Agreements;

     (n)  INSURANCE POLICIES.  Copies of all insurance policies required by
SECTION 8.5, together with loss payee endorsements in favor of the
Administrative Agent, for the benefit of the Lenders, with respect to all
insurance policies covering Collateral;

     (o)  UCC AND TAX AND JUDGMENT LIEN SEARCHES.  The results of Uniform
Commercial Code searches showing all financing statements and other documents or
instruments, and tax and judgment lien searches showing all tax and judgment
liens, on file against Borrower and Litho in such jurisdictions as the
Administrative Agent shall require, such searches to be  as of a date no more
than twenty (20) days prior to the date of the initial Advance;

     (p)  PERFECTION CERTIFICATE.  A Perfection Certificate, in substantially 
the form of EXHIBIT F hereto, properly completed and signed by the Chief
Executive or Chief Financial Officer or Vice President-Finance of Borrower and
the Guarantors;

     (q)  OPINION OF COUNSEL.  Favorable opinions as to the matters set forth in
EXHIBIT G hereto of (i) Small, Craig & Werkenthin, special Texas legal counsel
to Borrower and the Guarantors, and (ii) Bingham Dana & Gould, special
Massachusetts legal counsel to the Agents and the Lenders;

     (r)  ATTORNEYS' FEES AND EXPENSES.  Evidence that the costs and expenses
(including attorneys' fees) referred to in SECTION 13.1, to the extent incurred,
shall have been paid in full by Borrower;

                                       29
<PAGE>
 
     (s)  FEES.  Borrower shall have paid to the Agents for their own account,
the fees owed by Borrower to the Agents pursuant to the letter agreements of
even date herewith between Borrower and the Agents; and

     (t)  FEDERAL RESERVE BOARD FORM U-1.  For the Administrative Agent a
properly completed Federal Reserve Board Form U-1 duly executed by each Company
pledging stock of another Company.

     SECTION 6.2   ALL ADVANCES.  The obligation of each Lender to make any
Advance (including the initial Advance) is subject to the following additional
conditions precedent:

     (a)  ADVANCE REQUEST FORM.  The Administrative Agent shall have received, 
in accordance with SECTION 2.5, an Advance Request Form executed by an
authorized officer of Borrower;

     (b)  NO DEFAULT.  No Default shall have occurred and be continuing, or 
would result from such Advance;

     (c)  REPRESENTATIONS AND WARRANTIES.  All of the representations and
warranties contained in ARTICLE VII hereof and in each of the other Loan
Documents shall be true and correct on and as of the date of such Advance with
the same force and effect as if such representations and warranties had been
made on and as of such date, except to the extent that such representations and
warranties speak to a specific date or the facts on which such representations
and warranties are based have been changed by transactions contemplated by the
Loan Documents; and

     (d)  ADDITIONAL DOCUMENTATION.  The Administrative Agent shall have 
received such additional approvals, opinions, or documents as are required by
the terms and provisions of this Agreement or any other Loan Document.

                                  ARTICLE VII

                        REPRESENTATIONS AND WARRANTIES

     To induce the Agents and the Lenders to enter into this Agreement, Borrower
hereby represents and warrants to the Agents and the Lenders that:

     SECTION 7.1   EXISTENCE.

     (a)  CORPORATE EXISTENCE. Each of the Companies (other than the
Partnerships): (a) is a corporation duly organized, validly existing, and in
good standing under the laws of the jurisdiction of its incorporation; (b) has
all requisite corporate power and authority to own its assets and carry on its
business as now being or as proposed to be conducted; and (c) is qualified to do
business in all jurisdictions in which the nature of its business makes such
qualification necessary and where failure to so qualify would have a material
adverse effect on the business, condition (financial or otherwise), operations,
or properties of the Companies taken as a whole, Borrower, or any Material
Subsidiary. Each Company has the corporate power and authority to execute,
deliver, and perform its obligations under this Agreement and the other Loan
Documents to which it is or may become a party.

     (b)  PARTNERSHIP EXISTENCE. Each of the Partnerships: (a) is a general
partnership, limited partnership or limited liability company, as appropriate,
duly organized, validly existing, and in good standing under the laws of the
jurisdiction of its formation; (b) has all requisite partnership power and
authority or

                                       30
<PAGE>
 
company power and authority, as appropriate, to own its assets and carry on its
business as now being or as proposed to be conducted; and (c) is qualified to do
business in all jurisdictions in which the nature of its business makes such
qualification necessary and where failure to so qualify would have a material
adverse effect on the business, condition (financial or otherwise), operations,
or properties of the Companies taken as a whole, Borrower, or any Material
Subsidiary.

     SECTION 7.2   FINANCIAL STATEMENTS.  Borrower has delivered to the
Administrative Agent audited consolidated financial statements of the Companies
as of and for the fiscal year ended December 31, 1996, and unaudited
consolidated financial statements of Borrower for the one (1) month period ended
January 31, 1997.  Such financial statements have been prepared in accordance
with GAAP, and fairly present, on a consolidated basis, the financial condition
of the Companies and Litho and the Partnerships, as appropriate, as of the
respective dates indicated therein and the results of operations for the
respective periods indicated therein.  There has been no material adverse change
in the business, condition (financial or otherwise), operations, or properties
of the Companies taken as a whole, Borrower, or any Material Subsidiary since
the effective date of the most recent financial statements referred to in this
SECTION.

     SECTION 7.3   CORPORATE ACTION:  NO BREACH.  The execution, delivery, and
performance by each Company of this Agreement and the other Loan Documents to
which such Company is or may become a party and compliance with the terms and
provisions hereof and thereof have been duly authorized by all requisite
corporate action (or, if such Company is a partnership, then partnership action)
on the part of such Company and do not and will not (a) violate or conflict
with, or result in a breach of, or require any consent under (i) the articles of
incorporation or bylaws of such Company (or, if such Company is a partnership,
then the partnership agreement of such Company), (ii) any material applicable
law, rule, or regulation or any material order, writ, injunction, or decree of
any Governmental Authority or arbitrator, or (iii) any material agreement or
instrument to which such Company is a party or by which such Company or any of
its property is bound or subject (other than agreements and instruments relating
to Debt which will be paid off with the proceeds of the initial Advance), or (b)
constitute a material default under any such agreement or instrument (other than
agreements and instruments relating to Debt which will be paid off with the
proceeds of the initial Advance), or result in the creation or imposition of any
Lien (except as provided in ARTICLE V) upon any of the revenues or assets of any
of the Companies.

     SECTION 7.4   OPERATION OF BUSINESS.  Each of the Companies possesses all
licenses, permits, franchises, patents, copyrights, trademarks, and tradenames,
or rights thereto, necessary to conduct their respective businesses
substantially as now conducted and as presently proposed to be conducted.  None
of the Companies is in violation of any valid rights of others with respect to
any of the foregoing (except where the failure to do so would not have a
material adverse effect on the business, condition (financial or otherwise),
operations or properties of the Companies taken as a whole, Borrower, or any
Material Subsidiary).

     SECTION 7.5   LITIGATION AND JUDGMENTS.  As of the date hereof, except as
disclosed on SCHEDULE 7.5 hereto, there is no action, suit, investigation, or
proceeding before or by any  Governmental Authority or arbitrator pending, or to
the knowledge of Borrower, threatened against or affecting any of the Companies,
that would, if adversely determined, have a material adverse effect on the
business, condition (financial or otherwise), operations or properties of the
Companies taken as a whole, Borrower, or any Material Subsidiary or the ability
of Borrower to pay and perform the Obligations.  There are no outstanding
judgments against any Company.

     SECTION 7.6   RIGHTS IN PROPERTIES; LIENS.  Each of the Companies has good
and indefeasible title to or valid leasehold interests in their respective
material properties and assets, real and personal, including the properties,
assets, and leasehold interests reflected in the financial statements described
in SECTION 7.2, and

                                       31
<PAGE>
 
none of the properties, assets, or leasehold interests of any Company is subject
to any Lien, except as permitted by SECTION 9.2.

     SECTION 7.7   ENFORCEABILITY.  This Agreement constitutes, and the other
Loan Documents to which Borrower is a party, when delivered, shall constitute
the legal, valid, and binding obligations of Borrower, enforceable against
Borrower in accordance with their respective terms, except as limited by
bankruptcy, insolvency, or other laws of general application relating to the
enforcement of creditors' rights. The Loan Documents to which each Guarantor is
a party, when delivered, shall constitute the legal, valid, and binding
obligations of such Guarantor, enforceable against such Guarantor in accordance
with their respective terms, except as limited by bankruptcy, insolvency, or
other laws of general application relating to the enforcement of creditors'
rights.

     SECTION 7.8   APPROVALS.  No authorization, approval, or consent of, and
no filing or registration with, any Governmental Authority or third party is or
will be necessary for the execution, delivery, or performance by Borrower or any
Guarantor of this Agreement and the other Loan Documents to which Borrower or
any Guarantor is or may become a party or for the validity or enforceability
thereof.

     SECTION 7.9   DEBT.  As of the date hereof, the Companies have no Debt,
except as disclosed on SCHEDULE 7.9.

     SECTION 7.10  TAXES.  The Companies have filed or extended all tax returns
(federal, state, and local) required to be filed, including all income,
franchise, employment, property, and sales tax returns, and have paid all of
their respective liabilities for taxes, assessments, governmental charges, and
other levies that are due and payable.  Except as previously disclosed to the
Administrative Agent in writing, no Company knows of any pending investigation
of any of them by any taxing authority or of any pending but unassessed tax
liability of any of them.

     SECTION 7.11  USE OF PROCEEDS; MARGIN SECURITIES.  No Company is engaged
principally, or as one of its important activities, in the business of extending
credit for the purpose of purchasing or carrying margin stock (within the
meaning of Regulations G, T, U, or X of the Board of Governors of the Federal
Reserve System), and no part of the proceeds of any Advance will be used to
purchase or carry any margin stock or to extend credit to others for the purpose
of purchasing or carrying margin stock, except for purchases of Borrower's
capital stock  permitted by SECTION 9.4 hereof.

     SECTION 7.12  ERISA.  The Companies are in compliance in all material
respects with all applicable provisions of ERISA.  Neither a Reportable Event
nor a Prohibited Transaction has occurred and is continuing with respect to any
Plan.  No notice of intent to terminate a Plan has been filed, nor has any Plan
been terminated.  No circumstances exist which constitute grounds entitling the
PBGC to institute proceedings to terminate, or appoint a trustee to administer,
a Plan, nor has the PBGC instituted any such proceedings.  None of the Companies
nor any ERISA Affiliate has completely or partially withdrawn from a Multi-
employer Plan.  The Companies and each ERISA Affiliate have met their minimum
funding requirements under ERISA with respect to all of their Plans, and the
present value of all vested benefits under each Plan does not exceed the fair
market value of all Plan assets allocable to such benefits, as determined on the
most recent valuation, date of the Plan and in accordance with ERISA.  None of
the Companies nor any ERISA Affiliate has incurred any liability to the PBGC
under ERISA.

     SECTION 7.13  DISCLOSURE.  All factual information (taken as a whole)
furnished by or on behalf of Borrower in writing to any Agent or any Lender
(including, without limitation, all factual information contained in the Loan
Documents) for purposes of or in connection with this Agreement, the other Loan

                                       32
<PAGE>
 
Documents or any transaction contemplated herein or therein is, and all other
such factual information (taken as a whole) hereafter furnished by or on behalf
of Borrower in writing will be, true and accurate in all material respects on
the date as of which such factual information is dated or certified and is not
(and such factual information (taken as a whole) hereafter furnished will not
be) incomplete by omitting to state any facts necessary to make such factual
information (taken as a whole) not misleading in any material respect at such
time in light of the circumstances under which such factual information was
provided.

     SECTION 7.14  SUBSIDIARIES; PARTNERSHIPS.  Each of the Guarantors is a
direct or indirect wholly-owned Subsidiary of Borrower, and as of the date
hereof, together with the Partnerships listed on SCHEDULE 3, constitute all of
the Subsidiaries of Borrower.  SCHEDULE 7.14.1, as the same may be amended from
time to time to reflect transactions permitted by this Agreement, sets forth the
outstanding shares of capital stock  (or other ownership interests) and the name
of each shareholder of each of the Subsidiaries of Borrower.  All of the
outstanding capital stock of Borrower and each of its Subsidiaries has been
validly issued, is fully paid, and is nonassessable.  SCHEDULE 7.14.2, as the
same may be amended from time to time to reflect transactions permitted by this
Agreement, sets forth the outstanding partnership interests of the Partnerships
owned by each of the Companies.

     SECTION 7.15  AGREEMENTS.  Except as set forth on SCHEDULE 7.15, none of
the Companies is a party to any indenture, loan, or credit agreement, or to any
lease or other agreement or instrument, or subject to any charter or corporate
restriction which could reasonably be expected to have a material adverse effect
on the business, condition (financial or otherwise), operations or properties of
the Companies taken as a whole, Borrower, or any Material Subsidiary or the
ability of Borrower or any Guarantor to pay and perform its obligations under
the Loan Documents to which it is a party.  None of the Companies is in default
in any material respect in the performance, observance, or fulfillment of any of
the obligations, covenants, or conditions contained in any agreement or
instrument to which it is a party, which default, in the aggregate with all such
other defaults, would have a material adverse affect on the business, condition
(financial or otherwise), operations or properties of the Companies taken as a
whole, Borrower, or any Material Subsidiary.

     SECTION 7.16  COMPLIANCE WITH LEGAL REQUIREMENTS; GOVERNMENTAL
AUTHORIZATIONS.

     (a)  Except as set forth in SCHEDULE 7.16.1: (i) each Company is in
compliance in all material respects with each Legal Requirement that is or was
applicable to it or to the conduct or operation of its business or the ownership
or use of any of its assets; and (ii) no Company has received any notice or
other communication from any Governmental Authority or other Person of any event
or circumstance which could constitute a violation of, or failure to comply
with, any Legal Requirement.

     (b)  Except as set forth in SCHEDULE 7.16: (i) each Company is in material
compliance with all of the terms and requirements of each Governmental
authorization held by such Company; (ii) no Company has received any notice or
other communication from any Governmental Authority or other Person of, any
event or circumstance which could constitute a violation of, or failure to
comply with, any term or requirement of any Governmental Authorization, or of
any actual or potential revocation, withdrawal, cancellation or termination of,
or material modification to, any Governmental Authorization; (iii) all
applications required to have been filed for the renewal of any required
Governmental Authorizations have been duly filed on a timely basis with the
appropriate Governmental Authorities, and all other filings required to have
been made with respect to such Governmental Authouly made on a timely basis with
the appropriate Governmental Authorities; (iv) all Governmental Authorizations
of the Companies are transferable to the Companies; (v) upon consummation of the
transactions contemplated hereby, the Companies will lawfully hold all such
Governmental Authorizations; and (vi) none of such Governmental Authorizations
will terminate upon consummation of the transactions contemplated hereby. Except
as set forth on SCHEDULE 7.16, each of

                                       33
<PAGE>
 
the Companies possesses the necessary Governmental Authorizations (i) necessary
to permit each Company to lawfully conduct and operate its respective business
in the manner it currently conducts and operates such business and to permit
such Company to own and use its assets in the manner in which it currently owns
and uses such assets, and (ii) necessary to permit each Company, upon the
consummation of the transactions contemplated hereby, to lawfully conduct and
operate its business and to permit each Company to own and use its assets, where
the failure to have such Governmental Authorization would have a material
adverse effect on the business, condition (financial or otherwise), operations
or properties of the Companies taken as a whole, Borrower, or any Material
Subsidiary.

     SECTION 7.17  INVESTMENT COMPANY ACT.  No Company is an "investment
company" within the meaning of the Investment Company Act of 1940, as amended.

     SECTION 7.18  PUBLIC UTILITY HOLDING COMPANY ACT.  No Company is a
"holding company" or a "subsidiary company" of a "holding company" or an
"affiliate" of a "holding company" or a "public utility" within the meaning of
the Public Utility Holding Company Act of 1935, as amended.

     SECTION 7.19  ENVIRONMENTAL MATTERS.  Except as disclosed on SCHEDULE
7.19, as the same may be amended from time to time, hereto:

     (a)  Each of the Companies and all of their respective properties, assets,
and operations are in compliance in all material respects with all Environmental
Laws.  No Company is aware of, nor have any of them received notice of, any
past, present, or future conditions, events, activities, practices, or incidents
which may interfere with or prevent the material compliance or continued
material compliance of any Company with all material Environmental Laws; and

     (b)  The Companies have obtained all material permits, licenses and
authorizations that are required under applicable Environmental Laws, and all
such permits are in good standing and each Company is in compliance is all
material respects with all of the terms and conditions of such permits.

                                 ARTICLE VIII

                              POSITIVE COVENANTS

     Borrower hereby covenants and agrees that, as long as the Obligations or 
any part thereof are outstanding or any Lender has any Commitment hereunder,
Borrower will perform and observe each of the following positive covenants:

     SECTION 8.1   REPORTING REQUIREMENTS.  Borrower will furnish to the
Administrative Agent and each Lender:

     (a)  ANNUAL FINANCIAL STATEMENTS.  As soon as available, and in any event
within ninety-five (95) days after the end of each fiscal year of Borrower,
beginning with the fiscal year ending December 31, 1996, a copy of the annual
audit report of the Companies for such fiscal year containing, on a consolidated
and consolidating basis, balance sheets and statements of income, retained
earnings, and cash flow as at the end of such fiscal year and for the twelve
(12)-month period then ended, in each case setting forth in comparative form the
figures for the preceding fiscal year, audited by independent certified public
accountants of recognized standing, and accompanied by an opinion of such
independent certified public accountants stating that such report has been
prepared in accordance with GAAP;

                                       34
<PAGE>
 
     (b)  MONTHLY FINANCIAL STATEMENTS.  As soon as available, and in any event
within forty (40) days after the end of each month of each fiscal year of
Borrower, a copy of an unaudited financial report of the Companies as of the end
of such month and for the portion of the fiscal year then ended, containing, on
a consolidated and consolidating basis, balance sheets and statements of income,
retained earnings, and cash flow, in each case setting forth in comparative form
the figures for the corresponding period of the preceding fiscal year, certified
by the chief financial officer of Borrower to have been prepared in accordance
with GAAP and to fairly and accurately present (subject to year-end audit
adjustments) the financial condition and results of operations of the Companies,
on a consolidated and consolidating basis, at the date and for the periods
indicated therein;

     (c)  COMPLIANCE CERTIFICATE.  Concurrently with the delivery of each of the
financial statements referred to in SECTION 8.1(A) and within forty (40) days
after the end of each of the first three (3) fiscal quarters of each fiscal year
of Borrower, a certificate of the chief executive or chief financial officer of
Borrower, in substantially the form of EXHIBIT H, (i) stating that to such
officer's knowledge, no Default has occurred and is continuing, or if a Default
has occurred and is continuing, a statement as to the nature thereof and the
action that is proposed to be taken with respect thereto, and (ii) showing in
reasonable detail the calculations demonstrating compliance with ARTICLE X;

     (d)  ACCOUNTS RECEIVABLE AGING REPORT.  As soon as available and in any
event within forty (40) days after the end of each month, an aged listing of the
accounts receivable of each of Borrower and its Subsidiaries as of the end of
such month in a form reasonably satisfactory to the Administrative Agent;

     (e)  BUSINESS PLAN AND BUDGET.  As soon as available and in any event by
December 15 of each year, a copy of the annual budget and business plan of
Borrower and its Subsidiaries for the upcoming fiscal year, together with
details of the assumptions, if any, underlying such budget and business plan;

     (f)  MANAGEMENT LETTERS.  Promptly upon receipt thereof, a copy of any
management letter or written report submitted to any Company by independent
certified public accountants with respect to the business, condition (financial
or otherwise), operations, or properties of any Company;

     (g)  NOTICE OF LITIGATION.  Promptly after the commencement thereof, notice
of all actions, suits, and proceedings before any Governmental Authority or
arbitrator affecting Borrower or any of its Subsidiaries which, if determined
adversely to Borrower or any such Subsidiary, could have a material adverse
effect on the business, condition (financial or otherwise), options, or
properties of Borrower, any Subsidiary or the Companies (taken as a whole);

     (h)  NOTICE OF DEFAULT.  As soon as possible and in any event within five
(5) days after Borrower knows of the occurrence of each Default, a written
notice setting forth the details of such Default and the action that Borrower
has taken and proposes to take with respect thereto;

     (i)  ERISA REPORTS.  Promptly after the filing or receipt thereof, copies 
of all reports, including annual reports, and notices which any Company files 
with or receives from the PBGC or the U.S. Department of Labor under ERISA; and
as soon as possible and in any event within five (5) days after any Company 
knows or has reason to know that any Reportable Event or Prohibited Transaction
has occurred with respect to any Plan or that the PBGC, or any Company has
instituted or will institute proceedings under Title IV of ERISA to terminate
any Plan, a certificate of the chief financial officer of Borrower setting forth
the details as to such Reportable Event or Prohibited Transaction or Plan
termination and the action that Borrower proposes to take with respect thereto;

                                       35
<PAGE>
 
     (j)  REPORTS TO OTHER CREDITORS.  Promptly after the furnishing thereof,
copies of any statement or report furnished by Borrower or any of its
Subsidiaries to any other creditor to which any Company owes $250,000.00 or more
pursuant to the terms of any indenture, loan, or credit or similar agreement and
not otherwise required to be furnished to the Administrative Agent and the
Lenders pursuant to any other clause of this SECTION;

     (k)  PROXY STATEMENTS, ETC.  As soon as available, one (1) copy of each
financial statement, report, notice or proxy statement sent by Borrower to its
stockholders generally and one (1) copy of each regular, periodic or special
report, registration statement, or prospectus filed by Borrower with any
securities exchange or the Securities and Exchange Commission or any successor
agency including, without limitation, all Forms 10-K, 10-Q and 8-K and all other
periodic reports required to be filed under the Securities Exchange Act of 1934
and the rules and regulations promulgated thereunder;

     (l)  PARTNERSHIP LISTS.  As soon as available, and in any event (a) within
thirty (30) days after the Administrative Agent requests such information from
Borrower, a list of the names of each partner of each of the Partnerships and a
list of the names and addresses of each partner of each of the Partnerships;

     (m)  GOVERNMENTAL AUTHORIZATIONS.  Upon the request of the Administrative
Agent, but not more often than one (1) time during each fiscal year of Borrower,
a complete and accurate list of each Governmental Authorization held by each of
Companies or that otherwise relate to the business of, or to any of the assets
owned or used by, each of the Companies;

     (n)  LITHO AND PARTNERSHIP STATEMENTS.  As soon as available, and in any
event within forty (40) days after the end of each fiscal quarter of Borrower,
beginning with the fiscal quarter ended March 31, 1997, income and cash flow
statements for each of the Partnerships on a consolidated and consolidating
basis;

     (o)  PARTNERSHIP ACTIONS.  Promptly after the incurrence thereof, notice of
any Partnership's (i) incurrence of Debt, (ii) change in accounting treatment or
reporting practices (which change shall not affect any reporting requirements
set forth herein or the Loan Documents), except as permitted by GAAP and
disclosed to the Administrative Agent,  (iii) change in tax reporting treatment,
except as permitted by law,  (iv) amendment of any partnership agreement or
management agreement between such Partnership and any Company and copies of any
such amendment certified by an officer of Borrower as being true and correct,
and (v) change in its insurance; and

     (p)  GENERAL INFORMATION.  Promptly, such other information concerning
Borrower or any of its Subsidiaries as the Administrative Agent or any Lender
may from time to time reasonably request.

     SECTION 8.2   MAINTENANCE OF EXISTENCE; CONDUCT OF BUSINESS.  Borrower
will preserve and maintain its corporate existence and all of its leases,
privileges, licenses, permits, franchises, qualifications, and rights that are
necessary or desirable in the ordinary conduct of its business.  Borrower will
cause each of its Subsidiaries to preserve and maintain its corporate,
partnership or other similar existence and all of its leases, privileges,
licenses, permits, franchises, qualifications and rights that are necessary or
desirable in the ordinary conduct of its business, except, in each case, where
failure to do so would not have a material adverse effect on the business,
condition (financial or otherwise), operations or properties of the Companies
taken as a whole, Borrower, or any Material Subsidiary.  Borrower will conduct,
and will cause each of its Subsidiaries to conduct, its business in an orderly
and efficient manner in accordance with good business practices.

     SECTION 8.3   MAINTENANCE OF PROPERTIES.  Borrower will maintain, keep,
and preserve, and cause each of its Subsidiaries to maintain, keep, and
preserve, all of its properties (tangible and intangible) necessary

                                       36
<PAGE>
 
or useful in the proper conduct of its business in good working order and
condition, except, in each case, as permitted by SECTION 9.8 or 9.9 or where the
failure to do so would not have a material adverse effect on the business,
condition (financial or otherwise), operations or properties of the Companies
taken as a whole, Borrower, or any Material Subsidiary.

     SECTION 8.4   TAXES AND CLAIMS.  Borrower will pay or discharge, and will
cause each of its Subsidiaries to pay or discharge, at or before maturity or
before becoming delinquent (a) all material taxes, levies, assessments, and
governmental charges imposed on it or its income or profits or any of its
material property, and (b) all material lawful claims for labor, material, and
supplies, which, if unpaid, might become a Lien upon any of its property;
provided, however, that no Company shall be required to pay or discharge any
tax, levy, assessment, or governmental charge which is being contested in good
faith by appropriate proceedings diligently pursued, and for which adequate
reserves have been established.

     SECTION 8.5   INSURANCE.  Borrower will maintain, and will cause each of
its Subsidiaries to maintain (except in the case of the Partnerships, in which
case Borrower shall maintain for the Partnerships), insurance with financially
sound and reputable insurance companies in such amounts and covering such risks
as is usually carried by corporations engaged in similar businesses and owning
similar properties in the same general areas in which the Companies operate,
consistent with past practices of the Companies and to the extent available on
commercially reasonable terms, provided that in any event Borrower will maintain
and cause each of its Subsidiaries (except in the case of the Partnerships, in
which case Borrower shall maintain for the Partnerships) to maintain workmen's
compensation insurance, property insurance, comprehensive general liability
insurance, professional liability insurance, and business interruption insurance
reasonably satisfactory to the Lenders.  Each insurance policy covering
Collateral shall name the Administrative Agent as loss payee, for the benefit of
the Lenders, as its interests may appear and shall provide that such policy will
not be canceled or reduced without thirty (30) days' prior written notice to the
Administrative Agent. Borrower will annually provide the Administrative Agent
with all certificates of insurance evidencing all policies of insurance of
Borrower and its Subsidiaries.

     SECTION 8.6   INSPECTION RIGHTS.  At any reasonable time and from time to
time after reasonable notice to Borrower, Borrower will permit, and will cause
each of its Subsidiaries to permit, representatives of the Administrative Agent
and each Lender to examine, copy, and make extracts from its books and records,
to visit and inspect its properties, and to discuss its business, operations,
and financial condition with its officers, and independent certified public
accountants.  Prior to removing any such copies or extracts from a Company's
premises, such Company's representatives shall be provided a reasonable
opportunity to review such information and mark or identify it as "confidential"
or "confidential information" as reasonably deemed appropriate by such Company.

     SECTION 8.7   KEEPING BOOKS AND RECORDS.  Borrower will maintain, and will
cause each of its Subsidiaries to maintain, proper books of record and account
in which full, true, and correct entries in conformity with GAAP shall be made
of all dealings and transactions in relation to its business and activities.

     SECTION 8.8   COMPLIANCE WITH LAWS.  Borrower will comply, and will cause
each of its Subsidiaries to comply, in all material respects with all material
applicable laws, rules, regulations, orders, and decrees of any Governmental
Authority or arbitrator.

     SECTION 8.9   COMPLIANCE WITH AGREEMENTS.  Borrower will comply, and will
cause each of its Subsidiaries to comply, in all material respects with all
agreements, contracts, and instruments binding on it or affecting its properties
or business, except where the failure to do so would not have a material adverse

                                       37
<PAGE>
 
effect on the business, condition (financial or otherwise), operations or
properties of the Companies taken as a whole, Borrower, or any Material
Subsidiary.

     SECTION 8.10  FURTHER ASSURANCES.  Borrower will (a), and will cause each
of its Subsidiaries (other than the Partnerships) to, execute and deliver such
further agreements and  instruments and take such further action as may be
reasonably requested by the Administrative Agent to carry out the provisions and
purposes of this Agreement and the other Loan Documents and, (b) and will cause
each of its Subsidiaries (including the Partnerships) to, create, preserve, and
perfect the Liens of the Administrative Agent, for the benefit of the Lenders,
in the Collateral.

     SECTION 8.11  ERISA.  Borrower will comply, and will cause each of its
Subsidiaries to comply, with all minimum funding requirements, and all other
material requirements, of ERISA, if applicable, so as not to give rise to any
liability thereunder.

      SECTION 8.12  INFORMATION RELATING TO PROPOSED ACQUISITIONS.  Borrower
will use its best efforts to keep the Administrative Agent and the Lenders
informed of the relevant information and status of and will share with the
Administrative Agent and the Lenders and provide copies to the extent possible,
of all material due diligence information relating to any proposed Acquisition
with respect to which Borrower or any Subsidiary enters into a letter of intent
or acquisition agreement, during the term of this Agreement.

     SECTION 8.13  AFTER-ACQUIRED SUBSIDIARIES.  Concurrently upon the
formation or Acquisition by Borrower or any Subsidiary of any Wholly-Owned
Subsidiary after the date hereof (pursuant to a Permitted Acquisition or
otherwise) (an "AFTER-ACQUIRED SUBSIDIARY"), Borrower shall cause the After-
Acquired Subsidiary to deliver articles of incorporation, bylaws, and
resolutions (or other corresponding constituent documents) and such opinions as
the Administrative Agent shall require and to execute a Guaranty, Guarantor
Security Agreement, and Pledge Agreement (if applicable), as shall be required
by the Administrative Agent to create first priority Liens in favor of the
Administrative Agent, for the benefit of the Lenders, in such After-Acquired
Subsidiary's assets, to secure the Obligations.

     SECTION 8.14  SYNDICATION COOPERATION.  Borrower acknowledges that the
Agents intend promptly to commence to syndicate the Commitments of the Lenders
in accordance with the provisions of SECTION 13.6. Borrower agrees to actively
assist Agents and their Affiliates in achieving a syndication that is
satisfactory to Agents and Borrower and in preparing information requested by
Agents in connection with arranging and syndication of the Commitments of the
Lenders and to take such other action deemed necessary by Agents or their
Affiliates, including the holding of a formal presentation to prospective
Lenders to achieve a successful syndication of the Commitments by Agents.  The
syndication efforts will be accomplished by a variety of means, including the
preparation of a confidential information memorandum and other marketing
materials, direct contact during the syndication between senior management
(including, but not limited to, the chief executive officer, the chief financial
officer and treasurer of Borrower) and advisors and Affiliates of Borrower and
the proposed syndicate Lenders.

                                  ARTICLE IX

                               NEGATIVE COVENANTS

     Borrower hereby covenants and agrees that, as long as the Obligations or 
any part thereof are outstanding or any Lender has any Commitment hereunder,
Borrower will perform and observe the following negative covenants:

                                       38
<PAGE>
 
     SECTION 9.1   DEBT.  Borrower will not incur, create, assume, or permit to
exist, nor permit any of its Subsidiaries (other than the Partnerships) to
incur, create, assume, or permit to exist, any Debt, except:

     (a)  Debt owed to the Agents and the Lenders pursuant to the Loan
Documents;

     (b)  Existing Debt described on SCHEDULE 7.9 hereto;

     (c)  Debt owed to Borrower or to any Wholly-Owned Subsidiary;

     (d) Debt in an aggregate principal amount not to exceed $250,000.00 at any
time outstanding the proceeds of which are used by the Companies to purchase
equipment, other than lithotripters;

     (e) Any Company's obligations as general partner of a Partnership for the
Debt of such Partnership;

     (f) Any Company's Guarantee of Debt of any Partnership, if such Company is
a general partner of such Partnership; and

     (g)  Hedging Agreements as described in SECTION 11.1(M).

     SECTION 9.2   LIMITATION ON LIENS.  Borrower will not incur, create,
assume, or permit to exist, nor permit any of its Subsidiaries (other than the
Partnerships) to incur, create, assume, or permit to exist, any Lien upon any of
their respective properties, assets, or revenues, whether now owned or hereafter
acquired, except:

     (a)  Liens disclosed on SCHEDULE 9.2;

     (b)  Purchase money Liens securing Debt permitted by SECTION 9.1(d) and 
(e);

     (c)  Liens in favor of the Administrative Agent, for the benefit of the
Lenders;

     (d)  Encumbrances consisting of minor easements, zoning restrictions, or
other restrictions on the use of real property that do not (individually or in
the aggregate) materially affect the value of the assets encumbered thereby or
materially impair the ability of Borrower or any of its Subsidiaries to use such
assets in their respective businesses, and none of which is violated in any
material respect by existing or proposed structures or land use;

     (e)  Liens for taxes, assessments, or other governmental charges which are
not delinquent or which are being contested in good faith and for which adequate
reserves have been established;

     (f)  Liens of mechanics, materialmen, warehousemen, carriers, or other
similar statutory Liens securing obligations that are not yet due and are
incurred in the ordinary course of business; and

     (g)  Liens resulting from good faith deposits to secure payments of
workmen's compensation or other social security programs or to secure the
performance of tenders, statutory obligations, surety and appeal bonds, bids,
contracts (other than for payment of Debt), or leases made in the ordinary
course of business.

     SECTION 9.3   MERGERS, ETC.  Except upon the prior written consent of the
Required Lenders, Borrower will not become a party to a merger or consolidation,
except with another Company where Borrower is the surviving entity.  Borrower
will not, and will not permit any of its Subsidiaries (other than the

                                       39
<PAGE>
 
Partnerships) to, wind-up, dissolve or liquidate itself, unless the assets and
stock or other ownership interests of the Company being wound up, dissolved or
liquidated are transferred to another Company. Except as permitted by SECTION
9.5, Borrower will not, and will not permit any of its Subsidiaries (other than
the Partnerships) to, make any Acquisition other than a Permitted Acquisition.
Borrower will not, and will not permit any of its Subsidiaries (other than the
Partnerships) to, form, incorporate, acquire or make any investment in any
Subsidiary, except (a) the Subsidiaries listed on SCHEDULE 7.14.1, (b)
Subsidiaries acquired or formed through a Permitted Acquisition, and (c) 
Wholly-Owned Subsidiaries formed in accordance with SECTION 8.13.

     SECTION 9.4   RESTRICTED PAYMENTS.  Borrower will not declare or pay any
dividends or make any other payment or distribution (whether in cash, property,
or obligations) on account of its capital stock, or redeem, purchase, retire, or
otherwise acquire any of its capital stock, or permit any of its Subsidiaries to
purchase or otherwise acquire any capital stock of Borrower, or set apart any
money for a sinking or other analogous fund for any dividend or other
distribution on its capital stock or for any redemption, purchase, retirement,
or other acquisition of any of its capital stock; provided, however, that, from
the date hereof through and including the Termination Date, Borrower may redeem
or retire and/or the Companies may purchase shares of Borrower's capital stock
for an aggregate consideration of no more than $750,000.00.

     SECTION 9.5   INVESTMENTS.  Borrower will not make, nor permit any of its
Subsidiaries (other than the Partnerships) to make, any advance, loan, extension
of credit, or capital contribution to or investment in, or purchase or own, or
permit any of its Subsidiaries (other than the Partnerships) to purchase or own,
any stock, bonds, notes, debentures, or other securities of, any Person, except:

     (a)  The Companies, or any of them, may purchase (i) readily marketable
direct obligations of the United States of America or any agency thereof with
maturities of one year or less from the date of acquisition, (ii) fully insured
certificates of deposit with maturities of one year or less from the date of
acquisition issued by any commercial bank operating in the United States of
America having capital and surplus in excess of $1,000,000,000, and (iii)
commercial paper of a domestic issuer if at the time of purchase such paper is
rated in one (1) of the two (2) highest rating categories of Standard and Poor's
Rating Group, a division of McGraw Hill, Inc., a New York corporation, or
Moody's Investors Service, Inc.;

     (b)  The Companies, or any of them, may make loans to officers, directors 
and employees of any of them provided such loans are made in the ordinary course
of business, and are in an aggregate principal amount of not more than
$200,000.00 at any time outstanding;

     (c)  Borrower may continue to hold capital stock of American Physicians
Service Group, Inc. held by Borrower on the date hereof; and

     (d)  The Companies may create new Subsidiaries, hold stock in Subsidiaries
and themselves, and engage in the transactions permitted by SECTION 9.3 hereof,
provided that Borrower complies with SECTION 8.13.

     SECTION 9.6   LIMITATION ON ISSUANCE OF CAPITAL STOCK.  Borrower will not
permit any of its Subsidiaries to at any time issue, sell, assign, or otherwise
dispose of (a) any of its capital stock or other ownership interests, (b) any
securities exchangeable for or convertible into or carrying any rights to
acquire any of its capital stock or other ownership interests, or (c) any
option, warrant, or other right to acquire any of its capital stock or other
ownership interests; provided, however, that any Subsidiary of Borrower may
issue, sell, assign or otherwise dispose of its capital stock or other ownership
interests, or securities 

                                       40
<PAGE>
 
exchangeable for its capital stock or other ownership interests, to Borrower or
any other Wholly-Owned Subsidiary.

     SECTION 9.7   TRANSACTIONS WITH AFFILIATES.  Borrower will not enter into,
and will not permit any of its Subsidiaries to enter into, any transaction,
including, without limitation, the purchase, sale, or exchange of property or
the rendering of any service, with any Affiliate of Borrower or any Subsidiary
of Borrower, except in the ordinary course of Borrower's or such Subsidiary's
business and upon fair and reasonable terms no less favorable to Borrower or
such Subsidiary than would be obtained in a comparable arm's-length transaction
with a Person not an Affiliate of Borrower or such Subsidiary.

     SECTION 9.8   DISPOSITION OF ASSETS.  Borrower will not sell, lease,
assign, transfer, or otherwise dispose of any of its assets, nor permit any of
its Subsidiaries (other than the Partnerships) to do so with any of their
respective assets, except (subject to the mandatory prepayments required by
SECTION 3.3) (a) inter-Company transfers between Borrower and a Wholly-Owned
Subsidiary or between Wholly-Owned Subsidiaries, (b) dispositions of assets,
other than lithotripters, in the ordinary course of business for consideration
of up to an aggregate amount of $250,000.00 during the term of this Agreement,
(and the Administrative Agent agrees to execute and deliver releases of Liens in
connection with such dispositions), (c) dispositions by any Company of assets
used in connection with cardiac rehabilitation or diagnostic imaging, and (d)
dispositions of any tangible assets that are worn or obsolete, provided that
such tangible assets are replaced by assets of similar character where the
replacement of such asset is necessary or appropriate for the continued conduct
of such Company's business as presently conducted.

     SECTION 9.9   SALE AND LEASEBACK.  Borrower will not enter into, nor
permit any of its Subsidiaries (other than the Partnerships) to enter into, any
arrangement with any Person (other than another Company) pursuant to which it
leases from such Person equipment used in lithotripsy operations that has been
or is to be sold or transferred, directly or indirectly, by it to such Person;
provided, however, that the Companies may enter into any arrangement with any
Person pursuant to which it leases from such Person real or personal property
not used in lithotripsy operations that has been or is to be sold or
transferred, directly or indirectly, by it to such Person, in an aggregate
amount of up to but not to exceed $250,000.00 during the term of this Agreement.

     SECTION 9.10  PREPAYMENT OF DEBT.  Borrower will not prepay, nor permit
any of its Subsidiaries to prepay, any Debt, except the Obligations, if such
prepayment would result in Borrower being in violation of ARTICLE X hereof.

     SECTION 9.11  NATURE OF BUSINESS.  Borrower will not, and will not permit
any of its Subsidiaries (other than the Partnerships) to, engage in any business
other than the businesses in which they are engaged on the date hereof;
provided, however, that Borrower will not and will not permit any of its
Subsidiaries (other than the Partnerships) not already in the business of
providing non-medical management services to cardiac rehabilitation or
diagnostic imaging operations, to engage in either such business.

     SECTION 9.12  ENVIRONMENTAL PROTECTION.  Borrower will not, and will not
permit any of its Subsidiaries to, conduct any activity or use any of their
respective properties or assets in any manner that could reasonably be expected
to violate any Environmental Law or create any Environmental Liabilities for
which Borrower or any of its Subsidiaries would be responsible.

     SECTION 9.13  ACCOUNTING.  Borrower will not, and will not permit any of
its Subsidiaries (other than the Partnerships) to, change its fiscal year or
make any change (a) in accounting treatment or reporting 

                                       41
<PAGE>
 
practices, except as permitted by GAAP and disclosed to the Administrative
Agent, or (b) in tax reporting treatment, except as permitted by law.

     SECTION 9.14  AMENDMENT OF PARTNERSHIP AND MANAGEMENT AGREEMENTS.
Borrower will not, and will not permit any of its Subsidiaries to, amend any
partnership agreements of any of the Partnerships or any management agreements
between any Company and any of the Partnerships, if such amendment could
reasonably be expected to have a material adverse effect on the business,
condition (financial or otherwise), operations, or properties of the Companies
taken as a whole, Borrower, or any Material Subsidiary.

                                   ARTICLE X

                              FINANCIAL COVENANTS

     Borrower hereby covenants and agrees that, as long as the Obligations or
any part thereof are outstanding or any Lender has any Commitment hereunder,
Borrower will perform and observe the following financial covenants:

     SECTION 10.1  TOTAL DEBT TO EBITDA.  Borrower will not permit the Total
Debt to EBITDA Ratio, determined as of the last day of each fiscal quarter of
the Companies and for the four (4) fiscal quarter period then ending, to exceed
the ratio set forth opposite such period below:

     ========================================================
                  PERIOD                        RATIO   
     --------------------------------------------------------
     January 1, 1997 through December 31, 1997    3.00 to 1.0
     --------------------------------------------------------
     January 1, 1998 through December 31, 1998    2.75 to 1.0
     --------------------------------------------------------
     January 1, 1999 through December 31, 1999    2.25 to 1.0
     --------------------------------------------------------
     January 1, 2000 and thereafter               2.00 to 1.0
     ========================================================

For purposes of this SECTION 10.1, cash flows during the relevant period of any
entity acquired by the Companies during such period shall be included in the
calculation of EBITDA.

     SECTION 10.2  INTEREST COVERAGE RATIO.  Borrower will not permit the
Interest Coverage Ratio (a) as of the last day of March 31, 1997, June 30, 1997,
September 30, 1997 and December 31, 1997, in each case for the four (4) fiscal
quarters then ended, to be less than 3.75 to 1.0, (b) as of the last day of
March 31, 1998, June 30, 1998, September 30, 1998 and December 31, 1998, in each
case for the four (4) fiscal quarters then ended, to be less than 4.50 to 1.0,
and (c) as of the last day of each fiscal quarter of Borrower thereafter,
commencing March 31, 1999, to be less than 5.25 to 1.0.

     SECTION 10.3  TOTAL DEBT SERVICE COVERAGE RATIO.  Borrower will not permit
the Total Debt Service Coverage Ratio (a) as of the last day of each fiscal
quarter of Borrower thereafter, commencing March 31, 1997, to be less than 1.30
to 1.0.

     SECTION 10.4  CONSOLIDATED NET WORTH.  Borrower shall not permit, as of
any date during the following periods, its Consolidated Net Worth to be less
than the amount set forth opposite such period below, such amount to be (a)
increased on the last day of each successive fiscal quarter of Borrower,
beginning March 31, 1997 to and including March 31, 1998, by an amount equal to
one hundred percent (100%) of the increase in net worth arising from any
Acquisition or equity issuance, and (b) increased on the last day of each

                                       42
<PAGE>
 
successive fiscal quarter of Borrower beginning June 30, 1998, by an amount
equal to seventy-five percent (75%) of Consolidated Net Income for such fiscal
quarter:

     ===========================================================
                   PERIOD                             AMOUNT    
     -----------------------------------------------------------
     Date hereof through March 30, 1997           $65,000,000.00
     -----------------------------------------------------------
     March 31, 1997 through September 29, 1997    $70,000,000.00
     -----------------------------------------------------------
     September 30, 1997 through March 30, 1998    $75,000,000.00
     -----------------------------------------------------------
     March 31, 1998 and thereafter                $75,000,000.00
     ===========================================================

     SECTION 10.5  MINIMUM EBITDA.  Borrower will not permit (a) EBITDA for 
any one (1) fiscal quarter of the Companies to be less than $5,000,000.00, or
(b) EBITDA for any two (2) consecutive fiscal quarters of the Companies to be
less than $12,000,000.00. 

                                  ARTICLE XI

                                    DEFAULT

     SECTION 11.1  EVENTS OF DEFAULT.  Each of the following shall be deemed an
"EVENT OF DEFAULT":

     (a)  Borrower shall fail to pay when due any amount of principal under any
Note.

     (b)  Borrower shall fail to pay by the Administrative Agent or any Lender
(through the Administrative Agent), any interest on the Advances, any fees due
hereunder or under any other Loan Document, or any other part of the Obligations
which does not constitute principal under the Notes, and such failure shall
continue for three (3) Business Days after such payment became due.

     (c)  Any representation or warranty made or deemed made by Borrower or any
Obligated Party (or any of their respective officers) in any Loan Document or in
any certificate, report, notice, or financial statement furnished at any time in
connection with this Agreement shall be false, misleading, or erroneous in any
material respect when made or deemed to have been made and the effect thereof
shall not have been cured within ten (10) Business Days after notice thereof to
Borrower by the Administrative Agent or any Lender (through the Administrative
Agent).

     (d)  Borrower shall fail to perform, observe, or comply with any covenant,
agreement, or term contained in ARTICLE X; or Borrower or any Obligated
agreement or term contained in SECTION 8.1 (a), (b), (c) or (d), or ARTICLE IX
and such failure shall continue for a period of three (3) Business Days after
notice thereof to Borrower by the Administrative Agent or any Lender (through
the Administrative Agent); or Borrower or any Obligated Party shall fail to
perform, observe br comply with any other covenant, agreement, or term contained
in this Agreement or any other Loan Document (other than covenants to pay the
Obligations) and such failure shall continue for a period of ten (10) Business
Days after notice thereof to Borrower by the Administrative Agent or any Lender
(through the Administrative Agent).

     (e)  Any Company shall commence a voluntary proceeding seeking
liquidation, reorganization, or other relief with respect to itself or its debts
under any bankruptcy, insolvency, or other similar law now or hereafter in
effect or seeking the appointment of a trustee, receiver, liquidator, custodian,
or other similar 

                                       43
<PAGE>
 
official of it or a substantial part of its property or shall consent to any
such relief or to the appointment of or taking possession by any such official
in an involuntary case or other proceeding commenced against it or shall make a
general assignment for the benefit of creditors or shall generally fail to pay
its debts as they become due or shall take any corporate action to authorize any
of the foregoing.

     (f)  An involuntary proceeding shall be commenced against any Company
seeking liquidation, reorganization, or other relief with respect to it or its
debts under any bankruptcy, insolvency, or other similar law now or hereafter in
effect or seeking the appointment of a trustee, receiver, liquidator, custodian
or other similar official for it or a substantial part of its property, and such
involuntary proceeding shall remain undismissed and unstayed for a period of
forty-five (45) days.

     (g)  Any Company shall fail to discharge within a period of forty-five
(45) days after the commencement thereof any attachment, sequestration, or
similar proceeding or proceedings, including without limitation any order of
forfeiture, seizure or divestiture (whether under RICO or otherwise) involving
an aggregate amount in excess of Two Hundred Fifty Thousand and 00/100 Dollars
($250,000.00) against any of its assets or properties.

     (h)  A final judgment or judgments for the payment of money in excess of
Two Hundred Fifty Thousand and 00/100 Dollars ($250,000.00) in the aggregate
shall be rendered by a court or courts against any Company and the same shall
not be discharged (or provision shall not be made for such discharge), or a stay
of execution thereof shall not be procured, within forty-five (45) days from the
date of entry thereof and such Company shall not, within said period of forty-
five (45) days, or such longer period during which execution of the same shall
have been stayed, appeal therefrom and cause the execution thereof to be stayed
during such appeal.

     (i)  Any Company shall fail to pay when due any principal of or interest
on Debt in an aggregate principal amount of Two Hundred Fifty Thousand and
00/100 Dollars ($250,000.00) or more (other than the Obligations), or the
maturity of any such Debt shall have been accelerated, or any such Debt shall
have been required to be prepaid prior to the stated maturity thereof, or any
event shall have occurred that permits (or, with the giving of notice or the
lapse of time or both, would permit) any holder or holders of such Debt or any
Person acting on behalf of such holder or holders to accelerate the maturity
thereof or require any such prepayment.

     (j)  This Agreement or any other Loan Document shall cease to be in full
force and effect or shall be declared null and void or the validity or
enforceability thereof shall be contested or challenged by Borrower, any
Subsidiary of Borrower, any Obligated Party or any of their respective
shareholders, or Borrower or any Obligated Party shall deny that it has any
further liability or obligation under any of the Loan Documents, or any Lien or
security interest created by the Loan Documents shall for any reason cease to be
a valid, first priority perfected security interest in and Lien upon any of the
Collateral purported to be covered thereby.

     (k)  Any of the following events shall occur or exist with respect to
Borrower or any ERISA Affiliate: (i) any Prohibited Transaction involving any
Plan; (ii) any Reportable Event with respect to any Plan; (iii) the filing under
Section 4041 of ERISA of a notice of intent to terminate any Plan or the
termination of any Plan; (iv) any event or circumstance that might constitute
grounds entitling the PBGC to institute proceedings under Section 4042 of ERISA
for the termination of, or for the appointment of a trustee to administer, any
Plan, or the institution by the PBGC of any such proceedings; or (v) complete or
partial withdrawal under Section 4201 or 4204 of ERISA from a Multi-employer
Plan or the reorganization, insolvency, or termination of any Multi-employer
Plan; and in each case above, such event or condition, 

                                       44
<PAGE>
 
together with all other events or conditions, if any, have subjected or could in
the reasonable opinion of the Required Lenders subject Borrower, or any of its
Subsidiaries, to any tax, penalty, or other liability to a Plan, a Multi-
employer Plan, the PBGC, or otherwise (or any combination thereof) which in the
aggregate exceed or could reasonably be expected to exceed Two Hundred Fifty
Thousand and 00/100 Dollars ($250,000.00).

     (l)  Any Change in Control shall occur.

     (m)  Borrower shall fail to deliver to the Administrative Agent, for the 
benefit of the Lenders, interest rate hedging or other protection agreements (a
"HEDGING AGREEMENT") with a Lender or other person reasonably acceptable to the
Agents in a notional amount of at least Twenty Million and 00/100 Dollars
($20,000,000.00) in addition to the existing Hedging Agreements in the notional
amount of Twenty Million and 00/100 Dollars ($20,000,000.00) for a duration of
at least three (3) years, assuring that the net interest cost on such amount is
fixed, capped or hedged, in form and substance acceptable to the Administrative
Agent within ninety (90) days of the date hereof.

     SECTION 11.2  REMEDIES.  If any Event of Default shall occur and be
continuing, the Administrative Agent may (and if directed by the Required
Lenders, shall) do any one or more of the following:

          (a)   ACCELERATION.  Declare all outstanding principal of and
     accrued and unpaid interest on the Notes and all other obligations of
     Borrower under the Loan Documents immediately due and payable, and the
     same shall thereupon become immediately due and payable, without notice,
     demand, presentment, notice of dishonor, notice of acceleration, notice of
     intent to accelerate, protest, or other formalities of any kind, all of
     which are hereby expressly waived by Borrower;

          (b)   TERMINATION OF COMMITMENTS.  Terminate the Commitments
     without notice to Borrower;

          (c)   JUDGMENT.  Reduce any claim to judgment;

          (d)   FORECLOSURE.  Foreclose or otherwise enforce any Lien
     granted to the Administrative Agent for the benefit of itself and the
     Lenders to secure payment and performance of the Obligations in accordance
     with the terms of the Loan Documents; and

          (e)   RIGHTS.  Exercise any and all rights and remedies afforded
     by the laws of the Commonwealth of Massachusetts or any other
     jurisdiction, by any of the Loan Documents, by equity, or otherwise;

provided, however, that upon the occurrence of an Event of Default under
SUBSECTION (e) or (f) of SECTION 11.1, the Commitments of all of the Lenders
shall automatically terminate, and the outstanding principal of and accrued and
unpaid interest on the Notes and all other obligations of Borrower under the
Loan Documents shall thereupon become immediately due and payable without
notice, demand, presentment, notice of dishonor, notice of acceleration, notice
of intent to accelerate, protest, or other formalities of any kind, all of which
are hereby expressly waived by Borrower.

     SECTION 11.3  PERFORMANCE BY THE ADMINISTRATIVE AGENT.  If Borrower shall
fail to perform any covenant or agreement in accordance with the terms of the
Loan Documents, the Administrative Agent may, at the direction of the Required
Lenders, perform or attempt to perform such covenant or agreement on behalf of
Borrower.  In such event, Borrower shall, at the request of the Administrative
Agent, promptly pay any amount expended by the Administrative Agent or the
Lenders in connection with such performance or 

                                       45
<PAGE>
 
attempted performance to the Administrative Agent at the Principal Office,
together with interest thereon at the Default Rate from and including the date
of such expenditure to but excluding the date such expenditure is paid in full.
Notwithstanding the foregoing, it is expressly agreed that neither the
Administrative Agent nor any Lender shall have any liability or responsibility
for the performance of any obligation of Borrower under this Agreement or any of
the other Loan Documents.

                                  ARTICLE XII

                            THE ADMINISTRATIVE AGENT

     SECTION 12.1  APPOINTMENT, POWERS AND IMMUNITIES.  In order to expedite
the various transactions contemplated by this agreement, the Lenders hereby
irrevocably appoint and authorize FNBB to act as their Administrative Agent
hereunder and under each of the other Loan Documents.  FNBB consents to such
appointment and agrees to perform the duties of the Administrative Agent as
specified herein.  The Lenders authorize and direct the Administrative Agent to
take such action in their name and on their behalf under the terms and
provisions of the Loan Documents and to exercise such rights and powers
thereunder as are specifically delegated to or required of the Administrative
Agent for the Lenders, together with such rights and powers as are reasonably
incidental thereto.  The Administrative Agent is hereby expressly authorized to
act as the Administrative Agent on behalf of itself and the other Lenders:

          (a)   To receive on behalf of each of the Lenders any payment of
     principal, interest, fees or other amounts paid pursuant to this Agreement
     and the Notes and to distribute to each Lender its pro rata share of all
     payments so received as provided in this Agreement;
    
          (b)   To receive all documents and items to be furnished under the 
     Loan documents;
    
          (c)   To act as nominee for and on behalf of the Lenders in and under
     the Loan Documents;
    
          (d)   To arrange for the means whereby the funds of the Lenders are to
     be made available to Borrower;
    
          (e)   To distribute to the Lenders information, requests, notices,
     payments, prepayments, documents and other items received from Borrower,
     the other Obligated Parties, and other Persons;
    
          (f)   To execute and deliver to Borrower, the other Obligated Parties,
     and  other Persons, all requests, demands, approvals, notices, and consents
     received from the Lenders;
    
          (g)   To the extent permitted by the Loan Documents, to exercise on
     behalf of each Lender all rights and remedies of the Lenders upon the
     occurrence of any Event of Default;
    
          (h)   To accept, execute, and deliver the Security Agreement and any
     other security documents as the secured party; and
    
          (i)   To take such other actions as may be requested by the Required
     Lenders.

     Neither the Administrative Agent nor any of its Affiliates, officers, 
directors, employees, attorneys, or agents shall be liable to any Lender for any
action taken or omitted to be taken by any of them hereunder or otherwise in
connection with this Agreement or any of the other Loan Documents (INCLUDING ANY

                                       46
<PAGE>
 
ACTION TAKEN OR OMITTED TO BE TAKEN BY SUCH PARTIES NEGLIGENTLY), but excluding
such actions or omissions arising from such parties' own gross negligence or
willful misconduct. Without limiting the generality of the preceding sentence,
the Administrative Agent: (i) may treat the payee of any Note as the holder
thereof until the Administrative Agent receives written notice of the assignment
or transfer thereof signed by such payee and in form satisfactory to the
Administrative Agent; (ii) shall have no duties or responsibilities except those
expressly set forth in this Agreement and the other Loan Documents, and shall
not by reason of this Agreement or any other Loan Document be a trustee or
fiduciary for any Lender; (iii) shall not be required to initiate any litigation
or collection proceedings hereunder or under any other Loan Document except to
the extent requested by the Required Lenders; (iv) shall not be responsible to
the Lenders for any recitals, statements, representations or warranties
contained in this Agreement or any other Loan Document, or any certificate or
other document referred to or provided for in, or received by any of them under,
this Agreement or any other Loan Document, or for the value, validity,
effectiveness, enforceability, or sufficiency of this Agreement or any other
Loan Document or any other document referred to or provided for herein or
therein or for any failure by any Person to perform any of its obligations
hereunder or thereunder; (v) may consult with legal counsel (including counsel
for Borrower), independent public accountants, and other experts selected by it
and shall not be liable for any action taken or omitted to be taken in good
faith by it in accordance with the advice of such counsel, accountants, or
experts; and (vi) shall incur no liability under or in respect of any Loan
Document by acting upon any notice, consent, certificate, or other instrument or
writing believed by it to be genuine and signed or sent by the proper party or
parties. As to any matters not expressly provided for by this Agreement, the
Administrative Agent shall in all cases be fully protected in acting, or in
refraining from acting, here under in accordance with instructions signed by the
Required Lenders, and such instructions of the Required Lenders and any action
taken or failure to act pursuant thereto shall be binding on all of the Lenders;
provided, however, that the Administrative Agent shall not be required to take
any action which exposes the Administrative Agent to personal liability or which
is contrary to this Agreement or any other Loan Document or applicable law.

     SECTION 12.2  RIGHTS OF ADMINISTRATIVE AGENT AS A LENDER.  With respect to
its Commitment, the Advances made by it and the Note issued to it, FNBB in its
capacity as a Lender hereunder shall have the same rights and powers hereunder
as any other Lender and may exercise the same as though it were not acting as
the Administrative Agent, and the term "LENDER" or "LENDERS" shall, unless the
context otherwise indicates, include the Administrative Agent in its individual
capacity.  The Administrative Agent and its Affiliates may (without having to
account therefor to any Lender) accept deposits from, lend money to, act as
trustee under indentures of, provide merchant banking services to, and generally
engage in any kind of business with Borrower, any Subsidiary of Borrower, any
other Obligated Party, and any other Person who may do business with or own
securities of Borrower or any other Obligated Party, all as if it were not
acting as the Administrative Agent and without any duty to account therefor to
the Lenders.

     SECTION 12.3  SHARING OF PAYMENTS, ETC.  If any Lender shall obtain any
payment of any principal of or interest on any Advance made by it under this
Agreement or payment of any other obligation under the Loan Documents then owed
by Borrower or any other Obligated Party to such Lender, whether voluntary,
involuntary, through the exercise of any right of setoff, lender's lien,
counterclaim or similar right, or otherwise, in excess of its pro rata share,
such Lender shall promptly purchase from the other Lenders participations in the
Advances held by them hereunder in such amounts, and make such other adjustments
from time to time as shall be necessary to cause such purchasing Lender to share
the excess payment ratably with each of the other Lenders in accordance with its
pro rata portion thereof.  To such end, all of the Lenders shall make
appropriate adjustments among themselves (by the resale of participations sold
or otherwise) if all or any portion of such excess payment is thereafter
rescinded or must otherwise be restored.  Borrower agrees, to the fullest extent
it may effectively do so under applicable law, that any Lender so purchasing a
participation in the Advances made by the other Lenders may exercise all rights
of setoff, lender's lien, counterclaim, or 

                                       47
<PAGE>
 
similar rights with respect to such participation as fully as if such Lender
were a direct holder of Advances to Borrower in the amount of such
participation. Nothing contained herein shall require any Lender to exercise any
such right or shall affect the right of any Lender to exercise, and retain the
benefits of exercising, any such right with respect to any other indebtedness or
obligation of Borrower.

     SECTION 12.4  INDEMNIFICATION.  THE LENDERS HEREBY AGREE TO INDEMNIFY THE
ADMINISTRATIVE AGENT FROM AND HOLD THE ADMINISTRATIVE AGENT HARMLESS AGAINST (TO
THE EXTENT NOT REIMBURSED UNDER SECTIONS 13.1 AND 13.2, BUT WITHOUT LIMITING THE
OBLIGATIONS OF BORROWER UNDER SECTIONS 13.1 AND 13.2), RATABLY IN ACCORDANCE
WITH THEIR RESPECTIVE COMMITMENTS, ANY AND ALL LIABILITIES, OBLIGATIONS, LOSSES,
DAMAGES, PENALTIES, ACTIONS, JUDGMENTS, DEFICIENCIES, SUITS, COSTS, EXPENSES
(INCLUDING ATTORNEYS' FEES), AND DISBURSEMENTS OF ANY KIND OR NATURE WHATSOEVER
WHICH MAY BE IMPOSED ON, INCURRED BY, OR ASSERTED AGAINST THE ADMINISTRATIVE
AGENT IN ANY WAY RELATING TO OR ARISING OUT OF ANY OF THE LOAN DOCUMENTS OR ANY
ACTION TAKEN OR OMITTED TO BE TAKEN BY THE ADMINISTRATIVE AGENT UNDER OR IN
RESPECT OF ANY OF THE LOAN DOCUMENTS INCLUDING ANY PORTION OF THE FOREGOING TO
THE EXTENT CAUSED BY THE ADMINISTRATIVE AGENT'S SOLE OR CONTRIBUTORY NEGLIGENCE;
PROVIDED, FURTHER, THAT NO LENDER SHALL BE LIABLE FOR ANY PORTION OF THE
FOREGOING TO THE EXTENT CAUSED BY THE ADMINISTRATIVE AGENT'S GROSS NEGLIGENCE OR
WILLFUL MISCONDUCT. WITHOUT LIMITATION OF THE FOREGOING, IT IS THE EXPRESS
INTENTION OF THE LENDERS THAT THE ADMINISTRATIVE AGENT SHALL BE INDEMNIFIED
HEREUNDER FROM AND HELD HARMLESS AGAINST ALL OF SUCH LIABILITIES, OBLIGATIONS,
LOSSES, DAMAGES, PENALTIES, ACTIONS, JUDGMENTS, DEFICIENCIES, SUITS, COSTS,
EXPENSES (INCLUDING ATTORNEYS' FEES), AND DISBURSEMENTS OF ANY KIND OR NATURE
DIRECTLY OR INDIRECTLY ARISING OUT OF OR RESULTING FROM THE SOLE OR CONTRIBUTORY
NEGLIGENCE OF THE ADMINISTRATIVE AGENT.  WITHOUT LIMITING ANY OTHER PROVISION OF
THIS SECTION, EACH LENDER AGREES TO REIMBURSE THE ADMINISTRATIVE AGENT PROMPTLY
UPON DEMAND FOR ITS PRO RATA SHARE (CALCULATED ON THE BASIS OF THE COMMITMENTS)
OF ANY AND ALL OUT-OF-POCKET EXPENSES (INCLUDING ATTORNEYS' FEES) INCURRED BY
THE ADMINISTRATIVE AGENT IN CONNECTION WITH THE PREPARATION, EXECUTION,
DELIVERY, ADMINISTRATION, MODIFICATION, AMENDMENT OR ENFORCEMENT (WHETHER
THROUGH NEGOTIATIONS, LEGAL PROCEEDINGS, OR OTHERWISE) OF, OR LEGAL ADVICE IN
RESPECT OF RIGHTS OR RESPONSIBILITIES UNDER, THE LOAN DOCUMENTS, TO THE EXTENT
THAT THE ADMINISTRATIVE AGENT IS NOT REIMBURSED FOR SUCH EXPENSES BY BORROWER.

     SECTION 12.5  INDEPENDENT CREDIT DECISIONS.  Each Lender agrees that it
has independently and without reliance on any Agent or any other Lender, and
based on such documents and information as it has deemed appropriate, made its
own credit analysis of Borrower and decision to enter into this Agreement and
that it will, independently and without reliance upon any Agent or any other
Lender, and based upon such documents and information as it shall deem
appropriate at the time, continue to make its own analysis and decisions in
taking or not taking action under this Agreement or any of the other Loan
Documents.  The Administrative Agent shall not be required to keep itself
informed as to the performance or observance by Borrower or any Obligated Party
of this Agreement or any other Loan Document or to inspect the properties or
books of Borrower or any Obligated Party.  Except for notices, reports and other
documents and 

                                       48
<PAGE>
 
information expressly required to be furnished to the Lenders by the
Administrative Agent hereunder or under the other Loan Documents, the
Administrative Agent shall not have any duty or responsibility to provide any
Lender with any credit or other financial information concerning the affairs,
financial condition or business of Borrower or any Obligated Party (or any of
their Affiliates) which may come into the possession of the Administrative Agent
or any of its Affiliates.

     SECTION 12.6  SEVERAL COMMITMENTS.  The Commitments and other obligations
of the Lenders under this Agreement are several.  The default by any Lender in
making an Advance in accordance with its Commitment shall not relieve the other
Lenders of their obligations under this Agreement.  In the event of any default
by any Lender in making any Advance, each nondefaulting Lender shall be
obligated to make its Advance but shall not be obligated to advance the amount
which the defaulting Lender was required to advance hereunder.  In no event
shall any Lender be required to advance an amount or amounts which shall in the
aggregate exceed such Lender's Commitment.  No Lender shall be responsible for
any act or omission of any other Lender.

     SECTION 12.7  SUCCESSOR ADMINISTRATIVE AGENT.  Subject to the appointment
and acceptance of a successor Administrative Agent as provided below, the
Administrative Agent may resign at any time by giving notice thereof to the
Lenders and Borrower and the Administrative Agent may be removed at any time
with or without cause by the Required Lenders.  Upon any such resignation or
removal, the Required Lenders will have the right to appoint a successor
Administrative Agent from among the remaining Lenders.  If no successor
Administrative Agent shall have been so appointed by the Required Lenders and
shall have accepted such appointment within thirty (30) days after the retiring
Administrative Agent's giving of notice of resignation or the Required Lenders'
removal of the retiring Administrative Agent, then the retiring Administrative
Agent may, on behalf of the Lenders, appoint a successor Administrative Agent,
which shall be a commercial bank organized under the laws of the United States
of America or any State thereof and having combined capital and surplus of at
least One Billion Dollars ($1,000,000,000).  Upon the acceptance of its
appointment as successor Administrative Agent, such successor Administrative
Agent shall thereupon succeed to and become vested with all rights, powers,
privileges, immunities, and duties of the resigning or removed Administrative
Agent, and the resigning or removed Administrative Agent shall be discharged
from its duties and obligations under this Agreement and the other Loan
Documents.  After any Administrative Agent's resignation or removal as
Administrative Agent, the provisions of this ARTICLE XII shall continue in
effect for its benefit in respect of any actions taken or omitted to be taken by
it while it was the Administrative Agent.

     SECTION 12.8  INDEPENDENT CONTRACTOR.

     (a)  The relationship between each Agent and each of the Lenders is that 
of an independent contractor. The use of the term "AGENT" is for convenience
only and is used to describe, as a form of convention, the independent
contractual relationship between each Agent and each of the Lenders. Nothing
contained in this Agreement or the other Loan Documents shall be construed to
create an agency, trust or other fiduciary relationship between any Agent and
any of the Lenders.

     (b)  As an independent contractor empowered by the Lenders to exercise 
certain rights and perform certain duties and responsibilities hereunder and
under the other Loan Documents, the Administrative Agent is nevertheless a
"representative" of the Lenders, as that term is defined in Article 1 of the
Uniform Commercial Code, for purposes of actions for the benefit of the Lenders
and the Administrative Agent with respect to all collateral security and
guaranties contemplated by the Loan Documents. Such actions include the
designation of the Administration Agent as "secured party," "mortgagee" or the
like on all financing statements and other documents and instruments, whether
recorded or otherwise, relating to the attachment, 

                                       49
<PAGE>
 
perfection, priority or enforcement of any security interests, mortgages or
deeds of trust in collateral security intended to secure the payment or
performance of any of the Obligations, all for the benefit of the Lenders and
the Administrative Agent.

                                 ARTICLE XIII

                                 MISCELLANEOUS

     SECTION 13.1  EXPENSES.  Borrower hereby agrees to pay on demand: (a) all
reasonable costs and expenses of the Agents in connection with the preparation,
negotiation, syndication, execution, and delivery of this Agreement and the
other Loan Documents including, without limitation, the legal fees and
reasonable expenses of legal counsel for the Agents; (b) all reasonable costs
and expenses of the Agents in connection with any and all amendments,
modifications, renewals, extensions and supplements of any of the Loan
Documents; (c) all reasonable costs and expenses of the Agents and the Lenders
in connection with any Default and the enforcement of this Agreement or any
other Loan Document, including, without limitation, the fees and expenses of
legal counsel for the Agents and the Lenders; (d) all transfer, stamp,
documentary, or other similar taxes, assessments, or charges levied by any
Governmental Authority in respect of this Agreement or any of the other Loan
Documents; (e) all costs, expenses, assessments, and other charges incurred in
connection with any filing, registration, recording, or perfection of any
security interest or Lien contemplated by this Agreement or any other Loan
Document; and (f) all other reasonable costs and expenses incurred by the Agents
in connection with this Agreement or any other Loan Document, including, without
limitation, all costs, expenses, and other charges incurred in connection with
obtaining any mortgagee title insurance policy, survey, audit, appraisal in
respect of the Collateral, and other out-of-pocket costs and expenses.

     SECTION 13.2  INDEMNIFICATION.  BORROWER SHALL INDEMNIFY THE AGENTS AND
EACH LENDER AND EACH AFFILIATE THEREOF AND THEIR RESPECTIVE OFFICERS, DIRECTORS,
EMPLOYEES, ATTORNEYS, AND AGENTS FROM, AND HOLD EACH OF THEM HARMLESS AGAINST,
ANY AND ALL LOSSES, LIABILITIES, CLAIMS, DAMAGES, PENALTIES, JUDGMENTS,
DISBURSEMENTS, COSTS, AND EXPENSES (INCLUDING REASONABLE ATTORNEYS' FEES) TO
WHICH ANY OF THEM MAY BECOME SUBJECT WHICH DIRECTLY OR INDIRECTLY ARISE FROM OR
RELATE TO (A) THE NEGOTIATION, EXECUTION, DELIVERY, PERFORMANCE, ADMINISTRATION,
OR ENFORCEMENT OF ANY OF THE LOAN DOCUMENTS, (B) ANY OF THE TRANSACTIONS
CONTEMPLATED BY THE LOAN DOCUMENTS, (C) ANY BREACH BY BORROWER OF ANY
REPRESENTATION, WARRANTY, COVENANT, OR OTHER AGREEMENT CONTAINED IN ANY OF THE
LOAN DOCUMENTS, (D) THE PRESENCE, RELEASE, THREATENED RELEASE, DISPOSAL,
REMOVAL, OR CLEANUP OF ANY HAZARDOUS MATERIAL LOCATED ON, ABOUT, WITHIN, OR
AFFECTING ANY OF THE PROPERTIES OR ASSETS OF BORROWER OR ANY SUBSIDIARY OF
BORROWER, OR (E) ANY INVESTIGATION, LITIGATION, OR OTHER PROCEEDING, INCLUDING,
WITHOUT LIMITATION, ANY THREATENED INVESTIGATION, LITIGATION, OR OTHER
PROCEEDING RELATING TO ANY OF THE FOREGOING.  WITHOUT LIMITING THE FOREGOING,
THIS INDEMNITY SHALL APPLY TO ANY LOSS, LIABILITY, OBLIGATION, DAMAGE, PENALTY,
JUDGMENT, CLAIM, DEFICIENCY OR EXPENSE ARISING OUT OF THE SOLE OR CONCURRENT
NEGLIGENCE OF ANY AGENT OR ANY LENDER, BUT SHALL EXCLUDE ANY LOSS, LIABILITY,
OBLIGATION, DAMAGE, PENALTY, JUDGMENT, CLAIM, DEFICIENCY OR EXPENSE ARISING BY
REASON OF THE GROSS NEGLIGENCE OR WILFUL MISCONDUCT OF ANY AGENT OR LENDER.

                                       50
<PAGE>
 
     SECTION 13.3  NO DUTY.  All attorneys, accountants, appraisers, and other
professional Persons and consultants retained by the Agents and the Lenders
shall have the right to act exclusively in the interest of the Agents and the
Lenders and shall have no duty of disclosure, duty of loyalty, duty of care, or
other duty or obligation of any type or nature whatsoever to Borrower, any
shareholder or Subsidiary of Borrower or any other Person.

     SECTION 13.4  NO FIDUCIARY RELATIONSHIP.  The relationship between
Borrower and each Lender is solely that of debtor and creditor, and none of the
Agents nor any of the Lenders has any fiduciary or other special relationship
with Borrower, and no term or condition of any of the Loan Documents shall be
construed so as to deem the relationship between Borrower and any Lender to be
other than that of debtor and creditor.

     SECTION 13.5  NO WAIVER; CUMULATIVE REMEDIES.  No failure on the part of
the Agents or any Lender to exercise and no delay in exercising, and no course
of dealing with respect to, any right, power, or privilege under this Agreement
shall operate as a waiver thereof, nor shall any single or partial exercise of
any right, power, or privilege under this Agreement preclude any other or
further exercise thereof or the exercise of any other right, power, or
privilege.  The rights and remedies provided for in this Agreement and the other
Loan Documents are cumulative and not exclusive of any rights and remedies
provided by law.

     SECTION 13.6  SUCCESSORS AND ASSIGNS.

     (a)  This Agreement shall be binding upon and inure to the benefit of the
parties hereto and their respective successors and assigns. Borrower may not
assign or transfer any of its rights or obligations hereunder without the prior
written consent of the Administrative Agent and all of the Lenders. Any Lender
may sell participations to one or more banks or other institutions in or to all
or a portion of its rights and obligations under this Agreement and the other
Loan Documents (including, without limitation, all or a portion of its
Commitments and the Advances owing to it); provided, however, that (i) such
Lender's obligations under this Agreement and the other Loan Documents
(including, without limitation, its Commitments) shall remain unchanged, (ii)
such Lender shall remain solely responsible to Borrower for the performance of
such obligations, (iii) such Lender shall remain the holder of its Notes for all
purposes of this Agreement, (iv) Borrower shall continue to deal solely and
directly with such Lender in connection with such Lender's rights and
obligations under this Agreement and the other Loan Documents, and (v) such
Lender shall not sell a participation that conveys to the participant the right
to vote or give or withhold consents under this Agreement or any other Loan
Document, other than the right to vote upon or consent to (A) any increase of
such Lender's Commitments, (B) any reduction of the principal amount of, or
interest to be paid on, the Advances of such Lender, (C) any reduction of any
commitment fee or other amount payable to such Lender under any Loan Document,
or (D) any postponement of any date for the payment of any amount payable in
respect of the Advances of such Lender.

     (b)  Borrower and each of the Lenders agree that any Lender (an "ASSIGNING
LENDER") may at any time assign to one or more Eligible Assignees all, or a
portion of all, of its rights and obligations under this Agreement and the other
Loan Documents (including, without limitation, its Commitment and Advances)
(each an "ASSIGNEE"); provided, however, that (i) except in the case of an
assignment of all of a Lender's rights and obligations under this Agreement and
the other Loan Documents, or as otherwise acceptable to Borrower and the
Administrative Agent the amount of the Commitments of the assigning Lender being
assigned pursuant to each assignment (determined as of the date of the
Assignment and Acceptance with respect to such assignment) shall in no event be
less than $5,000,000.00, and (ii) the parties to each such assignment shall
execute and deliver to the Administrative Agent for its acceptance and recording
in the Register (as defined below), an Assignment and Acceptance, together with
the Note subject to such assignment, and a processing and recordation fee of
$3,000.00 (except that no fee will be required by any

                                       51
<PAGE>
 
Person for assignments by NationsBank of any portion of the Term Loan B). Upon
such execution, delivery, acceptance, and recording, from and after the
effective date specified in each Assignment and Acceptance, which effective date
shall be at least five (5) Business Days after the execution thereof, or, if so
specified in such Assignment and Acceptance, the date of acceptance thereof by
the Administrative Agent, (x) the assignee thereunder shall be a party hereto as
a "LENDER" and, to the extent that rights and obligations hereunder have been
assigned to it pursuant to such Assignment and Acceptance, have the rights and
obligations of a Lender hereunder and under the Loan Documents and (y) the
Lender that is an assignor thereunder shall, to the extent that rights and
obligations hereunder have been assigned by it pursuant to such Assignment and
Acceptance, relinquish its rights and be released from its obligations under
this Agreement and the other Loan Documents (and, in the case of an Assignment
and Acceptance covering all or the remaining portion of a Lender's rights and
obligations under the Loan Documents, such Lender shall cease to be a party
thereto).

     (c)  By executing and delivering an Assignment and Acceptance, the 
Assigning Lender and its Assignee confirm to and agree with each other and the
other parties hereto as follows: (i) other than as provided in such Assignment
and Acceptance, such Assigning Lender makes no representation or warranty and
assumes no responsibility with respect to any statements, warranties, or
representations made in or in connection with the Loan Documents or the
execution, legality, validity, and enforceability, genuineness, sufficiency, or.
value of the Loan Documents or any other instrument or document furnished
pursuant thereto; (ii) such Assigning Lender makes no representation or warranty
and assumes no responsibility with respect to the financial condition of
Borrower or any Obligated Party or the performance or observance by Borrower or
any Obligated Party of its obligations under the Loan Documents; (iii) the
Assignee confirms that it has received copies of the Loan Documents, together
with copies of the financial statements referred to in SECTION 7.2 and such
other documents and information as it has deemed appropriate to make its own
credit analysis and decision to enter into such Assignment and Acceptance; (iv)
the Assignee will, independently and without reliance upon the Administrative
Agent or such assignor and based on such documents and information as it shall
deem appropriate at the time, continue to make its own credit decisions in
taking or not taking action under this Agreement and the other Loan Documents;
(v) the Assignee confirms that it is an Eligible Assignee; (vi) the Assignee
appoints and authorizes the Administrative Agent to take such action as
Administrative Agent on its behalf and exercise such powers under the Loan
Documents as are delegated to the Administrative Agent by the terms thereof,
together with such powers as are reasonably incidental thereto; and (vii) the
Assignee agrees that it will perform in accordance with their terms all of the
obligations which by the terms of the Loan Documents are required to be
performed by it as a Lender.

     (d)  The Administrative Agent shall maintain at its Principal Office a 
copy of each Assignment and Acceptance delivered to and accepted by it and a
register for the recordation of the names and addresses of the Lenders and the
Commitment of, and principal amount of the Advances owing to, each Lender from
time to time (the "REGISTER"). The entries in the Register shall be conclusive
and binding for all purposes, absent manifest error, and Borrower, the
Administrative Agent, and the Lenders may treat each Person whose name is
recorded in the Register as a Lender hereunder for all purposes under the Loan
Documents. The Register shall be available for inspection by Borrower or any
Lender at any reasonable time and from time to time upon reasonable prior
notice.

     (e)  Upon its receipt of an Assignment and Acceptance executed by an 
assigning Lender and Assignee representing that it is an Eligible Assignee (or
other assignee permitted hereunder), together with any Note subject to such
assignment, the Administrative Agent shall, if such Assignment and Acceptance
has been completed and is in substantially the form of EXHIBIT A, (i) accept
such Assignment and Acceptance, (ii) record the information contained therein in
the Register, and (iii) give prompt written notice thereof to Borrower. Within
five (5) Business Days after its receipt of such notice, Borrower, at its
expense, shall execute and deliver to the Administrative Agent in exchange for
the surrendered Note a new Note to the order 

                                       52
<PAGE>
 
of such Eligible Assignee (or other assignee permitted hereunder) in an amount
equal to the portion of the Commitments assumed by it pursuant to such
Assignment and Acceptance and, if the Assigning Lender has retained a portion of
the Commitments, a new Note to the order of the Assigning Lender in an amount
equal to the portion of the Commitments retained by it hereunder (each such
promissory note shall constitute a "NOTE" for purposes of the Loan Documents).
Such new Notes shall be in an aggregate principal amount of the surrendered
Note, shall be dated the effective date of such Assignment and Acceptance, and
shall otherwise be in substantially the form of EXHIBIT B and EXHIBIT C.

     (f)  Any Lender may, in connection with any assignment or participation or
proposed assignment or participation pursuant to this SECTION, disclose to the
Assignee or participant or proposed Assignee or participant, any information
relating to Borrower or any Subsidiary of Borrower furnished to such, Lender by
or on behalf of Borrower or any of its Subsidiaries.

     (g)  Notwithstanding any other term of this Agreement to the contrary, any
Lender may (without requesting the consent of either the Administrative Agent or
Borrower) pledge its Notes to a Federal Reserve Bank in support of borrowings
made by such Lender from such Federal Reserve Bank.

     (h)  Notwithstanding any other term of this Agreement to the contrary, any
Lender may assign all, or a portion of all, of its rights and obligations under
this Agreement and the other Loan Documents (including, without limitation, its
Commitment and Advances) to an Affiliate of such Lender, any other Lender or an
Approved Fund with respect to such Lender or any other Lender, provided that:

          (i)  such assignor Lender has obtained the written consent of the
     Administrative Agent (which consent shall not be unreasonably delayed or
     withheld) if the effect of such assignment or delegation shall entitle such
     Affiliate or other Lender to claim compensation from Borrower pursuant to
     ARTICLE IV; and

          (ii) in every other case, such assignor Lender has furnished notice
     to, but not obtained the consent of, the Administrative Agent.

     SECTION 13.7  SURVIVAL.  All representations and warranties made in this
Agreement or any other Loan Document or in any document, statement, or
certificate furnished in connection with this Agreement shall survive the
execution and delivery of this Agreement and the other Loan Documents until the
Obligations have been paid and performed in full, and no investigation by the
Administrative Agent or any Lender or any closing shall affect the
representations and warranties or the right of the Administrative Agent or any
Lender to rely upon them.  Without prejudice to the survival of any other
obligation of Borrower hereunder, the obligations of Borrower under ARTICLE IV
and SECTIONS 13.1 and 13.2 shall survive repayment of the Notes and termination
of the Commitments.  The obligations of the Administrative Agent and the Lenders
under SECTION 13.18 shall survive repayment of the Notes and termination of the
Commitments.

     SECTION 13.8  ENTIRE AGREEMENT.  THIS AGREEMENT, THE NOTES, AND THE OTHER
LOAN DOCUMENTS REFERRED TO HEREIN EMBODY THE FINAL, ENTIRE AGREEMENT AMONG THE
PARTIES HERETO AND SUPERSEDE ANY AND ALL PRIOR COMMITMENTS, AGREEMENTS,
REPRESENTATIONS, AND UNDERSTANDINGS, WHETHER WRITTEN OR ORAL, RELATING TO THE
SUBJECT MATTER HEREOF AND MAY NOT BE CONTRADICTED OR VARIED BY EVIDENCE OF
PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OR DISCUSSIONS OF THE
PARTIES HERETO.  THERE ARE NO ORAL AGREEMENTS AMONG THE PARTIES HERETO.

                                       53
<PAGE>
 
     SECTION 13.9  AMENDMENTS, ETC.  No amendment or waiver of any provision of
this Agreement, the Notes, or any other Loan Document to which Borrower is a
party, nor any consent to any departure by Borrower therefrom, shall in any
event be effective unless the same shall be agreed or consented to by the
Required Lenders and Borrower, and each such waiver or consent shall be
effective only in the specific instance and for the specific purpose for which
given; provided, that no amendment, waiver, or consent shall, unless in writing
and signed by all of the Lenders and Borrower, do any of the following: (a)
increase Commitments of the Lenders or subject the Lenders to any additional
obligations; (b) reduce the principal of, or interest on, the Notes or any fees
or other amounts payable to the Lenders, (but not the Administrative Agent)
hereunder; (c) alter the allocation among Lenders of, or postpone any date fixed
for any payment or prepayment (whether or not mandatory) of principal of, or
interest on, the Notes or any fees or other amounts payable to the
Administrative Agent or the Lenders hereunder; (d) change the percentage of the
Commitments or of the aggregate unpaid principal amount of the Notes or the
number of Lenders which shall be required for the Lenders or any of them to take
any action under this Agreement; (e) change any provision contained in this
SECTION 13.9; or (f) release any material Guarantor or any material portion of
the Collateral, except in accordance with the relevant Loan Document.
Notwithstanding anything to the contrary contained in this SECTION, no
amendment, waiver, or consent shall be made with respect to ARTICLE XII without
the prior written consent of the Administrative Agent.

     SECTION 13.10 MAXIMUM INTEREST RATE.  No provision of this Agreement or of
any other Loan Document shall require the payment or the collection of interest
in excess of the maximum amount permitted by applicable law.  If any excess of
interest in such respect is hereby provided for, or shall be adjudicated to be
so provided, in any Loan Document or otherwise in connection with this loan
transaction, the provisions of this SECTION shall govern and prevail and neither
Borrower nor the sureties, guarantors, successors, or assigns of Borrower shall
be obligated to pay the excess amount of such interest or any other excess sum
paid for the use, forbearance, or detention of sums loaned pursuant hereto.  In
the event any Lender ever receives, collects, or applies as interest any such
sum, such amount which would be in excess of the maximum amount permitted by
applicable law shall be applied as a payment and reduction of the principal of
the indebtedness evidenced by the Notes; and, if the principal of the Notes has
been paid in full, any remaining excess shall forthwith be paid to Borrower.  In
determining whether or not the interest paid or payable exceeds the Maximum
Rate, Borrower and each Lender shall, to the extent permitted by applicable law,
(a) characterize any non-principal payment as an expense, fee, or premium rather
than as interest, (b) exclude voluntary prepayments and the effects thereof, and
(c) amortize, prorate, allocate, and spread in equal or unequal parts the total
amount of interest throughout the entire contemplated term of the indebtedness
evidenced by the Notes so that interest for the entire term does not exceed the
Maximum Rate.

     SECTION 13.11 NOTICES.  All notices and other communications provided for
in this Agreement and the other Loan Documents to which Borrower is a party
shall be given or made by telecopy or in writing and telecopied, mailed by
certified mail return receipt requested, or delivered to the intended recipient
at the "ADDRESS FOR NOTICES" specified below its name on the signature pages
hereof-, or, as to any party at such other address as shall be designated by
such party in a notice to each other party given in accordance with this
SECTION.  Except as otherwise provided in this Agreement, all such
communications shall be deemed to have been duly given when transmitted by
telecopy, subject to telephone confirmation of receipt, or when personally
delivered or, in the case of a mailed notice, when duly deposited in the mails,
in each case given or addressed as aforesaid; provided, however, notices to the
Administrative Agent pursuant to ARTICLE II shall not be effective until
received by the Administrative Agent.

     SECTION 13.12 GOVERNING LAW.  THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE COMMONWEALTH OF MASSACHUSETTS AND
THE APPLICABLE LAWS OF THE UNITED STATES OF AMERICA.

                                       54
<PAGE>
 
     SECTION 13.13 COUNTERPARTS.  This Agreement may be executed in one or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

     SECTION 13.14 SEVERABILITY.  Any provision of this Agreement held by a
court of competent jurisdiction to be invalid or unenforceable shall not impair
or invalidate the remainder of this Agreement and the effect thereof shall be
confined to the provision held to be invalid or illegal.

     SECTION 13.15 HEADINGS.  The headings, captions, and arrangements used in
this Agreement are for convenience only and shall not affect the interpretation
of this Agreement.

     SECTION 13.16 CONSTRUCTION.  Borrower, the Administrative Agent, and each
Lender acknowledges that each of them has had the benefit of legal counsel of
its own choice and has been afforded an opportunity to review this Agreement and
the other Loan Documents with its legal counsel.

     SECTION 13.17 INDEPENDENCE OF COVENANTS.  All covenants hereunder shall be
given independent effect so that if a particular action or condition is not
permitted by any of such covenants, the fact that it would be permitted by an
exception to, or be otherwise within the limitations of, another covenant shall
not avoid the occurrence of a Default if such action is taken or such condition
exists.

     SECTION 13.18 CONFIDENTIALITY.

     (a)  The Agents and the Lenders shall treat the Confidential Information in
confidence and undertake the following obligations with respect thereto:

          (i)   The Agents and each Lender and each Other Recipient (hereinafter
     defined) shall not make use of, disseminate, or in any way disclose,
     directly or indirectly, to any other Person other than the senior
     executives, employees, attorneys, accountants of and Governmental
     Authorities having jurisdiction over, the Agents and each Lender, who
     reasonably require access to the Confidential Information for the proper
     performance of their assigned duties, and any contemplated assignee of all
     or a portion of a Lender's rights and obligations under this Agreement
     (collectively, the "OTHER RECIPIENTS") any Confidential Information without
     receiving prior written permission from Borrower.  Each Other Recipient
     will be informed of the terms and provisions of this SECTION 13.18, and the
     Lenders shall be liable for any breach of any term or provision of this
     SECTION 13.18 by any Other Recipient as if such person was a signatory
     hereto, unless such Other Recipient has entered into a confidentiality
     agreement directly with Borrower; and

          (ii)  The Agents and each Lender and each Other Recipient shall use 
     the Confidential Information solely in connection with the Loan Documents
     or in connection with the ordinary course of business of the Agents or the
     Lenders (except if such ordinary course of business activities are adverse
     to the Companies' interests) and shall not use any of such Confidential
     Information for any other purpose or aid any Person (other than the Agents,
     any Lender or any Other Recipient) in learning of or using it or permit
     others to learn of or use it.

     (b)  In the event that any Agent, any Lender or any Other Recipient becomes
legally compelled to disclose any of the Confidential Information in any legal
proceeding, it shall provide Borrower with notice promptly after receiving
notice of such proceeding relating to such disclosure so that the Companies may
seek a protective order or other appropriate remedy. In the event that such
protective order or other remedy is not obtained on or before the date that
disclosure must be made, such Agent, such Lender or the Other Recipient, 

                                       55
<PAGE>
 
as the case may be, will furnish only that portion of the Confidential
Information which it is legally required to disclose.

     (c)  The Agents and the Lenders are aware, and agree to inform all Other
Recipients, that the United States securities laws prohibit any Person who has
received material, non-public information such as is the subject of this SECTION
13.18 from an issuer from purchasing or selling the securities of such issuer or
from communicating such information to any other Person under circumstances in
which it is reasonably foreseeable that such Person is likely to purchase or
sell such securities.

     (d)  The Companies and the Agents and the Lenders agree that monetary 
damages would not be a sufficient remedy for any breach of this SECTION 13.18 by
the Agents, the Lenders or any Other Recipient and that, in addition to all
other remedies, the Companies shall be entitled to specific performance and
injunction or other equitable relief as a remedy for any such breach.

     (e)  The restrictions and obligations of this SECTION 13.18 shall survive 
the repayment of the Obligations and shall continue to bind the Agents, the
Lenders and the Other Recipients.

     SECTION 13.19 RENEWAL AND INCREASE.  The Revolving Credit Loan is in
renewal, extension, modification, restatement, increase and amendment of the
Original Credit Agreement and the loan documents executed in connection
therewith, and all liens and security interests securing payment thereof.

     SECTION 13.20 WAIVER OF JURY TRIAL.  TO THE FULLEST EXTENT PERMITTED BY
APPLICABLE LAW, BORROWER HEREBY IRREVOCABLY AND EXPRESSLY WAIVES ALL RIGHT TO A
TRIAL BY JURY IN ANY ACTION, PROCEEDING, OR COUNTERCLAIM (WHETHER BASED UPON
CONTRACT, TORT, OR OTHERWISE) ARISING OUT OF OR RELATING TO ANY OF THE LOAN
DOCUMENTS OR THE TRANSACTIONS CONTEMPLATED THEREBY OR THE ACTIONS OF ANY AGENT
OR ANY LENDER IN THE NEGOTIATION, ADMINISTRATION, OR ENFORCEMENT THEREOF.

     SECTION 13.21 CHOICE OF FORUM; CONSENT TO SERVICE OF PROCESS AND
JURISDICTION.  Any suit, action or proceeding against Borrower with respect to
this Agreement or the Loan Documents, or any judgment entered by any court in
respect thereof, may be brought in the courts of the Commonwealth of
Massachusetts, County of Suffolk, or in the United States courts located in the
Commonwealth of Massachusetts as the Administrative Agent shall, at the
direction of the Required Lenders elect in their sole discretion, and Borrower
irrevocably submits to the non-exclusive jurisdiction of such courts for the
purpose of any suit, action or proceeding.  Borrower irrevocably consents to the
service of process in any suit, action or proceeding in said court by the
mailing thereof by the Administrative Agent by registered or certified mail,
postage prepaid to Borrower's address shown opposite its name on the signature
pages hereof.  Nothing herein or in any of the other Loan Documents shall affect
the right of the Administrative Agent to serve process in any other manner
permitted by law or shall limit the right of the Administrative Agent to bring
any action or proceeding against Borrower or with respect to any of its property
in courts in other jurisdictions.  Borrower irrevocably waives any objections
which it may now or hereafter have to laying of venue of any suit, action or
proceeding arising out of or relating to this Agreement or the other Loan
Documents brought in the courts located in the Commonwealth of Massachusetts,
County of Suffolk, and hereby further irrevocably waives any claim that any such
suit, action or proceeding brought in any such court has been brought in any
inconvenient forum.  Any action or proceeding by Borrower against the
Administrative Agent or any Lender shall be brought only in a court located in
Suffolk County, Massachusetts.

                     Remainder of page intentionally blank.

                                       56
<PAGE>
 
                            Signature pages follow.

                                       57
<PAGE>
 
     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement 
as of the day and year first above written.

                              BORROWER:

                              PRIME MEDICAL SERVICES, INC.



                              By:/s/ Cheryl Williams
                                 ---------------------------------------------
                                 Cheryl Williams
                                 Vice President - Finance

                              Address for Notices:

                              1301 Capital of Texas Highway
                              Suite C-300
                              Austin, Texas 78746
                              Attention: President

                              Fax No.: (512) 328-8510
                              Telephone No.: (512) 328-2892


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              FNBB:

                              THE FIRST NATIONAL BANK OF BOSTON,
                                as Administration Agent, and  a Lender



                              By:/s/ Elizabeth Everett
                                 ----------------------------------------------
                                 Elizabeth Everett
                                 Director, High Technology
                                 Division, Medical Technology Group

                              Address for Notices:

                              100 Federal Street
                              P.O. Box 2016
                              Boston, Massachusetts 02100
                              Attention:  Elizabeth Everett

                              Fax No.: (617)  434-0819
                              Telephone No.: (617)  434-2318

                              Lending Office for Base Rate Advances:
                              100 Federal Street
                              P. 0. Box 2016
                              Boston, Massachusetts 02100

                              Lending Office for Eurodollar Advances:
                              100 Federal Street
                              P.O. Box 2016
                              Boston, Massachusetts 02100


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              NATIONSBANK:

                              NATIONSBANK OF TEXAS, N.A.,
                              as Documentation Agent and a Lender



                              By: /s/ Teena Belcik
                                 ---------------------------------------------
                                 Teena Belcik
                                 Vice President

                         Address for Notices:
                         515 Congress Avenue, 11th Floor
                         Post Office Box 908
                         Austin, Texas  78701-0908
                         Attention: Teena Belcik

                         Fax No.: (512) 397-2052
                         Telephone No.: (512) 397-2841

                         Lending Office for Base Rate Advances:
                         515 Congress Avenue, 11th Floor
                         Post Office Box 908
                         Austin, Texas  78701-0908

                         Lending Office for Eurodollar Advances:
                         515 Congress Avenue, 11th Floor
                         Post Office Box 908
                         Austin, Texas  78701-0908


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              NATIONSBANC CAPITAL MARKETS, INC.,
                              as Syndication Agent



                              By: /s/ Gary L. Kahn
                                 ----------------------------------------------
                                 Gary L. Kahn
                                 Senior Vice President

                              Address for Notices:
                              901 Main Street, 66th Floor
                              Post Office Box 831000
                              Dallas, Texas 75283-1000
                              Attention: Gary L. Kahn

                              Fax No.: (214) 508-2881
                              Telephone No.: (214) 508-3507


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              OTHER LENDERS:

                              IMPERIAL BANK



                              By: /s/ Kelly Davis
                                 ----------------------------------------------
                                 Name:Kelly Davis
                                      -----------------------------------------
                                 Title: Vice President
                                       ----------------------------------------

                              Address for Notices:
                              226 Airport Parkway
                              San Jose, CA 95110
                              Attention: Kelly Davis
                                        -----------------------------           
   
                              Fax No.: (408) 451-8586
                              Telephone No.: (408) 451-8589
                                                  -------------------

                              Lending Office for Base Rate Advances:
                              Imperial Bank
                              ---------------------------------------
                              226 Airport Parkway
                              ---------------------------------------
                              San Jose, CA  95110
                              ---------------------------------------

                              Lending Office for Eurodollar Advances:
 
                              Imperial Bank
                              ---------------------------------------
                              226 Airport Parkway
                              ---------------------------------------
                              San Jose, CA  95110
                              ---------------------------------------
                              


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE 
 
<PAGE>
 
                              THE SUMITOMO BANK, LIMITED



                              By: /s/ John J. O'Neill
                                 --------------------------------------------- 
                                 Name: John J. O'Neill
                                      ----------------------------------------
                                 Title: VP
                                       ---------------------------------------

                              By: /s/ Bruce Portillo
                                 --------------------------------------------- 
                                 Name: Bruce Portillo 
                                      ----------------------------------------
                                 Title: VP
                                       ---------------------------------------

                              Address for Notices:
                              2 Houston Center, Suite 3750
                              Houston, TX 77010-1086
                              Attention: Bruce Portillo
                                        ------------------------- 

                              Fax No.: (713) 759-1419
                              Telephone No.: (713) 759-0770

                              Lending Office for Base Rate Advances:
                              233 South Wacker, Suite 5400
                              ---------------------------------------
                              Chicago, IL  60606
                              ---------------------------------------
                              Attn: Maria Martinez
                              ---------------------------------------

                              Lending Office for Eurodollar Advances:
                              233 South Wacker, Suite 5400
                              ---------------------------------------
                              Chicago, IL  60606
                              ---------------------------------------
                              Attn: Maria Martinez
                              ---------------------------------------
                              


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE

 
<PAGE>
 
                              BANK ONE, TEXAS, N.A.



                              By: /s/ Edward W. Lick, Jr.
                                 ----------------------------------------------
                                 Edward W. Lick, Jr.
                                 Vice President

                              Address for Notices:
                              221 West 6th Street, Suite 200
                              Austin, TX 78701
                              Attention: Ed Lick

                              Fax No.: (512) 479-1565
                              Telephone No.: (512) 479-5730

                              Lending Office for Base Rate Advances:
                              Bank One, Austin
                              221 West 6th Street, Suite 200
                              Austin, TX 78701

                              Lending Office for Eurodollar Advances:
                              Bank One, Austin
                              221 West 6th Street, Suite 200
                              Austin, TX 78701


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              CRESCENT/MACH PARTNERS, L.P.

                              By:  TCW ASSET MANAGEMENT COMPANY,
                                   Its Investment Manger



                                   By: /s/ Justin Driscoll
                                      ------------------------------------------
                                      Name: Justin Driscoll
                                           -------------------------------------
                                      Title:
                                            ------------------------------------


                              Address for Notices:

                              TCW Asset Management Company
                              200 Park Avenue, Suite 2200
                              New York, NY  10166-0228
                              Attention:  Mark J. Gold/Justin Driscoll

                              Fax No.: (212) 297-4159
                              Telephone No.: (212) 297-4000

                              With copies to:

                              Crescent/Mach I Partners, L.P.
                              c/o State Street Bank & Trust Co.
                              Two International Place
                              Boston, MA 02110
                              Attention: Jackie Kilroy

                              Fax No.: (617) 664-5366
                              Telephone No.: (617) 664-5477

                              Lending Office for Base Rate Advances:
                              TCW Asset Management Company
                              200 Park Avenue, Suite 2200
                              New York, NY  10166-0228

                              Lending Office for Eurodollar Advances:
                              TCW Asset Management Company
                              200 Park Avenue, Suite 2200
                              New York, NY  10166-0228


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              MERRILL LYNCH SENIOR FLOATING
                                RATE FUND, INC.



                              By: /s/ Douglas Henderson
                                 -----------------------------------------------
                                 Douglas Henderson
                                 Vice President



                              Address for Notices:

                              Merrill Lynch Senior Floating Rate Fund, Inc.
                              800 Scudders Mill Road, Area 1B
                              Plainsboro, NJ  08536
                              Attention:  Jill Montanye

                              Fax No.: (609) 282-2550
                              Telephone No.: (609) 282-3102

                              Lending Office for Base Rate Advances:
                              Merrill Lynch Senior Floating Rate Fund, Inc.
                              800 Scudders Mill Road, Area 1B
                              Plainsboro, NJ  08536

                              Lending Office for Eurodollar Advances:
                              Merrill Lynch Senior Floating Rate Fund, Inc.
                              800 Scudders Mill Road, Area 1B
                              Plainsboro, NJ  08536


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              PILGRIM AMERICA PRIME RATE TRUST



                              By: /s/ Michael J. Bacevich
                                 ----------------------------------------------
                                 Name: Michael J. Bacevich
                                      ----------------------------------------- 
                                 Title: Vice President
                                       ----------------------------------------


                              Address for Notices:

                              Pilgrim America Prime Rate Trust
                              Two Renaissance Square
                              40 North Central Avenue
                              Suite 1200
                              Phoenix, AZ  85004-4424
                              Attention:  Michael Bacevich

                              Fax No.: (602) 417-8327
                              Telephone No.: (602) 417-8258

                              Lending Office for Base Rate Advances:
                              Pilgrim America Prime Rate Trust
                              Two Renaissance Square
                              40 North Central Avenue
                              Suite 1200
                              Phoenix, AZ  85004-4424

                              Lending Office for Eurodollar Advances:
                              Pilgrim America Prime Rate Trust
                              Two Renaissance Square
                              40 North Central Avenue
                              Suite 1200
                              Phoenix, AZ  85004-4424


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              THE ING CAPITAL SENIOR SECURED
                                HIGH INCOME FUND, L.P.

                              By:  ING CAPITAL ADVISORS, INC., as Investment
                                   Advisor



                                   By: /s/ Kathleen Lenarcic                 
                                      ----------------------------------------
                                    Name: Kathleen Lenarcic 
                                         -------------------------------------
                                         Vice President - Portfolio Manager

                              Address for Notices:

                              ING Capital Advisors, Inc.
                              333 South Grand Avenue
                              Suite 4250
                              Los Angeles, CA  90071
                              Attention:  Kathleen Lenarcic

                              Fax No.: (213) 346-3995
                              Telephone No.: (213) 346-3971

                              Lending Office for Base Rate Advances:
                              ING Capital Advisors, Inc.
                              333 South Grand Avenue
                              Suite 4250
                              Los Angeles, CA  90071

                              Lending Office for Eurodollar Advances:
                              ING Capital Advisors, Inc.
                              333 South Grand Avenue
                              Suite 4250
                              Los Angeles, CA  90071


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                             VAN KAMPEN AMERICAN CAPITAL
                               PRIME RATE INCOME TRUST



                             By: /s/ Jeffrey W. Maillet
                                ---------------------------------------------
                                Jeffrey W. Maillet                 
                                Senior Vice President & Portfolio Manager

                             Address for Notices:

                             Van Kampen American Capital Prime Rate Income Trust
                             One Parkview Plaza
                             Oakbrook Terrace,  IL  60181
                             Attention:  Jeffrey W. Maillet

                             Fax No.: (630) 684-6740/41
                             Telephone No.: (630) 684-6438

                             Lending Office for Base Rate Advances:
                             Van Kampen American Capital Prime Rate Income Trust
                             One Parkview Plaza
                             Oakbrook Terrace,  IL  60181
 
                             Lending Office for Eurodollar Advances:
                             Van Kampen American Capital Prime Rate Income Trust
                             One Parkview Plaza
                             Oakbrook Terrace,  IL  60181


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE
<PAGE>
 
                              PARIBAS CAPITAL FUNDING LLC.



                              By: /s/ Eric Green
                                 ----------------------------------------------
                                 Name: Eric Green
                                      -----------------------------------------
                                 Title: Director
                                       ----------------------------------------

                              Address for Notices:

                              Paribas Capital Funding LLC
                              787 Seventh Avenue
                              32nd Floor
                              New York, NY  10019
                              Attention:  Michael Weinberg

                              Fax No.: (212) 841-2144
                              Telephone No.: (212) 841-2544

                              Lending Office for Base Rate Advances:
                              Paribas Capital Funding LLC
                              787 Seventh Avenue
                              32nd Floor
                              New York, NY  10019

                              Lending Office for Eurodollar Advances:
                              Paribas Capital Funding LLC
                              787 Seventh Avenue
                              32nd Floor
                              New York, NY  10019


                  SECOND AMENDED AND RESTATED LOAN AGREEMENT
                                SIGNATURE PAGE

<PAGE>
 
                                   EXHIBIT A

                             ADVANCE REQUEST FORM



TO:  The First National Bank of Boston, as Administrative Agent
     100 Federal Street
     Boston, Massachusetts 02110
     Attention: Elizabeth Everett

Ladies and Gentlemen:

The undersigned is an officer of Prime Medical Services, Inc. ("BORROWER"), and
is authorized to make and deliver this certificate pursuant to that certain
Second Amended and Restated Loan Agreement dated as of March 31, 1997, among
Borrower, The First National Bank of Boston, as Administrative Agent (the
"ADMINISTRATIVE AGENT"), and the Lenders named therein (as the same may be
amended, supplemented or modified from time to time, the "LOAN AGREEMENT").
Capitalized terms used and not otherwise defined herein shall have the same
meanings as set forth in the Loan Agreement.  In accordance with the Loan
Agreement, Borrower hereby (check whichever is applicable):

              1.  Requests that the Lenders make a Eurodollar Advance under the
- -------           Revolving Credit Commitments in the manner set forth in item
                  (c) below for the following Interest Period:

                                        
                                  One (1) month
                  ----------- 
                                  Two (2) months
                  ----------- 
                                  Three (3) months
                  ----------- 
                                  Six (6) months
                  ----------- 


              2.  Requests that the Lenders make an Alternate Rate Advance in
- -------           the amount set forth in item (c) below./1/
 

In connection with the foregoing and pursuant to the terms and provisions of the
Loan Agreement, the undersigned hereby certifies to the Administrative Agent and
the Lenders that the following statements are true and correct:

     (i)      The representation and warranties contained in ARTICLE VII of
              the Loan Agreement and in each of the other Loan Documents are
              true and correct on and as of the date hereof with the same
              force and effect as if made on and as of such date, except to
              the extent that such representations and warranties speak to a
              specific date or the facts on which such

- -------------------------

      1       Alternate Rate Advances shall only be available to the extent
              Eurodollar Advances are not available, as required by Article
              IV of the Loan Agreement.
<PAGE>
 
              representations and warranties are based have been changed by
              transactions permitted by the Loan Documents.

     (ii)     No Default has occurred and is continuing or would result from
              the Advance requested hereunder.

     (iii)    The amount of the Advance requested hereunder, when added to all
              outstanding Advances, will not exceed the Revolving Credit
              Commitments.

     (iv)     All information supplied below is true, correct, and complete
              as of the date hereof.

     (v)      If the proceeds of the requested Advance are to be used to finance
              a Permitted Acquisition, then the information set forth on
              SCHEDULE 1 attached hereto is true, correct, and complete as of
              the date hereof.

(a)  Outstanding principal amount of Advances under the Revolving
     Credit Commitments                                            $
                                                                    ---------
(b)  Net Availability for Advances:
     [The amount of the Revolving Credit Commitments minus
     outstanding Advances under the Revolving Credit Commitments]  $
                                                                    ---------

(c)  Amount of Requested Advance                                $
                                                                 ---------


                                    BORROWER:

                                    PRIME MEDICAL SERVICES, INC.



                                    By: 
                                       ---------------------------------------- 
                                       Name:
                                            -----------------------------------
                                       Title:
                                             ----------------------------------

Date of Requested Advance:  
                           ----------------------------------
                           [insert date of Requested Advance]

                                      -2-
<PAGE>
 
                                  SCHEDULE 1

                      PERMITTED ACQUISITION CERTIFICATION


Borrower hereby to the Administrative Agent and Lenders that:

1.   The name of the Person, or from which the business or assets to be,
     acquired is _________________.

2.   The proposed Acquisition by Borrower or its Subsidiary is of a business,
     assets or Person which is engaged in substantially the same business as the
     business conducted by Borrower or such Subsidiary, or any other business
     reasonably related thereto.

3.   The Acquisition has been approved and recommended by the board of directors
     or other applicable governing body of the Person to be acquired or from
     which such business or assets are to be acquired.

4.   After giving effect to such Acquisition, Borrower or the Subsidiary that is
     the acquiring party is Solvent and the Companies, on a consolidated basis,
     are Solvent.

5.   After giving effect to such Acquisition, no Default shall exist or occur as
     a result of, and after giving effect to, such Acquisition.

6.   If such Acquisition is a merger, Borrower or the Subsidiary that is the
     acquiring party will be the surviving entity after giving effect to such
     merger;

7.   (a)  The aggregate purchase price with respect to such Acquisition is
          $_____________________;

     (b)  The EBITDA of the Person acquired (for the four (4) fiscal quarters
          ending on the most recently ended fiscal period prior to the date of
          the Acquisition) times five (5) is $____________; and

     (c)  The excess of (b) over (a) is $_______.

8.   The aggregate consideration for such Acquisition does not exceed
     $10,000,000.00, and the aggregate cash consideration for all Acquisitions
     during the immediately preceding twelve (12) month period does not exceed
     $20,000,000.00.

9.   After giving effect to the Acquisition:

     (a)  The aggregate Debt of the Companies (including any Advances under the
          Revolving Credit Commitments) will be $______________.

     (b)  The EBITDA of the Companies (including EBITDA for the Person, assets
          or business acquired pursuant to the Acquisition) for the four
          (4) fiscal quarters ending on the closing of the Acquisition is
          $________________.

     (c)  2.75 or other applicable number pursuant to the definition of
          "PERMITTED ACQUISITION" times (b) = $_____________.




                                      -i-
<PAGE>
 
                                   EXHIBIT B

                       FORM OF ASSIGNMENT AND ACCEPTANCE

                           Dated ____________, 19__


     Reference is hereby made to that certain Amended and Restated Loan
Agreement dated as of March 31, 1997 (as the same may be amended, supplemented
or modified from time to time, the "LOAN AGREEMENT"), among PRIME MEDICAL
SERVICES, INC., a Delaware corporation ("BORROWER"), each of the Lenders or
other lending institutions which are or may from time to time become signatories
thereto (the "LENDERS"), and THE FIRST NATIONAL BANK OF BOSTON, as
Administrative Agent for itself and the other Lenders (in such capacity, the
"ADMINISTRATIVE AGENT").  Capitalized terms used herein and not otherwise
defined shall have the meanings assigned to such terms in the Loan Agreement.

                                                                             
    ______________________________________________________ (the "ASSIGNOR")

 and___________________________________ (the "ASSIGNEE") agree as follows:


     1.   The Assignor hereby sells and assigns to the Assignee, without
recourse, and the Assignee hereby purchases and assumes from the Assignor as of
the Effective Date (as defined in SECTION 4 below), the following (the "ASSIGNED
INTEREST"): [check and complete, as appropriate]

    [ ]   A   -  % interest in the Revolving Credit Commitment of the Assignor
            -----                                                             
          and of the outstanding principal amount owed to the Assignor in
          respect of its Advances under its Revolving Credit Commitment,
          together with all of the rights and obligations of the Assignor
          relating to such Assigned Interest under the Loan Agreement and the
          other Loan Documents.

    [ ]   A   -  % interest  the Term Loan A Commitment of the Assignor and
            -----                                                            
          of the outstanding principal amount owed to the Assignor in respect of
          its Advances under its Term Loan A Commitment, together with all of
          the rights and obligations of the Assignor relating to such Assigned
          Interest under the Loan Agreement and the other Loan Documents.

    [ ]   A   -  % interest in the Term Loan B Commitment of the Assignor and
            -----                                                            
          of the outstanding principal amount owed to the Assignor in respect of
          its Advances under its Term Loan B Commitment, together with all of
          the rights and obligations of the Assignor relating to such Assigned
          Interest under the Loan Agreement and the other Loan Documents.

    [ ]   100% of all of the Assignor's rights and obligations under the Loan
          Agreement and the other Loan Documents, including without limitation,
          100% of the Assignor's interest in its Revolving Credit Commitment,
          100% of the Assignor's interest in its Term Loan A Commitment and 100%
          of the total outstanding principal amount owed to the Assignor.

     2.   The Assignor: (i) represents that as of the date hereof, its Revolving
Credit Commitment is  $______________________ and the outstanding principal of
its Advances, if any, under its Revolving Credit Commitment is
$_________________________, the outstanding principal amount of its Term Loan A
Commitment, if any, is $______________________, the outstanding principal
balance of its Advances under its Term Loan A Commitment, if any, is
$____________________ (all as unreduced by any assignments which have not yet
become effective), its Term Loan B Commitment, if any, is $__________________,
and the outstanding principal balance of its Advances under the Term Loan B
Commitment, if any, is $________________________; (ii) makes no representation
or warranty and assumes no responsibility with respect to any statements,
warranties or representations made in or in connection with the
<PAGE>
 
Loan Agreement or any other Loan Document or the execution, legality, validity,
enforceability, genuineness, sufficiency or value of the Loan Agreement or any
other Loan Document, other than that it is the legal and beneficial owner of the
interest being assigned by it hereunder and that such interest is free and clear
of any adverse claim; (iii) makes no representation or warranty and assumes no
responsibility with respect to the financial condition of the Borrower, any
Guarantor or any other Obligated Party or the performance or observance by the
Borrower, any guarantor or any other Obligated Party of any of their obligations
under the Agreement or any other Loan Document; and (iv) attaches the Notes held
by Assignor and requests that the Administrative Agent exchange such Notes for
new Notes payable to the order of (A) Assignee in an amount equal to the
Commitments assumed by the Assignee pursuant hereto, and (B) the Assignor in an
amount equal to the Commitments, if any, retained by the Assignor under the Loan
Agreement, respectively, as specified above.

     3.   The Assignee: (i) represents and warrants that it is legally
authorized to enter in this Assignment and Acceptance; (ii) confirms that it has
received a copy of the Loan Agreement, together with copies of the most recent
financial statements delivered pursuant to SECTION 8.1 thereof and such other
documents and information as it has deemed appropriate to make its own credit
analysis and decision to enter into this Assignment and Acceptance; (iii) agrees
that it will, independently and without reliance upon the Administrative Agent,
the Assignor, or any other Lender and based on such documents and information as
it shall deem appropriate at the time, continue to make its own credit decisions
in taking or not taking action under the Loan Agreement and the other Loan
Documents; (iv) confirms that it is eligible to be an Assignee: (v) appoints and
authorizes the Administrative Agent to take such action as agent on its behalf
and to exercise such powers under the Loan Documents as are delegated to the
Administrative Agent by the terms thereof, together with such powers as are
reasonably incidental thereto; (v) agrees that it will perform in accordance
with their terms all the obligations which by the terms of the Loan Agreement
and the other Loan Documents are required to be performed by it as a Lender; [;
and (vii) attaches the forms prescribed by the Internal Revenue Service of the
United States certifying as to the Assignee's exemption from United States
withholding taxes with respect to all payments to be made to the Assignee under
the Loan Documents or such other documents as are necessary to indicate that all
such payments are subject to such tax at a rate reduced by an applicable tax
treaty]./1/

     4.   The effective date for this Assignment and Acceptance shall be _____,
19_______ (the "EFFECTIVE DATE")./2/  Following the execution of this Assignment
and Acceptance, it will be delivered to the Administrative Agent for acceptance
and recording by the Administrative Agent.

     5.   Upon such acceptance and recording, from and after the Effective Date,
(i) the Assignee shall be a party to the Loan Agreement and, to the extent
provided in this Assignment and Acceptance, shall have the rights and
obligations of a Lender thereunder and under the other Loan Documents and (ii)
the Assignor shall, to the extent provided in this Assignment and Acceptance,
relinquish its rights and be released from its obligations under the Loan
Agreement and the other Loan Documents.

     6.   Upon such acceptance and recording, from and after the Effective Date,
the Administrative Agent shall make all payments in respect of the interest
assigned hereby (including payments of principal, interest, fees, and other
amounts) to the Assignee.  The Assignor and Assignee shall make all appropriate
adjustments in payments for periods prior to the Effective Date by the
Administrative Agent or with respect to the making of this assignment directly
between themselves.

- --------------------------

     1    If the Assignee is organized under the laws of a jurisdiction outside
          the United States.

     2    Such date shall be at least five (5) Business Days after the execution
          of this Assignment and Acceptance and delivery thereof to the
          Administrative Agent.

                                      -2-
<PAGE>
 
     7.   This Assignment and Acceptance shall be governed by, and construed in
accordance with, the laws of the Commonwealth of Massachusetts and applicable
laws of the United States of America.

                                    [NAME OF ASSIGNOR],



                                    By: 
                                       ---------------------------------------- 
                                           Name:
                                                -------------------------------
                                           Title:
                                                 ------------------------------


                                    [NAME OF ASSIGNEE],



                                    By: 
                                       ---------------------------------------- 
                                           Name: 
                                                -------------------------------
                                           Title:
                                                 ------------------------------

ACCEPTED BY:

THE FIRST NATIONAL BANK OF BOSTON



By: 
   ---------------------------------- 
       Name:
            -------------------------
       Title:
             ------------------------
       Date:
            ------------------------- 

                                      -3-
<PAGE>
 
                                   EXHIBIT C

                         FORM OF REVOLVING CREDIT NOTE



$______________              Boston, Massachusetts               March 31, 1997


     FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
________________________________ ("PAYEE"), at the offices of The First National
Bank of Boston, as Administrative Agent (together with any successor as provided
in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100
Federal Street, Boston, Massachusetts, on April 30, 2001, in lawful money of the
United States of America, the principal sum of______________________________
DOLLARS ($_______________), or so much thereof as may be advanced and
outstanding hereunder together with the interest on the outstanding principal
balance from day to day remaining, as herein specified.

     This Note has been executed and delivered by Maker pursuant to the terms of
that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Revolving Credit Notes described therein.
Capitalized terms used and not otherwise defined herein shall have the same
meanings as set forth in the Agreement.

     Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's right as a result of the occurrence thereof.

     The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. Accrued and unpaid interest on this Note shall
be due and payable on each Payment Date and on the Termination Date. All past-
due principal and interest shall bear interest as the Default Rate.

     Notwithstanding anything to the contrary contained herein, no provisions of
this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate.  If and excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto.  If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in
<PAGE>
 
full, any remaining excess shall forthwith be paid to Maker. In determining
whether or not the interest paid or payable exceeds the Maximum Rate, Maker, the
Administrative Agent and Payee shall, to the extent permitted by applicable law,
(i) characterize any non-principal payment as an expense, fee, or premium rather
than as interest, (ii) exclude voluntary prepayments and the effects thereof,
and (iii) amortize, prorate, allocate, and spread in equal or unequal parts the
total amount of interest throughout the entire contemplated term of the
indebtedness evidenced by this Note so that the interest for the entire term
does not exceed the Maximum Rate.

     Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker.  Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

     If the Administrative Agent, Payee or the holder hereof expends any effort
in any attempt to enforce payment of all or any part or installment of any sum
due the holder hereunder, or if this Note is placed in the hands of an attorney
for collection, or if it is collected through any legal proceedings, Maker
agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, or the holder, including reasonable attorneys' fees.

     This Note shall be governed by and construed in accordance with the laws of
the Commonwealth of Massachusetts and the applicable laws of the United States
of America.

     Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder.  The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

     Maker hereby authorizes the Administrative Agent, Payee and the holder
hereof to endorse on the SCHEDULE attached to this Note or any continuation
thereof or to record in their internal records all Advances made to Maker
hereunder and all payments made on account of the principal thereof, which
endorsements or recordings shall be prima facie evidence as to the outstanding
principal amount of this Note; provided, however, any failure by the
Administrative Agent, Payee or the holder hereof to make any such endorsement or
recording shall not limit or otherwise affect the obligations of Maker under the
Agreement or this Note.

                                      -2-
<PAGE>
 
     [This Note, together with all the other Revolving Credit Notes issued on
the date hereof are given in renewal, amendment, increase and restatement, but
not extinguishment, of the Revolving Credit Notes issued under the Amended and
Restated Loan Agreement dated as of April 26, 1996 among Maker, NationsBank, the
Administrative Agent, and each of the other Lenders party thereto.]

                                       PRIME MEDICAL SERVICES, INC.



                                       By:
                                          --------------------------------------
                                           Cheryl Williams
                                           Vice President-Finance

                                      -3-
<PAGE>
 
                                   SCHEDULE

================================================================================
      Date           Advance           Principal Payment            Balance
================================================================================

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- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
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- --------------------------------------------------------------------------------
 
================================================================================

                                      -i-
<PAGE>
 
                                   EXHIBIT D

                              FORM OF TERM NOTE A


$_________________           Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
_______________________________________ ("PAYEE"), at the offices of The First
National Bank of Boston, as Administrative Agent (together with any successor as
provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at
100 Federal Street, Boston, Massachusetts, in lawful money of the United States
of America, the principal sum of ______________ DOLLARS ($_________), together
with interest on the outstanding principal balance from day to day remaining, as
herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Term Notes described therein. Capitalized terms
used and not otherwise defined herein shall have the same meanings as set forth
in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid or
payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent
<PAGE>
 
permitted by applicable law, (i) characterize any non-principa l payment as an
expense, fee, or premium rather than as interest, (ii) exclude voluntary
prepayments and the effects thereof, and (iii) amortize, prorate, allocate, and
spread in equal or unequal parts the total amount of interest throughout the
entire contemplated term of the indebtedness evidenced by this Note so that the
interest for the entire term does not exceed the Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

        [This Note, together with all the other Term Notes A issued on the date
hereof, are given in renewal, amendment, and restatement, but not extinguishment
of, the Term Notes issued under the Amended and Restated Loan Agreement dated as
of April 26, 1996 among Maker, NationsBank, the Administrative Agent and each of
the other Lenders party thereto.]

                                    PRIME MEDICAL SERVICES, INC.



                                    By:
                                       ---------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>
 
                                   EXHIBIT E

                              FORM OF TERM NOTE B


$_______________             Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of_______
("PAYEE"), at the offices of The First National Bank of Boston, as
Administrative Agent (together with any successor as provided in the Agreement,
hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100 Federal Street, Boston,
Massachusetts, in lawful money of the United States of America, the principal
sum of ________ DOLLARS ($_______), together with interest on the outstanding
principal balance from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By:
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>
 
$$NOFOLIO
                                   EXHIBIT F

                            PERFECTION CERTIFICATE

     The undersigned is an officer of PRIME MEDICAL SERVICES, INC., a Delaware
corporation ("BORROWER"), and is authorized to make and deliver this
certificate. Borrower hereby certifies, with reference to that certain Borrower
Security Agreement (herein so called) dated as of April 26, 1996 between
Borrower and The First National Bank of Boston, as Administrative Agent
("AGENT") for itself and certain other Lenders (the "LENDERS"), as amended and
those certain Guarantor Security Agreements (herein so called) dated as of April
26, 1996 between the Guarantors (as defined in that certain Second Amended and
Restated Loan Agreement of even date herewith among Borrower, the Administrative
Agent and the Lenders), as amended and the Administrative Agent (the Borrower
Security Agreement and the Guarantor Security Agreements being herein referred
to collectively as the "SECURITY AGREEMENTS") (capitalized terms used and not
otherwise defined herein shall have the same meanings as set forth in the
Security Agreements), to the Administrative Agent and each Lender as follows:

     1.   NAMES.

          (a) There have been no changes since April 26, 1996 in the exact
     corporate name of Borrower and each Guarantor as such name appears on each
     such company's Certificate of Incorporation or Articles of Incorporation
     is:



          (b) The following is a list of all other names (including trade names
     or similar appellations) used by Borrower and each Guarantor, or any other
     business or organization to which any such company has succeeded, now or at
     any time since April 26, 1996:

<PAGE>
 
     2.   CURRENT LOCATIONS.

          (a) Any change of the chief executive office of Borrower and each
     Guarantor since April 26, 1996 is at the address indicated for each such
     company below:


     Debtor:
     Mailing Address:
     County:
     State:


 
     Debtor:
     Mailing Address:
     County:
     State:



     (b) The following are all other new locations since April 26, 1996 in the
United States of America at which Borrower or any Guarantor maintains any books
or records relating to any of the Collateral consisting of accounts, contract
rights, chattel paper, general intangibles or mobile goods:


     Debtor:
     Mailing Address:   [Complete for Borrower and each Guarantor]
     County:
     State:



     (c) The following are the names and addresses of all persons or entities
other than Borrower and each Guarantor, such as lessees or consignees, which
since April 26, 1996 have possession or are intended to have possession of any
of the Collateral consisting of chattel paper, inventory or equipment:


     Name:
     Mailing Address:
     County:
     State:

                                      -2-
<PAGE>
 
     3.   CAPITALIZATION.  Any changes in the capitalization of each of the
Subsidiaries of Borrower since April 26, 1996 is as set forth below:

                        [Complete for each Subsidiary]


     4.   PARTNERSHIP INTERESTS.  Changes in the partnership interests acquired
by Borrower since April 26, 1996 and the Subsidiaries of Borrower and
information regarding each Partnership is set forth below:



     5.   UNUSUAL TRANSACTIONS.  Except as set forth in SCHEDULE 1 attached
hereto, all of the Collateral has been originated by the applicable company in
the ordinary course of such company's business or consists of goods which have
been acquired by such company in the ordinary course from a person in the
business of selling goods of that kind.

     EXECUTED as of March _________, 1997.



                                        --------------------------------------- 
                                        Cheryl Williams
                                        Chief Financial Officer

                                      -3-
<PAGE>
 
                                   EXHIBIT G

            FORM OF OPINION OF COUNSEL FOR BORROWER AND GUARANTORS

     1.   Borrower is a Delaware  corporation duly incorporated, validly
existing and in good standing under the laws of the State of Delaware, and has
all corporate power and authority required to own its property and carry on its
business as presently conducted and proposed to be conducted.  Borrower is duly
qualified or licensed to do business in each jurisdiction where the nature of
the business in which it is engaged makes such qualification or licensing
necessary including, without limitation, the States of ___________________./3/

     2.   Borrower has the corporate power and requisite authority to execute,
deliver and carry out the terms and provisions of the Loan Documents, and all
other documents and instruments delivered pursuant to the terms of such Loan
Documents, and has taken all corporate action necessary to duly authorize (i)
the execution, delivery and performance by Borrower of the terms and provisions
of the Loan Documents, and (ii) the performance by Borrower of its obligations
under the Loan Documents.

     3.   Each Guarantor has the corporate power and requisite authority to
execute, deliver and carry out the terms and provisions of the Loan Documents to
which it is a party, and all other documents and instruments delivered pursuant
to the terms of such Loan Documents, and has taken all corporate action
necessary to duly authorize (i) the execution, delivery and performance by such
Guarantor of the terms and provisions of the Loan Documents to which it is a
party, and (ii) the performance by such Guarantor of its obligations under the
Loan Documents to which it is a party.

     4.   Neither the execution and delivery by Borrower of the Loan Documents,
nor the performance by Borrower of its obligations thereunder, nor compliance by
Borrower with the terms and provisions thereof, will (a) contravene any
provision of law, statute, rule or regulation of the State of Texas (or any
political subdivision thereof) or the United States of America, to which
Borrower is subject, or conflict with, or result in any breach of, any material
agreement, mortgage, indenture, deed of trust or other instrument known to us to
which Borrower may be subject, including, without limitation, the agreements set
forth on EXHIBIT A attached hereto, or result in the creation of any mortgage,
lien, pledge or encumbrance in respect of any property of Borrower (other than
liens in your favor), (b) contravene any judgment, decree, license, order or
permit known to us to be applicable to Borrower, (c) violate any provision of
the certificate of incorporation or bylaws of Borrower, or (d) violate or cause
a result under any partnership agreement of any Partnership.  To the best of our
knowledge, after reasonable inquiry, no consent, approval, authorization or
order of any governmental or public body or authority, or of any third party, is
required in connection with the execution, delivery and performance by Borrower
of the Loan Documents or the borrowing and repayment of money by Borrower
thereunder.

     5.   Neither the execution and delivery by the Guarantors of the Loan
Documents, nor the performance by Guarantors of their respective obligations
thereunder, nor compliance by Guarantors with the terms and provisions thereof,
will (a) contravene any provision of law, statute, rule or regulation of the
State of Texas (or any political subdivision thereof) or the United States of
America, to which any Guarantor is subject, or conflict with, or result in any
breach of, any material agreement, mortgage, indenture, deed of trust or other
instrument known to us to which any Guarantor may be subject, including, without
limitation, the agreements set forth on EXHIBIT A attached hereto, or result in
the creation of any mortgage, lien, pledge or encumbrance in respect of any
property of any Guarantor (other than liens in your favor), (b) contravene any
judgment, decree, license, order or permit known to us to be applicable to any
Guarantor, (c) violate any provision of the certificate of incorporation or
bylaws of any Guarantor, or (d) violate or cause a default under any partnership
agreement of any Partnership.  To the best of our knowledge, after reasonable
inquiry, no consent, approval, authorization or order of any governmental or
public body or authority, or of any third party, is required in connection with
the execution, delivery and performance by Guarantors of the Loan Documents or
the borrowing and repayment of money by Guarantors thereunder.

- --------------------------

     3    Include a corresponding opinion for each Guarantor and each
          Partnership.

 
<PAGE>
 
    6.   ________________, __________________ of Borrower is authorized to
execute the Loan Documents on behalf of Borrower./4/

     7.   The Loan Documents to which Borrower is a party have been duly
executed, presented and delivered by Borrower and constitute the legal and
binding obligations of Borrower, enforceable in accordance with their respective
terms.

     8.   The Loan Documents to which each Guarantor is a party have been duly
executed, presented and delivered by such Guarantor and constitute the legal and
binding obligations of such Guarantor, enforceable in accordance with their
respective terms.

     9.   To the best of our knowledge, there are no legal or arbitral actions,
suits or proceedings pending or threatened against Borrower, any Guarantor or
any Partnership which, if adversely determined, would have a material adverse
effect on the financial condition, operations, properties, assets or business of
any of Borrower, Guarantors or the Partnerships or on the transactions
contemplated in the Loan Documents.

     10.  The Security Agreements and the Pledge Agreements create in favor of
the Administrative Agent, for the benefit of the Lenders, a valid lien and
security interest, which attaches to the Collateral.

     11.  Upon the filing of the Financing Statements in the Office of the
Secretary of State of ___________ and in the Real Property Records of the
__________ County, ___________________, the liens and security interests created
by the Security Agreements shall constitute perfected, first priority liens and
security interests in the Collateral.

     12.  ______________'s authorized capitalization consists of ____________
shares of common stock, $_____________ par value per share, of which
______________ shares are issued and outstanding.  The outstanding shares have
been authorized and validly issued and are fully paid and nonassessable./5/

     13.  Assuming that the Administrative Agent takes and keeps possession of
the Pledged Shares under the Security Agreements, all actions have been taken to
create and to perfect the security interest of the Administrative Agent, for the
benefit of the Lenders, in the Pledged Shares.

     14.  Borrower is not an "investment company" or a company "controlled" by
an "investment company," within the meaning of the Investment Company Act of
1940, as amended.

     15.  A Texas court, in a case properly presented, would uphold the
Massachusetts choice of law provisions in the Loan Documents.

     16.  The Loan, as evidenced by the Loan Documents, is not usurious.




- --------------------------

     4    Similar opinion for each Guarantor.

     5    Similar opinion for each Guarantor.

                                      -2-
<PAGE>
 
                                   EXHIBIT H

                        FORM OF COMPLIANCE CERTIFICATE


TO:  The First National Bank of Boston, as Administrative Agent
     and each of the Lenders party to the
     Loan Agreement (hereinbelow defined)
     100 Federal Street
     Boston, Massachusetts  02110
     Attention:  Elizabeth Everett

Ladies and Gentlemen:

     The undersigned is the __________ of PRIME MEDICAL SERVICES, INC.
("BORROWER"), and is authorized to make and deliver this certificate pursuant to
that certain Second Amended and Restated Loan Agreement (the "LOAN AGREEMENT")
dated as of March 31, 1997, among Borrower, each of the Lenders or other lending
institutions which is or may from time to time become a signatory thereto
(collectively, the "LENDERS" and individually, a "LENDER"), and The First
National Bank of Boston, as Administrative Agent for itself and the other
Lenders (together with its successors in such capacity, the "ADMINISTRATIVE
AGENT").  Capitalized terms used and not otherwise defined herein shall have the
same meanings as set forth in the Loan Agreement.

     This certificate is being delivered as of______ , 19________ [insert the
end of the most recent reporting period required by SECTION 8.1(c) of the Loan
Agreement (the "REPORT DATE") pursuant to SECTION 8.1(c) of the Loan Agreement.
All of the calculations set forth on EXHIBIT A hereto are as of the Report Date
and have been made pursuant to the terms of the Loan Agreement.

     The undersigned, as an authorized officer of Borrower, hereby certifies to
the Administrative Agent and the Lenders that:

     1.   DEFAULTS.  No Default has occurred and is continuing, or if a Default
has occurred, EXHIBIT B attached hereto describes the nature thereof and the
steps taken or to be taken by Borrower to remedy such Default.

     2.   REPRESENTATIONS.  The representations and warranties contained in the
Loan Agreement and each of the other Loan Documents are true and correct on and
as of the date hereof with the same force and effect as if made on and as of the
date hereof, except to the extent that such representations and warranties speak
to a specific date or the facts on which such representations and warranties are
based have been changed by transactions permitted by the Loan Documents.

     3.   CALCULATIONS.  Attached hereto as schedules are the calculations
supporting the computations set forth in EXHIBIT A hereto.  All information
contained in EXHIBIT A and on the attached schedules is true and correct.

     4.   GAAP FINANCIAL STATEMENTS.  The unaudited financial statements
attached hereto, if any, were prepared in accordance with GAAP and fairly
represent (subject to year-end audit adjustments) the financial conditions and
results of operations of the Companies on a consolidated or consolidating, as
the case may be, basis as of the date and for the periods indicated therein.
<PAGE>
 
     IN WITNESS WHEREOF, the undersigned has executed this Compliance
Certificate effective this day of _________________, 19____.


                                  By:
                                     ------------------------------------
                                     Name:
                                          -------------------------------
                                     Title:
                                           ------------------------------

                                      -2-
<PAGE>
 
                                   EXHIBIT A
                                      TO
                            COMPLIANCE CERTIFICATE


                                 CALCULATIONS

A.   TOTAL DEBT TO EBITDA.

     1.   Aggregate amount of Debt of the Companies          $   
                                                              ------------
     2.   EBITDA of the Companies (for the four (4) fiscal
          quarter period ending)                             $
                                                              ------------

     3.   Ratio of Debt to EBITDA (1 divided by 2)              
                                                              ------------

     4.   Maximum Permitted                                                /1/
                                                              ------------





- ----------------------

     1    Maximum permitted for the following periods:

     =====================================================================
                     PERIOD                                 RATIO    
     ---------------------------------------------------------------------
     January 1, 1997 through December 31, 1997           3.00 to 1.0  
     ---------------------------------------------------------------------
     January 1, 1998 through December 31, 1998           2.75 to 1.0
     ---------------------------------------------------------------------
     January 1, 1999 through December 31, 1999           2.25 to 1.0
     ---------------------------------------------------------------------
     January 1, 2000 and thereafter                      2.00 to 1.0
     =====================================================================


                                      -i-
<PAGE>
 
B.   INTEREST COVERAGE RATIO.                                                   
                                                                                
     1.   EBITDA                                             $                  
                                                              ------------      
                                                                                
     2.   Consolidated Interest Expense                      $                  
                                                              ------------      
                                                                                
     3.   Ratio of EBITDA to Interest Expense                                   
           (1 divided by 2)                            
                                                              ------------      
                                                                                
     4.   Minimum Required                                                 /2/  
                                                              ------------      




- ----------------------

     2    Minimum required for the following periods: 

     =====================================================================  
                     PERIOD                                 RATIO           
     ---------------------------------------------------------------------  
     As of the last day of March 31, 1997, June         3.75 to 1.0         
     30, 1997, September 30, 1997 and December                              
     31, 1997, in each case for the four (4)                                
     fiscal quarters then ended                                              
     ---------------------------------------------------------------------  
     As of the last day of March 31, 1998, June         4.50 to 1.0         
     30, 1998, September 30, 1998 and December                              
     31, 1997, in each case for the four (4)                                
     fiscal quarters then ended                                              
     ---------------------------------------------------------------------- 
     As of the last day of each fiscal quarter of       5.25 to 1.0         
     Borrower thereafter, commencing March 31,                              
     1999, in each case for the four (4) fiscal                             
     quarters then ended                                                    
     ====================================================================== 


                                     -ii-
<PAGE>
 
C.   TOTAL DEBT SERVICE COVERAGE RATIO.                                        
                                                                               
     1.   EBITDA                                             $                 
                                                              ------------     

     2.   Less: Capital Expenditures                         $                 
                                                              ------------     

     3.   EBITDA less Capital Expenditures (1-2)                                
                                                              ------------      

     4.   Total Principal and Interest Expense                                 
                                                              ------------      

     5.   Ratio of EBITDA to Total Debt Service                                
           (3 divided by 4)                                   
                                                              ------------      

     6.   Minimum Required                                                 /3/ 
                                                              ------------   





- ---------------------

     3    Minimum Required for the following periods: 

     ===================================================================== 
                     PERIOD                                 RATIO          
     --------------------------------------------------------------------- 
     As of the last day of each fiscal quarter of       1.30 to 1.0        
     Borrower thereafter, commencing March 31,                             
     1997, in each case for the four (4) fiscal                            
     quarters then ended                                                   
     ====================================================================== 


                                     -iii-
<PAGE>
 
D.   CONSOLIDATED NET WORTH.                                                    
                                                                                
     1.   Consolidated Net Worth                             $                  
                                                              ------------      
     2.   Required Minimum:

          a.  Base Minimum                          $             /4/
                                                     ------------      
                                                                                
          b.  Plus: Beginning June 30, 1996 to and           $              
              including March 30, 1998, an amount             ------------  
              equal to one hundred percent (100%)
              of the increase in net worth arising from
              any acquisition or equity issuance       
                                                                                
          c.  Plus: Beginning June 30, 1998, an amount       $              
              equal to seventy-five percent (75%) of          ------------  
              Consolidated Net Income for each fiscal
              quarter

     TOTAL REQUIRED MINIMUM:                                 $
                                                              ------------      





- ---------------------

     4    The base minimum is as follows:

     =====================================================================
                     PERIOD                                   AMOUNT
     ---------------------------------------------------------------------
     September 30, 1996 through March 30, 1997           $65,000,000.00
     ---------------------------------------------------------------------
     March 31, 1997 through September 29, 1997           $70,000,000.00
     ---------------------------------------------------------------------
     September 30, 1997 through March 30, 1998           $75,000,000.00
     ---------------------------------------------------------------------
     March 31, 1998 and thereafter                       $75,000,000.00
     =====================================================================


                                     -iv-
<PAGE>
 
E.   MINIMUM EBITDA.     

     1.  Last Quarter:

         a.  EBITDA for Current Fiscal Quarter    $
                                                   ------------
                                              
         b.  Required Minimum                                 $  5,000,000.00

     2.  Last Two Quarters:

         a.  EBITDA for last two (2) fiscal quarters          $
                                                               --------------

         b.  Required Minimum                                  $12,000,000.00.


                                      -v-
<PAGE>
 
                                  SCHEDULE 1

                      COMMITMENTS AND WIRING INFORMATION

- --------------------------------------------------------------------------------
ADMINISTRATIVE AGENT
- -----------------------------------------

The First National Bank of Boston
100 Federal Street
P.O. Box 2016
Boston, Massachusetts 02100
Attention: Elizabeth Everett
Fax No.: (617)  434-0819
Telephone No.: (617) 434-2318
 
Wiring Instructions:
 
The First National Bank of Boston
ABA # 011-000-390
Reference: Prime Medical Services, Inc.
Attention: HT & ENV SVCS. ADM 50, 60
Account # ____________________

- --------------------------------------------------------------------------------
                                    REVOLVING
                                     CREDIT        TERM LOAN A     TERM LOAN B
         LENDER                    COMMITMENTS     COMMITMENTS     COMMITMENTS
- --------------------------------------------------------------------------------

The First National Bank of Boston  $13,888,888.89  $12,500,000.00    $ 0.00
100 Federal Street
P.O. Box 2016
Boston, Massachusetts 02100
Attention: Elizabeth Everett
Fax No.: (617) 434-0819
Telephone No.: (617) 434-2318
 
Wiring Instructions:
 
The First National Bank of Boston
ABA # 011-000-390
Reference: Prime Medical Services, Inc.
Attention: HT & ENV SVCS. ADM 50, 60
Account # ___________________

- --------------------------------------------------------------------------------

                                     -i-
<PAGE>
 
- --------------------------------------------------------------------------------
                                    REVOLVING
                                     CREDIT        TERM LOAN A     TERM LOAN B
         LENDER                    COMMITMENTS     COMMITMENTS     COMMITMENTS
- --------------------------------------------------------------------------------
 
NationsBank of Texas, N.A.       $14,111,111.11   $12,500,000.00  $10,00,000.00
515 Congress Avenue, 11th Floor
Austin, Texas  78701
Attention: Teena Belcik
Fax No.: (512) 397-2052
Telephone No.: (512) 397-2841
 
Wiring Instructions:
 
NationsBank of Texas, N.A.
1401 Elm Street
Dallas, Texas  75202
Credit Account No. 0180019828
ABA # 111000025
Reference: Prime Medical 
 Services, Inc.
Attention: Teena Belcik
- --------------------------------------------------------------------------------

Imperial Bank                    $ 6,666,666.67   $ 7,500,000.00         $ 0.00
226 Airport Parkway
San Jose, CA  95110
Attention: Kelly Davis
Fax No.: (408) 451-8586
Telephone No.: (408) 451-8589
 
Wiring Instructions:
 
Imperial Bank
9920 South La Cienga Blvd.
Inglewood, CA 90301
Attention: Santa Clara
 Valley Regional Office
Routing #: 122201444
Account Name to Credit:
 Prime Medical
Account Number to Credit:
 717015211
- --------------------------------------------------------------------------------
The Sumitomo Bank Limited        $ 7,000,000.00   $ 5,000,000.00         $ 0.00
2 Houston Center, Suite 3750
Houston, TX  77010-1086
Attention: Bruce Portillo
Fax No.: (713) 759-1419
Telephone No.: (713) 759-0770
 
Wiring Instructions:
 
Sumitomo USCBD, Chicago
ABA #: 071001850
Reference: Prime Medical

================================================================================

                                     -ii-
<PAGE>
 
- --------------------------------------------------------------------------------
                                    REVOLVING
                                     CREDIT        TERM LOAN A     TERM LOAN B
         LENDER                    COMMITMENTS     COMMITMENTS     COMMITMENTS
- --------------------------------------------------------------------------------



Bank One, Texas, N.A.            $ 8,333,333.33   $ 7,500,000.00         $ 0.00
221 West 6th Street, Suite 200
Austin, TX  78701
Attention: Ed Lick
Fax No.: (512) 479-1565
Telephone No.: (512) 479-5730
 
Wiring Instructions:
 
Bank One, Texas, N.A.
ABA # 111000614
Acct: 0749905618
Reference: Prime Medical
 Services, Inc.
Loan Acct #: 1517169342
Attention: Lora Roberts
Telephone No.: (817) 884-4399
================================================================================

                                     -iii-
<PAGE>
 
- --------------------------------------------------------------------------------
                                    REVOLVING
                                     CREDIT        TERM LOAN A     TERM LOAN B
         LENDER                    COMMITMENTS     COMMITMENTS     COMMITMENTS
- --------------------------------------------------------------------------------


Crescent/MACH Partners,L.P.            $ 0.00         $ 0.00      $ 5,000,000.00
 
 
Address for Notices:
TCW Asset Management Company
200 Park Avenue, Suite 2200
New York, NY  10166-0228
Attention: Mark J. Gold/Justin Driscoll
Fax No.: (212) 297-4159
Telephone No.: (212) 297-4000
 
With copies to:
 
Crescent/Mach I Partners, L.P.
c/o State Street Bank & Trust Co.
Two International Place
Boston, MA 02110
Attention: Jackie Kilroy
Fax No.: (617) 664-5366
Telephone No.: (617) 664-5477
 
Wiring Instructions:
 
State Street Bank and Trust Co., Boston
ABA #: 011-00-0028
A/C #: 9900-126-5
Re: Crescent/MACH I
Ref: Prime Medical Services, Inc.
Agent Bank I.D. #: 987
Institutional I.D. #: 93548
Tax I.D. #: 95-431-9954
Attention: Steven Savage
Phone: (617) 664-5629
================================================================================

                                     -iv-
<PAGE>
 
- --------------------------------------------------------------------------------
                                    REVOLVING
                                     CREDIT        TERM LOAN A     TERM LOAN B
         LENDER                    COMMITMENTS     COMMITMENTS     COMMITMENTS
- --------------------------------------------------------------------------------

Merrill Lynch Senior                   $ 0.00          $ 0.00     $ 5,000,000.00
 Floating Rate Fund, Inc.
800 Scudders Mill Road, Area 1B
Plainsboro, NJ  08536
Attention: Jill Montanye
Fax No.: (609) 282-2550
Telephone No.: (609) 282-3102
 
Wiring Instructions:
 
Bank of New York
New York, NY
ABA #: 021000018
Account #: IOC # 612 Mutual Funds 
 Custody Incoming
Secondary Account #: 245215
Account Name: Merrill Lynch Senior 
 Floating Rate Fund, Inc.
Attention: Michelle Moore 
 (212) 495-2929
Reference: Prime Medical Services, 
 Inc.
- --------------------------------------------------------------------------------
Pilgrim America Prime Rate Trust       $ 0.00         $ 0.00      $5,000,000.00
Two Renaissance Square
40 North Central Avenue 
Suite 1200
Phoenix, AZ  85004-4424
Attention:  Michael Bacevich
Fax No.: (602) 417-8327
Telephone No.: (602) 417-8258
 
Wiring Instructions:
 
State Street Bank & Trust Co.
Boston, MA
ABA #: 011-00-0028
A/C #: 9903-942-2
Reference: Pilgrim America Prime 
 Rate Trust Prime Medical
================================================================================

                                      -v-
<PAGE>
 
- --------------------------------------------------------------------------------
                                    REVOLVING
                                     CREDIT        TERM LOAN A     TERM LOAN B
         LENDER                    COMMITMENTS     COMMITMENTS     COMMITMENTS
- --------------------------------------------------------------------------------

The ING Capital Senior                 $ 0.00         $ 0.00     $ 5,000,000.00
 Secured High Income Fund, L.P.
 
Address for Notices:
ING Capital Advisors, Inc.
333 South Grand Avenue
Suite 4250
Los Angeles, CA  90071
Attention: Kathleen Lenarcic
Fax No.: (213) 346-3995
Telephone No.: (213) 346-3971
 
Wiring Instructions:
 
State Street Bank & Trust Co.
Boston, MA
ABA # 0110-0002-8
Account: Corporate Trust Dept.,
 Acct. #9903-942-2
FFC ING Capital SSHIF
 Acct. #EW0673, Fund T91A
Attn: Lenore Crummey-Benoit,
 AVP Operations
Ref: Prime Medical Services, Inc.
- --------------------------------------------------------------------------------

Van Kampen American Capital Prime      $ 0.00         $ 0.00     $ 5,000,000.00
 Rate Income Trust
One Parkview Plaza
Oakbrook Terrace, IL  60181
Attention: Jeffrey W. Maillet
Fax No.: (630) 684-6740/41
Telephone No.: (630) 684-6438
 
Wiring Instructions:
 
State Street Bank & Trust,
 Boston, MA
ABA #: 011000028
Account #: 99001265
Re: VKAC PRIT - Prime Medical
- --------------------------------------------------------------------------------

                                     -vi-
<PAGE>
 
- --------------------------------------------------------------------------------
                                    REVOLVING
                                     CREDIT        TERM LOAN A     TERM LOAN B
         LENDER                    COMMITMENTS     COMMITMENTS     COMMITMENTS
- --------------------------------------------------------------------------------

Paribas Capital Funding LLC            $ 0.00           $ 0.00   $ 5,000,000.00
787 Seventh Avenue
32nd Floor
New York, NY  10019
Attention:  Michael Weinberg
Fax No.: (212) 841-2144
Telephone No.: (212) 841-2544
 
Wiring Instructions:
 
State Street Bank & Trust Company
Corporate Trust Department
ABA #: 011-00-0028
A/C#: 99039422
Reference: Paribas Capital
Attention: Matt Callahan
- --------------------------------------------------------------------------------
TOTAL COMMITMENTS                $ 50,000,000     $ 45,000,000    $ 40,000,000
================================================================================

                                     -vii-
<PAGE>
 
                                  SCHEDULE 2

                              LIST OF GUARANTORS

1.   Prime Medical Operating, Inc., a Delaware corporation
2.   Prime Management, Inc., a Nevada Corporation
3.   Prime Cardiac Rehabilitation Services, Inc., a Delaware corporation
4.   Prime Diagnostic Services, Inc., a Delaware corporation
5.   Prime Lithotripsy Services, Inc., a New York corporation
6.   Prime Kidney Stone Treatment, Inc., a New Jersey corporation
7.   Prime Diagnostic Corp. of Florida, a Delaware corporation
8.   Prime Lithotripter Operations, Inc., a New York corporation
9.   Rehab Leasing Corp., a New York corporation
10.  Texas Litho, Inc., a Delaware corporation
11.  R.R. Litho, Inc., a Texas corporation
12.  Ohio Litho, Inc., a Delaware corporation
13.  Alabama Renal Stone Institute, Inc., an Alabama corporation
14.  Sun Medical Technologies, Inc., a California corporation
15.  Sun Acquisition, Inc., a California corporation
16.  Lithotripters, Inc., a North Carolina corporation
17.  Prime Medical Management, L.P., a Delaware limited partnership
18.  Prostatherapies, Inc., a Delaware corporation

                                      -i-
<PAGE>
 
                                  SCHEDULE 3

                             LIST OF PARTNERSHIPS


1.   Metro Atlanta Stonebusters, G.P.
2.   Shasta Diagnostic Medical Group, J.V.
3.   Southern California Stone Center, L.L.C.
4.   Kidney Stone of South Florida, L.C.
5.   Texas ESWL/Laser Lithotripter, Ltd.
6.   Ohio Mobile Lithotripter, Ltd.
7.   Ohio Mobile Lithotripter II, Ltd.
8.   ARKLATX Mobile Lithotripter Limited
9.   Northern California Kidney Stone Center, Ltd.
10.  Mobile Kidney Stone Centers, Ltd.
11.  Northern California Lithotripsy Associates
12.  Lithotripter Institute of Northern California
13.  Fayetteville Lithotripters Limited Partnership - Arizona I
14.  Fayetteville Lithotripters Limited Partnership - Arkansas I
15.  California Lithotripter Limited Partnership II, L.P.
16.  Florida Lithotripters Limited Partnership I
17.  Indiana Lithotripters Limited Partnership I
18.  Louisiana Lithotripters Investment Limited Partnership
19.  Fayetteville Lithotripters Limited Partnership - Louisiana I
20.  Montana Lithotripters Limited Partnership I
21.  Pacific Medical Limited Partnership
22.  San Diego Lithotripters Limited Partnership
23.  Fayetteville Lithotripters Limited Partnership - South Carolina I
24.  Fayetteville Lithotripters Limited Partnership - South Carolina II
25.  Tennessee Lithotripters Limited Partnership
26.  Texas Lithotripsy Limited Partnership I L.P.
27.  Texas Lithotripsy Limited Partnership II L.P.
28.  Texas Lithotripsy Limited Partnership IV L.P.
29.  Texas Lithotripsy Limited Partnership V L.P.
30.  Fayetteville Lithotripters Limited Partnership - Utah I
31.  Fayetteville Lithotripters Limited Partnership - Virginia I
32.  California Lithotripters Limited Partnership III, L.P.
33.  Las Vegas Lithotripters Limited Partnership
34.  Mountain Lithotripsy Limited Partnership - I
35.  Texas Lithotripsy Limited Partnership III L.P.
36.  Pacific Lithotripsy
37.  Mountain Lithotripsy

                                      -i-
<PAGE>
 
                                  SCHEDULE 7.5

                              EXISTING LITIGATION


NONE.






                                      -i-
<PAGE>
 
                                 SCHEDULE 7.9

                                 EXISTING DEBT


1.   Promissory Note dated April 26, 1994, issued by Prime Lithotripsy Services,
     Inc. to Metro Atlanta Stonebusters, Inc. in the amount of $3,700,000.00.
     Current Balance $983,333.00

2.   Promissory Note dated July 15, 1992, issued by Prime Diagnostic Corp. of
     Florida, Inc. to Image America of Tampa, Inc. in the amount of
     $2,000,000.00.
     Current Balance  $40,000.00

3.   Promissory Note dated August 30, 1994, issued by Prime Lithotripter
     Operations to Baptist Medical Center - Montclair in the amount of
     $316,000.08.
     Current Balance $52,667.00

4.   Promissory Note dated December 15, 1994, issued by Mobile Kidney Stone
     Centers of California, Ltd. I to Imperial Bank in the amount of
     $400,000.00.
     Current Balance $200,000.00

5.   Promissory Note dated August 5, 1991, issued by Texas Litho, Inc. to Texas
     ESWL/Laser Lithotripter, Ltd. in the amount of $15,000.00.
     Current Balance $15,000.00

6.   Promissory Note dated August 1, 1991, issued by Ohio Litho, Inc. to Ohio
     Mobile Lithotripter, Ltd. in the amount of $10,000.00.
     Current Balance $10,000.00

7.   Promissory Note dated December 17, 1990, issued by R.R. Litho, Inc. to
     Arklatx Mobile Lithotripter, L.P. in the amount of $10,000.00.
     Current Balance $10,000.00

8.   Promissory Note dated December 31, 1995, issued by Ohio Litho, Inc. to Ohio
     Mobile Lithotripter II, Ltd. in the amount of $30,000.00.
     Current Balance $30,000.00

9.   Equipment Lease dated July 28, 1993 between Copelco Leasing Corp. and Sun
     Medical Technology, Inc., in the amount of $28,097.00.
     Current Balance $11,195.00

10.  Promissory Note dated February 6, 1996, issued by Fayetteville
     Lithotripters Limited Partnership - Arizona I to First Citizens Bank in the
     amount of $1,500,000.00.
     Current Balance $930,111.00

11.  Promissory Note dated August 26, 1996, issued by Mountain Lithotripsy
     Limited Partnership I to First Citizens Bank in the amount of
     $1,459,706.25.
     Current Balance $1,240,806.26

                                      -i-
<PAGE>
 
12.  Promissory Note dated April 16, 1996, issued by Florida Limited Partnership
     I to First Citizens Bank in the amount of $1,435,000.00.
     Current Balance $548,995.00

13.  Promissory Note dated November 14, 1995, issued by Fayetteville
     Lithotripters Limited Partnership - South Carolina I to First Citizens Bank
     in the amount of $600,000.00.
     Current Balance $256,236.00

                                     -ii-
<PAGE>
 
                                SCHEDULE 7.14.1

                        CAPITALIZATION OF SUBSIDIARIES


<TABLE>
<CAPTION>
                 COMPANY NAME                   CLASS/SERIES  PAR VALUE  AUTHORIZED  OUTSTANDING
- ------------------------------------------      -----------   ---------  ----------  -----------
<S>                                             <C>           <C>        <C>         <C>
Subsidiaries 100% Owned by Prime Medical
 Services, Inc.
Prime Medical Operating, Inc.                   Common            $ .05      10,000        1,000
Texas Litho, Inc.                               Common            $ .01       1,000        1,000
R.R. Litho, Inc.                                Common            $ .01     100,000        1,000
Ohio Litho, Inc.                                Common            $ .01       1,000        1,000
Lithotripters, Inc.                             Common           no par     100,000       40,000
FastStart, Inc.                                 Common           no par     100,000       10,000
National Lithotripters Association, Inc.        Common           no par     100,000          100
Prostatherapies, Inc.                           Common           no par       1,000          100 
 
Subsidiaries 100% Owned by Prime Medical
 Operating, Inc.
Prime Management, Inc.                          Common            $1.00       1,000        1,000
Prime Cardiac Rehabilitation Services, Inc.     Common           no par         100           50
Prime Diagnostic Services, Inc.                 Common           no par         100          100
Prime Lithotripsy Services, Inc.                Common           no par         200           60
Prime Diagnostic Corp. of Florida               Common           no par         100          100
Prime Lithotripter Operations, Inc.             Common           no par         200          200
Rehab Leasing Corp.                             Common            $ .01       1,000          100
Sun Medical Technologies, Inc.                  Common           no par  37,751,525    5,385,313
                                                Preferred-A      no par   3,853,475    3,853,475
                                                Preferred-B      no par  18,395,000   12,703,265 
 
Subsidiaries 100% Owned by Prime Lithotripsy
 Services, Inc.
Prime Kidney Stone Treatment, Inc.              Common           no par       1,000        1,000
Alabama Renal Stone Institute, Inc.             Common            $1.00       1,000        1,000 
 
Subsidiaries 100% Owned by Sun Medical
 Technologies, Inc.
Sun Acquisition, Inc.                           Common           no par  10,000,000      100,000 

</TABLE>

                                      -i-
<PAGE>
 
                                SCHEDULE 7.14.2

                         LIST OF PARTNERSHIP INTERESTS
                              OWNED BY COMPANIES

<TABLE>
<CAPTION>
 
                                                                            %
                                                                          ------
<C>  <S>                                                                  <C>
 
 1.  Metro Atlanta Stonebusters, G.P.                                      60.00
 2.  Shasta Diagnostic Medical Group, J.V.                                 50.00
 3.  Southern California Stone Center, L.L.C.                              32.50
 4.  Kidney Stone of South Florida L.C.                                    70.00
 5.  Texas ESWL/Laser Lithotripter, Ltd.                                   21.15
 6.  Ohio Mobile Lithotripter, Ltd.                                        17.64
 7.  Ohio Mobile Lithotripter II, Ltd.                                     27.33
 8.  ARKLATX Mobile Lithotripter Limited                                   19.25
 9.  Northern California Kidney Stone Center, Ltd.                         38.06
10.  Mobile Kidney Stone Centers, Ltd.                                     50.50
11.  Northern California Lithotripsy Associates                            19.35
12.  Lithotripsy Institute of Northern California                           1.00
13.  Fayetteville Lithotripters Limited Partnership - Arizona I            37.00
14.  Fayetteville Lithotripters Limited Partnership - Arkansas I           40.66
15.  California Lithotripters Limited Partnership II, L.P.                 20.00
16.  Florida Lithotripters Limited Partnership I                           20.00
17.  Indiana Lithotripters Limited Partnership I                           26.70
18.  Louisiana Lithotripters Investment Limited Partnership                 3.73
19.  Fayetteville Lithotripters Limited Partnership - Louisiana I          27.46
20.  Montana Lithotripters Limited Partnership I                           53.00
21.  Pacific Medical Limited Partnership                                   41.00
22.  San Diego Lithotripters Limited Partnership                           28.66
23.  Fayetteville Lithotripters Limited Partnership - South Carolina I     39.00
24.  Fayetteville Lithotripters Limited Partnership - South Carolina II    32.33
25.  Tennessee Lithotripters Limited Partnership                           33.00
26.  Texas Lithotripsy Limited Partnership I L.P.                          45.50
27.  Texas Lithotripsy Limited Partnership II L.P.                         46.00
28.  Texas Lithotripsy Limited Partnership IV L.P.                         50.00
29.  Texas Lithotripsy Limited Partnership V L.P.                          58.00
30.  Fayetteville Lithotripters Limited Partnership - Utah I               35.57
31.  Fayetteville Lithotripters Limited Partnership - Virginia I           36.19
32.  California Lithotripters Limited Partnership III, L.P.                20.00
33.  Las Vegas Lithotripters Limited Partnership                           27.00
34.  Mountain Lithotripsy Limited Partnership - I                          44.00
35.  Texas Lithotripsy Limited Partnership III L.P.                        55.96
36.  Pacific Lithotripsy                                                   90.91
37.  Mountain Lithotripsy                                                  44.00
</TABLE>

                                      -i-
<PAGE>
 
                                 SCHEDULE 7.15

                                  AGREEMENTS


Equipment Lease entered into by Texas ESWL/Laser Lithotripter, Ltd. (Lessee) and
Debis Financial Services, Inc. (Lessor) on October 5, 1992 in the amount of
$1,275,450.  Equipment covered is Dornier MFL-5000 Lithotripter and 1992 Calumet
Coach.  Monthly lease payments are $28,075.  Lease expires November 1997.

Vehicle Lease Service Agreement entered into by Texas ESWL/Laser Lithotripter,
Ltd. (Lessee) and Paccar Leasing Corporation (Lessor) on October 9, 1995.
Equipment covered is a 1996 Peterbilt tractor. Monthly lease payments are $1,705
plus $0.058 per mile.  Lease expires November 2000.

Lease Agreement entered into by ARKLATX Mobile Lithotripter, LP. (Lessee) and
Rollins Leasing Corp. (Lessor) on October 23, 1995.  Equipment covered is a 1996
Freightliner tractor.  Monthly lease payments are $1,574 plus $0.059 per mile.
Lease expires February 2001.

Lease Agreement entered into by Prime Kidney Stone Treatment, Inc. (Lessee) and
Rollins Leasing Corp. (Lessor) on January 18, 1996.  Equipment covered is a 1996
Ford tractor.  Monthly lease payments are $1,867 plus $0.073 per mile.  Lease
expires February 2001.

See SCHEDULE 7.9.

                                      -i-
<PAGE>
 
                                 SCHEDULE 7.16

                      COMPLIANCE WITH LEGAL REQUIREMENTS;
                          GOVERNMENTAL AUTHORIZATIONS


NONE.

                                      -i-
<PAGE>
 
                                 SCHEDULE 7.19

                             ENVIRONMENTAL MATTERS


NONE.

                                      -i-
<PAGE>
 
                                 SCHEDULE 9.2

                                     LIENS

<TABLE>
<CAPTION>
====================================================================================================================================

                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================

<S>                          <C>                 <C>                      <C>            <C>               <C>
Alabama Renal Stone          Alabama Secretary   A. Derrill Crowe and          94-28224  July 29, 1994     All cash, securities or
Institute, Inc.              of State            Paul R. Butrus                          at 11:31 a.m.     other property now or
                                                 100 Brookwood Place                                       hereafter held under
                                                 Suite 500                                                 escrow agreement at
                                                 Birmingham, AL 35209                                      First Alabama Bank of
                                                                                                           Birmingham; and all
                                                                                                           accounts and all other
                                                                                                           rights of Debtor to the
                                                                                                           payment of money, now
                                                                                                           existing or hereafter
                                                                                                           arising.
- ------------------------------------------------------------------------------------------------------------------------------------

Alabama Renal Stone          Texas Secretary     A. Derrill Crowe and         94-149806  July 29, 1994     All cash, securities or
Institute, Inc.              of State            Paul R. Butrus                          at 8:00 a.m.      other property now or
                                                 100 Brookwood Place                                       hereafter held under
                                                 Suite 500                                                 escrow agreement at
                                                 Birmingham, AL 35209                                      First Alabama Bank of
                                                                                                           Birmingham; and all
                                                                                                           accounts and all other
                                                                                                           rights of Debtor to the
                                                                                                           payment of money, now
                                                                                                           existing or hereafter
                                                                                                           arising
- ------------------------------------------------------------------------------------------------------------------------------------

ARKLATX Mobile               Orleans Parish,     DVI Capital Company           36-64439  March 13, 1992    1 Siemens Lithostar and
Lithotripter, L.P.           Louisiana           6611 Rockside Rd.                       at 3:05 p.m.      Calumet Coach Model
                                                 Suite 110                                                 MMT-483L,
                                                 Independence, OH 44131                                    Lease# 2124-01
- ------------------------------------------------------------------------------------------------------------------------------------

ARKLATX Mobile               Texas Secretary     DVI Capital Company        92-00050885  March 16, 1992    1 Siemens Lithostar and
Lithotripter, L.P.           of State            6611 Rockside Rd.                       at 8:00 a.m.      Calumet Coach Model
                                                 Suite 110                                                 MMT-483L,
                                                 Independence, OH 44131                                    Lease# 2124-01
- ------------------------------------------------------------------------------------------------------------------------------------

California Lithotripters     California          First-Citizens Bank &         91071264  April 4, 1991     1 Siemens Medical
Limited Partnership II,      Secretary of State  Trust Company of South                  at 11:44 a.m.     Systems, Inc. Lithostar
L.P.                                             Carolina                                                  extracorporeal
                                                 P.O. Box 29                                               shock-wave lithotripter
                                                 Columbia, SC 29202                                        S/N 3131 and 1 Calumet
                                                                                                           Coach VIN
                                                                                                           44KFB6487MWZ17358
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE> 
                                      -i-
<PAGE>
 
<TABLE>
<CAPTION>
====================================================================================================================================

                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================

<S>                          <C>                 <C>                      <C>            <C>               <C>
Fayetteville Lithotripters   Cumberland          First-Citizens Bank &           001613  February 15,      All accounts receivable,
Limited Partnership -        County, North       Trust Company                           1996 at 9:00      1 Siemens Lithostar
Arizona I                    Carolina Register   P.O. Box 27568                          a.m.              extracorporeal
                             of Deeds            Raleigh, NC 27611                                         shock-wave lithotripter
                                                                                                           and Calumet Coach
                                                                                                           Lithostar S/N 4005
- ------------------------------------------------------------------------------------------------------------------------------------

Fayetteville Lithotripters   North Carolina      First-Citizens Bank &          1309915  February 15,      All accounts receivable,
Limited Partnership -        Secretary of State  Trust Company                           1996 at 8:00      1 Siemens Lithostar
Arizona I                                        P.O. Box 27568                          a.m.              extracorporeal
                                                 Raleigh, NC 27611                                         shock-wave lithotripter
                                                                                                           and Calumet Coach
                                                                                                           Lithostar S/N 4005
- ------------------------------------------------------------------------------------------------------------------------------------

Fayetteville Lithotripters   Cumberland          First-Citizens Bank &           001847  February 23,      Lien canceled on
Limited Partnership -        County, North       Trust Company                           1996              February 23, 1996
Arkansas I                   Carolina Register   P.O. Box 27568
                             of Deeds            Raleigh, NC 27611
- ------------------------------------------------------------------------------------------------------------------------------------

Fayetteville Lithotripters   Cumberland          First-Citizens Bank &           001846  February 23,      1 Siemens Lithostar
Limited Partnership -        County, North       Trust Company                           1996 at 9:00      extracorporeal shockwave
Arkansas I                   Carolina Register   P.O. Box 27568                          a.m.              lithotripter S/N 1154
                             of Deeds            Raleigh, NC 27611
- ------------------------------------------------------------------------------------------------------------------------------------

Fayetteville Lithotripters   North Carolina      First-Citizens Bank &       1312452 &   February 26,      1 Siemens Lithostar
Limited Partnership -        Secretary of State  Trust Company                  1312453  1996 at 8:00      extracorporeal shockwave
Louisiana I                                      P.O. Box 27568                          a.m.              lithotripter S/N 3094
                                                 Raleigh, NC 27611
- ------------------------------------------------------------------------------------------------------------------------------------

Fayetteville Lithotripters   Cumberland          First-Citizens Bank &           010956  November 14,      All accounts receivable
Limited Partnership -        County, North       Trust Company                           1995              and 1 Lithostar
South Carolina I             Carolina Register   P.O. Box 27568                                            extracorporeal
                             of Deeds            Raleigh, NC 27611                                         shock-wave lithotripter
- ------------------------------------------------------------------------------------------------------------------------------------

Fayetteville Lithotripters   North Carolina      First-Citizens Bank &          1281907  November 15,      All accounts receivable
Limited Partnership -        Secretary of State  Trust Company                           1995 at 8:00      and 1 Lithostar
South Carolina I                                 P.O. Box 27568                          a.m.              extracorporeal
                                                 Raleigh, NC 27611                                         shock-wave lithotripter
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE> 

                                     -ii-
<PAGE>
 
<TABLE>
<CAPTION>
====================================================================================================================================

                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================

<S>                          <C>                 <C>                      <C>            <C>               <C>
Florida Lithotripters        Florida Secretary   First-Citizens Bank &     950000078107  April 18,1995     All accounts receivable
Partnership I                of State            Trust Company                           at 8:00 a.m.
                                                 P.O. Box 27568
                                                 Raleigh, NC 27611
- ------------------------------------------------------------------------------------------------------------------------------------

Florida Lithotripters        Florida Secretary   Siemens Credit            920000001815  January 9, 1992   Collateral covered under
Partnership I                of State            Corporation                             at 11:00 a.m.     Lease Agreement dated
                                                 2201 Corporate Blvd NW                                    January 1, 1992 for 1
                                                 Boca Raton, FL 33431                                      Siemens Mobile Lithostar
                                                                                                           S/N 03191 and Calumet
                                                                                                           Coach VIN
                                                                                                           44KFB6489MWZ17362
- ------------------------------------------------------------------------------------------------------------------------------------

Florida Lithotripters        North Carolina      First-Citizens Bank &          0822029  September 27,     1 Siemens Medical
Partnership I                Secretary of State  Trust Company                           1991 at 8:00      Systems, Inc. Lithostar
                                                 P.O. Box 789                            a.m.              extracorporeal
                                                 Fayetteville, NC 28302                                    shock-wave lithotripter
                                                                                                           S/N 3182 and Calumet
                                                                                                           Coach VIN
                                                                                                           44KFB6486MWZ17352
- ------------------------------------------------------------------------------------------------------------------------------------

Lithotripters, Inc           Cumberland          First-Citizens Bank &           001021  February 3, 1994  1 Siemens Medical
                             County, North       Trust Company                                             Systems Lithostar
                             Carolina Register   P.O. Box 789                                              extracorporeal
                             of Deeds            Fayetteville, NC 28302                                    shock-wave lithotripter
                                                                                                           and 1 Calumet Coach
- ------------------------------------------------------------------------------------------------------------------------------------

Lithotripters, Inc           Cumberland          First-Citizens Bank &           012307  December 27,      1 Lithostar S/N 1187 and
                             County, North       Trust Company                           1995              Calumet Coach VIN
                             Carolina Register   P.O. Box 27568                                            44KFB648XKW21706
                             of Deeds            Raleigh, NC 27611
- ------------------------------------------------------------------------------------------------------------------------------------

Lithotripters, Inc           Cumberland          First-Citizens Bank &          93-8129  July 27, 1993     Lien released on
                             County, North       Trust Company                                             February 23, 1996
                             Carolina Register   P.O. Box 789
                             of Deeds            Fayetteville, NC 28302
- ------------------------------------------------------------------------------------------------------------------------------------

Lithotripters, Inc.          North Carolina      First-Citizens Bank &          1074959  February 3,       1 Siemens Medical
                             Secretary of State  Trust Company                           1994 at 8:00      Systems Lithostar
                                                 P.O. Box 789                            a.m.              extracorporeal
                                                 Fayetteville, NC 28302                                    shock-wave lithotripter
                                                                                                           and 1 Calumet Coach
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE> 

                                     -iii-
<PAGE>
 
<TABLE>
<CAPTION>
====================================================================================================================================

                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================

<S>                          <C>                 <C>                      <C>            <C>               <C>
Lithotripters, Inc.          North Carolina      First-Citizens Bank &          1294590  December 28,      1 Lithostar S/N 1187 and
                             Secretary of State  Trust Company                           1995 at 8:00      Calumet Coach VIN
                                                 P.O. Box 27568                          a.m.              44KFB648XKW217061
                                                 Raleigh, NC 27611
- ------------------------------------------------------------------------------------------------------------------------------------

Metro Atlanta Stone          Travis County,      Metro Atlanta                    00984  April 28, 1994    60% undivided interest
Busters, G.P.                Texas County Clerk  Stonebusters, Inc.                      at 12:28 p.m.     in certain assets
                                                 428 Winn Court                                            obtained from Metro
                                                 Decatur, GA 30030                                         Atlanta Stonebusters,
                                                                                                           Inc.
- ------------------------------------------------------------------------------------------------------------------------------------

Mountain Lithotripsy         Colorado            First-Citizens Bank &        952045460  June 15, 1995     1 1995 Western Star
Limited Partnership I        Secretary of State  Trust Company                           at 12:37 p.m.     tractor-trailer VIN
                                                 P.O. Box 789                                              2WKPDCJH8SK936895 with
                                                 Fayetteville, NC 28302                                    Siemens Medical Systems,
                                                                                                           Inc. Lithostar
                                                                                                           extracorporeal
                                                                                                           shock-wave lithotripter
                                                                                                           S/N 04004 and all
                                                                                                           accounts receivable
- ------------------------------------------------------------------------------------------------------------------------------------

Mountain Lithotripsy         Cumberland          First-Citizens Bank &           005722  June 14, 1995     1 1995 Western Star
Limited Partnership I        County, North       Trust Company                                             tractor-trailer VIN
                             Carolina Register   P.O. Box 789                                              2WKPDCJH8SK936895 with
                             of Deeds            Fayetteville, NC 28302                                    Siemens Medical Systems,
                                                                                                           Inc. Lithostar
                                                                                                           extracorporeal
                                                                                                           shock-wave lithotripter
                                                                                                           S/N 04004 and all
                                                                                                           accounts receivable
- ------------------------------------------------------------------------------------------------------------------------------------

Mountain Lithotripsy         Nebraska            First-Citizens Bank &           659814  June 14, 1995     1 1995 Western Star
Limited Partnership I        Secretary of State  Trust Company                           at 10:09 a.m.     tractor-trailer VIN
                                                 P.O. Box 789                                              2WKPDCJH8SK936895 with
                                                 Fayetteville, NC 28302                                    Siemens Medical Systems,
                                                                                                           Inc. Lithostar
                                                                                                           extracorporeal
                                                                                                           shock-wave lithotripter
                                                                                                           S/N 04004 and all
                                                                                                           accounts receivable
- ------------------------------------------------------------------------------------------------------------------------------------

Mountain Lithotripsy         North Carolina      First-Citizens Bank &          1235086  June 15, 1995     1 1995 Western Star
Limited Partnership I        Secretary of State  Trust Company                           at 8:00 a.m.      tractor-trailer VIN
                                                 P.O. Box 789                                              2WKPDCJH8SK936895 with
                                                 Fayetteville, NC 28302                                    Siemens Medical Systems,
                                                                                                           Inc. Lithostar
                                                                                                           extracorporeal
                                                                                                           shock-wave lithotripter
                                                                                                           S/N 04004 and all
                                                                                                           accounts receivable
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE> 

                                     -iv-
<PAGE>
 
<TABLE>
<CAPTION>
====================================================================================================================================

                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================

<S>                          <C>                 <C>                      <C>            <C>               <C>
Prime Diagnostic Corp.       Florida Secretary   Copelco Leasing          93-0000165975  August 5, 1993    1 Alpha III System 160
of Florida                   of State            Corporation                             at 11:14 a.m.     Diagnostic Mammography
                                                 1700 Suckle Highway                                       System S/N A31916
                                                 Pennsauken, NJ 08110
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Diagnostic Corp.       Florida Secretary   Instrumentarium Finance  92-0000267315  December 30,      1 Alpha III System 160
of Florida                   of State            P.O. Box 767                            1992 at 12:17     Diagnostic Mammography
                                                 Bellevue, WA 98009                      p.m.              System S/N A31916
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Diagnostic Corp.       Florida Secretary   U.S. Concord, Inc.       92-0000193158  September 23,     1 Toshiba America
of Florida                   of State            40 Richards Avenue                      1992 at 12:30     Medical Systems Model
                                                 Norwalk, CT 06856                       p.m.              SSA-270A Ultrasound
                                                                                                           System with Spectral and
                                                                                                           Color Doppler including
                                                                                                           all parts, accessories
                                                                                                           and attachments
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Diagnostic Corp.       Texas Secretary     Copelco Leasing              93-154508  August 9, 1993    1 Alpha III System 160
of Florida                   of State            Corporation                                               Diagnostic Mammography
                                                 1700 Suckle Highway                                       System S/N A31916
                                                 Pennsauken, NJ 08110
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Diagnostic Corp.       Texas Secretary     U.S. Concord, Inc.           92-163143  August 17, 1992   1 Toshiba America
of Florida                   of State            40 Richards Avenue                      at 8:00a.m.       Medical Systems Model
                                                 Norwalk, CT 06856                                         SSA-270A Ultrasound
                                                                                                           System with Spectral and
                                                                                                           Color Doppler including
                                                                                                           all parts, accessories
                                                                                                           and attachments
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Lithotripsy            Dekalb County,      Metro Atlanta                 94-02947  April 28, 1994    60% undivided interest
Services, Inc.               Georgia Clerk of    Stonebusters, Inc.                      at 12:05 p.m.     in certain assets
                             Superior Court      428 Winn Court                                            obtained from Metro
                                                 Decatur, GA 30030                                         Atlanta Stonebusters,
                                                                                                           Inc.
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE> 

                                      -v-
<PAGE>
 
<TABLE>
<CAPTION>
====================================================================================================================================

                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================

<S>                          <C>                 <C>                      <C>            <C>               <C>
Prime Lithotripsy            Texas Secretary     Alabama Renal Stone        92-00128931  June 29, 1992     All cash, securities or
Services, Inc.               of State            Institute, Inc.                         at 8:00 a.m.      other property now or
                                                                                                           hereafter held under
                                                                                                           escrow agreement at
                                                                                                           First Alabama Bank of
                                                                                                           Birmingham; and all
                                                                                                           accounts and all other
                                                                                                           rights of Debtor to the
                                                                                                           payment of money, now
                                                                                                           existing or hereafter
                                                                                                           arising.
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Lithotripsy            Texas Secretary     Metro Atlanta              94-00082951  April 28, 1994    60% undivided interest
Services, Inc.               of State            Stonebusters, Inc.                      at 8:00 a.m.      in certain assets
                                                 428 Winn Court                                            obtained from Metro
                                                 Decatur, GA 30030                                         Atlanta Stonebusters,
                                                                                                           Inc.
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Lithotripsy            Travis County,      Metro Atlanta                    00983  April 28, 1994    60% undivided interest
Services, Inc.               Texas County Clerk  Stonebusters, Inc.                      at 12:28 p.m.     in certain assets
                                                 428 Winn Court                                            obtained from Metro
                                                 Decatur, GA 30030                                         Atlanta Stonebusters,
                                                                                                           Inc.
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Lithotripter           Alabama Secretary   Alabama Lithotripsy           94-33480  September 6,      Brother fax machine,
Operations, Inc.             of State            Associates, Inc.                        1994 at 2:30      Panasonic telephone,
                                                 2055 E South                            p.m.              desk with return,
                                                 Boulevard, Suite 507                                      computer work station, 2
                                                 Montgomery, AL 36116                                      metal shelves, wooden
                                                                                                           shelf, metal file
                                                                                                           cabinet, telephone
                                                                                                           number lease agreements,
                                                                                                           accounts receivable,
                                                                                                           prepaid insurance,
                                                                                                           prepaid maintenance, all
                                                                                                           governmental licenses
                                                                                                           listed in Sch 3.6, and
                                                                                                           all contract rights
                                                                                                           listed in Sch 3.12
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Lithotripter           Alabama Secretary   Baptist Medical Center -      94-33113  September 2,      Mon-A Therm Monitor,
Operations, Inc.             of State            Montclair                               1994 at 11:57     C0\\2\\ Monitor,
                                                 3500 Blue Lake Drive                    p.m.              Anesthesia Unit, Monitor
                                                 Birmingham, AL 35243                                      - Dinamap 8100, Curix
                                                                                                           Auto Processor,
                                                                                                           Lithotripter Unit,
                                                                                                           I.R.I.S. Unit, Personal
                                                                                                           Computer, Printer -
                                                                                                           Thermal, NEC Monitor,
                                                                                                           and Lithotripsy Trailer
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE> 

                                     -vi-
<PAGE>
 
<TABLE>
<CAPTION>
====================================================================================================================================

                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================

<S>                          <C>                 <C>                      <C>            <C>               <C>
Prime Lithotripter           Texas Secretary of  Alabama Lithotripsy          94-174429  September 6,      Brother fax machine,
Operations, Inc.             State               Associates, Inc.                        1994 at 8:00      Panasonic telephone,
                                                 2055 E. South Boulevard                 a.m.              desk with return,
                                                 Suite 507                                                 computer work station, 2
                                                 Montgomery, AL 36116                                      metal shelves, wooden
                                                                                                           shelf, metal file
                                                                                                           cabinet, telephone
                                                                                                           number lease agreements,
                                                                                                           accounts receivable,
                                                                                                           prepaid insurance,
                                                                                                           prepaid maintenance, all
                                                                                                           governmental licenses
                                                                                                           listed in Sch 3.6, and
                                                                                                           all contract rights
                                                                                                           listed in Sch 3.12
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Lithotripter           Texas Secretary of  Third National Bank          94-208378  October 24,       Dornier Extracorporeal
Operations, Inc.             State               P.O. Box 305110                         1994 at 8:00      Shock Wave Lithotripter
                                                 Nashville, TN                           a.m.              Model HM3 enclosed in a
                                                 37230-5110                                                48ft. Calumet Coach
                                                                                                           Trailer S/N 609201-DID
                                                                                                           3205 in a Model MMT-481
                                                                                                           Calumet Unit with S/N
                                                                                                           1T9FA0Z26GB021679
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Medical Services,      Texas Secretary of  Siemens Credit             92-00212305  October 27,       The equipment covered
Inc.                         State               Corporation                             1992 at 8:00      under Leasing Schedule
                                                 2201 Corporate Blvd NW                  a.m.              No 130-0001061-000 to
                                                 Boca Raton, FL 33431                                      Master Equipment Lease
                                                                                                           Agreement No
                                                                                                           130-0001060-000 (Siemens
                                                                                                           Magnetom Impact)
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Medical Services,      Texas Secretary of  Siemens Credit             92-00212306  October 27,       The equipment covered
Inc.                         State               Corporation                             1992 at 8:00      under Leasing Schedule
                                                 2201 Corporate Blvd NW                  a.m.              No 210-0001009-000 to
                                                 Boca Raton, FL 33431                                      Master Equipment Lease
                                                                                                           Agreement No
                                                                                                           130-0001060-000 (Siemens
                                                                                                           Litebox Workstation)
 
 
- ------------------------------------------------------------------------------------------------------------------------------------

Prime Medical Services,      Texas Secretary of  Siemens Credit             92-00212307  October 27,       The equipment covered
Inc.                         State               Corporation                             1992 at 8:00      under Leasing Schedule
                                                 2201 Corporate Blvd NW                  a.m.              No 110-0001030-000 to
                                                 Boca Raton, FL 33431                                      Master Equipment Lease
                                                                                                           Agreement No
                                                                                                           130-0001060-000 (Siemens
                                                                                                           Somatom AR.T)
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE> 

                                     -vii-
<PAGE>
 
<TABLE>
<CAPTION>
====================================================================================================================================
                             
                                                                                             DATE AND
                                                                                               TIME               DESCRIPTION
NAME                              LOCATION            SECURED PARTY         FILE NO.        OF FILING            OF COLLATERAL
====================================================================================================================================
                             
<S>                          <C>                 <C>                      <C>            <C>               <C>
Sun Medical Technologies,  California Secretary  Copelco Leasing               93162570  August 9, 1993    1 Versyss computerized
 Inc.                      of State              Corporation                             at 8:00 a.m.      billing system with
                                                 1700 Suckle Highway                                       hardware and software
                                                 Pennsauken, NJ 08110
- ------------------------------------------------------------------------------------------------------------------------------------
                             
Tennessee Lithotripters,   Tennessee Secretary   First-Citizens Bank &        910882052  May 17, 1991 at   All accounts receivable
 Limited Partnership I     of State              Trust Company                           4:47 p.m.
                                                 P.O. Box 789
                                                 Fayetteville, NC 28302
- ------------------------------------------------------------------------------------------------------------------------------------
                             
Tennessee Lithotripters,   Tennessee Secretary   Siemens Credit               910849844  February 4,       Equipment covered under
 Limited Partnership I     of State              Corporation                             1991 at 9:49      lease agreement
                                                 2201 Corporate Blvd NW                  a.m.              #01000969 for 1 Siemens
                                                 Boca Raton, FL 33431                                      Mobile Lithostar in
                                                                                                           Calumet Coach
- ------------------------------------------------------------------------------------------------------------------------------------
                             
Texas ESWL/Laser           Oklahoma County,      Prime Leasing, Inc.             062652  December 23,      (1) 1991 Ford E150
 Lithotripter, Ltd.        Oklahoma County       Two Continental Towers                  1991 at 12:06     Custom Lift Van and
                           Clerk                 1701 Golf Road                          p.m.              Accessories and (1)
                                                 Rolling Meadows, IL                                       Pulsolith Pulsed Dye
                                                 60008                                                     Laser and accessories.
- ------------------------------------------------------------------------------------------------------------------------------------
                             
Texas ESWL/Laser           Texas Secretary       Debis Financial            93-00004990  January 8, 1993   1 Dornier MFL-5000
 Lithotripter, Ltd.        of State              Services, Inc.                          at 8:00 a.m.      Lithotripter, Serial No
                                                 201 Merritt 7, Suite                                      5012, with Calumet
                                                 700                                                       Coach, Model MMT-451L
                                                 Norwalk, CT 06856                                         and all accessories.
- ------------------------------------------------------------------------------------------------------------------------------------
                             
Texas ESWL/Laser           Texas Secretary       Prime Leasing, Inc.        91-00242830  December 23,      (1) 1991 Ford E150
 Lithotripter, Ltd.        of State              Two Continental Towers                  1991 at 8:00      Custom Lift Van and
                                                 1701 Golf Road                          a.m.              Accessories and (1)
                                                 Rolling Meadows, IL                                       Pulsolith Pulsed Dye
                                                 60008                                                     Laser and accessories.
- ------------------------------------------------------------------------------------------------------------------------------------

</TABLE>

                                    -viii-


                          REVOLVING CREDIT NOTE



$14,111,111.11              Boston, Massachusetts               March 31, 1997


     FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
NATIONSBANK OF TEXAS, N.A.("PAYEE"), at the offices of The First National
Bank of Boston, as Administrative Agent (together with any successor as provided
in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100
Federal Street, Boston, Massachusetts, on April 30, 2001, in lawful money of the
United States of America, the principal sum of FOURTEEN MILLION ONE HUNDRED 
ELEVEN THOUSAND ONE HUNDRED ELEVEN AND 11/100 DOLLARS ($14,111,111.11), or so 
much thereof as may be advanced and outstanding hereunder together with the 
interest on the outstanding principal balance from day to day remaining, as 
herein specified.

     This Note has been executed and delivered by Maker pursuant to the terms of
that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Revolving Credit Notes described therein.
Capitalized terms used and not otherwise defined herein shall have the same
meanings as set forth in the Agreement.

     Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's right as a result of the occurrence thereof.

     The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. Accrued and unpaid interest on this Note shall
be due and payable on each Payment Date and on the Termination Date. All past-
due principal and interest shall bear interest as the Default Rate.

     Notwithstanding anything to the contrary contained herein, no provisions of
this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate.  If and excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto.  If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in
<PAGE>
 
full, any remaining excess shall forthwith be paid to Maker. In determining
whether or not the interest paid or payable exceeds the Maximum Rate, Maker, the
Administrative Agent and Payee shall, to the extent permitted by applicable law,
(i) characterize any non-principal payment as an expense, fee, or premium rather
than as interest, (ii) exclude voluntary prepayments and the effects thereof,
and (iii) amortize, prorate, allocate, and spread in equal or unequal parts the
total amount of interest throughout the entire contemplated term of the
indebtedness evidenced by this Note so that the interest for the entire term
does not exceed the Maximum Rate.

     Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker.  Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

     If the Administrative Agent, Payee or the holder hereof expends any effort
in any attempt to enforce payment of all or any part or installment of any sum
due the holder hereunder, or if this Note is placed in the hands of an attorney
for collection, or if it is collected through any legal proceedings, Maker
agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, or the holder, including reasonable attorneys' fees.

     This Note shall be governed by and construed in accordance with the laws of
the Commonwealth of Massachusetts and the applicable laws of the United States
of America.

     Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder.  The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

     Maker hereby authorizes the Administrative Agent, Payee and the holder
hereof to endorse on the SCHEDULE attached to this Note or any continuation
thereof or to record in their internal records all Advances made to Maker
hereunder and all payments made on account of the principal thereof, which
endorsements or recordings shall be prima facie evidence as to the outstanding
principal amount of this Note; provided, however, any failure by the
Administrative Agent, Payee or the holder hereof to make any such endorsement or
recording shall not limit or otherwise affect the obligations of Maker under the
Agreement or this Note.

                                      -2-
<PAGE>
 
     [This Note, together with all the other Revolving Credit Notes issued on
the date hereof are given in renewal, amendment, increase and restatement, but
not extinguishment, of the Revolving Credit Notes issued under the Amended and
Restated Loan Agreement dated as of April 26, 1996 among Maker, NationsBank, the
Administrative Agent, and each of the other Lenders party thereto.]

                                       PRIME MEDICAL SERVICES, INC.



                                       By: /s/ Cheryl Williams
                                          --------------------------------------
                                           Cheryl Williams
                                           Vice President-Finance

                                      -3-
<PAGE>
 
                                   SCHEDULE

================================================================================
      Date           Advance           Principal Payment            Balance
================================================================================

- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
================================================================================

                                      -i-
<PAGE>


                          REVOLVING CREDIT NOTE



$13,888,888.89              Boston, Massachusetts               March 31, 1997


     FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
THE FIRST NATIONAL BANK OF BOSTON("PAYEE"), at the offices of The First National
Bank of Boston, as Administrative Agent (together with any successor as provided
in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100
Federal Street, Boston, Massachusetts, on April 30, 2001, in lawful money of the
United States of America, the principal sum of THIRTEEN MILLION EIGHT HUNDRED 
EIGHTY EIGHT THOUSAND EIGHT HUNDRED EIGHTY EIGHT AND 89/100 DOLLARS 
($13,888,888.89), or so much thereof as may be advanced and outstanding 
hereunder together with the interest on the outstanding principal balance from 
day to day remaining, as herein specified.

     This Note has been executed and delivered by Maker pursuant to the terms of
that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Revolving Credit Notes described therein.
Capitalized terms used and not otherwise defined herein shall have the same
meanings as set forth in the Agreement.

     Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's right as a result of the occurrence thereof.

     The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. Accrued and unpaid interest on this Note shall
be due and payable on each Payment Date and on the Termination Date. All past-
due principal and interest shall bear interest as the Default Rate.

     Notwithstanding anything to the contrary contained herein, no provisions of
this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate.  If and excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto.  If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in
<PAGE>
 
full, any remaining excess shall forthwith be paid to Maker. In determining
whether or not the interest paid or payable exceeds the Maximum Rate, Maker, the
Administrative Agent and Payee shall, to the extent permitted by applicable law,
(i) characterize any non-principal payment as an expense, fee, or premium rather
than as interest, (ii) exclude voluntary prepayments and the effects thereof,
and (iii) amortize, prorate, allocate, and spread in equal or unequal parts the
total amount of interest throughout the entire contemplated term of the
indebtedness evidenced by this Note so that the interest for the entire term
does not exceed the Maximum Rate.

     Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker.  Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

     If the Administrative Agent, Payee or the holder hereof expends any effort
in any attempt to enforce payment of all or any part or installment of any sum
due the holder hereunder, or if this Note is placed in the hands of an attorney
for collection, or if it is collected through any legal proceedings, Maker
agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, or the holder, including reasonable attorneys' fees.

     This Note shall be governed by and construed in accordance with the laws of
the Commonwealth of Massachusetts and the applicable laws of the United States
of America.

     Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder.  The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

     Maker hereby authorizes the Administrative Agent, Payee and the holder
hereof to endorse on the SCHEDULE attached to this Note or any continuation
thereof or to record in their internal records all Advances made to Maker
hereunder and all payments made on account of the principal thereof, which
endorsements or recordings shall be prima facie evidence as to the outstanding
principal amount of this Note; provided, however, any failure by the
Administrative Agent, Payee or the holder hereof to make any such endorsement or
recording shall not limit or otherwise affect the obligations of Maker under the
Agreement or this Note.

                                      -2-
<PAGE>
 
     [This Note, together with all the other Revolving Credit Notes issued on
the date hereof are given in renewal, amendment, increase and restatement, but
not extinguishment, of the Revolving Credit Notes issued under the Amended and
Restated Loan Agreement dated as of April 26, 1996 among Maker, NationsBank, the
Administrative Agent, and each of the other Lenders party thereto.]

                                       PRIME MEDICAL SERVICES, INC.



                                       By: /s/ Cheryl Williams
                                          --------------------------------------
                                           Cheryl Williams
                                           Vice President-Finance

                                      -3-
<PAGE>
 
                                   SCHEDULE

================================================================================
      Date           Advance           Principal Payment            Balance
================================================================================

- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
================================================================================

                                      -i-
<PAGE>


                          REVOLVING CREDIT NOTE



$8,333,333.33              Boston, Massachusetts               March 31, 1997


     FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
BANK ONE, TEXAS,N.A.("PAYEE"), at the offices of The First National
Bank of Boston, as Administrative Agent (together with any successor as provided
in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100
Federal Street, Boston, Massachusetts, on April 30, 2001, in lawful money of the
United States of America, the principal sum of EIGHT MILLION THREE HUNDRED 
THIRTY-THREE THOUSAND THREE HUNDRED THIRTY-THREE AND 33/100 DOLLARS 
($8,333,333.33), or so much thereof as may be advanced and outstanding 
hereunder together with the interest on the outstanding principal balance from 
day to day remaining, as herein specified.

     This Note has been executed and delivered by Maker pursuant to the terms of
that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Revolving Credit Notes described therein.
Capitalized terms used and not otherwise defined herein shall have the same
meanings as set forth in the Agreement.

     Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's right as a result of the occurrence thereof.

     The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. Accrued and unpaid interest on this Note shall
be due and payable on each Payment Date and on the Termination Date. All past-
due principal and interest shall bear interest as the Default Rate.

     Notwithstanding anything to the contrary contained herein, no provisions of
this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate.  If and excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto.  If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in
<PAGE>
 
full, any remaining excess shall forthwith be paid to Maker. In determining
whether or not the interest paid or payable exceeds the Maximum Rate, Maker, the
Administrative Agent and Payee shall, to the extent permitted by applicable law,
(i) characterize any non-principal payment as an expense, fee, or premium rather
than as interest, (ii) exclude voluntary prepayments and the effects thereof,
and (iii) amortize, prorate, allocate, and spread in equal or unequal parts the
total amount of interest throughout the entire contemplated term of the
indebtedness evidenced by this Note so that the interest for the entire term
does not exceed the Maximum Rate.

     Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker.  Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

     If the Administrative Agent, Payee or the holder hereof expends any effort
in any attempt to enforce payment of all or any part or installment of any sum
due the holder hereunder, or if this Note is placed in the hands of an attorney
for collection, or if it is collected through any legal proceedings, Maker
agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, or the holder, including reasonable attorneys' fees.

     This Note shall be governed by and construed in accordance with the laws of
the Commonwealth of Massachusetts and the applicable laws of the United States
of America.

     Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder.  The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

     Maker hereby authorizes the Administrative Agent, Payee and the holder
hereof to endorse on the SCHEDULE attached to this Note or any continuation
thereof or to record in their internal records all Advances made to Maker
hereunder and all payments made on account of the principal thereof, which
endorsements or recordings shall be prima facie evidence as to the outstanding
principal amount of this Note; provided, however, any failure by the
Administrative Agent, Payee or the holder hereof to make any such endorsement or
recording shall not limit or otherwise affect the obligations of Maker under the
Agreement or this Note.

                                      -2-
<PAGE>
 
     [This Note, together with all the other Revolving Credit Notes issued on
the date hereof are given in renewal, amendment, increase and restatement, but
not extinguishment, of the Revolving Credit Notes issued under the Amended and
Restated Loan Agreement dated as of April 26, 1996 among Maker, NationsBank, the
Administrative Agent, and each of the other Lenders party thereto.]

                                       PRIME MEDICAL SERVICES, INC.



                                       By: /s/ Cheryl Williams
                                          --------------------------------------
                                           Cheryl Williams
                                           Vice President-Finance

                                      -3-
<PAGE>
 
                                   SCHEDULE

================================================================================
      Date           Advance           Principal Payment            Balance
================================================================================

- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
================================================================================

                                      -i-
<PAGE>


                          REVOLVING CREDIT NOTE



$6,666,666.67              Boston, Massachusetts               March 31, 1997


     FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
IMPERIAL BANK ("PAYEE"), at the offices of The First National
Bank of Boston, as Administrative Agent (together with any successor as provided
in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100
Federal Street, Boston, Massachusetts, on April 30, 2001, in lawful money of the
United States of America, the principal sum of SIX MILLION SIX HUNDRED 
SIXTY-SIX THOUSAND SIX HUNDRED SIXTY-SIX AND 67/100 DOLLARS 
($6,666,666.67), or so much thereof as may be advanced and outstanding 
hereunder together with the interest on the outstanding principal balance from 
day to day remaining, as herein specified.

     This Note has been executed and delivered by Maker pursuant to the terms of
that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Revolving Credit Notes described therein.
Capitalized terms used and not otherwise defined herein shall have the same
meanings as set forth in the Agreement.

     Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's right as a result of the occurrence thereof.

     The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. Accrued and unpaid interest on this Note shall
be due and payable on each Payment Date and on the Termination Date. All past-
due principal and interest shall bear interest as the Default Rate.

     Notwithstanding anything to the contrary contained herein, no provisions of
this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate.  If and excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto.  If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in
<PAGE>
 
full, any remaining excess shall forthwith be paid to Maker. In determining
whether or not the interest paid or payable exceeds the Maximum Rate, Maker, the
Administrative Agent and Payee shall, to the extent permitted by applicable law,
(i) characterize any non-principal payment as an expense, fee, or premium rather
than as interest, (ii) exclude voluntary prepayments and the effects thereof,
and (iii) amortize, prorate, allocate, and spread in equal or unequal parts the
total amount of interest throughout the entire contemplated term of the
indebtedness evidenced by this Note so that the interest for the entire term
does not exceed the Maximum Rate.

     Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker.  Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

     If the Administrative Agent, Payee or the holder hereof expends any effort
in any attempt to enforce payment of all or any part or installment of any sum
due the holder hereunder, or if this Note is placed in the hands of an attorney
for collection, or if it is collected through any legal proceedings, Maker
agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, or the holder, including reasonable attorneys' fees.

     This Note shall be governed by and construed in accordance with the laws of
the Commonwealth of Massachusetts and the applicable laws of the United States
of America.

     Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder.  The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

     Maker hereby authorizes the Administrative Agent, Payee and the holder
hereof to endorse on the SCHEDULE attached to this Note or any continuation
thereof or to record in their internal records all Advances made to Maker
hereunder and all payments made on account of the principal thereof, which
endorsements or recordings shall be prima facie evidence as to the outstanding
principal amount of this Note; provided, however, any failure by the
Administrative Agent, Payee or the holder hereof to make any such endorsement or
recording shall not limit or otherwise affect the obligations of Maker under the
Agreement or this Note.

                                      -2-
<PAGE>
 
     [This Note, together with all the other Revolving Credit Notes issued on
the date hereof are given in renewal, amendment, increase and restatement, but
not extinguishment, of the Revolving Credit Notes issued under the Amended and
Restated Loan Agreement dated as of April 26, 1996 among Maker, NationsBank, the
Administrative Agent, and each of the other Lenders party thereto.]

                                       PRIME MEDICAL SERVICES, INC.



                                       By: /s/ Cheryl Williams
                                          --------------------------------------
                                           Cheryl Williams
                                           Vice President-Finance

                                      -3-
<PAGE>
 
                                   SCHEDULE

================================================================================
      Date           Advance           Principal Payment            Balance
================================================================================

- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
================================================================================

                                      -i-
<PAGE>


                          REVOLVING CREDIT NOTE



$7,000,000.00              Boston, Massachusetts               March 31, 1997


     FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
THE SUMITOMO BANK, LIMITED ("PAYEE"), at the offices of The First National
Bank of Boston, as Administrative Agent (together with any successor as provided
in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100
Federal Street, Boston, Massachusetts, on April 30, 2001, in lawful money of the
United States of America, the principal sum of SEVEN MILLION AND 00/100 DOLLARS 
($7,000,000.00), or so much thereof as may be advanced and outstanding 
hereunder together with the interest on the outstanding principal balance from 
day to day remaining, as herein specified.

     This Note has been executed and delivered by Maker pursuant to the terms of
that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Revolving Credit Notes described therein.
Capitalized terms used and not otherwise defined herein shall have the same
meanings as set forth in the Agreement.

     Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's right as a result of the occurrence thereof.

     The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. Accrued and unpaid interest on this Note shall
be due and payable on each Payment Date and on the Termination Date. All past-
due principal and interest shall bear interest as the Default Rate.

     Notwithstanding anything to the contrary contained herein, no provisions of
this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate.  If and excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto.  If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in
<PAGE>
 
full, any remaining excess shall forthwith be paid to Maker. In determining
whether or not the interest paid or payable exceeds the Maximum Rate, Maker, the
Administrative Agent and Payee shall, to the extent permitted by applicable law,
(i) characterize any non-principal payment as an expense, fee, or premium rather
than as interest, (ii) exclude voluntary prepayments and the effects thereof,
and (iii) amortize, prorate, allocate, and spread in equal or unequal parts the
total amount of interest throughout the entire contemplated term of the
indebtedness evidenced by this Note so that the interest for the entire term
does not exceed the Maximum Rate.

     Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker.  Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

     If the Administrative Agent, Payee or the holder hereof expends any effort
in any attempt to enforce payment of all or any part or installment of any sum
due the holder hereunder, or if this Note is placed in the hands of an attorney
for collection, or if it is collected through any legal proceedings, Maker
agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, or the holder, including reasonable attorneys' fees.

     This Note shall be governed by and construed in accordance with the laws of
the Commonwealth of Massachusetts and the applicable laws of the United States
of America.

     Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder.  The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

     Maker hereby authorizes the Administrative Agent, Payee and the holder
hereof to endorse on the SCHEDULE attached to this Note or any continuation
thereof or to record in their internal records all Advances made to Maker
hereunder and all payments made on account of the principal thereof, which
endorsements or recordings shall be prima facie evidence as to the outstanding
principal amount of this Note; provided, however, any failure by the
Administrative Agent, Payee or the holder hereof to make any such endorsement or
recording shall not limit or otherwise affect the obligations of Maker under the
Agreement or this Note.

                                      -2-
<PAGE>
 
     [This Note, together with all the other Revolving Credit Notes issued on
the date hereof are given in renewal, amendment, increase and restatement, but
not extinguishment, of the Revolving Credit Notes issued under the Amended and
Restated Loan Agreement dated as of April 26, 1996 among Maker, NationsBank, the
Administrative Agent, and each of the other Lenders party thereto.]

                                       PRIME MEDICAL SERVICES, INC.



                                       By: /s/ Cheryl Williams
                                          --------------------------------------
                                           Cheryl Williams
                                           Vice President-Finance

                                      -3-
<PAGE>
 
                                   SCHEDULE

================================================================================
      Date           Advance           Principal Payment            Balance
================================================================================

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================================================================================

                                      -i-
<PAGE>

 
                                   TERM NOTE A


$12,500,000.00          Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
NATIONSBANK OF TEXAS, N.A. ("PAYEE"), at the offices of The First
National Bank of Boston, as Administrative Agent (together with any successor as
provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at
100 Federal Street, Boston, Massachusetts, in lawful money of the United States
of America, the principal sum of TWELVE MILLION FIVE HUNDRED THOUSAND AND 00/100
DOLLARS ($12,500,000.00), together with interest on the outstanding principal 
balance from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Term Notes described therein. Capitalized terms
used and not otherwise defined herein shall have the same meanings as set forth
in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid or
payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent
<PAGE>
 
permitted by applicable law, (i) characterize any non-principa l payment as an
expense, fee, or premium rather than as interest, (ii) exclude voluntary
prepayments and the effects thereof, and (iii) amortize, prorate, allocate, and
spread in equal or unequal parts the total amount of interest throughout the
entire contemplated term of the indebtedness evidenced by this Note so that the
interest for the entire term does not exceed the Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

        [This Note, together with all the other Term Notes A issued on the date
hereof, are given in renewal, amendment, and restatement, but not extinguishment
of, the Term Notes issued under the Amended and Restated Loan Agreement dated as
of April 26, 1996 among Maker, NationsBank, the Administrative Agent and each of
the other Lenders party thereto.]

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       ---------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

 
                                   TERM NOTE A


$12,500,000.00          Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
THE FIRST NATIONAL BANK OF BOSTON ("PAYEE"), at the offices of The First
National Bank of Boston, as Administrative Agent (together with any successor as
provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at
100 Federal Street, Boston, Massachusetts, in lawful money of the United States
of America, the principal sum of TWELVE MILLION FIVE HUNDRED THOUSAND AND 00/100
DOLLARS ($12,500,000.00), together with interest on the outstanding principal 
balance from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Term Notes described therein. Capitalized terms
used and not otherwise defined herein shall have the same meanings as set forth
in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid or
payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent
<PAGE>
 
permitted by applicable law, (i) characterize any non-principa l payment as an
expense, fee, or premium rather than as interest, (ii) exclude voluntary
prepayments and the effects thereof, and (iii) amortize, prorate, allocate, and
spread in equal or unequal parts the total amount of interest throughout the
entire contemplated term of the indebtedness evidenced by this Note so that the
interest for the entire term does not exceed the Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

        [This Note, together with all the other Term Notes A issued on the date
hereof, are given in renewal, amendment, and restatement, but not extinguishment
of, the Term Notes issued under the Amended and Restated Loan Agreement dated as
of April 26, 1996 among Maker, NationsBank, the Administrative Agent and each of
the other Lenders party thereto.]

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       ---------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

 
                                   TERM NOTE A


$7,500,000.00          Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
BANK ONE, TEXAS, N.A. ("PAYEE"), at the offices of The First National Bank 
of Boston, as Administrative Agent (together with any successor as
provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at
100 Federal Street, Boston, Massachusetts, in lawful money of the United States
of America, the principal sum of SEVEN MILLION FIVE HUNDRED THOUSAND AND 00/100
DOLLARS ($7,500,000.00), together with interest on the outstanding principal 
balance from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Term Notes described therein. Capitalized terms
used and not otherwise defined herein shall have the same meanings as set forth
in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid or
payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent
<PAGE>
 
permitted by applicable law, (i) characterize any non-principa l payment as an
expense, fee, or premium rather than as interest, (ii) exclude voluntary
prepayments and the effects thereof, and (iii) amortize, prorate, allocate, and
spread in equal or unequal parts the total amount of interest throughout the
entire contemplated term of the indebtedness evidenced by this Note so that the
interest for the entire term does not exceed the Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

        [This Note, together with all the other Term Notes A issued on the date
hereof, are given in renewal, amendment, and restatement, but not extinguishment
of, the Term Notes issued under the Amended and Restated Loan Agreement dated as
of April 26, 1996 among Maker, NationsBank, the Administrative Agent and each of
the other Lenders party thereto.]

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       ---------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

 
                                   TERM NOTE A


$7,500,000.00          Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
IMPERIAL BANK ("PAYEE"), at the offices of The First National Bank 
of Boston, as Administrative Agent (together with any successor as
provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at
100 Federal Street, Boston, Massachusetts, in lawful money of the United States
of America, the principal sum of SEVEN MILLION FIVE HUNDRED THOUSAND AND 00/100
DOLLARS ($7,500,000.00), together with interest on the outstanding principal 
balance from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Term Notes described therein. Capitalized terms
used and not otherwise defined herein shall have the same meanings as set forth
in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid or
payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent
<PAGE>
 
permitted by applicable law, (i) characterize any non-principa l payment as an
expense, fee, or premium rather than as interest, (ii) exclude voluntary
prepayments and the effects thereof, and (iii) amortize, prorate, allocate, and
spread in equal or unequal parts the total amount of interest throughout the
entire contemplated term of the indebtedness evidenced by this Note so that the
interest for the entire term does not exceed the Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

        [This Note, together with all the other Term Notes A issued on the date
hereof, are given in renewal, amendment, and restatement, but not extinguishment
of, the Term Notes issued under the Amended and Restated Loan Agreement dated as
of April 26, 1996 among Maker, NationsBank, the Administrative Agent and each of
the other Lenders party thereto.]

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       ---------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

 
                                   TERM NOTE A


$5,000,000.00          Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of
THE SUMITOMO BANK, LIMITED ("PAYEE"), at the offices of The First National Bank 
of Boston, as Administrative Agent (together with any successor as
provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at
100 Federal Street, Boston, Massachusetts, in lawful money of the United States
of America, the principal sum of FIVE MILLION AND 00/100 DOLLARS
($5,000,000.00), together with interest on the outstanding principal 
balance from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same may be amended, supplemented or modified from time to time, the
"AGREEMENT") and is one of the Term Notes described therein. Capitalized terms
used and not otherwise defined herein shall have the same meanings as set forth
in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid or
payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent
<PAGE>
 
permitted by applicable law, (i) characterize any non-principa l payment as an
expense, fee, or premium rather than as interest, (ii) exclude voluntary
prepayments and the effects thereof, and (iii) amortize, prorate, allocate, and
spread in equal or unequal parts the total amount of interest throughout the
entire contemplated term of the indebtedness evidenced by this Note so that the
interest for the entire term does not exceed the Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

        [This Note, together with all the other Term Notes A issued on the date
hereof, are given in renewal, amendment, and restatement, but not extinguishment
of, the Term Notes issued under the Amended and Restated Loan Agreement dated as
of April 26, 1996 among Maker, NationsBank, the Administrative Agent and each of
the other Lenders party thereto.]

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       ---------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

                              TERM NOTE B


$10,000,000.00             Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of 
NATIONSBANK OF TEXAS, N.A.("PAYEE"), at the offices of The First National Bank 
of Boston, as Administrative Agent (together with any successor as provided in 
the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100 Federal 
Street, Boston, Massachusetts, in lawful money of the United States of America, 
the principal sum of TEN MILLION AND 00/100 DOLLARS ($10,000,000.00), together 
with interest on the outstanding principal balance from day to day remaining, 
as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

                              TERM NOTE B


$5,000,000.00             Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of 
CRESCENT/MACH PARTNERS, L.P.("PAYEE"), at the offices of The First National Bank
of Boston, as Administrative Agent (together with any successor as provided in 
the Agreement, hereinbelow defined, the "ADMINISTRATIVE AGENT") at 100 Federal 
Street, Boston, Massachusetts, in lawful money of the United States of America, 
the principal sum of FIVE MILLION AND 00/100 DOLLARS ($5,000,000.00), together 
with interest on the outstanding principal balance from day to day remaining, 
as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

                              TERM NOTE B


$5,000,000.00             Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of 
MERRILL LYNCH SENIOR FLOATING RATE FUND, INC.("PAYEE"), at the offices of The 
First National Bank of Boston, as Administrative Agent (together with any 
successor as provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE
AGENT") at 100 Federal Street, Boston, Massachusetts, in lawful money of the 
United States of America, the principal sum of FIVE MILLION AND 00/100 DOLLARS 
($5,000,000.00), together with interest on the outstanding principal balance 
from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

                              TERM NOTE B


$5,000,000.00             Boston, Massachusetts               March 31, 1997


        FOR VALUE RECEIVED, the undersigned, PRIME MEDICAL SERVICES, INC., a
Delaware corporation ("MAKER"), hereby promises to pay to the order of 
PILGRIM AMERICA PRIME RATE TRUST ("PAYEE"), at the offices of The 
First National Bank of Boston, as Administrative Agent (together with any 
successor as provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE
AGENT") at 100 Federal Street, Boston, Massachusetts, in lawful money of the 
United States of America, the principal sum of FIVE MILLION AND 00/100 DOLLARS 
($5,000,000.00), together with interest on the outstanding principal balance 
from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

                              TERM NOTE B


$5,000,000.00             Boston, Massachusetts               March 31, 1997


     FOR VALUE  RECEIVED,  the  undersigned,  PRIME  MEDICAL  SERVICES,  INC., a
Delaware corporation  ("MAKER"),  hereby promises to pay to the order of THE ING
CAPITAL SENIOR SECURED HIGH INCOME FUND, L.P.  ("PAYEE"),  at the offices of The
First  National  Bank of Boston,  as  Administrative  Agent  (together  with any
successor as provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE
AGENT") at 100 Federal  Street,  Boston,  Massachusetts,  in lawful money of the
United States of America,  the principal sum of FIVE MILLION AND 00/100  DOLLARS
($5,000,000.00),  together with interest on the  outstanding  principal  balance
from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

                              TERM NOTE B


$5,000,000.00             Boston, Massachusetts               March 31, 1997


     FOR VALUE  RECEIVED,  the  undersigned,  PRIME  MEDICAL  SERVICES,  INC., a
Delaware corporation  ("MAKER"),  hereby promises to pay to the order of THE ING
VAN KAMPEN AMERICAN CAPITAL PRIME RATE INCOME TRUST ("PAYEE"), at the offices of
The First National Bank of Boston,  as  Administrative  Agent (together with any
successor as provided in the Agreement, hereinbelow defined, the "ADMINISTRATIVE
AGENT") at 100 Federal  Street,  Boston,  Massachusetts,  in lawful money of the
United States of America,  the principal sum of FIVE MILLION AND 00/100  DOLLARS
($5,000,000.00),  together with interest on the  outstanding  principal  balance
from day to day remaining, as herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

                              TERM NOTE B


$5,000,000.00             Boston, Massachusetts               March 31, 1997


     FOR VALUE  RECEIVED,  the  undersigned,  PRIME  MEDICAL  SERVICES,  INC., a
Delaware corporation  ("MAKER"),  hereby promises to pay to the order of THE ING
PARIBAS CAPITAL FUNDING LLC ("PAYEE"), at the offices of The First National Bank
of Boston, as  Administrative  Agent (together with any successor as provided in
the Agreement,  hereinbelow defined, the "ADMINISTRATIVE  AGENT") at 100 Federal
Street, Boston, Massachusetts,  in lawful money of the United States of America,
the principal sum of FIVE MILLION AND 00/100 DOLLARS  ($5,000,000.00),  together
with interest on the outstanding principal balance from day to day remaining, as
herein specified.

        This Note has been executed and delivered by Maker pursuant to the terms
of that certain Second Amended and Restated Loan Agreement of even date herewith
among Maker, Payee, the Administrative Agent and each of the other Lenders which
is or may become a party thereto or any successor or assignee thereof (as the
same has been amended through the date hereof and may be further amended,
supplemented or modified from time to time, the "AGREEMENT") and is one of the
Term B Notes described therein. Capitalized terms used and not otherwise defined
herein shall have the same meanings as set forth in the Agreement.

        Reference is hereby made to the Agreement for provisions affecting this
Note, including, without limitation, provisions regarding payments, prepayments
(optional and mandatory), Events of Default and the Administrative Agent's and
Payee's rights as a result of the occurrence thereof.

        The outstanding principal balance hereof shall bear interest prior to
maturity at a varying rate per annum which shall from day to day be equal to the
lesser of (a) the Maximum Rate, or (b) the Applicable Rate in effect from day to
day, each such change in the rate of interest charged hereunder to become
effective, without notice to Maker, on the effective date of each change in the
Applicable Rate or the Maximum Rate, as the case may be; provided, however, if
at any time the Applicable Rate shall exceed the Maximum Rate, thereby causing
the interest rate hereon to be limited to the Maximum Rate, then any subsequent
reduction in the Applicable Rate shall not reduce the rate of interest hereon
below the Maximum Rate until the total amount of interest accrued hereon equals
the amount of interest which would have accrued hereon if the Applicable Rate
had at all times been in effect. The unpaid principal balance of, and all
accrued and unpaid interest on, this Note shall be due and payable on the dates
and at the times set forth in the Agreement. All past-due principal and interest
shall bear interest at the Default Rate.

        Notwithstanding anything to the contrary contained herein, no provisions
of this Note shall require the payment or permit the collection of interest in
excess of the Maximum Rate. If any excess of interest in such respect is herein
provided for, or shall be adjudicated to be so provided, in this Note or
otherwise in connection with this loan transaction, the provisions of this
paragraph shall govern and prevail, and neither Maker nor the sureties,
guarantors, successors or assigns of Maker shall be obligated to pay the excess
amount of such interest, or any other excess sum paid for the use, forbearance
or detention of sums loaned pursuant hereto. If for any reason interest in
excess of the Maximum Rate shall be deemed charged, required or permitted by any
court of competent jurisdiction, any such excess shall be applied as a payment
and reduction of the principal of indebtedness evidenced by this Note; and, if
the principal amount hereof has been paid in full, any remaining excess shall
forthwith be paid to Maker. In determining whether or not the interest paid
<PAGE>
 
or payable exceeds the Maximum Rate, Maker, the Administrative Agent and Payee
shall, to the extent permitted by applicable law, (i) characterize any non-
principal payment as an expense, fee, or premium rather than as interest, (ii)
exclude voluntary prepayments and the effects thereof, and (iii) amortize,
prorate, allocate, and spread in equal or unequal parts the total amount of
interest throughout the entire contemplated term of the indebtedness evidenced
by this Note so that the interest for the entire term does not exceed the
Maximum Rate.

        Upon the occurrence of an Event of Default, the Administrative Agent may
(and if directed by the Required Lenders, shall) declare the entire unpaid
principal of and accrued interest on this Note immediately due and payable
without notice, demand or presentment, all of which are hereby waived, and upon
such declaration, the same shall become and shall be immediately due and
payable, and the Administrative Agent shall have the right to foreclose or
otherwise enforce all Liens or security interests, securing payment hereof, or
any part hereof, and offset against this Note any sum or sums owed by the
Administrative Agent, Payee or the holder hereof to Maker. Failure of the
Administrative Agent, Payee or the holder hereof to exercise this option shall
not constitute a waiver of the right to exercise the same upon the occurrence of
a subsequent Event of Default.

        If the Administrative Agent, Payee or the holder hereof expends any
effort in any attempt to enforce payment of all or any part or installment of
any sum due the holder hereunder, or if this Note is placed in the hands of an
attorney for collection, or if it is collected through any legal proceedings,
Maker agrees to pay all costs, expenses, and fees incurred by the Administrative
Agent, Payee or the holder, including reasonable. attorneys' fees.

        This Note shall be governed by and construed in accordance with the laws
of the Commonwealth of Massachusetts and the applicable laws of the United
States of America.

        Except as provided in the Agreement, Maker and each surety, guarantor,
endorser, and other party ever liable for payment of any sums of money payable
on this Note jointly and severally waive notice, presentment, demand for
payment, protest, notice of protest and non-payment or dishonor, notice of
acceleration, notice of intent to accelerate, notice of intent to demand,
diligence in collecting, grace, and all other formalities of any kind, and
consent to all extensions without notice for any period or periods of time and
partial payments, before or after maturity, and any impairment of any Collateral
securing this Note, all without prejudice to the Administrative Agent, Payee or
the holder. The Administrative Agent, Payee and the holder shall similarly have
the right to deal in any way, at any time, with one or more of the foregoing
parties without notice to any other party, and to grant any such party any
extensions of time for payment of any of said indebtedness, or to release or
substitute part or all of the Collateral securing this Note, or to grant any
other indulgences or forbearances whatsoever, without notice to any other party
and without in any way affecting the personal liability of any party hereunder.

                                    PRIME MEDICAL SERVICES, INC.



                                    By: /s/ Cheryl Williams
                                       -----------------------------------------
                                       Cheryl Williams, Vice President-Finance

                                      -2-
<PAGE>

<PAGE>
 
                             EMPLOYMENT AGREEMENT
                             --------------------


  This EMPLOYMENT AGREEMENT (this "Agreement") is by and between Prime Medical
Operating, Inc., a Delaware corporation ("Employer") and William J. Walsh, an
individual ("Employee") and shall be effective as of April 1, 1997 (the
"Effective Date").

                                   RECITALS:

  WHEREAS, Employee desires to enter into the employment of Employer, and
Employer desires to employ Employee provided that, in so doing, it can protect
its confidential information, business, accounts, patronage and goodwill.

  NOW, THEREFORE, in consideration of the foregoing recital and of the mutual
covenants set forth below, the parties hereto agree as follows:

  1.  Term; Termination.
      ----------------- 

      1.1. Employer hereby hires Employee and Employee accepts such employment
for a two (2) year term commencing on the Effective Date.

      1.2. After expiration of the two (2) year term described in Section 1.1
above, this Agreement shall remain in full force and effect unless and until
either party gives the other at least six (6) months prior written notice of its
determination to terminate this Agreement.
<PAGE>
 
            1.3. This Agreement shall be automatically terminated on the death
of Employee or on the permanent disability of Employee if Employee is no longer
able to perform in all material respects the usual and customary duties of its
employment hereunder. For purposes hereof, any condition which in reasonable
likelihood is expected to impair Employee's ability to materially perform its
duties hereunder for a period of three (3) months or more shall be considered to
be permanent.

            1.4.  Employer may terminate this Agreement for cause if:

            (a) Employee is convicted of an offense constituting a felony or
involving moral turpitude; or

            (b) in any material or substantial way, Employee (i) violates any
rule, regulation, practice or policy of the Employer; (ii) violates any
provision of this Agreement; (iii) is materially dishonest in the performance of
its duties hereunder or engages in a material conflict of interest with the
Employer that is not fully disclosed to and approved by the President of
Employer; (iv) fails to follow reasonable instructions or directions from the
President of Employer, or any other person authorized by the Board of Directors
to give such instructions (for purposes of this Agreement, the President of
Employer and/or such other authorized persons are collectively referred to as
the "President"); or (v) fails to perform the services required pursuant to this
Agreement.
<PAGE>
 
    A notice of termination pursuant to this Section 1.4 shall be in writing and
shall state the alleged reason for termination. Employee, within not less than
fifteen (15) nor more than thirty (30) days after such notice, shall be given
the opportunity to appear before the Board of Directors of the Employer, or a
committee thereof, to rebut or dispute the alleged reason for termination. If
the Board of Directors or committee determines, by a majority of the
disinterested directors, after having given Employee the opportunity to rebut or
dispute the allegations, that such reason is indeed valid, Employer may
immediately terminate Employee's employment under this Agreement for cause.
Immediately upon giving the notice contemplated by this paragraph, Employer may
elect, during the pendency of such inquiry, to relieve Employee of Employee's
regular duties.

      1.5.  Upon termination, Employee shall be entitled to the following:

            (a) If this Agreement and Employee's employment is terminated
pursuant to Section 1.3 as a result of Employee's death or disability, or by
Employee, then Employer shall pay Employee or Employee's representative, as the
case may be, Employee's then-current base salary (excluding any bonuses and non-
cash benefits) through the effective date of termination, and Employer shall
have no further obligations hereunder.

            (b) If Employer terminates this Agreement and Employee's employment
for cause pursuant to Section 1.4, or this Agreement is terminated at the end of
its initial or any
<PAGE>
 
renewal term by either party, Employee shall not be entitled to receive any
additional salary, bonus or benefits beyond those earned or accrued as of the
effective date of the termination.

            (c) If Employer terminates this Agreement and Employee's employment
without cause other than pursuant to the provisions of Section 1.2, then
Employee shall be entitled to continue to receive the base salary that Employee
was receiving immediately prior to such action by Employer, through the end of
the then-current initial or renewal term of this Agreement.

            1.6. Any termination of this Agreement or Employee's employment
shall not release either Employer or Employee from their respective obligations
to the date of termination nor from the provisions of Section 4 hereof.

            2.   Duties of Employee.
                 ------------------ 

            2.1. During the period of employment hereunder, Employee shall
devote substantially its entire time and best efforts to the business of
Employer for the profit, benefit and advantage of Employer, and shall perform
such other services as shall be designated, from time to time, by the President
of Employer; provided, however, that this Section shall not be construed as
preventing Employee from investing its personal assets in business ventures that
do not compete with Employer or Employer's Affiliates (as hereinafter defined)
or are not otherwise prohibited by this Agreement, and spending reasonable
amounts of personal time in the management thereof. Employee shall use its best
efforts to promote the interests of Employer and Employer's Affiliates,
<PAGE>
 
and to preserve their goodwill with respect to their employees, customers,
suppliers and other persons having business relations with Employer. Employee
agrees to accept and hold all such offices and/or directorships with Employer
and Employer's Affiliates as to which Employee may, from time to time, be
elected. For purposes of this Agreement, Employer's subsidiaries, parent
companies and other affiliates are collectively referred to as "Affiliates."

        2.2. Subject to the approvals by and the ultimate supervision of the
President of Employer, Employee during the term hereof shall serve as the Senior
Vice President of a subsidiary of the Employer (the "Operating Subsidiary").
Subject to the control of the President and in compliance with its instructions
and directives, Employee, as the Senior Vice President of a subsidiary of the
Employer, shall have the responsibilities commensurate with such office and as
provided in the Operating Subsidiaries' bylaws and other governing documents.

    3.  Salary; Expense Reimbursements.
        ------------------------------ 

        3.1. As compensation for Employee's service under and during the term of
this Agreement (or until terminated pursuant to the provisions hereof) Employer
shall pay Employee a salary of $12,500 per calendar month (prorated for partial
months), payable in accordance with the regular payroll practices of Employer,
as in effect from time to time. Such salary shall be subject to withholding for
the prescribed federal income tax, social security and other items as required
by law and for other items consistent with Employer's policy with respect to
health insurance and other
<PAGE>
 
benefit plans for similarly situated employees of Employer in which Employee may
elect to participate.

        3.2. During the term of this Agreement, Employee also shall be entitled
to two (2) weeks paid vacation per year and to receive such paid sick leave,
insurance and other fringe benefits as are made available to other personnel of
Employer in comparable positions, with comparable service credit and with
comparable duties and responsibilities. Any benefits in excess of those granted
other salaried employees of Employer shall be subject to the prior approval of
the Board of Directors of Employer.

        3.3. In the discretion of the President of the Employer, and without
implying any obligation on Employer ever to award a bonus to Employee, Employee
may from time to time be awarded a cash bonus or bonuses for services rendered
to the Employer during the term of Employee's employment under this Agreement.
If and to the extent a bonus is ever considered for Employee, it is expected
that any such bonus will be based not only on Employee's individual performance
and Employee's relative position, service tenure and responsibilities with
Employer, but also on the performance and profitability of the entire business
of Employer. During the second full year of this Agreement, Employee and
Employer may agree on a formula to be utilized in determining the amount of any
bonus for Employee. In the event Employer and Employee so agree, both parties
agree to execute an addendum to this Agreement specifying such bonus formula and
the terms and conditions thereof.
<PAGE>
 
        3.4. Employer shall reimburse all reasonable out-of-pocket travel and
business expenses incurred by Employee in connection with the performance of
Employee's duties pursuant to this Agreement. Employer may also reimburse
reasonable out-of-pocket moving costs incurred by Employee in connection with
Employee's move to Austin, Texas, including two trips to Austin, Texas, by
Employee's spouse, provided such reimbursable moving costs shall be mutually
agreed upon by Employer and Employee. Employee shall provide Employer with a
written accounting of Employee's expenses, on a form acceptable to Employer,
together with supporting documentation, which satisfies applicable federal
income tax reporting and record keeping requirements.

        3.5. The parties acknowledge and agree that Employee's employment duties
hereunder are performable in Austin, Texas, subject to business travel
commensurate with Employee's duties hereunder and as otherwise requested by
Employer.

        4. Employee's Restrictive Covenants. In consideration of this Agreement,
           --------------------------------
the employment of Employee hereunder, the salary paid hereunder, and other good
and valuable consideration the receipt and sufficiency of which Employee hereby
acknowledges, Employee acknowledges and agrees that:

        4.1. (a) In Employee's position of employment, Employee will be exposed
to confidential information and trade secrets ("Proprietary Information")
pertaining to, or arising from, the business of Employer and/or Employer's
Affiliates, that such Proprietary Information is unique and valuable and that
Employer and/or Employer's Affiliates would suffer irreparable injury if this
<PAGE>
 
information were divulged to those in competition with Employer or Employer's
Affiliates. Therefore, Employee agrees to keep in strict secrecy and confidence,
both during and after the period of Employee's employment, any and all
information which Employee acquires, or to which Employee has access, during
Employee's employment by Employer, that has not been publicly disclosed by
Employer or Employer's Affiliates or that is not a matter of common knowledge by
their respective competitors. The Proprietary Information covered by this
Agreement shall include, but shall not be limited to, information relating to
any inventions, processes, software, formulae, plans, devices, compilations of
information, technical data, mailing lists, management strategies, business
distribution methods, names of suppliers (of both goods and services) and
customers, names of employees and terms of employment, arrangements entered into
with suppliers and customers, including, but not limited to, proposed expansion
plans of Employer, marketing and other business and pricing strategies, and
trade secrets of Employer and/or Employer's Affiliates.

         (b) Except with prior written approval of Employer, either during or
after Employee's employment hereunder, Employee will neither: (i) directly or
indirectly, disclose any Proprietary Information to any person except authorized
personnel of Employer; nor, (ii) use Proprietary Information in any way. Upon
termination of employment, whether voluntary or involuntary, within forty-eight
(48) hours of termination, Employee will deliver to Employer (without retaining
copies thereof) all documents, records or other memorializations including
copies of documents and any notes which Employee has prepared, that contain
Proprietary Information or relate to Employer's or Employer's Affiliates'
business, all other tangible Proprietary Information in Employee's possession or
control, and all of Employer's and the Affiliates' credit
<PAGE>
 
cards, keys, equipment, vehicles, supplies and other materials that are in
possession or under Employee's control.

        4.2. (a) During the Employee's employment hereunder and for a period of
five (5) years after Employee ceases to be employed by the Employer, the
Employee shall not, directly or indirectly, for Employee's own account or
otherwise (i) solicit business from, divert business from, or attempt to convert
to other methods of using the same or similar products or services as provided
by the Employer or Employer's Affiliates, any client, account or location of the
Employer or Employer's Affiliates with which the Employee has had any contact as
a result of its employment hereunder; or (ii) solicit for employment or employ
any employee or former employee of the Employer or Employer's Affiliates.

             (b) For a period of five (5) years after the termination of the
Employee's employment hereunder (except as provided in the last sentence of this
paragraph), the Employee shall not, directly or indirectly, own, engage in,
manage, operate, join, control, or participate in the ownership, management,
operation, or control of, or be connected as a stockholder, director, officer,
employee, agent, partner, joint venturer, member, beneficiary or otherwise with
any corporation, limited liability company, partnership, sole proprietorship,
association, business, trust, or other organization, entity or individual which
in any way provides physician practice management services within one hundred
(100) miles of any physician practice that is managed by Employer, the Operating
Subsidiary or any other of Employer's Affiliates; provided, however, that (i)
                                                  --------  -------  
Employee may own, directly or indirectly, securities of any entity traded on any
national securities exchange
<PAGE>
 
or listed on the National Association of Securities Dealers Automated Quotation
System if Employee does not, directly or indirectly, own 3% or more of any class
of equity securities, or securities convertible into or exercisable or
exchangeable for 3% or more of any class of equity securities, of such entity,
and (ii) the one hundred (100) mile restriction shall only apply so as to
prohibit Employee with respect to physician practice management businesses that
are providing services to physicians of the same medical practice specialty as
those being serviced by Employer, the Operating Subsidiary or any of Employer's
Affiliates within the one hundred (100) mile restriction area at the time of
Employee's termination.

        4.3. Employee understands and acknowledges damages at law alone will be
an insufficient remedy for Employer and Employer will suffer irreparable injury
if Employee violates the terms of this Agreement. Accordingly, Employer, upon
application to a court of competent jurisdiction, shall be entitled to
injunctive relief to enforce the provisions of this Agreement in the event of
any breach, or threatened breach, of its terms. Employee hereby waives any
requirement that Employer post bond or other security prior to obtaining such
injunctive relief. Injunctive relief may be sought in addition to any other
available rights or remedies at law. Employer shall additionally be entitled to
reasonable attorneys' fees incurred in enforcing the provisions of this
Agreement.

        5.   Miscellaneous.
             -------------
<PAGE>
 
        5.1. This Agreement is performable in Travis County, Texas and is
governed by the laws of Texas. This Agreement supersedes all prior
understandings and agreements between the parties and contains the entire
understanding of the parties hereto with respect to the subject matter hereof;
and is binding upon the parties hereto, their successors and permitted assigns.
Employer may assign its interest in this Agreement and all covenants, conditions
and provisions hereunder shall inure to the benefit of and be enforceable by its
assignee or successor in interest. The rights and obligations of Employee under
this Agreement are personal to Employee, and no such rights, benefits or
obligations shall be subject to voluntary or involuntary alienation, assignment
or transfer.

        5.2. If any provision of this Agreement is held by a court of competent
jurisdiction to be invalid, illegal or unenforceable, that shall, in no way,
affect the validity or enforceability of any other provision of this Agreement
and that provision shall be deemed modified to the minimum extent necessary to
render it valid, legal and enforceable.

        5.3. No waiver by either the Employer or the Employee of a breach of any
provision of this Agreement shall operate as or be construed as a waiver of any
subsequent breach.
<PAGE>
 
EXECUTED by Employer and Employee to be effective for all purposes as of the
Effective Date provided above.


EMPLOYER:                           PRIME MEDICAL OPERATING, INC.


                                    By: /s/ Cheryl Williams
                                       -------------------------------------
                                    Printed Name: Cheryl Williams
                                                 ---------------------------
                                    Title:  Chief Financial Officer
                                           ---------------------------------
EMPLOYEE:

                                     /s/ William J. Walsh
                                    ----------------------------------------   
                                    William J. Walsh

<PAGE>
 
                             EMPLOYMENT AGREEMENT
                             --------------------


     This EMPLOYMENT AGREEMENT (this "Agreement") is by and between AK
Associates, L.L.C., a Texas limited liability company ("Employer") and Robert
Bachman ("Employee") and shall be effective as of October 8, 1997 (the
"Effective Date").

                                   RECITALS:

     WHEREAS, Employee desires to enter into the employment of Employer, and
Employer desires to employ Employee provided that, in so doing, it can protect
its confidential information, business, accounts, patronage and goodwill.

     NOW, THEREFORE, in consideration of the foregoing recital and of the mutual
covenants set forth below, the parties hereto agree as follows:

     1.  Term; Termination.
         ----------------- 

         1.1. Employer hereby hires Employee and Employee accepts such
employment for a two (2) year term commencing on the Effective Date.

         1.2. After expiration of the two (2) year term described in Section 1.1
above, this Agreement shall automatically terminate. However, Employee's
employment may continue thereafter as provided in Section 5.4 hereof.

         1.3. This Agreement shall be automatically terminated on the death of
Employee or on the permanent disability of Employee if Employee is no longer
able to perform in all material respects the usual and customary duties of its
employment hereunder.  For purposes hereof, any condition which in reasonable
likelihood is expected to impair Employee's ability to materially perform its
duties hereunder for a period of three (3) months or more shall be considered to
be permanent.

         1.4. Employer may, upon written notice to Employee, terminate this
Agreement for cause if:

              (a) Employee is convicted of an offense constituting a felony or
involving moral turpitude; or

              (b) Employee (i) violates any rule, regulation, practice or policy
of the Employer; (ii) violates, breaches, or is in default under any provision
of this Agreement or that certain Contribution Agreement dated effective
September 1, 1997 by and among Prime Kidney Stone Treatment, Inc., AK
Associates, Inc. ("AK"), Employee, Lawrence Sodomire and Employer (the
"Contribution Agreement"); (iii) is materially dishonest in the performance of
its duties hereunder or engages in a material conflict of interest with the
Employer that is not fully disclosed to and approved by the President of
Employer; (iv) fails to follow reasonable
<PAGE>
 
instructions or directions from the President of Employer, or any other person
authorized by the Board of Directors to give such instructions (for purposes of
this Agreement, the President of Employer and/or such other authorized persons
are collectively referred to as the "President"); or (v) fails to perform the
services required pursuant to this Agreement. Notwithstanding the foregoing,
prior to any termination by Employer for any of the reasons described in clauses
(i), (iv) or (v), Employee will be given written notice specifying such reason
and ten (10) days opportunity to cure such deficiency or condition. Furthermore,
notwithstanding the foregoing, prior to any termination by Employer for the
reason described in clause (ii), Employee will be given written notice
specifying such reason and thirty (30) days opportunity to cure such deficiency
or condition. However, Employer will not be required to give more than three (3)
notices and opportunities to cure pursuant to either or both of the preceding
two sentences. Employer also agrees to comply with such employee disciplinary
processes as may be provided, from time to time, in the employment manual (the
"Employment Manual") utilized by Prime Medical (as hereinafter defined) and its
subsidiaries with respect to their employees. Employee acknowledges having
received and read a current copy of the Employment Manual prior to entering into
this Agreement. To the extent such Employment Manual provides for a greater or
different notice and opportunity to cure than that provided in this paragraph,
then Employer shall be entitled to comply with such process without also giving
the written notice and opportunity to cure expressly provided for in this
paragraph.

         1.5. Upon termination, Employee shall be entitled to the following:

              (a) If this Agreement and Employee's employment is terminated
pursuant to Section 1.3, or by Employee, then Employer shall pay Employee or
Employee's representative, as the case may be, Employee's then-current base
salary (excluding any bonuses and non-cash benefits) through the effective date
of termination, and the amount of any accrued but unused benefits (but only if
and to the extent payment of such benefits upon termination is required by the
then current Employment Manual), and Employer shall have no further obligations
hereunder.

              (b) If Employer terminates this Agreement and Employee's
employment for cause pursuant to Section 1.4, or this Agreement automatically
terminates at the end of its term, Employee shall not be entitled to receive any
additional salary or benefits (but only as to accrued benefits payable upon
termination as required by the then current Employment Manual) beyond those
earned or accrued as of the effective date of the termination.

              (c) If Employer terminates this Agreement and Employee's
employment without cause prior to the end of the term described in Section 1.1,
then Employee shall be entitled to payment for any accrued and unused benefits
through the date of termination (but only if and to the extent payment of such
benefits upon termination is required by the then current Employment Manual) and
continue to receive the base salary described in Section 3.1 through the end of
the term described in Section 1.1.

         1.6. No termination or expiration of this Agreement or Employee's
employment shall release either Employer or Employee from (i) their respective
obligations

                                       2
<PAGE>
 
hereunder to the date of termination, or (ii) the provisions of Section 4
hereof, or (iii) their respective obligations under the Contribution Agreement.

     2.  Duties of Employee.  During the period of employment hereunder,
         ------------------                                              
Employee shall serve as Vice President of Employer and devote substantially its
entire time and best efforts, on a full-time basis, to the business of Employer
for the profit, benefit and advantage of Employer. The headquarters for the
services to be rendered by Employee hereunder shall be in the Chicago, Illinois,
area unless otherwise consented to by the Employee. Employee, together with the
other Vice President of Employer, and subject to the supervision of the
President of Employer, shall be responsible for the day-to-day management of the
operations of Employer, including sales and marketing efforts and overall shop
supervision, and shall have such other responsibilities as are normally accorded
to the Vice President of a company, consistent with the duties and
responsibilities which Employee had with respect to AK Associates, Inc. prior to
the acquisition of its assets by Employer. Employee shall further perform such
services as shall be designated, from time to time, by the President of
Employer. However, this Section shall not be construed as preventing Employee
from investing its personal assets in business ventures that do not compete with
Employer or are not otherwise prohibited by this Agreement or the Contribution
Agreement, and spending reasonable amounts of personal time in the management
thereof. Employer consents to Employee continuing to own and operate AK and be
an employee of AK, so long as it does not interfere with Employee's full-time
employment hereunder. Employee shall use its best efforts to promote the
interests of Employer, and to preserve Employer's goodwill with respect to
Employer's employees, customers, suppliers and other persons having business
relations with Employer. For purposes of this Agreement, Employer's
subsidiaries, parent companies and other affiliates are collectively referred to
as "Affiliates."

     3.  Salary; Options and Benefits.
         ---------------------------- 

         3.1. As compensation for Employee's service under and during the term
of this Agreement (or until terminated pursuant to the provisions hereof)
Employer shall pay Employee a salary of $150,000 per calendar year, payable in
accordance with the regular payroll practices of Employer, as in effect from
time to time. Such salary shall be subject to withholding for the prescribed
federal income tax, social security and other items as required by law and for
other items consistent with Employer's policy with respect to similarly situated
employees of Employer.

         3.2. During the term of this Agreement, Employee also shall be entitled
to vacation, sick leave, insurance and other fringe benefits as are generally
made available to other similarly situated personnel of Employer.

         3.3. As soon as reasonably practicable after the date of this
Agreement, Employee shall be issued a six-year stock option covering 25,000
shares of Common Stock of Prime Medical Services, Inc., a Delaware corporation
affiliated with Employer ("Prime Medical"), which option shall be granted
pursuant to Prime Medical's employee stock option plan. The per share exercise
price of such option shall be the closing price of the Common Stock of Employer
on the Closing Date (as such term is defined in the Contribution Agreement). One

                                       3
<PAGE>
 
fifth of the shares of Common Stock covered by such option shall vest on each of
the first, second, third, fourth and fifth anniversary, respectively, of the
date of the grant of such option. Employees rights under the option, including
Employee's right to exercise the option as to any shares vested thereunder,
shall terminate in the event Employee breaches or defaults under any of
Employee's obligations hereunder or under the Contribution Agreement (provided
Employee has been given written notice of any such breach or default under the
Contribution Agreement and has failed to cure such breach or default within
thirty (30) days thereafter).

         3.4. Employer shall reimburse all reasonable out-of-pocket travel and
business expenses incurred by Employee in connection with the performance of
Employee's duties pursuant to this Agreement. Employee shall provide Employer
with a written accounting of Employee's expenses, on a form acceptable to
Employer, together with supporting documentation, which satisfies applicable
federal income tax reporting and record keeping requirements.

     4.  Employee's Restrictive Covenants.
         -------------------------------- 

         4.1. In consideration of this Agreement, the employment of Employee
hereunder, the salary paid hereunder, and other good and valuable consideration
the receipt and sufficiency of which Employee hereby acknowledges, Employee
acknowledges and agrees that:

              (a) In Employee's position of employment, Employee will be exposed
to confidential information and trade secrets pertaining to, or arising from,
the business of Employer and/or Employer's affiliates, that such information and
trade secrets are unique and valuable and that Employer and/or Employer's
affiliates would suffer irreparable injury if this information or trade secrets
were divulged to those in competition with Employer or Employer's affiliates.
Therefore, Employee agrees to keep in strict secrecy and confidence, both during
and after the period of Employee's employment, any and all information
concerning Employer and Employer's affiliates which Employee acquires, or to
which Employee has access, during Employee's employment by Employer, that has
not been publicly disclosed by Employer or that is not a matter of common
knowledge by Employer's competitors (collectively, "Proprietary Information").
The Proprietary Information covered by this Agreement shall include, but shall
not be limited to, information relating to any inventions, processes, software,
formulae, plans, devices, compilations of information, technical data, mailing
lists, management strategies, business distribution methods, names of suppliers
(of both goods and services) and customers, names of employees and terms of
employment, arrangements entered into with suppliers and customers, including,
but not limited to, proposed expansion plans of Employer, marketing and other
business and pricing strategies, and trade secrets of Employer and/or Employer's
affiliates.

              (b) Except with prior written approval of Employer, either during
or after Employee's employment hereunder, Employee will neither: (i) directly or
indirectly, disclose any Proprietary Information to any person except authorized
personnel of Employer; nor, (ii) use Proprietary Information in any way. Upon
termination of employment, whether voluntary or involuntary, within forty-eight
(48) hours of termination, Employee will deliver to Employer (without retaining
copies thereof) all documents, records or other memorializations including

                                       4
<PAGE>
 
copies of documents and any notes which Employee has prepared, that contain
Proprietary Information or relate to Employer's or Employer's affiliates'
business, all other tangible Proprietary Information in Employee's possession or
control, and all of Employer's and the affiliates' credit cards, keys,
equipment, vehicles, supplies and other materials that are in possession or
under Employee's control.

     4.2.  Employee understands and acknowledges damages at law alone will be an
insufficient remedy for Employer and Employer will suffer irreparable injury if
Employee violates any of the terms of this Section 4.  Accordingly, Employer,
upon application to a court of competent jurisdiction, shall be entitled to
injunctive relief to enforce the provisions of this Agreement in the event of
any breach, or threatened breach, of its terms.  Employee hereby waives any
requirement that Employer post bond or other security prior to obtaining such
injunctive relief.  Injunctive relief may be sought in addition to any other
available rights or remedies at law.  Employer shall additionally be entitled to
reasonable attorneys' fees incurred in enforcing the provisions of this
Agreement.

     5.  Miscellaneous.
         ------------- 

         5.1. This Agreement is performable in Illinois and is governed by the
laws of Illinois. This Agreement supersedes all prior understandings and
agreements between the parties and contains the entire understanding of the
parties hereto with respect to the subject matter hereof; and is binding upon
the parties hereto, their successors and permitted assigns. Employer may assign
its interest in this Agreement and all covenants, conditions and provisions
hereunder shall inure to the benefit of and be enforceable by its assignee or
successor in interest. The rights and obligations of Employee under this
Agreement are personal to Employee, and no such rights, benefits or obligations
shall be subject to voluntary or involuntary alienation, assignment or transfer.

         5.2. If any provision of this Agreement is held by a court of competent
jurisdiction to be invalid, illegal or unenforceable, that shall, in no way,
affect the validity or enforceability of any other provision of this Agreement
and that provision shall be deemed modified to the minimum extent necessary to
render it valid, legal and enforceable.

         5.3. No waiver by either the Employer or the Employee of a breach of
any provision of this Agreement shall operate as or be construed as a waiver of
any subsequent breach.

         5.4  Upon expiration of the term of this Agreement described in Section
1.1, Employee's employment with Employer (if not previously terminated) shall
not automatically terminate, and Employee shall continue thereafter as an
at-will employee of Employer until Employee's employment is terminated by either
Employee or Employer. However, any employment that continues after the
expiration of the two-year term described in Section 1.1 shall not be governed
by the terms of this Agreement, and thereafter only the post-termination
provisions contained in Section 4 shall continue to apply.

                                       5
<PAGE>
 
                               SIGNATURE PAGE TO
                         BACHMAN EMPLOYMENT AGREEMENT


     EXECUTED by Employer and Employee to be effective for all purposes as of
the Effective Date provided above.

EMPLOYER:                               AK ASSOCIATES, L.L.C.

                                        /s/ Michael S. Madler
                                        ---------------------------------------
                                        Michael S. Madler, President

EMPLOYEE:

                                        /s/ Robert Bachman
                                        --------------------------------------- 
                                        Robert Bachman

                                       6

<PAGE>
 
                             EMPLOYMENT AGREEMENT
                             --------------------


     This EMPLOYMENT AGREEMENT (this "Agreement") is by and between AK
Associates, L.L.C., a Texas limited liability company ("Employer") and Lawrence
Sodomire ("Employee") and shall be effective as of October 8, 1997 (the
"Effective Date").

                                   RECITALS:

     WHEREAS, Employee desires to enter into the employment of Employer, and
Employer desires to employ Employee provided that, in so doing, it can protect
its confidential information, business, accounts, patronage and goodwill.

     NOW, THEREFORE, in consideration of the foregoing recital and of the mutual
covenants set forth below, the parties hereto agree as follows:

     1.  Term; Termination.
         ----------------- 

         1.1. Employer hereby hires Employee and Employee accepts such
employment for a two (2) year term commencing on the Effective Date.

         1.2. After expiration of the two (2) year term described in Section 1.1
above, this Agreement shall automatically terminate. However, Employee's
employment may continue thereafter as provided in Section 5.4 hereof.

         1.3. This Agreement shall be automatically terminated on the death of
Employee or on the permanent disability of Employee if Employee is no longer
able to perform in all material respects the usual and customary duties of its
employment hereunder. For purposes hereof, any condition which in reasonable
likelihood is expected to impair Employee's ability to materially perform its
duties hereunder for a period of three (3) months or more shall be considered to
be permanent.

         1.4. Employer may, upon written notice to Employee, terminate this
Agreement for cause if:

              (a) Employee is convicted of an offense constituting a felony or
involving moral turpitude; or

              (b) Employee (i) violates any rule, regulation, practice or policy
of the Employer; (ii) violates, breaches, or is in default under any provision
of this Agreement or that certain Contribution Agreement dated effective
September 1, 1997 by and among Prime Kidney Stone Treatment, Inc., AK
Associates, Inc. ("AK"), Employee, Robert Bachman and Employer (the
"Contribution Agreement"); (iii) is materially dishonest in the performance of
its duties hereunder or engages in a material conflict of interest with the
Employer that is not fully disclosed to and approved by the President of
Employer; (iv) fails to follow reasonable
<PAGE>
 
instructions or directions from the President of Employer, or any other person
authorized by the Board of Directors to give such instructions (for purposes of
this Agreement, the President of Employer and/or such other authorized persons
are collectively referred to as the "President"); or (v) fails to perform the
services required pursuant to this Agreement. Notwithstanding the foregoing,
prior to any termination by Employer for any of the reasons described in clauses
(i), (iv) or (v), Employee will be given written notice specifying such reason
and ten (10) days opportunity to cure such deficiency or condition. Furthermore,
notwithstanding the foregoing, prior to any termination by Employer for the
reason described in clause (ii), Employee will be given written notice
specifying such reason and thirty (30) days opportunity to cure such deficiency
or condition. However, Employer will not be required to give more than three (3)
notices and opportunities to cure pursuant to either or both of the preceding
two sentences. Employer also agrees to comply with such employee disciplinary
processes as may be provided, from time to time, in the employment manual (the
"Employment Manual") utilized by Prime Medical (as hereinafter defined) and its
subsidiaries with respect to their employees. Employee acknowledges having
received and read a current copy of the Employment Manual prior to entering into
this Agreement. To the extent such Employment Manual provides for a greater or
different notice and opportunity to cure than that provided in this paragraph,
then Employer shall be entitled to comply with such process without also giving
the written notice and opportunity to cure expressly provided for in this
paragraph.

         1.5.  Upon termination, Employee shall be entitled to the following:

              (a) If this Agreement and Employee's employment is terminated
pursuant to Section 1.3, or by Employee, then Employer shall pay Employee or
Employee's representative, as the case may be, Employee's then-current base
salary (excluding any bonuses and non-cash benefits) through the effective date
of termination, and the amount of any accrued but unused benefits (but only if
and to the extent payment of such benefits upon termination is required by the
then current Employment Manual), and Employer shall have no further obligations
hereunder.

              (b) If Employer terminates this Agreement and Employee's
employment for cause pursuant to Section 1.4, or this Agreement automatically
terminates at the end of its term, Employee shall not be entitled to receive any
additional salary or benefits (but only as to accrued benefits payable upon
termination as required by the then current Employment Manual) beyond those
earned or accrued as of the effective date of the termination.

              (c) If Employer terminates this Agreement and Employee's
employment without cause prior to the end of the term described in Section 1.1,
then Employee shall be entitled to payment for any accrued and unused benefits
through the date of termination (but only if and to the extent payment of such
benefits upon termination is required by the then current Employment Manual) and
continue to receive the base salary described in Section 3.1 through the end of
the term described in Section 1.1.

         1.6. No termination or expiration of this Agreement or Employee's
employment shall release either Employer or Employee from (i) their respective
obligations

                                       2
<PAGE>
 
hereunder to the date of termination, or (ii) the provisions of Section 4
hereof, or (iii) their respective obligations under the Contribution Agreement.

     2.  Duties of Employee.   During the period of employment hereunder,
         ------------------                                              
Employee shall serve as Vice President of Employer and devote substantially its
entire time and best efforts, on a full-time basis, to the business of Employer
for the profit, benefit and advantage of Employer. The headquarters for the
services to be rendered by Employee hereunder shall be in the Chicago, Illinois,
area unless otherwise consented to by the Employee. Employee, together with the
other Vice President of Employer, and subject to the supervision of the
President of Employer, shall be responsible for the day-to-day management of the
operations of Employer, including sales and marketing efforts and overall shop
supervision, and shall have such other responsibilities as are normally accorded
to the Vice President of a company, consistent with the duties and
responsibilities which Employee had with respect to AK Associates, Inc. prior to
the acquisition of its assets by Employer. Employee shall further perform such
services as shall be designated, from time to time, by the President of
Employer.  However, this Section shall not be construed as preventing Employee
from investing its personal assets in business ventures that do not compete with
Employer or are not otherwise prohibited by this Agreement or the Contribution
Agreement, and spending reasonable amounts of personal time in the management
thereof. Employer consents to Employee continuing to own and operate AK and be
an employee of AK, so long as it does not interfere with Employee's full-time
employment hereunder. Employee shall use its best efforts to promote the
interests of Employer, and to preserve Employer's goodwill with respect to
Employer's employees, customers, suppliers and other persons having business
relations with Employer. For purposes of this Agreement, Employer's
subsidiaries, parent companies and other affiliates are collectively referred to
as "Affiliates."

     3.  Salary; Options and Benefits.
         ---------------------------- 

         3.1. As compensation for Employee's service under and during the term
of this Agreement (or until terminated pursuant to the provisions hereof)
Employer shall pay Employee a salary of $150,000 per calendar year, payable in
accordance with the regular payroll practices of Employer, as in effect from
time to time. Such salary shall be subject to withholding for the prescribed
federal income tax, social security and other items as required by law and for
other items consistent with Employer's policy with respect to similarly situated
employees of Employer.

         3.2. During the term of this Agreement, Employee also shall be entitled
vacation, sick leave, insurance and other fringe benefits as are generally made
available to other similarly situated personnel of Employer.

         3.3. As soon as reasonably practicable after the effective date of this
Agreement, Employee shall be issued a six-year stock option covering 25,000
shares of Common Stock of Prime Medical Services, Inc., a Delaware corporation
affiliated with Employer ("Prime Medical"), which option shall be granted
pursuant to Prime Medical's employee stock option plan. The per share exercise
price of such option shall be the closing price of the Common Stock of Employer
on the Closing Date (as such term is defined in the Contribution Agreement). One

                                       3
<PAGE>
 
fifth of the shares of Common Stock covered by such option shall vest on each of
the first, second, third, fourth and fifth anniversary, respectively, of the
date of the grant of such option. Employees rights under the option, including
Employee's right to exercise the option as to any shares vested thereunder,
shall terminate in the event Employee breaches or defaults under any of
Employee's obligations hereunder or under the Contribution Agreement (provided
Employee has been given written notice of any such breach or default under the
Contribution Agreement and has failed to cure such breach or default within
thirty (30) days thereafter).

         3.4. Employer shall reimburse all reasonable out-of-pocket travel and
business expenses incurred by Employee in connection with the performance of
Employee's duties pursuant to this Agreement. Employee shall provide Employer
with a written accounting of Employee's expenses, on a form acceptable to
Employer, together with supporting documentation, which satisfies applicable
federal income tax reporting and record keeping requirements.

     4.  Employee's Restrictive Covenants.
         -------------------------------- 

         4.1.  In consideration of this Agreement, the employment of Employee
hereunder, the salary paid hereunder, and other good and valuable consideration
the receipt and sufficiency of which Employee hereby acknowledges, Employee
acknowledges and agrees that:

              (a) In Employee's position of employment, Employee will be exposed
to confidential information and trade secrets pertaining to, or arising from,
the business of Employer and/or Employer's affiliates, that such information and
trade secrets are unique and valuable and that Employer and/or Employer's
affiliates would suffer irreparable injury if this information or trade secrets
were divulged to those in competition with Employer or Employer's affiliates.
Therefore, Employee agrees to keep in strict secrecy and confidence, both during
and after the period of Employee's employment, any and all information
concerning Employer and Employer's affiliates which Employee acquires, or to
which Employee has access, during Employee's employment by Employer, that has
not been publicly disclosed by Employer or that is not a matter of common
knowledge by Employer's competitors (collectively, "Proprietary Information").
The Proprietary Information covered by this Agreement shall include, but shall
not be limited to, information relating to any inventions, processes, software,
formulae, plans, devices, compilations of information, technical data, mailing
lists, management strategies, business distribution methods, names of suppliers
(of both goods and services) and customers, names of employees and terms of
employment, arrangements entered into with suppliers and customers, including,
but not limited to, proposed expansion plans of Employer, marketing and other
business and pricing strategies, and trade secrets of Employer and/or Employer's
affiliates.

              (b) Except with prior written approval of Employer, either during
or after Employee's employment hereunder, Employee will neither: (i) directly or
indirectly, disclose any Proprietary Information to any person except authorized
personnel of Employer; nor, (ii) use Proprietary Information in any way. Upon
termination of employment, whether voluntary or involuntary, within forty-eight
(48) hours of termination, Employee will deliver to Employer (without retaining
copies thereof) all documents, records or other memorializations including

                                       4
<PAGE>
 
copies of documents and any notes which Employee has prepared, that contain
Proprietary Information or relate to Employer's or Employer's affiliates'
business, all other tangible Proprietary Information in Employee's possession or
control, and all of Employer's and the affiliates' credit cards, keys,
equipment, vehicles, supplies and other materials that are in possession or
under Employee's control.

         4.2. Employee understands and acknowledges damages at law alone will be
an insufficient remedy for Employer and Employer will suffer irreparable injury
if Employee violates any of the terms of this Section 4. Accordingly, Employer,
upon application to a court of competent jurisdiction, shall be entitled to
injunctive relief to enforce the provisions of this Agreement in the event of
any breach, or threatened breach, of its terms. Employee hereby waives any
requirement that Employer post bond or other security prior to obtaining such
injunctive relief. Injunctive relief may be sought in addition to any other
available rights or remedies at law. Employer shall additionally be entitled to
reasonable attorneys' fees incurred in enforcing the provisions of this
Agreement.

     5.  Miscellaneous.
         ------------- 

         5.1. This Agreement is performable in Illinois and is governed by the
laws of Illinois. This Agreement supersedes all prior understandings and
agreements between the parties and contains the entire understanding of the
parties hereto with respect to the subject matter hereof; and is binding upon
the parties hereto, their successors and permitted assigns. Employer may assign
its interest in this Agreement and all covenants, conditions and provisions
hereunder shall inure to the benefit of and be enforceable by its assignee or
successor in interest. The rights and obligations of Employee under this
Agreement are personal to Employee, and no such rights, benefits or obligations
shall be subject to voluntary or involuntary alienation, assignment or transfer.

         5.2. If any provision of this Agreement is held by a court of competent
jurisdiction to be invalid, illegal or unenforceable, that shall, in no way,
affect the validity or enforceability of any other provision of this Agreement
and that provision shall be deemed modified to the minimum extent necessary to
render it valid, legal and enforceable.

         5.3. No waiver by either the Employer or the Employee of a breach of
any provision of this Agreement shall operate as or be construed as a waiver of
any subsequent breach.

         5.4 Upon expiration of the term of this Agreement described in Section
1.1, Employee's employment with Employer (if not previously terminated) shall
not automatically terminate, and Employee shall continue thereafter as an at-
will employee of Employer until Employee's employment is terminated by either
Employee or Employer. However, any employment that continues after the
expiration of the two-year term described in Section 1.1 shall not be governed
by the terms of this Agreement, and thereafter only the post-termination
provisions contained in Section 4 shall continue to apply.

                                       5
<PAGE>
 
                               SIGNATURE PAGE TO
                         SODOMIRE EMPLOYMENT AGREEMENT


     EXECUTED by Employer and Employee to be effective for all purposes as of
the Effective Date provided above.

EMPLOYER:                                    AK ASSOCIATES, L.L.C.


                                             /s/ Michael S. Madler
                                             -----------------------------------
                                             Michael S. Madler, President

EMPLOYEE:
                                             Lawrence Sodomire
                                             -----------------------------------
                                             Lawrence Sodomire

                                       6

<PAGE>
 
                    PARTNERSHIP INTEREST PURCHASE AGREEMENT


                                     Among


                         TENN-GA STONE GROUP TWO, L.P.,
                        a Tennessee Limited Partnership,

                                  NGST, INC.,
                            a Tennessee Corporation,

                      PRIME LITHOTRIPTER OPERATIONS, INC.,

                                      And

                           ALL OF THE SHAREHOLDERS OF
                                   NGST, INC.



                              ___________________
                                        

                               Dated  May 1, 1997

                              ___________________

                                        

- --------------------------------------------------------------------------------
<PAGE>
 
                               TABLE OF CONTENTS
 
                                                                        Page
                                                                        ----
 
ARTICLE I Agreement of Purchase and Sale                                  1
1.1     Agreement                                                         1
1.2     Closing                                                           2
1.3     No Assumption of Liabilities                                      2
 
ARTICLE II Representations and Warranties of Prime                        4
2.1     Due Organization and Principal Executive Office                   4
2.2     Due Authorization                                                 4
2.3     Claims and Proceedings                                            5
2.4     Certain Consents                                                  5
2.5     Liens                                                             5
 
ARTICLE III Representations and Warranties to Prime                       6
3.1     Due Organization                                                  6
3.2     Subsidiaries                                                      7
3.3     Due Authorization                                                 7
3.4     Financial Statements                                              8
3.5     Conduct of Business; Certain Actions                              8
3.6     Ownership of Assets:  Licenses, Permits, etc                     10
3.7     Environmental Issues.                                            11
3.8     Intellectual Property Rights                                     12
3.9     Compliance with Laws                                             12
3.10    Insurance                                                        12
3.11    Employee Benefit Matters                                         13
3.12    Contracts and Agreements                                         13
3.13    Claims and Proceedings                                           14
3.14    Taxes                                                            14
3.15    Personnel                                                        15
3.16    Business Relations                                               16
3.17    Accounts Receivable                                              17
3.18    Agents                                                           17
3.19    Indebtedness To and From Partners and Employees                  17
3.20    Commission Sales Contracts                                       17
3.21    Certain Consents                                                 17
3.22    Interest in Competitors, Suppliers, and Customers                17
3.23    Warranties                                                       18
3.24    Partnership Interests                                            18
3.25    NGST Shareholders                                                18
3.26    No Known Breaches by Other Parties                               19
<PAGE>
 
ARTICLE IV Covenants                                                     19
4.1     Inspection                                                       19
4.2     Compliance                                                       19
4.3     Satisfaction of All Conditions Precedent                         20
4.4     No Solicitation                                                  20
4.5     Notice of Developments                                           20
4.6     Notice of Breach                                                 20
4.7     Notice of Litigation by Partnership and NGST                     21
4.8     Notice of Litigation by Prime                                    21
4.9     Continuation of Insurance Coverage                               22
4.10    Maintenance of Credit Terms                                      22
4.11    Updating Information                                             22
4.12    Financial Statements                                             22
4.13    Interim Operations of the Partnership                            23
4.14    Cooperation Relating to Financial Statements                     25
4.15    Necessary Filings                                                25
4.16    Compliance with Laws                                             25

ARTICLE V Conditions to Closing                                          26
5.1     Conditions to Obligations of Prime                               26
5.2     Conditions to Obligations of the Parties Other than Prime        28
 
ARTICLE VI Termination                                                   29
 
ARTICLE VII Indemnification of Prime                                     30
7.1     Indemnification of Prime                                         30
7.2     Defense of Third-Party Claims                                    32
 
ARTICLE VIII Indemnification of the Partnership, NGST and the            
        Shareholders                                                     34
8.1     Indemnification of the Partnership, NGST and the Shareholders    34
8.2     Defense of Third-Party Claims                                    34
 
ARTICLE IX Noncompetition Agreements                                     36
 
ARTICLE X Miscellaneous                                                  40
10.1    Collateral Agreements, Amendments, and Waivers                   40
10.2    Successors and Assigns                                           40
10.3    Expenses                                                         41
10.4    Invalid Provisions                                               41
10.5    Information and Confidentiality                                  41
10.6    Waiver                                                           42
10.7    Notices                                                          42
10.8    Survival of Representations, Warranties, and Covenants           43
<PAGE>
 
10.9    Further Assurances                                               43
10.10   No Third-Party Beneficiaries                                     43
10.11   Construction                                                     43
10.12   Arbitration                                                      44
10.13   Counterparts                                                     44
10.14   Definition of Knowledge                                          45
 

Exhibit A - Form of Amended and Restated Partnership Agreement

Exhibit B - Financial Statements of the Partnership and NGST

Exhibit C - Form of Assignment Agreement

Exhibit D - Form of Noncompetition Agreement
<PAGE>
 
                              SUMMARY OF SCHEDULES
                                       TO
                    PARTNERSHIP INTEREST PURCHASE AGREEMENT


Schedule 3.6 - Liens and Encumbrances

Schedule 3.12 - Contracts, Leases and Other Agreements

Schedule 3.13 - Claims and Proceedings

Schedule 3.15 - Personnel

Schedule 3.21 - Third Party Consents

Schedule 3.22 - Interest in Competitors, Suppliers and Customers

Schedule 3.24 - Partnership Interests

Schedule 3.25 - List of NGST Shareholders and Percentage of Stock Holdings
<PAGE>
 
                    PARTNERSHIP INTEREST PURCHASE AGREEMENT

     This Partnership Interest Purchase Agreement (this "Agreement") is entered
into to be effective as of May 1, 1997 (the "Effective Time"), among Prime
Lithotripter Operations, Inc., a New York corporation ("Prime"), Tenn-Ga Stone
Group Two, L.P., a Tennessee limited partnership (the "Partnership"), NGST,
Inc., a Tennessee corporation ("NGST"), and all of the shareholders of NGST
(each of which is individually referred to herein as a "Shareholder" and all of
which are collectively referred to herein as the "Shareholders")  Thomas C.
Bright, M.D.; Argil J. Wheelock, M.D.; R. Smith Murray, M.D.; Richard S. Lasky,
M.D.; John F. Bryant, M.D.; Marty Scheinberg, M.D.; James E. McKinney, M.D.;
Paul E. Henson, M.D.; Oliver Benton, III, M.D.; Stephen W. Jackson, M.D.; C. A.
Kyle, Jr., M.D.; Nicholas Newton, M.D.; Jack Monnig, M.D.; Samuel M. Currin,
M.D.; J. Patrick Dilworth, M.D.; David Sahaj, M.D.; John Bryan, M.D.; Paula
Willingham and Robert DeBord.

     The parties hereto agree as follows:

                                   ARTICLE I

                         Agreement of Purchase and Sale
                         ------------------------------

     1.1  Agreement.  Upon the basis of the representations and warranties, for
          ---------                                                            
the consideration, and subject to the terms and conditions set forth in this
Agreement, (a) NGST and the Shareholders will cause all of the general partners
of the Partnership (the "Partners"), as of the Effective Time, to execute the
Partnership Agreement (the "Amended Partnership
<PAGE>
 
Agreement"), the form of which is attached hereto as Exhibit A, (b) as of, or
prior to, the Effective Time, NGST and the Shareholders will cause the Partners
to take such action as shall be necessary to convert the Partnership into a
general partnership to be governed by the Amended Partnership Agreement, which
general partnership will include all assets, liabilities, rights and business of
the Partnership, and will have the same capital accounts for the Partners as
existed prior to such conversion; and (c) Prime agrees to purchase, as of the
Effective Time, from NGST, a 38.25% general partnership interest in the
Partnership for a total purchase price of $3,470,000 to be paid in cash or
certified funds at the Closing (as hereinafter defined), and Prime will execute
the Amended Partnership Agreement in the form attached hereto as Exhibit A.
Immediately after such purchase, Prime's beginning capital account shall be
zero. The parties hereto that are also Partners agree that, by execution of this
Agreement, they have given all necessary consents to the transactions
contemplated in this Section 1.1 and that no further or separate consents from
them will be necessary for purposes of complying with the organizational and
governing documents of the Partnership. For purposes of this Agreement, the term
"Partnership" shall be deemed to mean and include both the Partnership
identified above as it exists immediately prior to the execution of this
Agreement, as well as the Partnership as it will be reconstituted immediately
after the transactions contemplated in (a) and (b) of this Section 1.1.

     1.2  Closing.  The closing of the transactions contemplated by Section 1.1
          -------                                                              
(the "Closing") shall, subject to the parties right to terminate pursuant to
ARTICLE VI, take place at such time and place as Prime and NGST may agree.  The
date on which the Closing occurs is hereinafter referred to as the "Closing
Date."
<PAGE>
 
     1.3  No Assumption of Liabilities.  All parties hereto acknowledge and
          ----------------------------                                     
agree that neither Prime nor any affiliate of Prime shall, by virtue of entering
into and performing this Agreement or by virtue of the consummation of the
transactions contemplated hereby, assume any liabilities or obligations of any
kind whatsoever from any Partners, NGST, or any of the Shareholders.
Furthermore, neither Prime nor any affiliate of Prime shall, by virtue of
entering into and performing this Agreement or by virtue of the consummation of
the transactions contemplated hereby, assume any liabilities or obligations of
any kind whatsoever from, or relating to, the Partnership to the extent such
liabilities or obligations are existing on the Closing Date, or arise out of
events or omissions occurring prior to the Closing Date. Without limiting the
generality of the foregoing, the parties hereto expressly acknowledge and agree
that Prime is not assuming any debts, liabilities, or obligations of the
Partnership, any Partners, NGST or any of the Shareholders, or any claims
against the Partnership, any Partners, NGST or any of the Shareholders, whether
known or unknown, or absolute, contingent or otherwise (including, but not
limited to, federal, state, and local taxes, any sales taxes, any taxes arising
from the transactions contemplated by this Agreement and any liabilities arising
from any civil, criminal or regulatory litigation or action involving or related
to the Partnership, any Partners, NGST or any of the Shareholders or their
businesses), and the Partnership, NGST and the Shareholders each hereby agree
(severally and not jointly) to indemnify Prime and hold Prime harmless from and
against any such debts, liabilities and obligations; provided, however, that
with regard to the Partnership only, the foregoing shall not be construed to
preclude Prime's liability, in its role as a general partner of the Partnership
after the Closing with respect to claims, debts, liabilities or obligations that
arise wholly out of actions, events or omissions occurring after the Closing
Date.
<PAGE>
 
                                   ARTICLE II

                    Representations and Warranties of Prime
                    ---------------------------------------

     Prime represents and warrants to the other parties hereto as follows (with
the understanding that the other parties hereto are relying materially on such
representations and warranties in entering into and performing this Agreement):

     2.1  Due Organization and Principal Executive Office.  Prime is a
          -----------------------------------------------             
corporation duly organized, validly existing, and in good standing under the
laws of the State of New York and has full corporate power and authority to
carry on its business as now conducted and to enter into and perform this
Agreement and each other agreement, instrument and document required to be
executed by Prime in connection herewith.  Prime's principal executive offices
are located at 1301 Capital of Texas Highway, Austin, Texas 78746.

     2.2  Due Authorization.  This Agreement and each other agreement,
          -----------------                                           
instrument, and document required to be executed by Prime have been duly and
validly authorized, executed and delivered by Prime and constitute the valid and
binding obligations of Prime enforceable against it in accordance with its
terms.  The execution, delivery, and performance of this Agreement and each
other agreement, instrument, and document required to be executed by Prime will
not (a) to the best knowledge of Prime, violate any federal, state, county, or
local law, rule, or regulation applicable to Prime or its properties, (b)
violate or conflict with, or permit the cancellation of, any agreement to which
Prime is a party or by which it or its properties are bound, (c) permit the
acceleration of the maturity of any indebtedness of, or any indebtedness secured
by the property of, Prime or (d) violate or conflict with any provision of the
certificate of incorporation or bylaws
<PAGE>
 
of Prime. No action, consent, or approval of, or filing with, any federal,
state, county, or local governmental authority is required by Prime in
connection with the execution, delivery or performance of this Agreement (or any
agreement, instrument or other document executed in connection herewith by
Prime).

     2.3  Claims and Proceedings.  Prime is not a party to any claims, actions,
          ----------------------                                               
suits, proceedings, or investigations affecting it, or any of its properties or
assets, at law or in equity, before or by any court, municipal or other
governmental department, commission, board, agency, or instrumentality which
seeks to restrain or prohibit the carrying out of the transactions contemplated
by this Agreement or to challenge the validity of such transactions or any part
thereof or seeking damages on account thereof; and, to the knowledge of Prime,
no such claim, action, suit, proceeding or investigation is threatened.

     2.4  Certain Consents.  There are no consents, waivers or approvals
          ----------------                                              
required to be executed and/or obtained by Prime from third parties in
connection with the execution, delivery and performance of this Agreement, which
have not been so executed and/or obtained.

     2.5  Liens.  It is acknowledged that Prime's partnership interest in the
          -----                                                              
Partnership shall be subject to a lien that arises as a result of Prime's credit
facility with the Bank of Boston and NationsBank. By execution hereof, all
parties hereto grant, and agree to cause any Partners who are not parties hereto
to grant, all consents necessary with respect to the creation, continuance and
enforcement of such lien; provided such consents shall not be deemed to allow
the lienholder to become a substitute partner in the Partnership and such
lienholder, upon enforcement of such lien, shall only be entitled to the
financial rights of Prime as a partner, and not as to rights with respect to
governance matters.
<PAGE>
 
                                  ARTICLE III

                    Representations and Warranties to Prime
                    ---------------------------------------

     Each of the parties hereto, other than Prime, hereby (severally, and not
jointly) represents and warrants to Prime as follows (with the understanding
that Prime is relying materially on each such representation and warranty in
entering into and performing this Agreement). If a particular representation and
warranty is expressly stated below to be made, in whole or in part, about the
"Shareholders," each Shareholder will be deemed to be making that representation
and warranty only about themselves, except with regard to Section 3.26.
Representations and warranties expressly about the "Partnership" will be deemed
to be made by the Partnership, NGST and such of the Shareholders who are also
Partners. Representations and warranties expressly about "NGST" will be deemed
to be made by NGST and each of the Shareholders. Otherwise, all parties hereto,
other than Prime, severally (and not jointly) are making each of the
representations and warranties in this ARTICLE III as to all matters stated
therein (including without limitation Section 3.26).

     3.1  Due Organization.  The Partnership, prior to the Closing, was a
          ----------------                                               
limited partnership, and immediately prior to and after the Closing (as of the
Effective Time) will be a general partnership, duly organized, validly existing,
and in good standing under the laws of the State of Tennessee and has full power
and authority to carry on its business as now conducted and as proposed to be
conducted.  Complete and correct copies of the limited partnership agreement and
all amendments thereto have been delivered to Prime.  NGST is a corporation duly
organized, validly existing, and in good standing under the laws of the State of
Tennessee
<PAGE>
 
and has full power and authority to carry on its businesses as now conducted and
as proposed to be conducted. Complete and correct copies of the Articles of
Incorporation, Charter and Bylaws of NGST and all amendments thereto, have been
delivered to Prime. Each of the Partnership and NGST is qualified to do business
and is in good standing in every jurisdiction where such qualification is
required for the business and transactions contemplated by this Agreement.

     3.2  Subsidiaries.  The Partnership does not directly or indirectly have
          ------------                                                       
(or possess any options or other rights to acquire) any subsidiaries or any
direct or indirect ownership interests in any person, business, corporation,
partnership, association, joint venture, trust, or other entity.

     3.3  Due Authorization.  The Partnership, NGST and each of the Shareholders
          -----------------                                                     
has full power and authority to enter into and perform this Agreement and each
other agreement, instrument, and document required to be executed by it in
connection herewith.  The execution, delivery, and performance of this Agreement
and such other agreements, instruments, and documents have been, or prior to
Closing will be, duly authorized by the Partners of the Partnership and the
Shareholders and directors of NGST.  This Agreement has been duly and validly
executed and delivered by the Partnership, NGST and each of the Shareholders and
constitutes a valid and binding obligation of the Partnership, NGST and each of
the Shareholders enforceable against them in accordance with its terms.  The
execution, delivery, and performance of this Agreement by the Partnership, NGST
and each of the Shareholders shall not (a) to the best knowledge of the
Partnership, NGST and each of the Shareholders, violate any federal, state,
county, or local law, rule, or regulation applicable to the Partnership, NGST or
any of the Shareholders, or their properties, (b) violate or conflict with, or
permit the cancellation of, any agreement to which the Partnership or NGST is a
party, or by which they or any of their
<PAGE>
 
properties are bound, or result in the creation of any lien, security interest,
charge, or encumbrance upon any of such properties, (c) permit the acceleration
of the maturity of any indebtedness of, or indebtedness secured by the property
of, the Partnership or NGST , or (d) violate or conflict with any provision of
the limited partnership agreement of the Partnership or the Articles of
Incorporation, Charter or Bylaws of NGST. No action, consent, or approval of, or
filing with, any governmental authority is required by the Partnership, NGST or
any of the Shareholders in connection with the execution, delivery, or
performance of this Agreement (or any agreement or other document executed by
the Partnership, NGST or any of the Shareholders in connection herewith).

     3.4  Financial Statements.  The unaudited balance sheet and income
          --------------------                                         
statement of each of the Partnership and NGST as of and for the years ended
December 31, 1995 and 1996 and the unaudited balance sheet and income statement
of the Partnership as of and for the three (3) months ended March 31, 1997
(collectively, the "Financial Statements") are attached hereto as Exhibit B.
The Financial Statements have been prepared on a consistent basis throughout the
periods indicated and fairly present the financial position and results of
operations of the Partnership and NGST as of the indicated dates and for the
indicated periods.  Except to the extent reflected or provided for in the
Financial Statements (including the notes thereto), neither the Partnership nor
NGST has had any liabilities of a type that would be required to be reflected as
such in the Financial Statements (including the notes thereto) other than
current liabilities on open account incurred in the ordinary course of business
of NGST and the Partnership subsequent to December 31, 1996 and March 31, 1997,
respectively.  Since March 31, 1997 (with respect to the Partnership) and
December 31, 1996 (with respect to NGST), there has been
<PAGE>
 
no material adverse change in the financial position, assets, results of
operations, or business of the Partnership or NGST.

     3.5  Conduct of Business; Certain Actions.  Since March 31, 1997, the
          ------------------------------------                            
Partnership has conducted its business and operations in the ordinary course and
consistent with its past practices and has not (a) purchased or retired any
indebtedness or partnership interest from any of its partners, (b) increased the
compensation of any of its partners, or employees, (c) incurred any indebtedness
exceeding $10,000 in the aggregate (other than open accounts payable arising in
the ordinary course of business), (d) sold any asset (or any group of related
assets) in any transaction (or series of related transactions) in which the
purchase price for such asset (or group of related assets) exceeded $10,000
(other than sales of inventory in the ordinary course of business), (e) made or
guaranteed any loans or advances whatsoever, (f) suffered or permitted any lien,
security interest, claim, charge, or other encumbrance to arise or be granted or
created against or upon any of the assets of the Partnership, real or personal,
tangible or intangible, (g) canceled, waived, or released any of the
Partnership's debts, rights, or claims against third parties, (h) had any
amendments to its partnership agreement, (i) made or paid any severance or
termination payment to any employee or consultant in excess of $10,000, (j) made
any change in the method of accounting of the Partnership, (k) made any
investment or commitment therefor in any person, business, corporation,
association, partnership, joint venture, trust, or other entity, (l) made,
entered into, amended, or terminated any written employment contract, or
created, made, amended, or terminated any bonus, stock option, pension,
retirement, profit sharing, or other employee benefit plan or arrangement, or
withdrawn from any "multi-employer plan" (as defined in Section 414(f) of the
Internal Revenue Code of 1986, as amended (the "Code")) so as to create
<PAGE>
 
any liability under ERISA (as hereinafter defined) to any entity, (m) amended,
terminated or experienced a termination of any material contract, agreement,
lease, franchise, or license to which the Partnership is a party, (n) entered
into any other material transactions except in the ordinary course of business,
(o) entered into any contract, commitment, agreement, or understanding to do any
acts described in the foregoing clauses (a)-(n) of this Section, or (p) suffered
any material damage, destruction, or loss (whether or not covered by insurance)
to any assets.

     3.6  Ownership of Assets:  Licenses, Permits, etc.  NGST has good and
          --------------------------------------------                    
marketable title to the partnership interest being purchased by Prime pursuant
hereto, subject to no liens or encumbrances whatsoever, and at the Closing,
Prime will be acquiring a 38.25% general partnership interest in the Partnership
subject to no liens, claims or encumbrances whatsoever, other than  the lien
described in Section 2.5 hereof. The Partnership has good and marketable title
to all of its assets subject only to the liens and encumbrances described on
Schedule 3.6.  The Partnership has such property and assets, real, personal and
- ------------                                                                   
mixed, tangible and intangible, including leases, which are required for, or
used in connection with, the operation of the Partnership as currently
conducted.  Except as set forth on Schedule 3.6 attached hereto, the real and
                                   ------------                              
personal properties of the Partnership are free and clear of all liens, security
interests, claims, rights of another, and encumbrances of any kind whatsoever.
To the best knowledge of the Partnership, NGST and each of the Shareholders, the
Partnership is in compliance with the terms and conditions of all federal,
state, county, and local governmental licenses, certificates, certificates of
need and permits, the violation of which would materially and adversely affect
the business and properties of the Partnership. To the best knowledge of the
Partnership, NGST and
<PAGE>
 
each of the Shareholders, no additional license, certificate, certificate of
need or permit is required from any federal, state, county, or local
governmental agency or body thereof in connection with the conduct of the
business of the Partnership which, if not obtained, would materially and
adversely affect the business or properties of the Partnership. The Partnership
has not received any written notice of any claim by any governmental authority
(and, to the knowledge of the Partnership, no such claim has been threatened) to
the effect that a license, permit, certificate, certificate of need or order not
possessed by the Partnership is necessary with respect to the business conducted
by the Partnership.

     3.7  Environmental Issues.
          -------------------- 
     (a) For purposes of this Agreement, the term "environmental laws" shall
mean all laws of any applicable jurisdiction as in effect as of the Effective
Date and/or the Closing Date relating to the manufacture, processing,
distribution, use, treatment, storage, disposal, transport, or handling, or the
emission, discharge, or release, of any pollutant, contaminant, chemical, or
industrial toxic or hazardous substance or waste and any order related thereto.

     (b) To the best knowledge of the Partnership, NGST and each of the
Shareholders, the Partnership has complied in all material respects with and
obtained all authorizations and made all filings required by all applicable
environmental laws. To the best knowledge of the Partnership, NGST and each of
the Shareholders, the properties occupied or used by the Partnership have not
been contaminated with any hazardous wastes, hazardous substances, or other
hazardous or toxic materials in violation of any applicable environmental law.

     (c) The Partnership has not received any written notice from the United
States Environmental Protection Agency that it is a potentially responsible
party under the
<PAGE>
 
Comprehensive Environmental Response, Compensation and Liability Act ("Superfund
Notice"), any citation from any federal, state or local governmental authority
for non-compliance with its requirements with respect to air, water or
environmental pollution, or the improper storage, use or discharge of any
hazardous waste, other waste or other substance or other material pertaining to
its business ("Citations") or any written notice from any private party alleging
any such non-compliance; and there are no pending or unresolved Superfund
Notices, Citations or written notices from private parties alleging any such
non-compliance.

     3.8  Intellectual Property Rights.  There are no patents, trademarks, trade
          ----------------------------                                          
names, or copyrights, and no applications therefor, registered in the name of
the Partnership. The Partnership is not a party to any license agreements,
either as licensor or licensee, with respect to any patents, trademarks, trade
names, or copyrights.  The Partnership has not received any written notice that
it is infringing any patent, trademark, trade name, or copyright of others.

     3.9  Compliance with Laws. To the best knowledge of the Partnership, NGST
          --------------------                                                
and each of the Shareholders, the Partnership has complied in all material
respects, and the Partnership is in compliance in all material respects, with
all federal, state, county, and local laws and regulations currently in effect
and applicable to its business, the violation of which would have a material
adverse impact on the assets, business or financial condition of the
Partnership. No claim has been made by any governmental authority (and, to the
knowledge of the Partnership, no such claim has been threatened) against the
Partnership to the effect that the business conducted by the Partnership fails
to comply, in any material respect, with any law, rule, regulation, or
ordinance.
<PAGE>
 
     3.10  Insurance.  Prime has been provided with access to copies of all
           ---------                                                       
policies of fire, liability, business interruption, and other forms of insurance
and all fidelity bonds held by or applicable to the Partnership. To the best
knowledge of the Partnership, NGST and each of the Shareholders, no event
directly relating to the Partnership has occurred which will result in a
retroactive upward adjustment of premiums under any such policies.  There has
been no material change in the type of insurance coverage maintained by the
Partnership during the period since the formation of the Partnership which has
resulted in any period during which the Partnership had no insurance coverage.
Excluding insurance policies which have expired and been replaced, no insurance
policy of the Partnership has been canceled within the last three years and, to
the knowledge of the Partnership, no threat has been made to cancel any
insurance policy of the Partnership within such period.

     3.11  Employee Benefit Matters.  Except for the maintenance of major
           ------------------------                                      
medical and disability insurance, the Partnership does not maintain nor does it
contribute nor is it required to contribute to any "employee welfare benefit
plan" (as defined in section 3(1) of the Employee Retirement Income Security Act
of 1974 (and any sections of the Code amended by it) and all regulations
promulgated thereunder, as the same have from time to time been amended
("ERISA")) or any "employee pension benefit plan" (as defined in section 3(2) of
ERISA and not exempted under section 4(b) or 201 of ERISA).  The Partnership
does not presently maintain and has never maintained, or had any obligation of
any nature to contribute to, a "defined benefit plan" within the meaning of
Section 414(j) of the Code, without regard to whether such defined benefit plan
met the requirements of section 401(a) of the Code.
<PAGE>
 
     3.12  Contracts and Agreements.  Attached hereto as Schedule 3.12 is a list
           ------------------------                      -------------          
of all written or oral contracts, commitments, leases, and other agreements
(including, without limitation, promissory notes, loan agreements, and other
evidences of indebtedness) to which the Partnership is a party or by which the
Partnership or its properties are bound, pursuant to which the obligations
thereunder of either party thereto are, or are contemplated as being, in respect
of any such individual contracts, commitments, leases, or other agreements
during any year during the term thereof, $5,000 or greater, or which are
otherwise material to the business of the Partnership; including, without
limitation, all mortgages, deeds of trust, security agreements, pledge
agreements, lithotripsy service agreements, and similar agreements and
instruments and all confidentiality agreements (collectively, the "Contracts").
The Partnership is not and, to the best knowledge of the Partnership, NGST and
each of the Shareholders no other party thereto, is in default (and no event has
occurred which, with the passage of time or the giving of notice, or both, would
constitute a default by the Partnership or, to the best knowledge of the
Partnership, by any other party thereto) under any of the Contracts, and the
Partnership has not waived any material right under any of the Contracts, which
default or waiver would have a material adverse impact on the assets, business
or financial condition of the Partnership.  Except as set forth on Schedule 3.12
                                                                   -------------
attached hereto, the Partnership has not guaranteed any obligations of any other
person or entity.

     3.13  Claims and Proceedings.  Except as set forth on Schedule 3.13, there
           ----------------------                          -------------       
are no claims, actions, suits, proceedings, or investigations pending or, to the
knowledge of the Partnership, NGST and each of the Shareholders, threatened
against the Partnership or affecting any of its properties or assets, at law or
in equity, or before or by any court, municipal or other
<PAGE>
 
governmental department, commission, board, agency, or instrumentality which, if
decided adversely to the Partnership, would have a material adverse impact on
the assets, or the business or financial condition of the Partnership. No
inquiry, action, or proceeding has been asserted, instituted, or, to the best
knowledge of the Partnership, NGST and each of the Shareholders, threatened
against the Partnership to restrain or prohibit the carrying out of the
transactions contemplated by this Agreement or to challenge the validity of such
transactions or any part thereof or seeking damages on account thereof.

     3.14  Taxes.  All federal, foreign, state, county, and local income, gross
           -----                                                               
receipts, excise, property, franchise, license, sales, use, withholding, and
other tax (collectively, "Taxes") returns, reports, and declarations of
estimated tax (collectively, "Returns") which were required to be filed by the
Partnership on or before the date hereof have been filed within the time
(including any applicable extensions) and in the manner provided by law, and all
such Returns are true and correct in all material respects and accurately
reflect the Tax liabilities of the Partnership.  All Taxes, assessments,
penalties, and interest which have become due pursuant to such Returns have been
paid or adequately accrued in the Financial Statements.  The provisions for
Taxes reflected on the balance sheet contained in the Financial Statements are
adequate to cover all of the Partnership's estimated Tax liabilities for the
respective periods then ended and all prior periods.  As of the Closing, no
Taxes for any period prior to the Closing will be due and payable by the
Partnership.  The Partnership has not executed any presently effective waiver or
extension of any statute of limitations against assessments and collection of
Taxes.  There are no pending or, to the best knowledge of the Partnership, NGST
and each of the Shareholders, threatened claims, assessments, notices, proposals
to assess, deficiencies, or audits (collectively, "Tax
<PAGE>
 
Actions") against the Partnership with respect to any Taxes owed or allegedly
owed by the Partnership. The Partnership's federal income tax returns have not
been audited. There are no tax liens on any of the assets of the Partnership.
Proper and accurate amounts have been withheld and remitted by the Partnership
from and in respect of all persons from whom it is required by applicable law to
withhold for all periods in compliance with the tax withholding provisions of
all applicable laws and regulations. The Partnership is not a party to any tax
sharing agreement with any partner or any other person. The Partnership utilizes
the cash method of accounting for federal income tax purposes. The entering into
and performance of this Agreement, and the consummation of the transactions
contemplated hereby, will not constitute or cause a termination or liquidation
of the Partnership for tax purposes.

     3.15  Personnel.  Schedule 3.15 lists the names and annual rates of
           ---------   -------------                                    
compensation of the employees of the Partnership whose rates of compensation, on
an annualized basis, during the fiscal year ended December 31, 1996 (including
base salary, bonus, commissions, and incentive pay) exceeded $20,000.  Prime has
been provided with access to information regarding the bonus, profit sharing,
percentage compensation, company automobile, club membership, and other like
benefits, if any, paid or payable by the Partnership to such employees from
December 31, 1996 through the date hereof.  Prime has been provided with access
to employment agreements and confidentiality agreements to which the Partnership
is a party and all severance benefits which any director, officer, employee, or
sales representative of the Partnership is or may be entitled to receive.  The
Partnership has delivered to Prime accurate and complete copies of all such
employment agreements, confidentiality agreements, and all other
<PAGE>
 
agreements, plans, and other instruments to which the Partnership is a party and
under which its employees are entitled to receive benefits of any nature. None
of the employees of the Partnership are represented by any labor union or
organization. There is no unfair labor practice claim against the Partnership
before the National Labor Relations Board or any strike, labor dispute, work
slowdown, or work stoppage pending or, to the best knowledge of the Partnership,
NGST and the Shareholders, threatened against or involving the Partnership.

     3.16  Business Relations.  The Partnership, NGST and the Shareholders have
           ------------------                                                  
no knowledge that any supplier or customer of the Partnership will cease or
refuse to do business with the Partnership as a result of or soon after the
consummation of the transactions contemplated hereby in the same manner as
previously conducted with the Partnership.  The Partnership has not received any
notice of any disruption (including delayed deliveries or allocations by
suppliers) in the availability of the materials or products used by the
Partnership.

     3.17  Accounts Receivable.  To the best knowledge of the Partnership, NGST
           -------------------                                                 
and the Shareholders, all of the accounts, notes, and loans receivable that have
been recorded on the books of the Partnership are bona fide and represent
amounts validly due.

     3.18  Agents.  Except for the Partners of the Partnership and Mr. Tom
           ------                                                         
Johnson, the Partnership has not designated or appointed any person or other
entity to act for it or on its behalf pursuant to any power of attorney or any
agency which is presently in effect. Prior to the Closing, the Partnership will
have terminated Tom Johnson's authority to act for it or on its behalf.

     3.19  Indebtedness To and From Partners and Employees.  The Partnership
           -----------------------------------------------                  
does not owe any indebtedness to any of its partners or employees or, have
indebtedness owed to it from any of its partners or employees, excluding
indebtedness for travel advances or similar advances
<PAGE>
 
for expenses incurred on behalf of and in the ordinary course of business of the
Partnership and consistent with the Partnership's past practices.

     3.20  Commission Sales Contracts.  The Partnership does not employ or have
           --------------------------                                          
any relationship with any individual, corporation, partnership, or other entity
whose compensation from the Partnership is in whole or in part determined on a
commission basis.

     3.21  Certain Consents.  Except for the consent of Charles Hawkins, M.D.
           ----------------                                                  
("Hawkins"), and except as set forth on Schedule 3.21 attached hereto, there are
                                        -------------                           
no consents, waivers, or approvals required to be executed and/or obtained by
the Partnership from third parties in connection with the execution, delivery
and performance of this Agreement.

     3.22  Interest in Competitors, Suppliers, and Customers.  Except as set
           -------------------------------------------------                
forth in Schedule 3.22, no Partner or employee of the Partnership or any
         -------------                                                  
affiliate of any partner or employee has any ownership interest in any
competitor, customer or supplier of the Partnership or any property used in the
operation of the business of the Partnership.

     3.23  Warranties.  Except as set forth in those contracts and agreements
           ----------                                                        
described on Schedule 3.12, there are no warranties or guarantees made by the
             -------------                                                   
Partnership to third parties with respect to any products sold or services
rendered by it.  No claims for breach of product or service warranties have been
made against the Partnership since January 1, 1995.

     3.24  Partnership Interests.  Schedule 3.24 contains a complete listing of
           ---------------------   -------------                               
the name and address of each general and limited partner of the Partnership,
including their ownership percentages in the Partnership, both as such will be
in effect immediately before and immediately after the Closing. There are no
outstanding rights for any party hereto or any third party, to acquire any
interest of any kind in the ownership, cash flow, or profits of the Partnership.
<PAGE>
 
Hawkins, is the only Partner who is not a party to this Agreement. Hawkins owns
a 2.7% general partnership interest in the Partnership, has been retired from
the practice of medicine for approximately two (2) years as of the Effective
Time, has not referred any patients or other customers to the Partnership for
lithotripsy services or other services provided by the Partnership in the two
(2) year period ending on the Closing Date, and has given, or prior to Closing
will give, all consents and approvals necessary to consummate the transactions
contemplated hereby.

     3.25  NGST Shareholders.  Schedule 3.25 contains a complete listing of the
           -----------------   -------------                                   
name, address and NGST stock holdings (by number of shares and percentage of
total) of each shareholder of NGST, both as such will be in effect immediately
before and immediately after the Closing. There are no outstanding rights,
options or warrants for any person or entity that is not a party hereto to
acquire any stock or other ownership interest in NGST.

     3.26  No Known Breaches by Other Parties.  The Shareholders, NGST and the
           ----------------------------------                                 
Partnership each severally, and not jointly, represent and warrant to Prime that
they have no knowledge of any breach or default of any representation, warranty,
covenant or other agreement contained in this Agreement, by any of the other
parties hereto.

                                   ARTICLE IV

                                   Covenants
                                   ---------

     4.1  Inspection.  From the date hereof to the Closing, the Partnership
          ----------                                                       
shall give Prime and its officers, attorneys, accountants, and representatives
free, full, and complete access during reasonable business hours to all books,
records, tax returns, files, correspondence, personnel, facilities, and
properties of the Partnership and provide Prime and its officers, attorneys,
<PAGE>
 
accountants, and representatives all information and material pertaining to the
business and affairs of the Partnership as Prime may deem necessary or
appropriate.  Any investigation by Prime or its officers, attorneys,
accountants, or representatives shall not in any manner affect the
representations and warranties contained herein, unless an officer of Prime has
actual knowledge of the untruth or inaccuracy of any such representation and
warranty.  Any investigation by the Partnership or its attorneys, accountants,
or representatives shall not in any manner affect the representations and
warranties of Prime contained herein, unless the Partnership has knowledge of
the untruth or inaccuracy of any representation of Prime.

     4.2  Compliance.  From the date hereof to the Closing, none of the parties
          ----------                                                           
hereto shall take or fail to take any action which action or failure to take
such action shall cause the respective representations and warranties made by
such parties herein to be untrue or incorrect as of the Closing.

     4.3  Satisfaction of All Conditions Precedent.  From the date hereof to the
          ----------------------------------------                              
Closing, each party shall use its best efforts to cause all conditions precedent
to the obligations of the other parties hereunder to be satisfied by the
Closing.

     4.4  No Solicitation.  From the date hereof to the Closing, the Partners
          ---------------                                                    
and the Partnership shall not offer any interest in the Partnership or any
material part of its assets in one transaction or a series of transactions for
sale, or solicit offers to buy any interest in the Partnership or any material
part of its assets in one transaction or in a series of related transactions, or
hold discussions with any party (other than Prime) looking toward such an offer
or solicitation or toward a merger or consolidation of the Partnership with or
into another entity or any similar transaction.  From the date hereof to the
Closing, neither the Partnership nor the
<PAGE>
 
Partners shall enter into any agreement with any party other than Prime with
respect to the sale or other disposition of either partnership interests or the
assets of the Partnership or with respect to any merger, consolidation, or
similar transaction involving the Partnership.

     4.5  Notice of Developments.  From the date hereof to the Closing, the
          ----------------------                                           
parties hereto, other than Prime, shall notify Prime of any material problems or
material adverse developments with respect to the business or operations of the
Partnership.

     4.6  Notice of Breach.  From the date hereof to the Closing, the parties
          ----------------                                                   
hereto shall, immediately upon becoming aware thereof, give detailed written
notice to all the other parties hereto of the occurrence of, or the impending or
threatened occurrence of, any event which would cause or constitute a breach, or
would have caused or constituted a breach had such event occurred or been known
to such party prior to the date of this Agreement, of any of their covenants,
agreements, representations, or warranties contained or referred to herein or in
any document delivered in accordance with the terms hereof.

     4.7  Notice of Litigation by Partnership and NGST.  From the date hereof to
          --------------------------------------------                          
the Closing, immediately upon becoming aware thereof, the parties hereto, other
than Prime, shall notify Prime of (a) any suit, action, or proceeding
(including, without limitation, any Tax Action or proceeding involving a labor
dispute or grievance or union recognition) to which the Partnership or NGST
becomes a party or which is threatened against the Partnership or NGST, (b) any
order or decree or any complaint praying for an order or decree restraining,
enjoining or otherwise adversly affecting the consummation of this Agreement or
the transactions contemplated hereby, or (c) any notice from any tribunal of its
intention to institute an investigation into, or to institute a suit or
proceeding to restrain, enjoin or otherwise adversely
<PAGE>
 
affect the consummation of, this Agreement or the transactions contemplated
hereby or to nullify or render ineffective this Agreement or such transactions
if consummated.

     4.8  Notice of Litigation by Prime.  From the date hereof to the Closing,
          -----------------------------                                       
immediately upon becoming aware thereof, Prime shall notify the other parties
hereto of (a) any order or decree or any complaint praying for an order or
decree restraining, enjoining or otherwise adversly affecting the consummation
of this Agreement or the transactions contemplated hereby or (b) any notice from
any tribunal of its intention to institute an investigation into, or to
institute a suit or proceeding to restrain, enjoin or otherwise adversely affect
the consummation of, this Agreement or the transactions contemplated hereby or
to nullify or render ineffective this Agreement or such transactions if
consummated.

     4.9  Continuation of Insurance Coverage.  From the date hereof to the
          ----------------------------------                              
Closing, the Partnership shall keep in full force and effect all insurance
coverage for the Partnership and its assets and operations as is now maintained
covering the Partnership and its assets and operations.

     4.10  Maintenance of Credit Terms.  From the date hereof to the Closing,
           ---------------------------                                       
the Partnership shall continue to effect sales of its services only on the terms
that have been offered by the Partnership consistent with past practices of the
Partnership or on such other terms which are no less favorable.

     4.11  Updating Information.  As of the Closing, the parties hereto, other
           --------------------                                               
than Prime, shall advise Prime of any material changes in the information set
forth in the schedules to this Agreement.

     4.12  Financial Statements.  Until the Closing, as soon as available, and
           --------------------                                               
in any event within 30 days after the end of each calendar month, the
Partnership shall furnish to Prime a
<PAGE>
 
balance sheet and statement of income for such month prepared on a cash basis,
but otherwise prepared in accordance with the same accounting principles applied
in the preparation of the Financial Statements. Such monthly financial
statements shall fairly present the financial position, results of operations,
and changes in financial position as of the indicated dates and for the
indicated periods. In addition to the monthly Financial Statements, until the
Closing, as soon as available, and in any event within 30 days after the end of
each calendar quarter after March 31, 1997, the Partnership shall furnish to
Prime a balance sheet and statement of income as of the end of the quarter and
for the calendar quarter and year-to-date period then ended prepared on an
accrual basis, and otherwise prepared in accordance with the same accounting
principles applied in the preparation of the Financial Statements. Such
quarterly financial statements shall fairly present the financial position,
results of operation and changes in financial position as of the indicated dates
and for the indicated periods.

     4.13  Interim Operations of the Partnership.
           ------------------------------------- 
     (a) From the date hereof to the Closing, the Partnership shall conduct its
business only in the ordinary course consistent with past practice, and the
Partnership shall not, unless Prime gives its prior express written approval,
(i) amend or otherwise change its partnership agreement as such document is in
effect on the date hereof, (ii) issue or sell, or authorize for issuance or
sale, additional partnership interests of any class or type, or issue, grant, or
enter into any subscription, option, warrant, right, convertible security, or
other agreement or commitment of any character obligating the Partnership to
issue additional partnership interests, (iii) redeem, purchase, or otherwise
acquire, directly or indirectly, any of its partnership interests, (iv) except
in the ordinary course of business, sell, pledge,
<PAGE>
 
dispose of, or encumber, or agree to sell, pledge, dispose of, or encumber, any
assets of the Partnership, or authorize any capital expenditure in excess of
$5000, (v) acquire (by merger, consolidation, or acquisition of stock or assets)
any corporation, partnership, or other business organization or division
thereof, or enter into any contract, agreement, commitment, or arrangement with
respect to any of the foregoing, (vi) incur any indebtedness for borrowed money,
issue any debt securities, or enter into or modify any contract, agreement,
commitment, or arrangement with respect thereto, (vii) enter into, amend, or
terminate any employment agreement with any director, officer, or key employee
or sales representative of the Partnership, or enter into, amend, or terminate
any employment agreement (other than the termination of any such agreement that
may exist with Mr. Tom Johnson) with any other person otherwise than in the
ordinary course of business, or take any action with respect to the grant or
payment of any severance or termination pay other than pursuant to policies or
agreements of the Partnership in effect on the date hereof, (viii) enter into,
extend, or renew any lease for office or manufacturing space otherwise than in
the ordinary course of business, (ix) except as required by law, adopt, amend,
or terminate any bonus, profit sharing, compensation, stock option, pension,
retirement, deferred compensation, employment, or other employee benefit plan,
agreement, trust, fund, or arrangement for the benefit or welfare of any
employee, or sales representative of the Partnership, or withdraw from any
multi-employer plan so as to create any liability under ERISA to any entity, (x)
grant any increase in compensation to any employee or sales representative of
the Partnership, except for wage and salary increases made in the ordinary
course of business and consistent with past practices of the Partnership, or
(xi) declare, set aside, make or pay any distribution of revenues received after
the Effective Time.
<PAGE>
 
     (b) From the date hereof to the Closing, the Partnership shall use its best
efforts to preserve intact the business organization of the Partnership, to keep
available in all material respects the services of its present employees, to
preserve intact its banking relationships and credit facilities, to preserve the
goodwill of those having business relationships with it, and to comply with all
applicable laws the violation of which would have a material adverse impact on
the assets or the business or financial position of the Partnership.

     (c) Immediately prior to the Closing the Partnership may make a cash
distribution to the Partners according to their interests, in an amount equal to
all available cash on-hand, less a reasonable reserve for anticipated cash
expenses and capital expenditures for the thirty (30) days after the Closing
Date; provided, however that (i) no distribution by the Partnership of revenues
received by it on or after the Effective Time will be made unless and until
approved after the Closing Date by Prime and the other Partners, and (ii) the
Partnership will have reasonable reserves for the anticipated cash expenses and
capital expenditures for the thirty (30) days after the Closing Date on hand
immediately after the Closing.

     4.14  Cooperation Relating to Financial Statements.  The Partnership and
           --------------------------------------------                      
the Partners who are parties hereto agree to cooperate with Prime in the
preparation of, and/or audit related to, any financial statements of the
Partnership for any period prior to the Closing, which Prime or its affiliates
may be required by any applicable law to prepare.

     4.15  Necessary Filings.  The Partnership and the Partners who are parties
           -----------------                                                   
hereto agree to timely prepare, execute and file a cancellation of the
Certificate of Limited Partnership and all other certificates, documents,
notices or instruments required with respect to the Partnership in connection
with the transactions contemplated by this Agreement.
<PAGE>
 
     4.16  Compliance with Laws.  All parties hereto acknowledge and agree that,
           --------------------                                                 
to the best of their knowledge, the transactions contemplated by this Agreement
comply with now current health laws, including the so-called "Stark" laws. While
the parties acknowledge that Congressman Stark has stated that the "Stark" laws
do not apply to lithotripsy operations, the parties nonetheless acknowledge and
agree that none of them is able to guarantee to any of the others that such
transactions will not be found to be in violation of such health care laws or
will not be subject to investigation or possible enforcement action under such
health care laws, and no party to this Agreement shall be deemed to be in breach
hereof, or to have any indemnity obligation hereunder, with respect to any loss
sustained, or claim asserted, to the extent any such loss or claim is based on,
or alleges, that the transactions contemplated hereby violates any of such
health care laws.

                                   ARTICLE V

                             Conditions to Closing
                             ---------------------

     5.1  Conditions to Obligations of Prime.  The obligations of Prime to
          ----------------------------------                              
consummate the transactions contemplated hereby are subject to the fulfillment
of each of the following conditions:

     (a) The representations and warranties of the parties hereto, other than
Prime, contained in this Agreement shall be true and correct at and as of the
Closing with the same effect as through such representations and warranties had
been made on and as of the Closing; the parties hereto, other than Prime, shall
have performed and complied with all agreements
<PAGE>
 
required by this Agreement to be performed or complied with by them at or prior
to the Closing; and Prime shall have received a certificate to the foregoing
effect, dated as of the Closing Date, signed on behalf of such parties.

     (b) No action or proceeding shall have been instituted or threatened for
the purpose or with the probable effect of enjoining, preventing or otherwise
adversly affecting the consummation of this Agreement or seeking damages on
account thereof.

     (c) Prior to the Closing, there shall not have occurred any material
casualty or damage (whether or not insured) to any facility, property, or
equipment owned or used by the Partnership which would have a material adverse
impact on the assets, business or financial condition of the Partnership; and,
except as specifically permitted in this Agreement, the business of the
Partnership shall have been conducted only in the ordinary course consistent
with past practices.

     (d) All consents and approvals required in connection with the execution,
delivery, and performance of this Agreement shall have been obtained, and the
obtaining of such consents and approvals shall not have required any guaranty by
Prime.

     (e) All necessary action (by vote of its partners and otherwise) shall have
been taken by the Partnership to authorize, approve, and adopt this Agreement
and the consummation and performance of the transactions contemplated hereby,
and the certificate to be received by Prime as described in Section 5.1(a)
above, shall contain a statement to the foregoing effect.  The form of ballot
and resolutions utilized by the Partnership for obtaining the approval of the
transaction contemplated hereby by the Partners shall be in form and substance
acceptable to Prime.

     (f) All of the Partners shall have executed the Amended Partnership
Agreement. Furthermore, NGST shall have assigned a 38.25% general partnership
interest in the Partnership
<PAGE>
 
to Prime by execution and delivery of the Assignment Agreement in the form
attached hereto as Exhibit C.

     (g) Any Partner who has any loan outstanding and payable to the Partnership
shall have repaid such loan (including, without limitation, all accrued
interest) in full on the Closing Date.

     (h) Each Partner (other than Hawkins), each Shareholder and HealthTronics,
Inc., a Georgia corporation ("HealthTronics") shall have executed a
Noncompetition Agreement in the form of Exhibit D attached hereto.

     (i) The Partnership and NGST shall have delivered such good standing
certificates, officer's certificates, and similar documents and certificates as
counsel for Prime shall have reasonably requested prior to the Closing Date.

     The decision of Prime to consummate the transactions contemplated hereby
without the satisfaction of any of the preceding conditions shall not constitute
a waiver of any of the Partnership's representations, warranties, covenants, or
indemnities herein; provided, however, that Prime, prior to or at the Closing,
shall advise the Partnership in writing of any failure to satisfy such
conditions of which Prime has actual knowledge on the Closing Date.

     5.2  Conditions to Obligations of the Parties Other than Prime.  The
          ---------------------------------------------------------      
obligations of the Parties other than Prime to consummate the transactions
contemplated hereby are subject to the fulfillment of the following conditions:

     (a) Prime's representations and warranties contained in this Agreement
shall be true and correct at and as of the Closing with the same effect as
though such representations and warranties had been made as of the Closing; all
agreements to be performed and complied with
<PAGE>
 
hereunder by Prime at or prior to the Closing shall have been performed or
complied with; and the Partnership shall have received a certificate, dated as
of the Closing Date, signed by the President of Prime to the foregoing effects.

     (b) No action or proceeding shall have been instituted or threatened for
the purpose or with the probable effect of enjoining, preventing or otherwise
adversly affecting the consummation of this Agreement or seeking damages on
account thereof.

     (c) Prime shall have executed the Amended Partnership Agreement.

     (d) NGST shall have received from Prime $3,470,000 in cash or certified
funds.

     (e) All consents and approvals required in connection with the execution,
delivery, and performance of this Agreement shall have been obtained.

     (f) All necessary action (corporate or otherwise) shall have been taken by
Prime to authorize, approve, and adopt this Agreement and the consummation and
performance of the transactions contemplated hereby, and the Partnership and
NGST shall have received a copy of the corresponding board resolution or
consent, dated as of the Closing Date and certified by the President of Prime.

     (g) Prime shall have delivered to the Partnership and NGST such good
standing certificates, officer's certificates, and similar documents and
certificates as counsel for the Partnership and NGST shall have reasonably
requested prior to the Closing Date.

     The decision of the Partnership, NGST and the Shareholders to consummate
the transactions contemplated hereby without the satisfaction of any of the
preceding conditions shall not constitute a waiver of any of Prime's
representations, warranties, covenants, or indemnities herein; provided,
however, that the Partnership, NGST and the Shareholders, prior to or at the
<PAGE>
 
Closing, shall each advise Prime in writing of any failure to satisfy such
conditions of which the Partnership, NGST or the Shareholders has actual
knowledge on the Closing Date.

                                   ARTICLE VI

                                  Termination
                                  -----------

     This Agreement may be terminated prior to the Closing by (a) the unanimous
written consent of all parties hereto, (b) the Partnership, NGST and the
Shareholders upon the failure of Prime to substantially perform or comply with
any of Prime's covenants or agreements contained herein prior to the Closing or
if any representation or warranty of Prime hereunder shall not have been true
and correct in any material respect as of the time at which such was made, if
Prime has been provided with written notice of any such failure which is not
cured within ten (10) business days after such notice is received or deemed
received, (c) Prime upon the failure of the Partnership, NGST or any of the
Shareholders to substantially perform or comply with any of their covenants or
agreements contained herein prior to the Closing or if any representation or
warranty of the Partnership, NGST or any of the Shareholders hereunder shall not
have been true and correct in any material respect as of the time at which such
was made, if Prime has provided the Partnership, NGST  and the Shareholders with
written notice of any such failure which is not cured within ten (10) business
days after such notice is received or deemed received, or (d) any of the parties
hereto if the Closing does not occur by May 9, 1997; provided, that no party may
terminate this Agreement pursuant to (b) or (c) above if such party is, at the
time of any such attempted termination, in breach of any term hereof.
<PAGE>
 
     Each of the parties hereto agree to use its reasonable efforts (which does
not include the waiver of any rights under this Agreement) to bring about the
satisfaction of the conditions set forth in ARTICLE V.  If any condition of
Closing is not satisfied on or prior to May 9, 1997, the party for whose benefit
of such condition is stated may proceed with the Closing or may terminate this
Agreement by notice in writing to the other party; provided, however, that such
party may not terminate this Agreement without first notifying the other party
of the condition which has not been satisfied and allowing at least ten business
(10) days opportunity after such notice is received or deemed received to cure
such failure.  Upon any such termination, this Agreement shall thereupon cease
to have any further force and effect and no party hereto shall have any
liability hereunder of any nature whatsoever to any other party hereto.

                                  ARTICLE VII

                            Indemnification of Prime
                            ------------------------

     7.1  Indemnification of Prime.  The Partnership (but not Hawkins by virtue
          ------------------------                                             
of his being a general partner of the Partnership), NGST and the Shareholders
each severally, and not jointly, agree to indemnify and hold Prime and each
officer, director, employee, and affiliate of Prime (collectively, the "Prime
Indemnified Parties") harmless from and against any and all damages, losses,
claims, liabilities, demands, charges, suits, penalties, costs, and expenses
(including court costs and attorneys' fees and expenses incurred in
investigating and preparing for any litigation or proceeding) (collectively,
"Indemnified Costs") in connection with the commencement or assertion of any
action, proceeding, demand, or claim by a third party (collectively, a "third-
party action") which any of the Prime Indemnified Parties may sustain,
<PAGE>
 
arising out of, or with respect to, (a) any breach or default by the
Partnership, NGST or any of the Partners of any of the representations,
warranties, covenants or agreements contained in this Agreement or any agreement
or document executed in connection herewith (including, without limitation, the
certificates to be delivered pursuant to Section 5.1(a) and 5.1(e), or (b) any
obligations or liabilities, including without limitation, any professional
liability claims, claims by any finder, broker or sales agent engaged or
retained by the Partnership, NGST or any of the Partners or Shareholders, or
other claims, against or involving the Partnership, or due from the Partnership,
which obligations, liabilities or claims existed at the Closing Date, or arise,
in whole or in part, out of events, actions or omissions that occurred prior to
the Closing Date.

     The liability of each Shareholder under this Section 7.1 shall be limited
to its allocable share (determined ratably based on each Shareholder's
respective ownership percentage of common stock of NGST ("Ownership Percentage")
as set forth on Schedule 3.25 of each Indemnified Cost, except in instances
                -------------                                              
where a particular representation, warranty or covenant is expressly made by a
particular Shareholder, in which case Indemnified Costs arising out of or
relating to a breach or default of such a representation, warranty or covenant
shall be the obligation solely of the applicable Shareholder, and allocated
among them based on their respective Ownership Percentages if there is more than
one such Shareholder. The indemnity obligations of the Partnership and NGST
shall not be so limited; provided the Partnership's indemnity obligation shall
be limited to the value of its assets at the time the indemnity obligation
arises.

     7.2  Defense of Third-Party Claims.  A Prime Indemnified Party shall give
          -----------------------------                                       
prompt written notice to the Partnership, NGST and the Shareholders of the
commencement or assertion
<PAGE>
 
of any third party action in respect of which such Prime Indemnified Party shall
seek indemnification hereunder. Any failure so to notify the Partnership, NGST
and the Shareholders shall not relieve the Partnership, NGST and the
Shareholders from any liability that they may have to such Prime Indemnified
Party under this Article VII unless the failure to give such notice materially
and adversely prejudices the Partnership, NGST and the Shareholders. The
Partnership, NGST and the Shareholders shall have the right to assume control of
the defense of, settle, or otherwise dispose of such third-party action on such
terms as they deem appropriate; provided, however, that:

     (a) The Prime Indemnified Party shall be entitled, at his, her, or its own
expense, to participate in the defense of such third-party action;

     (b) The Partnership, NGST and the Shareholders shall obtain the prior
written approval of the Prime Indemnified Party, which approval shall not be
unreasonably withheld or delayed, before entering into or making any settlement,
compromise, admission, or acknowledgment of the validity of such third-party
action or any liability in respect thereof if, pursuant to or as a result of
such settlement, compromise, admission, or acknowledgment, injunctive or other
equitable relief would be imposed against the Prime Indemnified Party or if, in
the reasonable opinion of the Prime Indemnified Party, such settlement,
compromise, admission, or acknowledgment would have a material adverse effect on
its business or, in the case of a Prime Indemnified Party who is a natural
person, on his or her assets or interests;

     (c) The Partnership, NGST and the Shareholders shall not consent to the
entry of any judgment or enter into any settlement that does not include as an
unconditional term thereof the
<PAGE>
 
giving by each claimant or plaintiff to each Prime Indemnified Party of a
release from all liability in respect of such third-party action; and

     (d) The Partnership, NGST and the Shareholders shall not be entitled to
control (but shall be entitled to participate at their own expense in the
defense of), and the Prime Indemnified Party shall be entitled to have sole
control over, the defense or settlement, compromise, admission, or
acknowledgment of any third-party action (i) as to which the Partnership, NGST
and the Shareholders fail to assume the defense within a reasonable length of
time or (ii) to the extent the third-party action seeks an order, injunction, or
other equitable relief against the Prime Indemnified Party which, if successful,
would materially adversely affect the business, operations, assets, or financial
condition of the Prime Indemnified Party; provided, however, that the Prime
                                          --------  -------                
Indemnified Party shall make no settlement, compromise, admission, or
acknowledgment which would give rise to liability on the part of the
Partnership, NGST or the Shareholders without the prior written consent of the
Partnership, NGST and the Shareholders.

     (e) The Partnership, NGST and the Shareholders shall make payments of all
amounts required to be made pursuant to the foregoing provisions of this Section
to or for the account of the Prime Indemnified Party from time to time promptly
upon receipt of bills or invoices relating thereto or when otherwise due and
payable, provided that the Prime Indemnified Party has agreed in writing to
reimburse the Partnership, NGST and the Shareholders for the full amount of such
payments if the Prime Indemnified Party is ultimately determined not to be
entitled to such indemnification.

     (f) The parties hereto shall extend reasonable cooperation in connection
with the defense of any third-party action pursuant to this ARTICLE VII and, in
connection therewith,
<PAGE>
 
shall furnish such records, information, and testimony and attend such
conferences, discovery proceedings, hearings, trials, and appeals as may be
reasonably requested.

                                  ARTICLE VIII

         Indemnification of the Partnership, NGST and the Shareholders
         -------------------------------------------------------------

     8.1  Indemnification of the Partnership, NGST and the Shareholders.  Prime
          -------------------------------------------------------------        
agrees to indemnify and hold harmless the Partnership, NGST and each
Shareholder, and their respective officers, directors, employees, and affiliates
(collectively, the "Partnership Indemnified Parties") from and against any and
all Indemnified Costs in connection with (a) the commencement or assertion of
any action, proceeding, demand or claim by a third party which any of the
Partnership Indemnified Parties may sustain, arising out of any breach or
default by Prime of any of the representations, warranties, covenants or
agreements contained in this Agreement or any agreement or document executed in
connection herewith, including, without limitation, the certificates to be
delivered pursuant to Sections 5.2(a) and 5.2(f), or (b) any obligations or
liabilities to any finder, broker or sales agent engaged or retained by Prime.

     8.2  Defense of Third-Party Claims.  A Partnership Indemnified Party shall
          -----------------------------                                        
give prompt written notice to Prime of the commencement or assertion of any
third party action in respect of which such the Partnership Indemnified Party
shall seek indemnification hereunder.  Any failure so to notify Prime shall not
relieve Prime from any liability that it may have to such the Partnership
Indemnified Party under this Article VIII unless the failure to give such notice
materially and adversely prejudices Prime.  Prime shall have the right to assume
control of the
<PAGE>
 
defense of, settle, or otherwise dispose of such third-party action on such
terms as it deems appropriate; provided, however, that:

     (a) The Partnership Indemnified Party shall be entitled, at his, her, or
its own expense, to participate in the defense of such third-party action;

     (b) Prime shall obtain the prior written approval of the Partnership
Indemnified Party, which approval shall not be unreasonably withheld or delayed,
before entering into or making any settlement, compromise, admission, or
acknowledgment of the validity of such third-party action or any liability in
respect thereof if, pursuant to or as a result of such settlement, compromise,
admission, or acknowledgment, injunctive or other equitable relief would be
imposed against the Partnership Indemnified Party or if, in the reasonable
opinion of the Partnership Indemnified Party, such settlement, compromise,
admission, or acknowledgment would have a material adverse effect on its
business or, in the case of an the Partnership Indemnified Party who is a
natural person, on his or her assets or interests;

     (c) Prime shall not consent to the entry of any judgment or enter into any
settlement that does not include as an unconditional term thereof the giving by
each claimant or plaintiff to each the Partnership Indemnified Party of a
release from all liability in respect of such third-party action; and

     (d) Prime shall not be entitled to control (but shall be entitled to
participate at its own expense in the defense of), and the Partnership
Indemnified Party shall be entitled to have sole control over, the defense or
settlement, compromise, admission, or acknowledgment of any third-party action
(i) as to which Prime fails to assume the defense within a reasonable length of
time or (ii) to the extent the third-party action seeks an order, injunction, or
other equitable relief
<PAGE>
 
against the Partnership Indemnified Party which, if successful, would materially
adversely affect the business, operations, assets, or financial condition of the
Partnership Indemnified Party; provided, however, that the Partnership
                               --------  -------
Indemnified Party shall make no settlement, compromise, admission, or
acknowledgment which would give rise to liability on the part of Prime without
the prior written consent of Prime.

     (e) Prime shall make payments of all amounts required to be made pursuant
to the foregoing provisions of this Section to or for the account of the
Partnership Indemnified Party from time to time promptly upon receipt of bills
or invoices relating thereto or when otherwise due and payable, provided that
the Partnership Indemnified Party has agreed in writing to reimburse Prime for
the full amount of such payments if the Partnership Indemnified Party is
ultimately determined not to be entitled to such indemnification.

     (f) The parties hereto shall extend reasonable cooperation in connection
with the defense of any third-party action pursuant to this ARTICLE VIII and, in
connection therewith, shall furnish such records, information, and testimony and
attend such conferences, discovery proceedings, hearings, trials, and appeals as
may be reasonably requested.

                                   ARTICLE IX

                           Noncompetition Agreements
                           -------------------------

     Each of the parties hereto, severally and not jointly, hereby agree that,
until the expiration of their respective Restriction Period (as defined for each
below), they will not directly or indirectly, either through any kind of
ownership (other than ownership of securities of a publicly held corporation of
which they own less than five percent of any class of outstanding securities),
<PAGE>
 
or as a principal, agent, employer, advisor, consultant, co-partner or in any
individual or representative capacity whatever, either for their own benefit or
for the benefit of any other person, firm or corporation, without the prior
written consent of the other parties hereto, commit any of the following acts,
which acts shall be considered violations of this covenant not to compete:

     A.  Except for services provided by the Partnership, directly or indirectly
provide lithotripsy services, including without limitation, patient lithotripsy
services, lithotripsy management services, lithotripter leasing, or similar
lithotripsy services, anywhere within 50 miles of the Chattanooga, Hamilton
County, Tennessee Courthouse;

     B.  Directly or indirectly request or advise any patient or physician or
any other person, firm or corporation having a business relationship with Prime,
any of Prime's affiliates or the Partnership to withdraw, curtail, or cancel its
business with such entity; or

     C.  Directly or indirectly hire any employee of Prime, any of Prime's
affiliates or the Partnership or induce or attempt to influence any employee of
Prime, any of Prime's affiliates or the Partnership to terminate his or her
employment with such entity.

         Provided, however, that nothing in this Agreement shall be construed to
limit or infringe upon the professional medical judgment or ability to practice
medicine of any party hereto that is a physician (including, but not limited to,
the selection of appropriate facilities for medical care), and no exercise of
such a party's professional medical judgment or act constituting the practice of
medicine shall be considered a violation of this Agreement.

         Notwithstanding the foregoing, or anything else contained herein to the
contrary (i) Prime shall not be restricted as described in B. above with respect
to any of its own business
<PAGE>
 
relationships or any of the business relationships of its affiliates, (ii) Prime
shall not be restricted as set forth in C. above with respect to its own
employees or the employees of its affiliates, (iii) upon any merger of NGST and
HealthTronics such transaction shall not constitute a breach of this ARTICLE IX
by NGST or any of the Shareholders for so long as HealthTronics continues to
comply with the provisions of the Noncompetition Agreement entered into by it in
connection with the Closing of the transactions contemplated by this Agreement,
and (iv) Prime shall not be deemed in violation of this ARTICLE IX in connection
with its providing of lithotripsy services and related services to and/or at the
Cleveland Community Hospital in Cleveland, Tennessee (and its successors and
assigns). Furthermore, the parties agree that in the event there is a need or
opportunity to provide lithotripsy services as contemplated in subparagraph A.
above at a location within the restricted area at which none of Prime, any of
Prime's affiliates or the Partnership then provides such services, the parties
will cooperate in good faith to agree on the appropriate method of providing
such services as between Prime and the Partnership, it being understood that, in
any event, Prime and/or Prime's affiliates shall be entitled to provide such
services in the event the technology preferred by the third party to be
contracting for the services is not the technology which the Partnership has
available at that time, and the Partnership, with Prime abstaining from voting,
does not elect to acquire and implement such technology within the time frame
necessary to provide the services requested before the contracting third party
looks elsewhere for a service provider.

  For purposes of this Agreement, the "Restriction Period" for the parties shall
be as follows:
<PAGE>
 
  (i) The Restriction Period for the Partnership and Prime shall begin on the
Closing Date and continue until five (5) years after the date that Prime, or
Prime's successors or permitted assigns, is no longer a partner in the
Partnership; and

  (ii) The Restriction Period for NGST and each of the Shareholders shall begin
on the Closing Date and continue until five (5) years after the date that such
party is no longer, directly or indirectly, (a) a partner in the Partnership,
(b) an owner of any equity or other voting ownership interest, or any right
convertible into any equity or other voting ownership interest, in any partner
in the Partnership, or of any affiliate of the Partnership or of any partner in
the Partnership, or (3) an affiliate of either the Partnership or any of the
other partners in the Partnership. For purposes of this Agreement, the
Partnership shall include the Partnership and its successors and assigns, and
the references to a "partner" in the Partnership shall be deemed to include any
owner of any equity or other voting ownership interest in any such successor or
assign of the Partnership.

  The parties have each reviewed and carefully considered the provisions of this
Article and, having done so, agree that the restrictions set forth herein (a)
are fair and reasonable with respect to time, geographic area and scope, (b) are
not unduly burdensome, and (c) are reasonably required for the protection of the
respective interests of the parties.

  The parties each agree that a violation on its part of any covenant contained
in this Article will cause the other parties irreparable damage for which
remedies at law may be insufficient, and for that reason, each agrees that the
other parties shall each, independently be entitled as a matter of right to
equitable remedies, including specific performance and injunctive relief,
therefor.  The right to specific performance and injunctive relief shall be
cumulative and in
<PAGE>
 
addition to whatever other remedies, at law or in equity, may be available,
including, specifically, recovery of additional damages.

                                   ARTICLE X

                                 Miscellaneous
                                 -------------

  10.1  Collateral Agreements, Amendments, and Waivers.  This Agreement
        ----------------------------------------------                 
(together with the documents delivered pursuant hereto) supersedes all prior
documents, understandings, and agreements, oral or written, relating to these
transactions and constitutes the entire understanding among the parties with
respect to the subject matter hereof.  Any modification or amendment to, or
waiver of, any provision of this Agreement (or any document delivered pursuant
to this Agreement unless otherwise expressly provided therein) may be made only
by an instrument in writing executed by each party thereto.

  10.2  Successors and Assigns. No parties' rights or obligations under this
        ----------------------                                              
Agreement may be assigned without the express written consent of all parties
hereto; except that Prime shall be entitled to assign its rights and obligations
hereunder to any entity, more than fifty percent (50%) of the voting equity
ownership interests of which is at the time owned, directly or indirectly, by
Prime Medical Services, Inc., a Delaware corporation; provided no such
assignment shall relieve Prime of its obligations hereunder to any of the
parties hereto.  Any assignment in violation of the foregoing shall be null and
void.  Subject to the preceding sentences of this Section, the provisions of
this Agreement (and, unless otherwise expressly provided therein, of any
document delivered pursuant to this Agreement) shall be binding upon and inure
to the benefit of the parties hereto and their respective heirs, legal
representatives,
<PAGE>
 
successors, and assigns. The parties acknowledge and agree that the shareholders
of NGST may engage in a transaction or transactions pursuant to which some or
all of their shares in NGST will be transferred to HealthTronics, and all
parties hereto agree that such transfer of ownership of NGST is hereby consented
to for all purposes of this Agreement and the Amended Partnership Agreement.

  10.3  Expenses.  Except as set forth in the following sentence, regardless of
        --------                                                               
whether the transactions contemplated hereby are consummated, each party hereto
shall pay all of its costs and expenses incurred by it in connection with this
Agreement, including the fees and disbursements of its counsel.

  10.4  Invalid Provisions.  If any provision of this Agreement is held to be
        ------------------                                                   
illegal, invalid, or unenforceable under present or future laws, such provision
shall be fully severable, this Agreement shall be construed and enforced as if
such illegal, invalid, or unenforceable provision had never comprised a part of
this Agreement, and the remaining provisions of this Agreement shall remain in
full force and effect and shall not be affected by the illegal, invalid, or
unenforceable provision or by its severance from this Agreement.

  10.5  Information and Confidentiality.  Each party hereto agrees that such
        -------------------------------                                     
party shall hold in strict confidence, and shall not use for the benefit of
itself or any third party, any and all information and documents received from
any other party hereto, and if the Closing does not occur each such party shall
return to the other parties hereto all such documents then in such receiving
party's possession without retaining copies; provided, however, that each
party's obligations under this Section shall not apply to (a) any information or
document required to be disclosed by law, (b) any information or document in the
public domain due to no breach of the
<PAGE>
 
terms of this Section, or (c) any information or document that Prime discloses
to any potential lender to or investor in Prime or Prime's affiliates; provided
Prime has required any such lender or investor to agree to maintain the
confidentiality of the disclosure.

  10.6  Waiver.  No failure or delay on the part of any party in exercising any
        ------                                                                 
right, power, or privilege hereunder or under any of the documents delivered in
connection with this Agreement shall operate as a waiver of such right, power,
or privilege; nor shall any single or partial exercise of any such right, power,
or privilege preclude any other or future exercise thereof or the exercise of
any other right, power or privilege.

  10.7  Notices.  Any notices required or permitted to be given under this
        -------                                                           
Agreement (and, unless otherwise expressly provided therein, under any document
delivered pursuant to this Agreement) shall be given in writing and shall be
deemed received (a) when personally delivered to the relevant party at its
address as set forth below or (b) if sent by mail, on the third day following
the date when deposited in the United States mail, certified or registered mail,
postage prepaid, to the relevant party at its address indicated below:

  Prime:                 Prime Lithotripter Operations, Inc.
                         1301 Capital of Texas Highway
                         Suite C-300
                         Austin, Texas  78746
                         Attention:  President

  with a copy to:        Mr. Timothy L. LaFrey
                         Akin, Gump, Strauss, Hauer & Feld, L.L.P.
                         816 Congress Avenue, Suite 1900
                         Austin, Texas  78701

  the Partnership, NGST  Attn: Argil Wheelock, M.D.
  and the Shareholders:  1000 Scenic Highway
                         Lookout Mountain, Tennessee 37350
<PAGE>
 
  with a copy to:        Mr. Roy C. Maddox, Jr.
                         Horton, Maddox and Anderson, P.L.L.C.
                         One Central Plaza, Suite 600
                         Chattanooga, Tennessee 37402

Each party may change its address for purposes of this Section by proper notice
to the other parties.

  10.8  Survival of Representations, Warranties, and Covenants.  Regardless of
        ------------------------------------------------------                
any investigation at any time made by or on behalf of any party hereto or of any
information any party may have in respect thereof, all covenants, agreements,
indemnity obligations, representations, and warranties made hereunder or
pursuant hereto or in connection with the transactions contemplated hereby shall
survive the Closing for a period of five (5) years after the Closing Date.
Notwithstanding the foregoing, (i) the provisions of ARTICLE IX shall not expire
as set forth in the preceding sentence and shall, instead, be governed by the
expiration provisions for each of the parties described in ARTICLE IX, and (ii)
a party's indemnity obligation hereunder shall not expire as to any
indemnifiable event, act or omission including without limitation the defense of
a third party claim, with respect to which notice and demand for indemnification
was given to the party or parties obligated to indemnify hereunder prior to the
expiration of the five (5) year period described in the preceding sentence.

  10.9  Further Assurances.  At, and from time to time after, the Closing, each
        ------------------                                                     
party shall, at the request of another party, but without further consideration,
execute and deliver such other instruments of conveyance, assignment,
assumption, transfer and delivery and take such other action as such party may
reasonably request in order more effectively to consummate the transactions
contemplated hereby.
<PAGE>
 
  10.10  No Third-Party Beneficiaries.  No person or entity not a party to this
         ----------------------------                                          
Agreement shall be deemed to be a third-party beneficiary hereunder or entitled
to any rights hereunder.

  10.11  Construction.  This Agreement and any documents or instruments
         ------------                                                  
delivered pursuant hereto or in connection herewith shall be construed without
regard to the identity of the person who drafted the various provisions of the
same.  Each and every provision of this Agreement and such other documents and
instruments shall be construed as though all of the parties participated equally
in the drafting of the same.  Consequently, the parties acknowledge and agree
that any rule of construction that a document is to be construed against the
drafting party shall not be applicable either to this Agreement or such other
documents and instruments.

  10.12  Arbitration.  Except as set forth in ARTICLE IX, any controversy
         -----------                                                     
between the parties regarding this Agreement and any claims arising out of this
Agreement or its breach shall be submitted to arbitration by either party.  Any
such dispute will be detailed in writing and submitted by the complaining party
for binding arbitration by a retired judge associated with Judicial Arbitration
and Mediation Services, Inc. ("JAMS") to take place in a location to be agreed
upon by the parties, but in the event of a failure to so agree, in Denver,
Colorado, and a copy shall be sent to the other parties pursuant to the notice
provision of this Agreement.  The parties agree that if JAMS is unavailable,
such dispute shall be submitted instead to any arbitrator or organization of a
similar nature mutually agreed to by the parties.  The parties may agree on a
retired judge from the JAMS panel for the binding arbitration.  If they are
unable to agree, JAMS will provide a list of three (3) available judges and each
party may strike one (1), with the party requesting arbitration striking first.
The remaining judge will serve as arbitrator.  The parties agree that their sole
remedy in the event of such dispute shall be binding arbitration pursuant to
<PAGE>
 
the terms of this Section and that judgment upon the arbitrator's award may be
entered in any court having jurisdiction thereof.

  10.13  Counterparts.  This Agreement may be executed in several counterparts,
         ------------                                                          
each of which shall constitute an original and all of which together shall
constitute one and the same instrument.  Any party hereto may execute this
Agreement by signing any one counterpart.

  10.14  Definition of Knowledge.  Whenever there are references in this
         -----------------------                                        
Agreement to "the knowledge of" a party or "to the best knowledge of" a party,
or similar references to a party's "knowledge", such provision shall be
construed as follows:  (a) with regard to the Partnership, the Partnership shall
be deemed to have knowledge if any of the Partners has actual knowledge of such
applicable fact or matter; (b) with regard to NGST, NGST shall be deemed to have
knowledge if any Shareholder, or any officer or director, of NGST has actual
knowledge of the applicable fact or matter; and (c) with regard to Prime, Prime
shall be deemed to have knowledge if any officer of Prime has actual knowledge
of the applicable fact or matter.

  IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as of
the day and year first above written.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT

                               PRIME LITHOTRIPTER OPERATIONS, INC.


                               By: /s/ Cheryl Williams
                                  ---------------------------------
                                  Cheryl Williams, Treasurer
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                               TENN-GA STONE GROUP TWO, L.P.,
                               a Tennessee Limited Partnership


                               By: /s/ Argil J. Wheelock, M.D.
                                  ---------------------------------

                               Printed Name: Argil J. Wheelock, M.D.
                                            -----------------------
                               Title: Partner
                                     ------------------------------
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                               PARTNERS:
                                        
                                        
                               NGST, Inc., a Tennessee corporation
                                        
                               By:  /s/ Argil J. Wheelock, M.D.
                                  ---------------------------------

                               Printed Name:Argil J. Wheelock, M.D.
                                            -----------------------
                               Title: Partner
                                     ------------------------------
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT

                              /s/ Thomas C. Bright, M.D.
                              -------------------------------------
                              Thomas C. Bright, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Argil J. Wheelock, M.D.
                              -------------------------------------
                              Argil J. Wheelock, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ R. Smith Murray, M.D.
                              -------------------------------------
                              R. Smith Murray, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Richard S. Lasky, M.D.
                              -------------------------------------
                              Richard S. Lasky, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ John F. Bryant, M.D.
                              -------------------------------------
                              John F. Bryant, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Marty Scheinberg, M.D.
                              -------------------------------------
                              Marty Scheinberg, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ James E. McKinney, M.D.
                              -------------------------------------
                              James E. McKinney, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Paul E. Henson, M.D.
                              -------------------------------------
                              Paul E. Henson, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Oliver Benton, III, M.D.
                              -------------------------------------
                              Oliver Benton, III, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Stephen W. Jackson, M.D.
                              -------------------------------------
                              Stephen W. Jackson, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ C. A. Kyle, Jr., M.D.
                              -------------------------------------
                              C. A. Kyle, Jr., M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Nicholas Newton, M.D.
                              -------------------------------------
                              Nicholas Newton, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Jack Monnig, M.D.
                              -------------------------------------
                              Jack Monnig, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Samuel M. Currin, M.D.
                              -------------------------------------
                              Samuel M. Currin, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ J. Patrick Dilworth, M.D.  
                              -------------------------------------
                              J. Patrick Dilworth, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ David Sahaj, M.D.
                              -------------------------------------
                              David Sahaj, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ John Bryan, M.D.
                              -------------------------------------
                              John Bryan, M.D.
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Paula Willingham
                              -------------------------------------
                              Paula Willingham
<PAGE>
 
           SIGNATURE PAGE TO PARTNERSHIP INTEREST PURCHASE AGREEMENT


                              /s/ Robert DeBord
                              -------------------------------------
                              Robert DeBord
<PAGE>
 
                                   EXHIBIT A


                            PARTNERSHIP AGREEMENT OF
                            ------------------------
                                        
                            TENN-GA STONE GROUP TWO
                            -----------------------
                                        
                        A TENNESSEE GENERAL PARTNERSHIP
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  This Partnership Agreement is made effective the 1st day of May, 1997, by and
among the  Partners (as hereinafter defined).

                                    RECITALS

  WHEREAS, the Partners, other than Prime Lithotripter Operations, Inc., a New
York Corporation ("Prime"), were the sole partners of Tenn-Ga Stone Group Two,
L.P. a Tennessee Limited Partnership (the "Prior Partnership"); and

  WHEREAS, pursuant to that certain Partnership Interest Purchase Agreement
dated May 1, 1997, the parties thereto agreed that the Prior Partnership, if not
previously converted into a general partnership, would be converted into a
general partnership and Prime would purchase a 38.25% general partnership
interest therein from NGST, Inc., and all of the Partners would execute this
Agreement.

  NOW, THEREFORE, in consideration of the foregoing and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:
<PAGE>
 
  1.  Definitions.  As used in this Agreement, the following terms have the
      -----------                                                          
meanings indicated:

      "Act" means the Tennessee Uniform Partnership Act, Tennessee Code
Annotated Section 61-1-101 et. seq., as amended from time to time.
                           --  ---                                

      "Agreement" means Partnership Agreement, as amended, modified, or
supplemented from time to time.

      "Bankruptcy" of a Partner shall be deemed to have occurred upon the
happening of any of the following: (1) the filing of an application by a Partner
for, or a consent to, the appointment of a trustee of the Partner's assets, (2)
the filing by a Partner of a voluntary petition in bankruptcy or the filing of a
pleading in any court of record admitting in writing the Partner's inability to
pay the Partner's debts as they become due, (3) the making by a Partner of a
general assignment for the benefit of creditors, (4) the filing by a Partner of
an answer admitting the material allegations of, or consenting to, or defaulting
in answering a bankruptcy petition filed against the Partner in any bankruptcy
proceeding, or (5) the entry of an order, judgment or decree by a court of
competent jurisdiction adjudicating a Partner a bankrupt or appointing a trustee
of the Partner's assets, and that order, judgment, or decree continuing unstayed
and in effect for a period of sixty (60) days.

      "Code" shall mean the Internal Revenue Code of 1986, as amended, or
corresponding provisions of future laws.

                                       2
<PAGE>
 
      "Managing Partner" means NGST, Inc., a Tennessee corporation, or such
other persons or entities designated from time to time by a Majority Vote of the
Partners.

      "Majority Vote" means a vote of the Partners which, to be valid, must
include the affirmative vote of at least 75% of the Percentage Interests owned
by the Partners.

      "Partners" means, collectively, those persons and/or entities that appear
on Exhibit A to this Agreement, and who have executed a counterpart of this
   ---------
Agreement. References to a "Partner" shall be to any one of the Partners.
"Additional Partners" and "Substituted Partners" shall mean those persons
subsequently admitted to the Partnership in accordance with the provisions of
this Agreement.

      "Partnership" means the General Partnership carried on pursuant to this
Agreement.

      "Percentage Interests" means the respective ownership percentages of the
Partners in the Partnership as set forth in Exhibit A hereto.
                                            ---------        

  2.  Continuation of Prior Partnership.  The Partners hereby create a general
      ---------------------------------                                       
Partnership formed pursuant to the Act and other applicable laws of the State of
Tennessee, which shall in all respects be the successor to the Prior
Partnership, and not a new partnership, and the Partnership hereby assumes all
of the assets (tangible and intangible), properties, rights, liabilities,
obligations, business and goodwill of the Prior Partnership.  The rights and
duties shall be as provided in the Act except as modified by this Agreement.
The Partners (other than Prime) shall promptly take

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<PAGE>
 
such action and make such filings as shall be required under applicable laws to
give effect to the provisions of this Agreement and to vest fully in the
Partnership all right, title and interest in and to all of the assets (tangible
and intangible), properties, rights, business and goodwill of the Prior
Partnership.

  3.  Name and Place of Business.  The name of the Partnership is "Tenn-Ga Stone
      --------------------------                                                
Group Two" and the principal office and place of business of the Partnership
shall be 725 Glenwood Drive, Suite E484, Chattanooga, Tennessee, or such other
name or location as the Partners shall hereafter designate by Majority Vote.

  4.  Purposes.  The Partnership has been formed to operate one or more mobile
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Lithotripters to provide high technology, state of the art equipment to patients
in the east Tennessee and north Georgia areas; to provide a diversification of
skill and an increased ability to meet competition; and such other business
purposes as the Partners, by Majority Vote, may specify.

  5.  Term.  The Partnership shall terminate on December 31, 2034, unless
      ----                                                               
earlier terminated as provided in this Agreement or as provided by law.

  6.  Capital Contributions and Capital Accounts.
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      (a) Interests in Partnership Capital. The individual Percentage Interests
          --------------------------------
of the Partners in Partnership capital are shown on Exhibit A.
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<PAGE>
 
      (b) No Partner Contribution Obligations. No Partner shall be required to
          -----------------------------------
make any contribution to capital whatsoever and no Partner shall be required to
lend funds to the Partnership or guarantee any debts of the Partnership or any
Partner.

      (c) Withdrawal and Return of Capital Contribution. No Partner shall be
          ---------------------------------------------
entitled to withdraw any part of its capital contribution or capital account or
to receive any distributions from the Partnership except as provided by this
Agreement.

      (d) Capital Accounts. An individual capital account shall be maintained
          ----------------
for each Partner. The capital account balances will not earn interest. The
capital account of a Partner shall consist of the original contribution of
capital, if any, increased by (1) the balance in any capital account purchased
by such Partner from another Partner upon purchase of some or all of another
Partner's Percentage Interest in the Partnership, (2) any additional
contributions to capital and (3) such Partner's share of Partnership profits and
gains; and decreased by (4) distributions to such Partner and (5) such Partner's
share of Partnership losses. Notwithstanding the preceding sentence, the
beginning capital account of Prime shall be zero, as Prime's capital account is
not to include any portion of the balance of NGST, Inc.'s capital account which
is attributable to that portion of NGST, Inc.'s Percentage Interest in the
Partnership which was initially purchased by Prime (being 38.25% Percentage
Interest).

     (e) Negative Capital Accounts. If, upon the dissolution and liquidation of
         -------------------------
the Partnership, after crediting all income upon sale of the Partnership's
assets that have been sold, any

                                       5
<PAGE>
 
Partner has a negative capital account, then the Partner shall be obligated to
contribute to the Partnership an amount equal to the amount of his negative
capital account for distribution to creditors of the Partnership or to other
Partners who have positive capital account balances.

     (f) Transfer of Partnership Interest. If a Partnership interest is
         --------------------------------
transferred, the transferee shall be assigned the capital account balance of the
transferor Partner at the time of the transfer, unless otherwise agreed by a
Majority Vote of the Partners.

     (g) Alternative Allocation. Subject to the last sentence of paragraph 6(d),
         ----------------------
if any allocation is required by the Code to be allocated in a manner contrary
to the terms of this Agreement, the allocations under this Agreement shall be
automatically reformed to comply with the Code requirements and the capital
accounts of the Partners shall be adjusted accordingly.

  7.  Rights, Powers and Obligations of the Partners.
      ---------------------------------------------- 

     (a)  Management by Partners.  The Partners each have equal rights in the
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management of the Partnership business. Except where a Majority Vote is
required, a decision receiving a 2/3 (in Percentage Interests) vote of the
Partners constitutes the action by the Partners. Subject in all respects to the
approvals required pursuant to this Paragraph 7(a), the day-to-day Partnership
business shall be carried out by the Managing Partner. Notwithstanding the
foregoing, or anything else contained herein, the following acts and
transactions by the Partnership shall require the prior approval of the Partners
by Majority Vote:

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<PAGE>
 
        (i)  Amending this Agreement.

        (ii) Terminating, altering or amending the Partnership's licensing
status with applicable regulatory authorities.

        (iii) Purchasing any lithotripter (except for a lithotripter to replace
a lithotripter already owned by the Partnership.)

        (iv) Issuing, selling, purchasing or redeeming any interest in the
Partnership or any other form of debt or equity security.

        (v) Admitting an additional Partner of the Partnership.

        (vi) Assigning the rights in specific Partnership property to any
Partner.

        (vii) Dissolving, liquidating, or filing bankruptcy or seeking relief
under any debtor relief law.

        (viii) Confessing a judgment, initiating arbitration or litigation or
granting releases, indemnities or waivers, or entering into any settlements of
same where the amount at issue exceeds Twenty-Five Thousand Dollars ($25,000).

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<PAGE>
 
        (ix) Restricting or removing from the Partnership's principal place of
business, the organization and financial books and records of the Partnership or
the access and availability of such books and records for all Partners.

        (x) Any other act or transaction involving the Partnership not in the
ordinary course of business as currently conducted or contemplated by any budget
approved by a Majority Vote of the Partners.

        (xi) Performing any act or taking any action which may make it
impossible to carry on the ordinary business of the Partnership or any of its
subsidiaries.

        (xii) Incurring any debt or liability on behalf of the Partnership, that
is not contemplated by the then current, Partner approved, budget of the
Partnership, in excess of Twenty-Five Thousand Dollars ($25,000).

        (xiii) Entering into any transaction or agreement with a Partner or any
affiliate of a Partner, or engaging in any other act which directly or
indirectly constitutes self-dealing.

        (xiv) Amending, waiving or failing to enforce the Partnership's rights
under any agreement between the Partnership and any third party.

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<PAGE>
 
        (xv) Investing funds of the Partnership other than in (i) accounts or
instruments fully insured by the United States Government or an agency thereof,
or (ii) obligations of the federal government or agencies thereof.

        (xvi) Encumbering assets of the Partnership or incurring debt, whether
direct or contingent, by way of guaranty or otherwise.

        (xvii) Opening bank or other depository accounts and establishing or
altering the signature withdrawal authority for any such accounts.

        (xviii) Hiring or termination of any executive or managerial employee,
consultant or agent, or entering into any employment or other benefits
agreements or plans except as may be required to comply with applicable law or
in connection with the compliance with regulations relating to "affiliated
service group" issues.

        (xix)  Making any tax election under the Code.

        (xx) Organizing any subsidiary of the Partnership, including the
adoption of all organizational documents for any such subsidiary.

        (xxi) Materially changing any accounting principles or methods of the
Partnership.

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<PAGE>
 
        (xxii) Adoption of annual operating and capital expenditure budgets for
the Partnership.

        (xxiii) Any other matter which, by the terms of this Agreement, requires
a Majority Vote of the Partners.

     Notwithstanding the foregoing, none of the Partners will unreasonably
refuse to consent to approve the conversion of the Partnership to a Limited
Liability Company in the event the Partnership's independent, outside
accountants and/or legal counsel render an opinion that such conversion would be
advantageous to the Partners.

     (b) Partners' Fees. The Partners shall not receive compensation for their
         --------------
services as Partners. The Managing Partner shall receive Forty Thousand Dollars
($40,000.00) per year as compensation for its services as Managing Partner,
unless the Partnership engages another person or entity to provide management
services, in which case the compensation otherwise payable to the Managing
Partner will be reduced dollar-for-dollar by the amount paid such other person
or entity. The Partners agree that the Managing Partner may engage the services
of HealthTronics, Inc. to provide such management services. Such compensation
may be changed by a Majority Vote of Partners. Such payments to the Managing
Partner shall be made at least annually or at such other interval as the
Partners may elect. All payments to the Managing Partner as provided in this
Paragraph shall be a normal operating expense of the Partnership.

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<PAGE>
 
     (c) Other Business Ventures. During the existence of the Partnership, the
         -----------------------
Partners shall devote such time and effort to the Partnership business as may be
necessary to promote adequately the interest of the Partnership and the mutual
interests of the Partners. Any Partner or any officer, director, employee,
shareholder or other person holding a legal or beneficial interest in any entity
which is a Partner, may engage in or possess an interest in other business
ventures of every nature and description, independently or with others, and
neither the Partnership nor the other Partners shall have any right by virtue of
this Agreement in or to such independent ventures or to the income or profits
derived therefrom; provided, however, that nothing contained in this Paragraph
is intended to absolve the Partners from any liability to the Partnership or the
Partners arising as a result of any breach of fiduciary obligations to the
Partnership or the Partners. Furthermore, notwithstanding the foregoing or
anything else contained herein to the contrary, each of the Partners (severally
and not jointly) hereby agrees that, as long as they are Partners in the
Partnership, they will not directly or indirectly, either through any kind of
ownership (other than ownership of securities of a publicly held corporation of
which they own less than five percent of any class of outstanding securities),
or as a principal, agent, employer, advisor, consultant, co-partner or in any
individual or representative capacity whatever, either for their own benefit or
for the benefit of any other person, firm or corporation, without the prior
written consent of all the other Partners:

        (i) Except for services provided by the Partnership, directly or
indirectly provide lithotripsy services, including without limitation, patient
lithotripsy services, lithotripsy 

                                       11
<PAGE>
 
management services, lithotripter leasing, or similar lithotripsy services,
anywhere within 50 miles of the Chattanooga, Hamilton County, Tennessee
Courthouse;

        (ii) Directly or indirectly request or advise any patient or physician
or any other person, firm or corporation having a business relationship with the
Partnership to withdraw, curtail, or cancel its business with the Partnership;
or

        (iii) Directly or indirectly hire any employee of the Partnership or
induce or attempt to influence any employee of the Partnership to terminate his
or her employment with the Partnership.

  Provided, however, that nothing in this Agreement shall be construed to limit
or infringe upon the professional medical judgment or ability to practice
medicine of any Partner who is a physician (including, but not limited to, the
selection of appropriate facilities for medical care), and no exercise of such
Partner's professional medical judgment or act constituting the practice of
medicine shall be considered a violation of this Agreement.

  Notwithstanding the foregoing, or anything else contained herein to the
contrary, Prime shall not be deemed in violation of this Agreement in connection
with its providing of lithotripsy services and related services to and/or at the
Cleveland Community Hospital in Cleveland, Tennessee (and its successors and
assigns). Furthermore, the parties agree that in the event there is a need or
opportunity to provide lithotripsy services as contemplated in subparagraph (i)
above at a location within the restricted area at which none of Prime, any of

                                       12
<PAGE>
 
Prime's affiliates or the Partnership then provides such services, the parties
will cooperate in good faith to agree on the appropriate method of providing
such services as between Prime and the Partnership, it being understood that, in
any event, Prime and/or Prime's affiliates shall be entitled to provide such
services in the event the technology preferred by the third party to be
contracting for the services is not the technology which the Partnership has
available at that time, and the Partnership, with Prime abstaining from voting,
does not elect to acquire and implement such technology within the time frame
necessary to provide the services requested before the contracting third party
looks elsewhere for a service provider.

     (d) Indemnification of Partners. The Partnership shall indemnify and hold
         ---------------------------
harmless any Partner from and against any claim, loss, expense, liability,
action or damage resulting from any act or omission, or alleged act or omission,
arising out of its activities on behalf of the Partnership in furtherance of the
interests of the Partnership including, without limitation, reasonable costs and
expenses of litigation and appeal (including reasonable fees and expenses of
attorneys engaged by such Partner in defense of such act or omission) if the
act, omission or alleged act or omission upon which the actual or threatened
action, proceeding, or claim is based was for a purpose reasonably believed to
be in the best interests of the Partnership. However, a Partner shall not be
entitled to be indemnified or held harmless due to, or arising from, its fraud,
bad faith, gross negligence, malfeasance or its failure to comply with any
representation, warranty, covenant, condition or other agreement contained
herein, provided that any indemnification under this Paragraph shall be paid out
of and only to the extent of Partnership assets.

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<PAGE>
 
     (e) Net Worth of Partners. Each Partner and any Additional or Substituted
         ---------------------
Partner shall have and maintain at all times during which it is a Partner an
aggregate net worth sufficient to conduct the Partnership business in a prudent
manner and to preserve the classification of "partnership" for federal income
tax purposes.

  8.  Transfer of Partnership Interests.
      --------------------------------- 

     (a) Transfer of Partnership Interests. Subject to the right of first
         ---------------------------------
refusal contained in Paragraph 8(f) below, a Partner may sell, transfer, assign,
                     --------------
pledge or hypothecate ("transfer") all or part of its interest in the
Partnership, but no purchaser, transferee or assignee ("transferee") of a
Partner shall become a Substituted Partner in the place of his seller,
transferor, or assignor (the "transferor") unless the provisions of Paragraph
                                                                    ---------
8(c) have been satisfied. Any attempt to transfer a Partnership interest without
- ----
the prior written consent of all the other Partners shall be null and void ab
                                                                           --
initio. The Partnership shall have no obligation to recognize, or furnish
- ------
information or make distributions to, any transferee of a Partner who does not
become a Substituted Partner, and such transferee's rights shall be only against
his transferor. The transferee is not entitled to any of the rights, powers, or
privileges of his predecessor in interest.

     (b) Changes of Control. The change of control of ownership or management of
         ------------------
any legal entity that is a Partner shall not constitute a "transfer" for
purposes of this Agreement and shall not require any approvals of the other
Partners. Furthermore, the transfer of all or a portion of a Partner's interest
in the Partnership to an entity that controls, is controlled by, or is under
common control with, such Partner, shall not constitute a "transfer" or require
any approval of the other

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<PAGE>
 
Partners, provided the person or entity to whom such a permitted transfer is
made executes a counterpart of this Agreement and agrees to be bound by all the
terms hereof.

     (c) Substitution or Admission of a Partner. A new Partner or transferee of
         --------------------------------------
the whole or any part of a Partnership interest of a Partner shall not be
substituted or admitted as a Partner without the prior written consent of all
the other Partners, which consent is solely within the discretion of the other
Partners and which the Partners are under no obligation to give. In addition to
the foregoing, the Partners shall not allow a new Partner to be admitted or a
transferee of a Partner to become a substituted Partner until such new partner
or transferee shall have:

        (i) Executed and acknowledged such instruments as the Partners may
reasonably deem necessary or desirable to effect such substitution or admission,
including the written acceptance and adoption by the new partner or transferee
of the provisions of this Agreement;

        (ii) Provided an opinion of counsel, in form and substance reasonably
satisfactory to counsel for the Partnership, that neither the offering nor the
transfer of the Partnership interest violates any registration provisions of any
Federal or State securities law or will have an adverse effect on the
Partnership under the Code; and

        (iii) Paid such reasonable expenses as the Partnership may incur in
connection with such substitution or admission.

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<PAGE>
 
     (d) Limitation on Sale or Exchange of Partnership Interest. Notwithstanding
         ------------------------------------------------------
anything in this Agreement to the contrary, no transfer of a Partnership
interest or any portion thereof shall be made if such transfer would in the
opinion of the Partnership's counsel result in a termination of the Partnership
for federal income tax purposes or jeopardize unreasonably, or result in the
loss of, any exemption under federal or state securities laws.

     (e) Survival of Liabilities. No substitution of a transferee as a Partner
         -----------------------
shall operate to relieve the transferor of any liabilities imposed on such
transferor under the Act.

     (f) Right of First Refusal. Subject to the right of first refusal granted
         ----------------------
herein, a Partner may sell, transfer, assign or subject to a security interest,
any or all of the Partnership Interest owned by such Partner, provided, however,
that such Partner and the purchaser, transferee or assignee execute, acknowledge
and deliver to the Partners such instruments of transfer and assignment with
respect to such transaction as are in form and substance reasonably satisfactory
to the Partners. Each Partner agrees that, at least thirty (30) days prior to
any sale, transfer (by operation of law or otherwise) or assignment of an
interest, such Partner will give written notice thereof to the other Partners
including all of the terms, conditions and other material details of such sale,
transfer or assignment. The Partnership shall have the right of first refusal
for twenty days (20) following receipt of such written notice in which to elect
to consummate such sale, transfer or assignment itself on the same price, terms
and conditions. If the Partnership does not elect to exercise its option to
purchase such Partnership interest, the Partner is free to sell, transfer or
assign its interest to the proposed purchaser, transferee or assignee on the
terms and conditions

                                       16
<PAGE>
 
contained in the notice to the other Partners. However, if the Partner shall not
consummate the sale, transfer or assignment within ten (10) days after the
expiration of the Partnership's right of first refusal, such interest shall
again be subject to the right of first refusal contained herein.

  9.  Allocation of Profit and Loss.
      ----------------------------- 

     (a) Definition of Net Profit and Net Loss. "Net profit" and "net loss"
         -------------------------------------
shall mean the income or loss of the Partnership after taking into account all
expenses incurred in connection with the Partnership's business, including fees
paid to the Managing Partner, and interest on any Partnership obligations, but
without any allowance for depreciation of the Partnership's property and assets
or other non-cash expenses. The Partnership has no right to the professional
fees billed by any physician, whether such physician is a Partner or not, for
any services including, but not limited to, administering treatment using the
Partnership's facilities, interpreting results or rendering a diagnosis at the
Partnership's facility. The Partnership shall maintain its books and records on
the cash receipts and disbursements method of accounting.

    (b) Allocation of Net Profit or Net Loss.
        ------------------------------------ 

        (i) For each fiscal year in which there is a net profit in the
Partnership, such net profit shall be allocated as of the last day of each year
in which there is a net profit to the Partners ratably in accordance with their
respective Percentage Interests. For each fiscal year in which there is a net
loss in the Partnership, such net loss shall be allocated as of the last day of
each

                                       17
<PAGE>
 
Partnership year in which there is a net loss to the Partners ratably in
accordance with their respective Percentage Interests.

        (ii) Any allocation to a Partner of a share of the net profit earned or
net loss incurred by the Partnership under this Paragraph shall be deemed to be
an allocation to that Partner of the same pro rata share of each item of income,
gain, loss, deduction or credit, that is earned, realized, or available by or to
the Partnership for federal income tax purposes.

       (c) Allocation of Gain or Loss Upon Sale of Assets. Notwithstanding
           ----------------------------------------------
anything in this Agreement to the contrary, the net gain or loss from a sale or
other disposition of Partnership capital assets shall be allocated among the
Partners ratably in proportion to their respective Percentage Interests as of
the date such sale or other disposition is consummated.

  10.  Distributions.
       ------------- 

       (a) Definition of Distributable Cash. The term "Distributable Cash" shall
           --------------------------------
mean the net profit or loss for the taxable year (as defined in Paragraph 9(a),
                                                                --------------
above) decreased by (i) principal payments on any indebtedness of the
Partnership for the year, and (ii) provisions for adequate reserves for
reasonably anticipated cash expenses and potential expansion of services and
contingencies, which provisions are in the reasonable discretion of the
Partners, but consistent with Partnership budgets approved by a Majority Vote of
the Partners. The Partners shall not create reserves in order to avoid
distributions.

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<PAGE>
 
     (b) Distribution of Distributable Cash. To the extent that Distributable
         ----------------------------------
Cash for a taxable year exists or is projected, the Partnership will make
distributions of such Distributable Cash to the Partners from time-to-time as
the Managing Partner deems reasonably prudent, but not less frequently than
quarterly. Such distributions shall be made to the persons recognized as holders
of interests as of the date of distribution in proportion to the Partners'
respective Percentage Interests.

     (c) Distribution of Proceeds of Refinancing and Sale. The term "Net
         ------------------------------------------------
Proceeds" shall mean the net proceeds resulting from the refinancing of any
loan, from the sale of all or a portion of the Partnership's business or assets,
from the liquidation of the property of the Partnership following a dissolution
of the Partnership, from hazard or casualty insurance payments in excess of
amounts expended in the restoration or repair of Partnership property or applied
to Partnership obligations, from awards resulting from the condemnation of
Partnership property, or any part thereof, in excess of the amount expended in
restoration of property affected by the condemnation or applied to Partnership
obligations and from other voluntary or involuntary conversions of Partnership
property. Net Proceeds shall be distributed and applied in the following order
of priority (except that Paragraph 10(c)(i) will be applicable only in the event
                         ------------------
of liquidation):

        (i)  To the payment of the expenses of liquidation, and the debts and
liabilities of the Partnership, including indebtedness to any Partner;

                                       19
<PAGE>
 
          (ii) To the establishment of reasonable reserves, if, after the
payment of all Partnership liabilities and obligations, the Partners deem it
reasonably necessary to set up reserves for any contingent or unforeseen
liabilities or obligations of the Partnership, provided, however, that said
reserves shall be deposited with a bank or trust company designated by the
Partners for the purpose of disbursing such reserves for the payment of any of
the aforementioned contingencies and, at the expiration of such period as the
Partners may deem advisable, for the purpose of distributing the balance
thereafter remaining as hereinafter provided; and

          (iii) All such Net Proceeds remaining, or subsequently distributed
from the reserves established pursuant to (ii) above, shall be distributed to
the Partners in proportion to their respective Percentage Interests.

      (d) Good Faith Distribution by Partners. Upon the determination to
          -----------------------------------
distribute funds in the manner herein provided made in good faith, the Partners
shall incur no liability on account of such distribution, even though such
distribution may have resulted in the Partnership retaining insufficient funds
for the operation of its business which insufficiency resulted in loss to the
partnership or necessitated the borrowing of funds by the Partnership.

  11.  Books of Account and Partnership Records.
       ---------------------------------------- 

      (a) Books of Account. The Partners shall keep and maintain, or cause to be
          ----------------
kept and maintained, complete and accurate books, records and accounts of the
Partnership, which reflect all Partnership transactions and other matters
relative to the Partnership's business and shall

                                       20
<PAGE>
 
be appropriate and adequate for the Partnership's business. The expense of
maintaining the books of account shall be an expense of the Partnership.

      (b) Inspection. All books, records and accounts of the Partnership,
          ----------
together with executed copies of this Agreement and any amendments, shall be
kept at all times at the principal office of the Partnership. All Partners and
their duly authorized representatives shall have the right to examine such
books, records and accounts at any and all reasonable times and to make copies
or extracts therefrom.

      (c) Financial Reports. The Partners will be provided with monthly,
          -----------------
quarterly and annual reports detailing the performance of the Partnership during
the preceding month, quarter and calendar year, respectively. Each monthly
report shall be due not later than the 15th day of the immediately following
month, each quarterly report shall be due no later than the 15th day of the
immediately following quarter and each annual report shall be due no later than
January 31 of the immediately following year. These reports shall contain, among
other things, a balance sheet and a profit and loss statement as of the end of
the applicable month, quarter or year, as well as aged accounts receivable
listings categorized by payor class, procedure code and such narrative
explanation as reasonably necessary to make the reports informative and not
misleading. The monthly balance sheets and profit and loss statements shall be
prepared on a cash basis. The annual and quarterly balance sheets and profit and
loss statements shall be prepared on an accrual basis. The cost of preparing the
foregoing financial statements shall be borne by the Partnership, as shall the
costs of any audits thereof that may be required in order for any of the
Partners to comply with applicable securities laws. In addition to the
foregoing, as soon as practicable after the close of each

                                       21
<PAGE>
 
fiscal year but in no event later than April 1 of the next succeeding year, the
Managing Partner shall deliver to each Partner a financial report of the
Partnership for such fiscal year showing (i) distributions to the Partners and
allocations to the Partners of Partnership taxable income, gains, losses,
deductions, credits and items of tax preference, and (ii) all necessary tax
reporting information required by the Partners for preparation of their
respective income tax returns.

      (d) Accounting Decisions. All decisions as to accounting matters, except
          --------------------
as specifically provided to the contrary herein, shall be made by the Partners.
Such decisions must be acceptable to the Partnership's accountants.


      (e) Tax Returns, Taxable Year and Accounting Method. All books and records
          -----------------------------------------------
of the Partnership shall be kept on the basis of an annual accounting period
ending December 31st of each year, except for the final accounting period, which
shall end on the dissolution or termination of the Partnership. The
Partnership's taxable and fiscal years shall be the calendar year. Subject to
(f) below, all elections required or permitted to be made by the Partnership
under the Code shall be made by the Partners in such manner as will, in the
opinion of the Partnership's accountants, be most advantageous to the Partners.
At least thirty (30) days prior to its due date, the Managing Partner shall
distribute a draft of the Partnership's federal tax return to the Partners and
will not file such return unless it is approved by a Majority Vote; provided no
Partner may unreasonably withhold such approval. If the Partnership's federal
tax return is prepared in accordance with federal tax laws, no Partner may
withhold approval; and if a Partner withholds approval in such a situation that
Partner shall indemnify and hold harmless all other Partners from any loss,
claim, penalty or taxes imposed or sustained as a result of the withholding of
such

                                       22
<PAGE>
 
approval. All references herein to "fiscal year of the Partnership" or to
"fiscal year" or to "taxable year" are to the annual accounting period ending
December 31st of each year, whether the same shall consist of twelve months or
less.

     (f) Budget and Business Plan. By no later than November of each year, the
         ------------------------
Managing Partner shall prepare and submit to the Partners for their approval (i)
a budget setting forth the estimated income and expenditures (capital, operating
and other) of the Partnership for the next calendar year, and (ii) a business
plan setting forth the activities and projects to be undertaken and the services
to be performed by the Partnership for the next calendar year. Once approved by
a Majority Vote of the Partners, the Partners shall implement the approved
budgets and business plans and shall be authorized to make the expenditures and
incur the obligations provided for in the approved budgets and business plans.
The Partners shall not pursue any activities or business on behalf of the
Partnership which are not contemplated by approved budgets and business plans
except with the prior approval by Majority Vote of the Partners.

  12.  Bank Accounts.  All funds of the Partnership are to be deposited in the
       -------------                                                          
Partnership's name in such separate bank account or accounts or invested in such
interest-bearing or non-interest-bearing investments as may be designated by the
Partners.  Funds of the Partnership shall be held in the name of the Partnership
and shall not be commingled with those of any other person.

  13.  Death, Incompetency, Bankruptcy or Dissolution of a Partner.  Upon the
       -----------------------------------------------------------           
death or legal incompetency of an individual Partner, the liquidation,
dissolution or other cessation to exist as a legal entity of a Partner not an
individual, or the insolvency or bankruptcy of any Partner, the

                                       23
<PAGE>
 
Partnership shall not dissolve or terminate, unless such Partner was the last
remaining partner and subject to Paragraphs 14(d), 14(e) and 14(f) hereof, and
                                 ---------------------------------
the personal representative or successor in interest of such Partner shall have
such rights of a Partner as are necessary for the purpose of settling or
managing his estate or its affairs and the same power as said Partner had to
constitute a transferee of such Partner's Partnership interest as a substituted
Partner, but said representative shall not become a substituted Partner without
complying with the requirements of Paragraph 8(c).
                                   -------------- 

  14.  Resignation, Removal or Change of a Partner.
       ------------------------------------------- 

       (a) Withdrawal by a Partner. A Partner shall have the right to resign or
           -----------------------
withdraw from the Partnership only with the prior written consent of all the
remaining Partners; provided however, the withdrawal shall not be effective
until such time as the Partnership shall have received an opinion of counsel,
satisfactory to counsel for the Partnership, that the permitted withdrawal will
not result in (1) the reclassification of the Partnership as an association
taxable as a corporation for federal income tax purposes, (2) a termination of
the Partnership under the then existing provisions of the Code and applicable
regulations, or (3) that such withdrawal will not result in a default under any
loan agreement to which the Partnership is a party.

       (b) Removal of a Partner. Partners owning more than 67% of the Percentage
           --------------------
Interests shall have the right, for cause, exercisable by written notice given
to the Partner they seek to remove and all other Partners, to cause the removal
of a Partner. In that event, the removed Partner must sell its Partnership
interest to the Partnership, the purchase price to be the balance in such
Partner's capital account plus any debts or obligations owed to such removed
Partner by the

                                       24
<PAGE>
 
Partnership and less any debt or obligation owed to the Partnership by such
removed Partner. For purposes hereof, cause shall mean bad faith, gross
negligence, misfeasance, fraud, or intentional misconduct. In the event the
removed Partner shall contest the propriety of such removal, such dispute shall
be arbitrated in accordance with the rules then in effect of the American
Arbitration Association.

     (c) Change of Last Remaining Partner. Upon the withdrawal, bankruptcy,
         --------------------------------
dissolution, death, or legal incapacity of the last remaining Partner, such
Partner or the heirs, executors, administrators or personal representatives of
such Partner shall within ninety (90) days from his withdrawal, bankruptcy,
dissolution, death, or legal incapacity, select a successor Partner or Partners
who shall receive all or a portion of the Partnership interest of such Partner
and shall be admitted as a Partner upon compliance with Paragraph 14(d).
                                                        ---------------

     (d) Appointment of Substituted or Additional Partners. The Partners may, by
         -------------------------------------------------
Majority Vote, appoint one or more Substituted or Additional Partners, who, upon
obtaining the written consent of all the Partners, shall assume all of the
rights and obligations of the Partners designated herein. No Substituted or
Additional Partner may be appointed hereunder unless the Partnership shall have
received:

        (i) Executed and acknowledged instruments as the Partners may reasonably
deem necessary or desirable to effect such substitution or admission, including
the written acceptance and adoption by the successor or additional Partner of
the provisions of this Agreement;

                                       25
<PAGE>
 
          (ii) An opinion of counsel, in form and substance reasonably
satisfactory to counsel for the Partnership, that the admission or substitution
of the Partner will not violate any registration provisions of any federal or
state securities law or have an adverse effect on the Partnership under the
Code; and

          (iii) Payment of such reasonable expenses as the Partnership may incur
in connection with such substitution or admission.

      (e) Reformation of Partnership. If at any time there is not at least one
          --------------------------
(1) Partner in office, the holders of a majority of the Percentage Interests
may, within three (3) months following the date on which there ceased to be at
least one (1) Partner, vote to reform the Partnership and elect one or more
Partners to continue the business of the Partnership, which Substituted or
Additional Partners will be required to purchase all of the interest of the last
remaining Partner at a price equal to the capital account of such predecessor
Partner. Expenses incurred in the reformation or attempted reformation of the
Partnership shall be deemed expenses of the Partnership.

      (f) No Dissolution. The retirement, withdrawal, bankruptcy, dissolution,
death, disability, legal incapacity, or removal of a Partner or any other event
which results in such person ceasing to be a Partner shall not cause the
dissolution of the Partnership unless there is no remaining Partner to continue
the business of the Partnership, and (1) there is no transfer of a

                                       26
<PAGE>
 
Partnership interest to a person who is admitted as a Partner pursuant to this
Paragraph 14, or (2) the Partnership is not reformed pursuant to Paragraph 14.
- ------------                                                     ------------
      
       (g) Accounting. If the withdrawal or removal of a Partner does not
           ----------      
result in the dissolution and winding up of the Partnership's business because
such business is being continued, the remaining Partners shall promptly have an
accounting prepared by the Partnership's accountants covering the transactions
of the Partnership since the end of the immediately preceding fiscal year
through the date of such withdrawal or removal.

       (h) Continuing Liability of Partner. Any Partner who resigns or withdraws
           -------------------------------
from the Partnership in violation of the provisions of this Paragraph 14 shall
                                                            ------------
remain liable for payment of all debts, obligations, liabilities and commitments
of the Partnership incurred while it was a Partner to the extent the Partnership
does not have funds available for such payment and to the extent he would
otherwise have been liable. In addition, such withdrawing Partner shall be
liable to the Partnership and the other Partners for any damages sustained by
reason of such withdrawal.
 
  15.  Dissolution of the Partnership.
       ------------------------------ 

       (a) Events Causing Dissolution. The Partnership shall be dissolved and
           --------------------------
its affairs wound up on the first to occur of the following:

           (i) The withdrawal or removal of a sole remaining Partner, unless the
Partnership is reformed pursuant to Paragraph 14, above;
                                    ------------        

                                       27
<PAGE>
 
        (ii) An election to dissolve the Partnership made in writing by all the
Partners;

        (iii) The sale or other disposition by the Partnership of all or
substantially all of the Partnership's assets and the distribution of the net
proceeds from such sale; or

        (iv) The happening of an event that, under Tennessee law, causes the
dissolution of a general partnership.

     (b) Liquidation of Assets and Application of Proceeds. Upon the dissolution
         -------------------------------------------------
of the Partnership the person required by law to wind up the Partnership's
affairs (the "Liquidating Trustee") shall liquidate and reduce to cash the
assets of the Partnership as promptly as is consistent with obtaining the fair
value thereof and apply and distribute the proceeds of such liquidation in
accordance with Paragraph 10 hereof, provided that if such dissolution resulted
                ------------
from the withdrawal of a Partner in contravention of this Agreement, any payment
to that Partner pursuant to said Paragraph 10 shall be subject to offset for any
                                 ------------
such claim for damages against such Partner resulting from such withdrawal. In
connection with any such winding up and liquidation, the Partnership's
accountants shall audit the balance sheet of the Partnership as of the date of
dissolution, and such balance sheet shall promptly be furnished to all Partners.

     (c) Indemnification of Liquidating Trustee. The Liquidating Trustee shall
         --------------------------------------
be indemnified and held harmless by the Partnership from and against any and all
claims, demands,

                                       28
<PAGE>
 
liabilities, costs, damages and causes of action of any nature whatsoever
arising out of or incidental to the Liquidating Trustee's taking of any action
authorized under or within the scope of this Agreement.

       (d) Distribution in Kind. In the event it becomes necessary for the
           --------------------
Liquidating Trustee to make distribution of the Partnership property in kind,
such property shall be transferred and conveyed to the Partners so as to vest in
each of them, as tenants-in-common, an undivided interest in the whole of said
property equal to that Partner's interest in the capital of the Partnership.

  16.  Miscellaneous.
       ------------- 

       (a) Notices. All notices, demands, requests, consents or other
           -------
communications required or permitted to be given or made under this Agreement
shall be in writing and signed by the party giving the same and shall be deemed
given or made when mailed by certified or registered mail, postage prepaid, to
the intended recipient at the address set forth in this Agreement or any other
address of which prior written notice has been given. A copy of any notice given
to NGST, Inc. shall also be given to Argil J. Wheelock, M.D.

       (b) Severability. Each provision hereof is intended to be severable and
           ------------
the invalidity or illegality of any portion of this Agreement shall not affect
the validity or legality of the remainder hereof.

                                       29
<PAGE>
 
     (c) Captions. Paragraph captions contained in this Agreement are inserted
         --------
only as a matter of convenience and for reference and in no way define, limit,
or extend or describe the scope of this Agreement or the intent of any provision
hereof.

     (d) Person and Gender. The masculine gender shall include the feminine and
         -----------------
neuter genders, the singular shall include the plural and the word "person"
shall include a corporation, firm, partnership or other form of association.

     (e) Binding Agreement. Subject to the restrictions on assignment herein
         -----------------
contained, the terms and provisions of this Agreement shall be binding upon, and
inure to the benefit of, the successors, assigns, personal representatives,
estates, heirs and legatees of the respective Partners.

     (f) Applicable Law. Notwithstanding the place where this Agreement may be
         --------------
executed by any of the parties hereto, the parties expressly agree that all the
terms and provisions hereof shall be construed under the laws of the State of
Tennessee.

     (g) Investment Representations. The parties hereby represent each to the
         --------------------------
others that they are over twenty-one (21) years of age, that they are acquiring
interests in this Partnership with the purpose of investment and not for the
purpose of resale.

                                       30
<PAGE>
 
     (h) Entire Agreement. This Agreement constitutes the entire agreement of
         ----------------
the parties hereto with respect to the matters set forth herein and supersedes
any prior understanding or agreement, oral or written, with respect thereto.

     (i) Modifications. No change, modification or amendment of this Agreement
         -------------
shall be valid or binding upon the Partners unless it is in writing and signed
by all of the Partners.

     (j) Agreement in Counterparts. This Agreement may be executed in several
         -------------------------
counterparts and all so executed shall constitute one Agreement, binding on all
the parties hereto, notwithstanding that all the parties are not signatories to
the original or the same counterpart.

  IN WITNESS WHEREOF, the parties hereto have entered into this Agreement as of
the date first above written.

                                       31
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT


                                    /s/ Argil J. Wheelock, M.D.    
                                    ------------------------------------ 
                                    Argil J. Wheelock, M.D.

                                       32
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT


                                    /s/ Richard S. Lasky, M.D.
                                    ------------------------------------ 
                                    Richard S. Lasky, M.D.

                                       33
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    /s/ R. Smith Murray, M.D.
                                    ------------------------------------ 
                                    R. Smith Murray, M.D.

                                       34
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    /s/ Thomas C. Bright, M.D
                                    ------------------------------------ 
                                    Thomas C. Bright, M.D.

                                       35
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    /s/ Marty Scheinberg, M.D.
                                    ------------------------------------ 
                                    Marty Scheinberg, M.D.

                                       36
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    /s/ James E. McKinney, M.D.
                                    ------------------------------------ 
                                    James E. McKinney, M.D.

                                       37
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    /s/ Paul E. Henson, M.D.
                                    ------------------------------------ 
                                    Paul E. Henson, M.D.

                                       38
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    /s/  Charles Hawkins, M.D.
                                    ------------------------------------ 
                                    Charles Hawkins, M.D.

                                       39
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    /s/ John F. Bryant, M.D.
                                    ------------------------------------ 
                                    John F. Bryant, M.D.

                                       40
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    NGST, INC.


                                    By: /s/ Argil J. Wheelock, M.D. 
                                       --------------------------------- 

                                    Printed Name: Argil J. Wheelock, M.D. 
                                                 ----------------------- 

                                    Title: President
                                          ------------------------------ 

                                       41
<PAGE>
 
                    SIGNATURE PAGE TO PARTNERSHIP AGREEMENT



                                    PRIME LITHOTRIPTER
                                    OPERATIONS, INC.


                                    By: /s/ Cheryl Williams
                                       --------------------------------- 

                                    Printed Name:  Cheryl Williams
                                                 ----------------------- 

                                    Title: Treasurer
                                          ------------------------------ 

                                       42
<PAGE>
 
                                   EXHIBIT A

                                       TO

                             PARTNERSHIP AGREEMENT

                                      FOR

                            TENN-GA STONE GROUP TWO



                                                      Ownership
                                                     Percentage
Partners                                              Interests
- --------                                              ---------   
Thomas C. Bright, M.D.
700 Olympic Plaza Circle                               2.777%
Suite 910
Tyler, Texas 75701
 
John F. Bryant, M.D.                                            
779 E. Third Street                                    2.777%
Suite 702
Chattanooga, TN 37403
 
 
Charles Hawkins, M.D.                                       
409 Dodds Avenue                                       2.777%
Chattanooga, TN 37404
 
 
Paul E. Henson, M.D.                          
1837 Wood Valley Drive                                 2.777%
Chattanooga, TN 30720
 
 
Richard S. Lasky, M.D.                                        
8320 E. Crestwood Circle                               2.777%
Tucson, AZ
 
 
James E. McKinney, M.D.                     
1109 Burleyson Drive                                   2.777%
Dalton, GA 30720

                                       43
<PAGE>
 
                                                     Ownership
                                                    Percentage
Partners                                             Interests
- --------                                             ---------   
 
R. Smith Murray, M.D.
725 Glenwood Drive                                     2.777%
Suite 484
Memorial Medical Bldg. East
Chattanooga, TN 37404
 
Marty Scheinberg, M.D.                        
779 E. Third Street                                    2.777%
Suite 702
Chattanooga, TN 37403
 
 
Argil J. Wheelock                                            
1000 Scenic Highway                                    2.777%
Lookout Mountain, TN 37350
 
 
NGST, Inc.                                            36.75 %
One Central Plaza
Sixth Floor
835 Georgia Avenue
Chattanooga, TN  37402
 
Prime Lithotripter Operations, Inc.                   38.25 %
1301 Capital of Texas Highway
Suite C-300
Austin, Texas 78746                                       
 
                                                      ------
                                     TOTAL            100.0 %
                                                      ======

                                       44


<PAGE>
 
                                   EXHIBIT C



                             ASSIGNMENT AGREEMENT
                             --------------------



     NGST, Inc., a Tennessee corporation ("Assignor") for and in consideration
of the sum of Ten and No/100 Dollars ($10.00) and other good and valuable
consideration paid by Prime Lithotripter Operations, Inc., a New York
corporation ("Purchaser"), the receipt and sufficiency of which is hereby
acknowledged, and in accordance with the terms and provisions of that certain
Partnership Interest Purchase Agreement (the "Purchase Agreement") made and
entered into effective as of the 1st day of May, 1997, between and among
Purchaser, Tenn-Ga Stone Group Two, L.P., a Tennessee limited partnership (the
"Limited Partnership"); Assignor; and all the shareholders of Assignor, hereby
assigns, transfers and sets over to Purchaser, its successors and assigns, with
such representations, warranties and covenants as are expressly set forth in the
Purchase Agreement, all of Assignor's right, title and interest in and to a
thirty-eight and one-fourth percent (38.25%) general partnership interest in
Tenn-Ga Stone Group Two, a Tennessee general partnership (the "Partnership").



     Assignor acknowledges and agrees that Purchaser does not assume any
liabilities or obligations of any kind whatsoever from the Partnership, the
Partnership's predecessor - the Limited Partnership, Assignor or any of the
other parties to the Purchase Agreement. Without limiting the generality of the
foregoing, Assignor hereby expressly acknowledges and agrees that Purchaser is
not assuming any debts, liabilities, or obligations of the Partnership, the
Limited Partnership, Assignor, any of the shareholders of Assignor or any of the
other partners of the Partnership or of the Limited Partnership, or any claims
against the Partnership, the Limited Partnership, Assignor, any of the
shareholders of Assignor or any of the other partners of the
<PAGE>
 
Partnership or of the Limited Partnership, whether known or unknown, or
absolute, contingent or otherwise (including, but not limited to, any
liabilities arising from any civil, criminal or regulatory litigation or action
involving or related to the Partnership, the Limited Partnership, Assignor, any
of the shareholders of Assignor or any of the other partners in the Partnership
or of the Limited Partnership, or their businesses) and Assignor hereby agrees
to indemnify Purchaser and hold Purchaser harmless from and against any such
debts, liabilities and obligations. However, nothing contained herein is
intended or should be construed to preclude Purchaser's liability, in its role
as a general partner of the Partnership after the Closing (as defined in the
Purchase Agreement) with respect to claims, debts, liabilities or obligations
that arise wholly out of actions, events or omissions occurring after the
Closing Date (as defined in the Purchase Agreement), and Assignor shall have no
indemnity obligation to Purchaser with respect to such claims, debts,
liabilities or obligations.



     IN WITNESS WHEREOF, Assignor has caused this Assignment to be executed by
its duly authorized representative effective for all purposes the 1st day of
May, 1997.



ASSIGNOR:                                     NGST, INC.



                                         By: /s/ Argil J. Wheelock, M.D. 
                                                 -------------------------------

                                         Printed Name: Argil J. Wheelock, M.D.
                                                       ---------------------
                                                              
                                         Title:     President
                                                    ----------------------------
<PAGE>
 
                                   EXHIBIT D



                           NONCOMPETITION AGREEMENT
                           ------------------------



  This Noncompetition Agreement (this "Agreement") is entered into as of the 1st
day of May, 1997, by _____________________________________________ (the
"Affiliate") for the benefit of Prime Lithotripter Operations, Inc., a New York
corporation ("Prime"), and Tenn-Ga Stone Group Two, a Tennessee general
partnership (the "Partnership").


                                   RECITALS:


  WHEREAS, Affiliate either (i) owns a partnership interest in the Partnership,
(ii) owns shares in NGST, Inc., a Tennessee corporation ("NGST"), which is the
owner of a partnership interest in the Partnership, and/or (iii) is otherwise
affiliated with, or otherwise has certain common equity owners with, either the
Partnership, NGST, or one or more of the other partners in the Partnership; and

  WHEREAS, concurrently with the execution of this Agreement, Prime, NGST, the
shareholders of NGST and the Partnership are consummating that certain
Partnership Interest Purchase Agreement dated effective May 1, 1997 (the
"Purchase Agreement"), pursuant to which Prime will become a general partner in
the Partnership, as more fully described in the Purchase Agreement.
<PAGE>
 
 WHEREAS, in order to induce Prime to consummate the transactions contemplated
by the Purchase Agreement, Affiliate has agreed to certain restrictions on
Affiliate's activities, which restrictions Affiliate deems reasonable in light
of the circumstances.

  THEREFORE, the parties hereto agree as follows:


                                  AGREEMENTS:


  1.  Noncompetition.  During the term of this Agreement, Affiliate hereby
      --------------                                                      
agrees that, without the prior written consent of Prime, Affiliate shall not
directly or indirectly acquire any interest in (other than ownership of
securities of a publicly held corporation of which Affiliate owns less than five
percent (5%) of any class of outstanding securities), or in any way act as
principal, employee, officer, director, agent, advisor, consultant, co-partner
or in any other capacity of or to, any business venture which competes with
Prime or the Partnership. A business entity shall be considered to compete with
Prime or the Partnership if it directly or indirectly, provides extracorporeal
shockwave lithotripsy services including without limitation, patient lithotripsy
services, lithotripsy management services, lithotripter leasing, or similar
lithotripsy services, anywhere within fifty (50) miles of the Chattanooga,
Hamilton County, Tennessee Courthouse. Further, Affiliate, to the fullest extent
allowed by law, agrees not to:


      (i) directly or indirectly request or advise any corporation, firm,
   association, entity or individual, having a business relationship with the
   Partnership or Prime to withdraw, curtail or cancel its business with the
   Partnership or Prime;

                                       2
<PAGE>
 
      (ii) directly or indirectly induce or attempt to influence any employee of
   the Partnership or Prime to terminate his or her employment with the
   Partnership or Prime; or



      (iii) directly or indirectly make any statement, written or oral, or
   perform any other act or omission which is, or is likely to be, materially
   detrimental to the goodwill of the Partnership or Prime.


     Provided, however, that nothing in this Agreement shall be construed to
limit or infringe upon Affiliate's professional medical judgment or ability to
practice medicine (including, but not limited to, the selection of appropriate
facilities for medical care), and no exercise of his or her professional medical
judgment or act constituting the practice of medicine shall be considered a
violation of this Agreement.


  2.  Term and Termination.  The term of this Agreement shall begin on the date
      --------------------                                                     
hereof and continue until five (5) years after the date that Affiliate is no
longer, directly or indirectly, (i) a partner in the Partnership, (ii) an owner
of any equity or other voting ownership interest, or any right convertible into
any equity or other voting ownership interest, in any partner in the Partnership
or of any affiliate of the Partners or of any partner in the Partnershp, or
(iii) an affiliate of, or affiliated through any common equity owners with,
either the Partnership, or any of partners in the Partnership. For purposes of
this Agreement, the Partnership shall include the Partnership and its successors
and assigns, and the references to a "partner" in the Partnership shall be
deemed to

                                       3
<PAGE>
 
include any owner of any equity or other voting ownership interest in any such
successor or assign of the Partnership. If during any calendar month within the
term of this Agreement Affiliate is not in compliance with the terms of this
Agreement, the Partnership and Prime shall be entitled to, among all other
remedies, compliance by Affiliate with the terms of this Agreement for an
additional number of full calendar months that equals the number of calendar
months during which such noncompliance occurred. The term of this Agreement
shall also include this additional period. The two immediately preceding
sentences of this Section 2 and the terms of Section 3 hereof shall not in any
way relieve Affiliate of any obligations hereunder or otherwise reduce
Affiliate's liability for damages for breach hereof.


  3.  Breach.  Affiliate agrees that a violation of any covenant contained in
      ------                                                                 
Section 1 will irreparably damage the Partnership and Prime for which remedies
at law may be insufficient, and for that reason, Affiliate further agrees that
the Partnership and Prime shall each, independently be entitled as a matter of
right to equitable remedies, including specific performance and injunctive
relief, therefor.  The right to specific performance and injunctive relief shall
be cumulative and in addition to whatever other remedies, at law or in equity,
that the Partnership or Prime may have, including, specifically, recovery of
additional damages. This Agreement is made for the independent benefit of each
of Prime and the Partnership, and Prime and the Partnership shall be entitled to
enforce this Agreement, or seek damages for any breach or threatened breach
hereof without any requirement of acting jointly. Furthermore, any waiver by the
Partnership or Prime on any one or more occasions shall not be deemed to be a
waiver of the right of the other beneficiary hereof or to constitute a further
or continuing waiver of either beneficiary's rights hereunder. No release by
either Prime or the Partnership of any rights or causes of action against
Affiliate will

                                       4
<PAGE>
 
constitute a release of the rights of the other beneficiary, it being understood
and agreed that neither Prime nor the Partnership has the right to amend, waive,
discharge, release or otherwise modify any terms or conditions of this Agreement
or the obligations of Affiliate hereunder, for or on behalf of the other
beneficiary of this Agreement.

  4.  Reasonableness of Restrictions.  Affiliate and Affiliate's counsel have
      ------------------------------                                         
reviewed and carefully considered the provisions of this Agreement, and, having
done so, Affiliate agrees that the restrictions set forth herein (a) are fair
and reasonable with respect to time, geographic area and scope, (b) are not
unduly burdensome to Affiliate, and (c) are reasonably required for the
protection of the interests of the Partnership and Prime.

  5.  Miscellaneous.
      ------------- 

      (a) Entirety and Amendments. This Agreement may be modified or amended
          -----------------------
   only by an instrument in writing executed by each of Affiliate, the
   Partnership and Prime.

      (b) Headings. The headings contained in this Agreement are for reference
          -------- 
   purposes only and shall not affect in any way the meaning or interpretation
   of this Agreement.

      (c) Counterparts. This Agreement may be executed in any number of
          ------------   
   counterparts, each of which shall be deemed an original, but in making proof
   hereof it shall not be necessary to produce or account for more than one such
   counterpart.

                                       5
<PAGE>
 
      (d)  Governing Law.  This Agreement shall be construed and enforced in
           -------------                                                    
   accordance with the laws of the State of Tennessee.

      (e) Parties Bound. This Agreement shall be binding upon, inure to the
          -------------
   benefit of and be enforceable by and against, the Partnership, Prime,
   Affiliate and their respective successors, representatives and permitted
   assigns. This Agreement is personal to Affiliate and may not be assigned by
   Affiliate in whole or in part, without the prior express written consent of
   all parties hereto in each instance.

      (f) Invalid Provisions. If any provision of this Agreement (including,
          ------------------
   without limitation, any provision relating to the activities covered by, or
   time period of, the covenants contained in Section 1 of this Agreement) is
   held to be illegal, invalid or unenforceable under present or future laws
   effective during the term hereof, such provision shall be fully severable;
   this Agreement shall be construed and enforced as if such illegal, invalid or
   unenforceable provision had never comprised a part hereof; and the remaining
   provisions shall remain in full force and effect and shall not be affected by
   the illegal, invalid or unenforceable provision or by its severance herefrom.
   Furthermore, in lieu of such illegal, invalid or unenforceable provision,
   there shall be added automatically as a part of this Agreement a provision as
   similar in terms to such illegal, invalid or unenforceable provision as may
   be possible and be legal, valid and enforceable.

      (g) Construction. This Agreement shall be construed without regard to the
          ------------
   identity of the person who drafted the various provisions of this Agreement.
   Each and every

                                       6
<PAGE>
 
   provision of this Agreement shall be construed as though all of the parties
   participated equally in the drafting of this Agreement. Consequently, the
   parties acknowledge and agree that any rule of construction that a document
   is to be construed against the drafting party shall not be applicable to this
   Agreement.

  EXECUTED to be effective as of the date first above written.



PRIME:                          PRIME LITHOTRIPTER OPERATIONS, INC.



                                By: /s/ Cheryl Williams
                                   ----------------------------------- 
                                    Cheryl Williams, Treasurer

                                       7
<PAGE>
 
                  SIGNATURE PAGE TO NONCOMPETITION AGREEMENT



PARTNERSHIP:                         TENN-GA STONE GROUP TWO,
                                     a Tennessee general partnership


                                     By: /s/ Argil J. Wheelock.
                                        ------------------------------
                                     Printed Name: Argil J. Wheelock, M.D
                                                   -------------------
                                     Title: Partner
                                           ---------------------------

                                       8
<PAGE>
 
                  SIGNATURE PAGE TO NONCOMPETITION AGREEMENT



AFFILIATE:


                                     By:
                                        ------------------------------
                                     Printed Name:
                                                   -------------------
                                     Title:
                                           ---------------------------

                                       9


<PAGE>
 
                      PRIME LITHOTRIPTER OPERATIONS, INC.
                                        


                              Closing Certificate
                              -------------------



     I, Michael S. Madler, as President of Prime Lithotripter Operations, Inc.,
a New York corporation ("Prime"), pursuant to the requirements of that certain
Partnership Interest Purchase Agreement ("Purchase Agreement") made and entered
into effective the 1st day of May, 1997, between and among Tenn-Ga Stone Group
Two, L.P., a Tennessee limited partnership, (the "Partnership"), NGST, Inc., a
Tennessee corporation ("NGST"), and all of the shareholders of NGST (each of
which is individually referred to in the Purchase Agreement as a "Shareholder"
and all of which are collectively referred to therein as the "Shareholders")
Thomas C. Bright, M.D.; Argil J. Wheelock, M.D.; R. Smith Murray, M.D.; Richard
S. Lasky, M.D.; John F. Bryant, M.D.; Marty Scheinberg, M.D.; James E. McKinney,
M.D.; Paul E. Henson, M.D.; Oliver Benton, III, M.D.; Stephen W. Jackson, M.D.;
C. A. Kyle, Jr., M.D.; Nicholas Newton, M.D.; Jack Monnig, M.D.; Samuel M.
Currin, M.D.; J. Patrick Dilworth, M.D.; David Sahaj, M.D.; John Bryan, M.D.;
Paula Willingham and Robert DeBord., do hereby certify:



     (1) All of the representations and warranties contained in the Purchase
Agreement by Prime are true and correct at and as of the Closing.



     (2) All agreements to be performed and complied with by Prime under the
Purchase Agreement at or prior to the Closing have been performed or complied
with by Prime.



     (3) Prime is aware of no breach by the Partnership, NGST or the
Shareholders of (i) their respective representations and warranties contained in
the Purchase Agreement, or (ii) any of their respective agreements to be
performed or complied with at or prior to the Closing, pursuant to the Purchase
Agreement.



     The terms as used herein, not otherwise defined herein, shall have the
respective meanings assigned to such terms in the Purchase Agreement.



     IN WITNESS WHEREOF, I have hereunto set my hand on this 13th day of May,
1997.



                                PRIME LITHOTRIPTER OPERATIONS, INC.




                                By /s/ Michael S. Madler                      
                                  ----------------------------------------
                                  Michael S. Madler, President

<PAGE>
 
                           STOCK PURCHASE AGREEMENT
                                        
                              With Respect to All
                         Outstanding Capital Stock of

                      EXECUTIVE MEDICAL ENTERPRISES, INC.
                                        



                         EFFECTIVE DATE: JUNE 1, 1997
<PAGE>
 
                               TABLE OF CONTENTS
                                        

                                                                            Page
                                                                            ----
                                                                                
ARTICLE I - AGREEMENT OF PURCHASE AND SALE AND CLOSING......................   1
            1.1 Purchase and Sale...........................................   1
            1.2 Purchase Price..............................................   1
            1.3 Earn-Out Adjustments........................................   2
            1.4 Closing.....................................................  12

ARTICLE II - REPRESENTATIONS AND WARRANTIES OF SUN MEDICAL..................  12
            2.1 Due Organization and Principal Executive Office.............  12
            2.2 Due Authorization...........................................  13
            2.3 Brokers and Finders.........................................  13
            2.4 Claims and Proceedings......................................  14
            2.5 Investment Intent...........................................  14

ARTICLE III - REPRESENTATIONS AND WARRANTIES OF THE SELLERS.................  15
            3.1 Due Organization............................................  15
            3.2 Subsidiaries................................................  15
            3.3 Due Authorization...........................................  16
            3.4 Financial Statements........................................  17
            3.5 Capital Stock...............................................  18
            3.6 Conduct of Business; Certain Actions........................  19
            3.7 Ownership of Assets:  Licenses, Permits, etc................  20
            3.8 Liabilities.................................................  22
            3.9 Environmental Issues........................................  23
            3.10 Intellectual Property Rights...............................  24
            3.11 Compliance with Laws.......................................  24
            3.12 Insurance..................................................  24
            3.13 Employee Benefit Matters...................................  25
            3.14 Contracts and Agreements...................................  26
            3.15 Claims and Proceedings.....................................  26
            3.16 Taxes......................................................  27
            3.17 Personnel..................................................  28
            3.18 Business Relations.........................................  29
            3.19 Accounts Receivable........................................  29
            3.20 Agents.....................................................  29
            3.21 Indebtedness To and From Partners and Employees............  29
            3.22 Commission Sales Contracts.................................  30
            3.23 Certain Consents...........................................  30
            3.24 Brokers....................................................  30
            3.25 Interest in Competitors, Suppliers, and Customers..........  30
            3.26 Warranties.................................................  31


                                       i
<PAGE>
 
            3.27 Extinguishment of Indebtedness.............................  31
            3.28 No Known Breaches..........................................  31

ARTICLE IV - COVENANTS AND AGREEMENTS.......................................  32
            4.1 Cooperation Relating to Financial Statements................  32
            4.2 Strip-Out Transactions......................................  32
            4.3 Guaranty of Prime...........................................  33
            4.4 Conduct of EME Post-Closing.................................  33
            4.5 Qualification in Washington and Oregon......................  33

ARTICLE V - CLOSING OBLIGATIONS.............................................  34
            5.1 Sun Medical's Closing Obligations...........................  34
            5.2 The Sellers' Closing Obligations............................  35

ARTICLE VI - INDEMNIFICATION OF SUN MEDICAL.................................  36
            6.1 Survival of Representations; Time Limits; Knowledge.........  36
            6.2 Indemnification of Sun Medical..............................  37
            6.3 Defense of Third-Party Claims...............................  39
            6.4 Limitations.................................................  41

ARTICLE VII - INDEMNIFICATION OF THE SELLERS................................  42
            7.1 Survival of Representations; Time Limits; Knowledge.........  42
            7.2 Indemnification of the Sellers..............................  43
            7.3 Defense of Third-Party Claims...............................  43
            7.4 Limitations.................................................  45

ARTICLE VIII - NON-COMPETITION..............................................  47

ARTICLE IX - POST CLOSING AGREEMENTS........................................  49

ARTICLE X - MISCELLANEOUS...................................................  50
            10.1 Collateral Agreements, Amendments, and Waivers.............  50
            10.2 Successors and Assigns.....................................  51
            10.3 Expenses...................................................  51
            10.4 Invalid Provisions.........................................  51
            10.5 Information and Confidentiality............................  52
            10.6 Waiver.....................................................  52
            10.7 Notices....................................................  52
            10.8 Survival of Representations, Warranties, and Covenants.....  53
            10.9 Further Assurances.........................................  54
            10.10 Construction..............................................  54
            10.11 Arbitration...............................................  54
            10.12 Governing Law.............................................  55
            10.13 Counterparts..............................................  55


                                      ii
<PAGE>
 
Exhibit A  --  EMEI Financial Statements

Exhibit B  --  Form of Assignment and Stock Power

Exhibit C  --  Form of Lease Agreement





                                      iii
<PAGE>
 
                           STOCK PURCHASE AGREEMENT
                                        

     This Stock Purchase Agreement (this "Agreement") is entered into effective
as of the close of business on June 1, 1997 (the "Effective Time"), between Sun
Medical Technologies, Inc., a California corporation ("Sun Medical"), Prime
Medical Services, Inc., a Delaware corporation ("Prime"), Executive Medical
Enterprises, Inc., a Delaware corporation ("EME"), Joseph Fazio ("Fazio"),
Vernon Gordon ("Gordon") and John Pecora ("Pecora"). Fazio, Gordon and Pecora
are hereinafter referred to collectively as the "Sellers" and individually as a
"Seller."

     The parties hereto agree as follows:

                                   ARTICLE I

                  AGREEMENT OF PURCHASE AND SALE AND CLOSING
                  ------------------------------------------
                                        
     1.1    PURCHASE AND SALE.  Upon the basis of the representations and
            -----------------                                           
warranties, for the consideration, and subject to the terms and conditions set
forth in this Agreement, Sellers agree to sell to Sun Medical and Sun Medical
agrees to purchase from Sellers, all of the issued and outstanding shares of
capital stock, including without limitation all common and preferred stock,
(collectively, the "Shares") of EME.

     1.2    PURCHASE PRICE.  The aggregate purchase price (the "Purchase Price")
            --------------                                              
for the Shares shall equal (i) $1,339,000, to be paid in cash or wired funds at
the Closing (the "Closing Payment") and to be allocated among the Sellers
ratably in accordance with their respective percentage ownership of the Shares
as set forth on Schedule 1.2(a) attached hereto (the "Ownership Percentages"),
                ---------------                                
subject to the Earn-Out Adjustments determined in accordance with
<PAGE>
 
Section 1.3, plus (ii) the amount of those certain expenses of EME as set forth
on Schedule 1.2(b).
   --------------- 

     1.3    EARN-OUT ADJUSTMENTS.  The Purchase Price shall be increased or
            --------------------                                           
decreased by the following adjustments described in subsections a-g below (the
"Earn-Out Adjustments").

            a. The parties have estimated that EME service $400,000, and (ii)
1.75 times the difference agreements set forth under the heading "Class A
between $309,000 and the Projected Revenue (as Contracts" on Schedule 1.3 (the
                                                             ------------ 
"Class A defined below) from those of the Class A Contracts Contracts"),
generate $309,000 of revenue to EME which are renewed. As used in the foregoing
annually. The Purchase Price will be increased by sentence "Projected Revenue"
shall mean, with an amount equal to the sum of (i) respect to any Class A
Contract that is renewed, the product of (A) the estimated annualized number of
procedures for such Class A Contract, as set forth on Schedule 1.3 hereto
                                                      ------------ 
opposite such Class A Contract, multiplied by (B) the per-procedure amount
payable to EME under such renewed Class A Contract. A Class A Contract shall be
deemed to be "renewed" if either (A) it is formally renewed or extended or a new
contract is entered into by the parties thereto after the Closing Date but prior
to the applicable date for such contract as set forth in (I) or (II) of clause
(B) of this sentence, or (B) EME continues to provide lithotripsy services
thereunder at any time (I) after January 31, 1998, with respect to the "Antelope
Valley" and "General Hospital" Class A Contracts or (II) after April 15, 1998,
with respect to the "Centinela Hospital" and "Ridgecrest Hospital" Class A
Contracts. If the foregoing calculation yields a positive number, such amount
will be paid to Sellers in cash on April 30, 1998, to be allocated among them
ratably in


                                       2
<PAGE>
 
accordance with their Ownership Percentages. If the calculation yields zero or a
negative number, then no additional amount will be due Sellers under this
subsection a. The following example (which is purely for purposes of
illustration) reflects the foregoing methodology:
 
 Estimated Annual Revenue
  - Class A Contracts...................    $309,000
 Projected Revenue - Class
  A Contracts Renewed...................    $245,000 
                                           ---------
 Shortfall (deficiency of
  Projected from Estimated)                 ($64,000)
 Multiplied by 1.75.....................     x  1.75
                                           ---------
                                           ($112,000)

 Add $400,000...........................    $400,000           
                                           ---------
 Earn-Out Adjustment -
  Payable ratably to
  Sellers 4/30/98.......................    $288,000
                                           =========
 
            b. The parties have estimated that EME service agreements set forth
unde the heading "Class B" Contracts on Schedule 1.3 (the "Class B Contracts"),
                                        ------------
generate $753,000 of revenue to EME annually. The Purchase Price will be
increased by an amount equal to the sum of (i) $939,000, and (ii) 1.75 times the
difference between $753,000 and the Projected Revenue (as defined below) from
those of the Class B Contracts which are renewed during 1998. As used in the
foregoing sentence, "Projected Revenue" shall mean, with respect to any Class B
Contract renewed in 1998, the product of (A) the estimated annualized number of
procedures for such Class B Contract, as set forth on Schedule 1.3 hereto
                                                      ------------ 
opposite such Class B Contract, multiplied by (B) the per-procedure amount
payable to EME under such renewed Class B Contract. A Class B Contract shall be
deemed to be "renewed in 1998" if either (A) it is formally renewed or


                                       3
<PAGE>
 
extended or a new contract is entered into by the parties thereto after the
Closing Date but prior to January 30, 1999, OR (B) EME continues to provide
lithotripsy services under such Class B Contract at any time after January 30,
1999. If the foregoing calculation yields a positive number, such amount will be
paid to Sellers in cash on February 15, 1999, to be allocated among them ratably
in accordance with their Ownership Percentages. If the calculation yields zero
or a negative number, then no additional amount will be due Sellers under this
subsection b. The following example (which is purely for purposes of
illustration) reflects the foregoing methodology:



 Estimated Annual Revenue - Class B Contracts...................   $753,000

 Projected Revenue - Class B Contracts Renewed in 1998..........   $866,000
                                                                 ----------

 Excess of Projected over Estimated.............................   $113,000

 Multiplied by 1.75.............................................   x   1.75
                                                                 ----------
                                                                   $197,750
                                         
 Add $939,000...................................................   $939,000  
                                                                 ----------

 Earn-Out Adjustment - Payable ratably to Sellers 2/15/99....... $1,136,750
                                                                 ==========


          c.  The contracts described in Schedule 1.3 as "Class C Contracts"
                                         ------------                       
will not be considered in determining the Earn-Out Adjustments described in
subsections a. and b. above. Sun Medical will pay Sellers (to be allocated
ratably amongst them in accordance with their Ownership Percentages) an amount
equal to fifty percent (50%) of the Gross Revenue from Class C Contracts in each
of the three (3) years ending June 1, 1998, 1999 and 2000. As used in



                                       4
<PAGE>
 
the foregoing sentence, "Gross Revenue" shall mean the aggregate amounts billed
by EME pursuant to the Class C Contracts, less (i) the amount of applicable
medical director fees, if any, and (ii) reasonable reserves for uncollectible
amounts billed under the Class C contracts for such years, and contractual
reserves related thereto, as established throughout the three (3) year period
based on historical experience. However, if Sun Medical utilizes a new
partnership or other new entity with physician investors to provide lithotripsy
services to any hospital subject to a Class C Contract, then with regard to that
hospital, the amount payable from that point forward through the end of the
three (3) years will be reduced to 50% of the net income earned by Sun Medical
with respect to its ownership interest in such partnership or entity to the
extent such net income is attributable to lithotripsy services provided by the
partnership or entity to that hospital, after deduction of all direct costs
associated therewith and an allocable share of all indirect costs (which
indirect costs will be allocated ratably based on the number of lithotripsy
procedures performed at each hospital or other facility serviced by the
partnership or entity). Any amounts due Sellers under this subsection c. will be
paid in cash within 45 days after the end of the year for which the payment was
due.


          d.  The EME service agreements listed under the heading "Class D
Contracts" on Schedule 1.3 hereto (the "Class D Contracts") will be subject to
              ------------                                                    
the adjustments described in this subsection d. and not pursuant to subsections
a., b., or c. above.

              (i) From the Effective Time through September 30, 1997, EME shall
lease from Newco (as defined in Section 4.2 below) the HM-4 and tractor
identified as the

                                       5
<PAGE>
 
"Leased Equipment" on Schedule 1.3d.(i) (the "Leased Equipment") in exchange for
                      -------------
a monthly lease payment of $7,000, and pursuant to the form of lease agreement
attached hereto as Exhibit C;
                   --------- 

              (ii)  On or before October 30, 1997, Sun Medical will pay to the
Sellers, to be allocated amongst them ratably in accordance with their Ownership
Percentages, 50% of the EME Net Income with respect to each such Class D
Contract from the Effective Time through September 30, 1997.   As used in the
foregoing sentence, and in clauses (iii) and (v) below, "EME Net Income" with
respect to any Class D Contract shall mean the aggregate amounts billed by EME
with respect thereto during the applicable period less (i) any direct operating
expenses (including, without limitation, rental payments from EME to Newco)
incurred by EME in servicing such Class D Contract, and (ii) reasonable reserves
for uncollectible amounts billed under the Class D Contracts for the applicable
period, and contractual reserves related thereto, as established based on
historical experience;

              (iii) If all Class D Contracts are renewed in 1997 (as described
in clause (A) of the definition for renewal, and without any being renewed
pursuant to clause (B) of such definition) without Sun Medical utilizing a new
partnership or other entity with physician investors, on September 30, 1997 Sun
Medical or EME will pay to Newco $250,000 in exchange for Newco's transfer to
Sun Medical or EME of all right, title and interest in and to the Leased
Equipment, subject to no liens, claims or encumbrances whatsoever. Furthermore,
for any Class D Contracts renewed in 1997, within 45 days following each of the

                                       6
<PAGE>
 
twelve-month periods ended September 30, 1998, 1999 and 2000, Sun Medical will
pay to the Sellers, to be allocated amongst them ratably in accordance with
their Ownership Percentages, 50% of the EME Net Income with respect to each such
renewed Class D Contract during such twelve-month period.   As used in this
subsection d., a Class D Contract shall be deemed to be "renewed in 1997" if
either (A) prior to September 30, 1997, it is formally renewed or extended or a
new contract is entered into by the parties thereto, without Sun Medical
utilizing a new partnership or other entity with physician investors, or (B) EME
continues to provide lithotripsy services thereunder at any time after September
30, 1997;

              (iv) If any such Class D Contract is not renewed in 1997 but, on
or before September 30, 1997, Sun Medical utilizes a new partnership or other
entity with physician investors to provide lithotripsy services to any hospital
subject to a Class D Contract, then (A) within six (6) months after the date
such entity is formed Sun Medical, at its discretion, will either (I) pay to
Newco $250,000 in exchange for Newco's transfer to Sun Medical of full and clear
title to the Leased Equipment as described in paragraph (iii) above, or (II) in
the event partnership or other entity determines to utilize different
lithotripsy equipment, other than a Dornier HM-4, (which could include equipment
then owned or used by Sun Medical, Prime or any of their respective affiliates)
enter into a month-to-month lease with respect to the Leased Equipment (until
such time as such different lithotripsy equipment is utilized) upon such terms
and conditions, if any, as may be mutually satisfactory to Newco and Sun
Medical, and (B) within 45 days following each of the twelve-month periods ended
September 30, 1998, 1999 and 2000, Sun Medical will pay to the Sellers, to be
allocated amongst them ratably in


                                       7
<PAGE>
 
accordance with their Ownership Percentages, 50% of the net income earned by Sun
Medical with respect to its ownership interest in such partnership or entity
during such twelve-month period, to the extent such net income is attributable
to lithotripsy services provided by the partnership or entity providing
lithotripsy services to that hospital, after deduction of all direct costs
associated therewith and an allocable share of all indirect costs (which
indirect costs will be allocated ratably based on the number of lithotripsy
procedures performed at each hospital or other facility serviced by the
partnership or entity);

              (v)  If any such Class D Contract is not renewed in 1997, and
clause (iv) of this subsection d. does not apply, but, on or before September
30, 1997, Sun Medical notifies the Sellers that it has commenced good faith
negotiations with physician investors regarding the utilization of a new
partnership or other entity with physician investors to provide lithotripsy
services to any hospital subject to a Class D Contract, then

                   (A)  Sun Medical shall have until March 31, 1998 to form such
partnership or other entity; and if such partnership or other entity is so
formed, the provisions of clause (iv)(A) above shall apply (except that Sun
Medical shall not have the additional six (6) month period described in that
clause) and the provisions of clause (iv)(B) shall apply with respect to such
hospital for each of the twelve-month periods ended September 30, 1998, 1999 and
2000; and


                                      8
<PAGE>
 
                   (B)  from September 30, 1997 until the date such new
partnership or other entity is formed (or the date on which Sun Medical
terminates negotiations relating thereto), Sun Medical may lease from Newco the
Leased Equipment on such terms and conditions, if any, that may be mutually
agreeable to Sun Medical and Newco; and

                   (C)  Within 30 days following the date such new partnership
or other entity is formed, and for a period of 36 months after the Effective
Time, Sun Medical will pay to the Sellers, in accordance with their relative
Ownership Percentages, 50% of the net income earned by Sun Medical with respect
to its ownership interest in the new partnership or other entity to the extent
such net income is attributable to lithotripsy services provided by the
partnership or entity to the applicable hospital after deduction of direct and
indirect costs using the same methodology described in subsections c. and d.(iv)
above; and

             (vi)  At any time EME is leasing the Leased Equipment from Newco
pursuant to this subsection d., EME (or Sun Medical) shall, at its expense, (A)
maintain the Leased Equipment in a reasonably good operating condition, and (B)
insure the Leased Equipment with liability coverage and physical damage
coverage, consistent with such coverage

                                       9
<PAGE>
 
maintained on Sun Medical's own equipment; and with Newco named as an additional
insured with respect to such coverage.

          e.  With respect to the renewal of service agreements being considered
in determining any Earn-Out Adjustments under subsections a.-d. above, (i) if
any of such service agreements are not renewed, but are replaced during the
period for which Earn-Out Adjustments would otherwise be due for such
agreements, with lithotripsy service agreements (or such other form of agreement
by which lithotripsy services are provided) from any affiliate of Sun Medical or
Prime, then such contracts shall be deemed to have been renewed when so
replaced, and the replacement agreement, if entered into during the prescribed
period for which Earn-Out Adjustments would otherwise be due for such
agreements, will be analyzed for purposes of calculating any applicable Earn-Out
Adjustments, and (ii) if Prime or any affiliate of Prime or Sun Medical enters
into a partnership or other entity with physician investors with respect to any
of the hospitals covered by the Class C Contracts during the period for which
Earn-Out Adjustments would otherwise be due for such agreements, as described in
subsection c., or the Class D Contracts during the period for which Earn-Out
Adjustments would otherwise be due for such agreements, as described in
subsection d., then the Sellers shall be entitled to the payments described in
subsection c. or subsection d., as applicable, as if Sun Medical had entered
into such partnership or entity.

          f.  At the Closing, Sellers shall be entitled to retain all EME cash
on hand as of the Effective Time, and Sun Medical shall assign to Newco all
accounts receivable of EME in


                                      10
<PAGE>
 
existence as of the Effective Time. Thereafter, Sun Medical shall, on a monthly
basis, remit to Newco any collections received by EME after the Effective Time
which were payments of EME accounts receivable in existence as of the Effective
Time. Sun Medical agrees to cause EME to use commercially reasonable efforts to
collect the accounts receivable assigned to Newco, provided such efforts will
not require EME or Sun Medical to institute or threaten legal action, or to
withhold or alter, or threaten to withhold or alter, services.

          g.  Promptly upon the occurrence of any Earn-Out Adjustment (or upon
any payment by Sun Medical or EME to Sellers or Newco in respect of any Earn-Out
Adjustment), Sun Medical shall provide to each Seller a written summary setting
forth in reasonable detail the amount of such Earn-Out Adjustment and the method
by which it was calculated.  Sun Medical shall also promptly provide to Sellers
such directly applicable supporting documentation as any Seller may reasonably
request regarding the determination of any Earn-Out Adjustment.

          h.  At any time and from time to time from the Closing Date until the
date of the final Earn-Out Adjustment, (but not more than twice during any
calendar year), upon reasonable advance written notice from any Seller, and at
such Seller's expense, Sun Medical shall (and shall cause EME and, if
applicable, Prime and all affiliates of Sun Medical and Prime) provide such
Seller, and such Seller's attorneys, accountants and representatives, full
access, during regular business hours, to all directly relevant books, financial
and accounting records, 



                                      11
<PAGE>
 
and other directly relevant records relating to the nature, amount and
calculation of any Earn-Out Adjustment.

     1.4    CLOSING.  The closing of the transactions contemplated by this
            -------                                                         
Agreement (the "Closing") shall take place at the offices of Akin, Gump,
Strauss, Hauer & Feld, L.L.P., 816 Congress Avenue, Suite 1900, Austin, Texas
78701, and shall be effective as of the Effective Time.  The date on which the
Closing occurs is hereinafter referred to as the "Closing Date."

                                  ARTICLE II

                 REPRESENTATIONS AND WARRANTIES OF SUN MEDICAL
                 ---------------------------------------------

     Sun Medical represents and warrants to the Sellers that each of the
following matters is true and correct in all respects as of the Closing Date
(with the understanding that the Sellers are relying materially on such
representations and warranties in entering into and performing this Agreement),
which representations and warranties shall also be deemed made as of the
Effective Time and which shall survive the Closing and not be merged therein:

     2.1    DUE ORGANIZATION AND PRINCIPAL EXECUTIVE OFFICE.  Sun Medical is a
            -----------------------------------------------                     
corporation duly organized, validly existing, and in good standing under the
laws of the State of California and has full corporate power and authority to
carry on its business as now conducted and to enter into and perform this
Agreement and each other agreement, instrument and document required to be
executed by Sun Medical in connection herewith.  Sun Medical's principal
executive offices are located at 1301 Capital of Texas Highway, Austin, Texas
78746.



                                      12
<PAGE>
 
     2.2    DUE AUTHORIZATION.  This Agreement and each other agreement,
            -----------------                                             
instrument, and document required herein to be executed by Sun Medical have been
duly and validly authorized, executed and delivered by Sun Medical and
constitute the valid and binding obligations of Sun Medical enforceable against
it in accordance with its terms, subject to bankruptcy, insolvency,
conservatorship, receivership and other similar laws of general application
affecting the rights and remedies of creditors.  The execution, delivery, and
performance of this Agreement and each other agreement, instrument, and document
required herein to be executed by Sun Medical will not (a) violate any federal,
state, county, or local law, rule, or regulation applicable to Sun Medical or
its properties, (b) violate or conflict with, or permit the cancellation of, any
agreement to which Sun Medical is a party or by which it or its properties are
bound, (c) permit the acceleration of the maturity of any indebtedness of, or
any indebtedness secured by the property of, Sun Medical or (d) violate or
conflict with any provision of the Certificate of Incorporation or Bylaws of Sun
Medical.  Other than such notification filings as may be required by applicable
state or federal securities law (which filings shall timely be effected by Sun
Medical after the date hereof), no action, consent, or approval of, or filing
with, any federal, state, county, or local governmental authority is required by
Sun Medical in connection with the execution, delivery or performance of this
Agreement (or any agreement, instrument or other document executed in connection
herewith by Sun Medical).

     2.3    BROKERS AND FINDERS.  Sun Medical has not engaged, or caused to be
            -------------------                                                 
incurred any liability to, or will pay any money to or enter into an arrangement
with, any finder, broker, or sales agent (or has paid, or will pay, any finder's
fee or similar fee or commission to any person)


                                      13
<PAGE>
 
in connection with the execution, delivery, or performance of this Agreement or
the transactions contemplated hereby.

     2.4    CLAIMS AND PROCEEDINGS.  Sun Medical is not a party to any claims,
            ----------------------                                              
actions, suits, proceedings, or investigations, at law or in equity, before or
by any court, municipal or other governmental department, commission, board,
agency, or instrumentality which seeks to restrain or prohibit the carrying out
of the transactions contemplated by this Agreement or to challenge the validity
of such transactions or any part thereof or seeking damages on account thereof;
and, to the knowledge of Sun Medical, no such claim, action, suit, proceeding or
investigation is threatened.

     2.5    INVESTMENT INTENT.  Sun Medical (a) is acquiring the Shares for
            -----------------                                                 
its own account for investment and not with a view to or in connection with a
distribution (within the meaning of the Securities Act of 1933, as amended (the
"Act") thereof, (b) is an "accredited investor" within the meaning of Rule 501
under the Act, (c) will not sell or transfer the Shares unless such Shares are
registered under the Act or such sale or transfer is exempt from such
registration requirements, (d) is able to bear the economic risk of its
acquisition of the Shares and (e) has such knowledge and experience in financial
and business matters that it is capable of evaluating the merits of, and
protecting its interests with respect to, its acquisition of the Shares.


                                      14
<PAGE>
 
                                  ARTICLE III

                 REPRESENTATIONS AND WARRANTIES OF THE SELLERS
                 ---------------------------------------------
                                        
     The Sellers, jointly and severally, hereby represent and warrant to Sun
Medical that the following matters are true and correct in all respects as of
the Closing Date(with the understanding that Sun Medical is relying materially
on each such representation and warranty in entering into and performing this
Agreement), which representations and warranties shall also be deemed made as of
the Effective Time and which shall survive the Closing and not be merged
therein:

     3.1    DUE ORGANIZATION.  EME is a corporation duly organized, validly
            ----------------                                                 
existing, and in good standing under the laws of the State of Delaware and has
full power and authority to carry on its business as now conducted and as
proposed to be conducted.  Complete and correct copies of EME's Articles of
Incorporation, Bylaws, all board of directors' resolutions, all shareholders'
resolutions, and all amendments thereto, have been delivered to Sun Medical.
EME is qualified to do business and is in good standing in the states set forth
on Schedule 3.1 attached hereto, which states, except as set forth on Schedule
   ------------                                                       --------
3.1, represent every jurisdiction where such qualification is required for the
- ----                                                                          
conduct of EME's business.

     3.2    SUBSIDIARIES.  EME does not directly or indirectly have, or
            ------------                                                 
possess any options or other rights to acquire, any subsidiaries, or any direct
or indirect ownership interest, in whole or in part, in any person, business,
corporation, partnership, limited liability company, association, joint venture,
trust, or other entity.


                                      15
<PAGE>
 
     3.3    DUE AUTHORIZATION.  Each Seller represents and warrants that (i)
            -----------------                                                
such Seller has full power and authority to enter into and perform this
Agreement and each other agreement, instrument, and document required to be
executed by such Seller in connection herewith; (ii) the execution, delivery,
and performance of this Agreement and such other agreements, instruments, and
documents have been duly authorized by all necessary action of the Sellers;
(iii) this Agreement has been duly and validly executed and delivered by the
Sellers and constitutes a valid and binding obligation of the Sellers
enforceable against them in accordance with its terms, subject to bankruptcy,
insolvency, conservatorship, receivership and other similar laws of general
application affecting the rights and remedies of creditors; (iv) the execution,
delivery, and performance of this Agreement, and each other agreement,
instrument and document required herein to be executed by the Sellers does not
(a) cause any Seller to violate any federal, state, county, or local law, rule,
or regulation applicable to such Seller or its properties, (b) cause EME or any
Seller to violate, or conflict with or permit the cancellation of, any agreement
to which such Seller or EME is a party, or by which such Seller or EME or any of
their respective properties are bound, or result in the creation of any lien,
security interest, charge, or encumbrance upon any of such properties, (c)
permit the acceleration of the maturity of any indebtedness of, or indebtedness
secured by the property of, any Seller or EME, or (d) cause EME or any Seller to
violate, or conflict with any provision of, the documents creating or governing
the Seller or EME, in each of cases (a)-(d) unless such violation, conflict,
cancellation, or acceleration would not, individually or in the aggregate, have
a material adverse effect on EME's financial condition, assets, business  or
operations; and (v) no action, consent, waiver or approval of, or filing with,
any governmental authority is required by any Seller or EME in



                                      16
<PAGE>
 
connection with the execution, delivery, or performance of this Agreement (or
any agreement or other document executed in connection herewith by such Seller),
unless the failure to obtain or effect the same would not have a material
adverse effect on EME's financial condition, assets, business or operations.
Notwithstanding anything in this Agreement to the contrary, each Seller is
making the representations in this Section 3.3 as to themselves only (and as to
EME where applicable) and is not making any representation or warranty with
respect to any of the matters addressed in this Section 3.3 relating to any
other Seller. For purposes of this Agreement, whenever there are references to
"material" or "materially", such terms shall be deemed to mean an economic
impact exceeding $25,000 with respect to the fact or matter being referred to or
described.

     3.4  FINANCIAL STATEMENTS.
          --------------------   

          (a)  The consolidated unaudited balance sheet and income statement of
EME as of and for the years ended December 31, 1995 and 1996 and its
consolidated unaudited balance sheet and income statement as of and for the four
(4) months ended April 30, 1997 (collectively, the "EME Financial Statements")
are attached hereto as Exhibit A.  The EME Financial Statements have been
                       ---------                                         
prepared in accordance with generally accepted accounting principles (except as
specifically noted therein or in Schedule 3.4) applied on a consistent basis
                                 ------------                               
throughout the periods indicated and fairly present the consolidated financial
position and results of operations of EME as of the indicated dates and for the
indicated periods, except that (a) the Financial Statements do not contain
footnotes as required by generally accepted accounting


                                      17
<PAGE>
 
principles and, (b) the balance sheet and income statement for the interim
period ended April 30, 1997 may be subject to year-end adjustments (which
adjustments will not be material in the aggregate). Except to the extent
reflected or provided for in the EME Financial Statements or in Schedule 3.4,
                                                                ------------  
EME has no liabilities of a type that would be required to be reflected as such
in the EME Financial Statements other than current liabilities on open account
incurred in the ordinary course of business subsequent to April 30, 1997. Except
as set forth in Schedule 3.4, since April 30, 1997, there has been no material
                ------------
adverse change in the financial position, assets, results of operations, or
business of EME.

     3.5    CAPITAL STOCK.  The authorized and issued shares of all classes of
            -------------                                                       
capital stock of EME are described in Schedule 3.5 attached hereto, all such
                                      ------------                          
shares are duly authorized, validly issued, outstanding, fully paid, and non-
assessable, and all such shares are owned beneficially and of record by the
Sellers, free and clear of all liens.  There are no outstanding securities,
obligations, conversion or other rights, subscriptions, warrants, options,
phantom stock rights, or (except for this Agreement) other contracts of any kind
that give any person or entity the right to (a) purchase or otherwise receive or
be issued any shares of capital stock of EME or any security or obligation of
any kind convertible into or exchangeable for any shares of capital stock of
EME, or (b) receive any benefits or rights that are similar to those enjoyed by
or accruing to any holder of any of the Shares, or that entitle the holder to
participate in the equity, income or election of directors or officers of EME.
Upon the Closing, Sun Medical will own one hundred percent (100%) of each and
every class of outstanding capital stock of EME, subject to no liens, claims or
encumbrances whatsoever (other than restrictions on transfer imposed by Federal
and applicable state securities laws).


                                      18
<PAGE>
 
          3.6  CONDUCT OF BUSINESS; CERTAIN ACTIONS.  Except for the Strip-Out
               ------------------------------------                             
Transactions (as defined in Section 4.2, below) or as set forth in Schedule 3.6,
                                                                   ------------ 
since December 31, 1996, EME has conducted its business and operations in the
ordinary course and consistent with its past practices and has not (a) purchased
or retired any indebtedness from any Seller or any of its shareholders,
partners, members or other owners (an "Equity Holder") and has not purchased,
retired, or redeemed any stock, partnership or membership interest, or other
ownership interest from any Seller or Equity Holder, (b) increased the
compensation of any of the Sellers, shareholders, partners, members or other
owners, or key employees or, except for wage and salary increases made in the
ordinary course of business and consistent with the past practices of EME,
increased the compensation of any other employees of EME, (c) made capital
expenditures exceeding $10,000 individually or $25,000 in the aggregate, (d)
sold any asset (or any group of related assets) in any transaction (or series of
related transactions) in which the purchase price for such asset (or group of
related assets) exceeded $10,000 (other than sales of inventory in the ordinary
course of business), (e) discharged or satisfied any lien or encumbrance or paid
any material obligation or liability, absolute or contingent, other than current
liabilities incurred and paid in the ordinary course of business, (f) made or
guaranteed any loans or advances (other than advances made to employees in the
ordinary course of business consistent with past practices) whatsoever, (g)
suffered or permitted any lien, security interest, claim, charge, or other
encumbrance to arise or be granted or created against or upon any of its assets,
real or personal, tangible or intangible, (h) canceled, waived, or released any
of its material debts, rights, or claims against third parties, (i) amended its
articles of incorporation, articles of organization, bylaws, partnership
agreement or other organizational documents, (j) made or paid


                                      19
<PAGE>
 
any severance or termination payment to any employee or consultant, (k) made any
change in its method of accounting, (l) made any investment or commitment
therefor in any person, business, corporation, association, partnership, limited
liability company, joint venture, trust, or other entity, (m) made, entered
into, amended, or terminated any written employment contract, (n) created, made,
amended, or terminated any bonus, stock option, pension, retirement, profit
sharing, or other employee benefit plan or arrangement, or withdrawn from any
"multi-employer plan" (as defined in Section 414(f) of the Internal Revenue Code
of 1986, as amended (the "Code")) so as to create any liability under Article IV
of ERISA (as hereinafter defined) to any person or entity, (o) amended,
terminated or experienced a termination of any material contract, agreement,
lease, franchise, or license to which it is a party, (p) entered into any other
material transactions except in the ordinary course of business, (q) entered
into any contract, commitment, agreement, or understanding to do any acts
described in the foregoing clauses (a)-(p) of this Section, (r) suffered any
material damage, destruction, or loss (whether or not covered by insurance) to
any assets, (s) experienced any strike, slowdown, or demand for recognition by a
labor organization by or with respect to any of its employees, or (t)
experienced or effected any shutdown, slow-down, or cessation of any operations
conducted by, or constituting part of, it.

     3.7  OWNERSHIP OF ASSETS:  LICENSES, PERMITS, ETC.
          ---------------------------------------------

          (a)  Except as set forth on Schedule 3.7(a-1), EME has good and
                                      -----------------                  
marketable title to all of its Assets (as hereinafter defined) free and clear of
all liens, security interests, claims, rights of another, and encumbrances of
any kind whatsoever.  The term "Assets" shall


                                      
                                      20
<PAGE>
 
mean all of the business and assets, tangible or intangible, wherever situated,
including without limitation those necessary or convenient to the providing of
the extracorporeal shockwave lithotripsy and related services ("Lithotripsy
Operations") provided by EME as of April 30, 1997, such Assets to include,
without limitation, accounts receivable; all contract rights, including without
limitation service agreements and management contracts; licenses, certificates
of need and other permits; all trade names and other intellectual property;
leases; computer software; lithotripters and other equipment; other items of
personal property; and all the Assets specifically set out on Schedule 3.7(a-2)
                                                              -----------------
attached hereto; provided, that the Assets shall not include (i) the Retained
Assets (as defined in Section 4.2 below) or (ii) all cash of EME on hand
immediately preceding the Effective Time. EME has such Assets as are required
for the continued operation of its Lithotripsy Operations as currently conducted
and as conducted on April 30, 1997, except for the Retained Assets.

          (b) The Assets of EME are in reasonably good operating condition and
repair, subject to ordinary wear and tear, taking into account the respective
ages of the properties involved and are adequate for the conduct of its
Lithotripsy Operations.

          (c) Attached hereto as Schedule 3.7(c) is a description of all
                                 ---------------                        
federal, state, county, and local governmental licenses, certificates,
certificates of need and permits held or applied for by EME.  EME has complied
in all material respects, and each is in compliance in all material respects,
with the terms and conditions of any such licenses, certificates, certificates
of need and permits.  Except as described in Schedule 3.7(c), no additional
                                             ---------------               
license, certificate,


                                      21
<PAGE>
 
certificate of need or permit is required from any federal, state, county, or
local governmental agency or body thereof in connection with the conduct of the
business of EME, which, if not obtained, would materially and adversely affect
the Lithotripsy Operations or other business activities of EME. Except as set
forth on Schedule 3.7(c), no claim has been made or threatened by any
         ---------------
governmental authority to the effect that a license, permit, certificate,
certificate of need or order not possessed by EME is necessary in respect of the
business conducted by EME. None of the licenses, permits, certificates and
certificates of need noted on the attached Schedule 3.7(c) will be terminated as
                                           ---------------
a result of the transfer of the Shares to Sun Medical.

     3.8  LIABILITIES.  Except to the extent specifically reflected in the EME
          -----------                                                           
Financial Statements or in Schedule 3.4, there were no liabilities against, owed
                           ------------                                         
by, relating to or affecting EME as of April 30, 1997 that individually or in
the aggregate have or may reasonably be expected to have a material adverse
effect on the business, condition (financial or otherwise) or result of
operations of EME.  Except as set forth in Schedule 3.4, since April 30, 1997,
                                           ------------                       
EME has not incurred or suffered any liabilities that individually or in the
aggregate have or may reasonably be expected to have a material adverse effect
on the business, condition (financial or otherwise), or results of operations of
EME.


                                      22
<PAGE>
 
     3.9  ENVIRONMENTAL ISSUES.
          --------------------   

          (a)  For purposes of this Agreement, the term "environmental laws"
shall mean all laws and regulations relating to the manufacture, processing,
distribution, use, treatment, storage, disposal, transport, or handling, or the
emission, discharge, or release, of any pollutant, contaminant, chemical, or
industrial toxic or hazardous substance or waste and any order related thereto.

          (b)  EME has complied in all material respects with and obtained all
material authorizations and made all material filings required by all applicable
environmental laws.  The properties occupied or used by EME have not been
contaminated with any hazardous wastes, hazardous substances, or other hazardous
or toxic materials in violation of any applicable environmental law.

          (c)  Except as set forth in Schedule 3.9(c) neither EME has received
                                      ---------------                         
any notice from the United States Environmental Protection Agency that it is a
potentially responsible party under the Comprehensive Environmental Response,
Compensation and Liability Act ("Superfund Notice"), any citation from any
federal, state or local governmental authority for non-compliance with its
requirements with respect to air, water or environmental pollution, or the
improper storage, use or discharge of any hazardous waste, other waste or other
substance or other material pertaining to its business ("Citations") or any
written notice from any private party



                                      23
<PAGE>
 
alleging any such non-compliance; and there are no pending or unresolved
Superfund Notices, Citations or written notices from private parties alleging
any such non-compliance.

     3.10 INTELLECTUAL PROPERTY RIGHTS.  There are no patents, trademarks,
          ----------------------------                                      
tradenames, or copyrights, and no applications therefor, owned by or registered
in the name of EME or in which EME has any right, license, or interest. EME is
not a party to any license agreement, either as licensor or licensee, with
respect to any patents, trademarks, tradenames, or copyrights. EME has not
received any notice that it is infringing any patent, trademark, trade name, or
copyright of others.

     3.11 COMPLIANCE WITH LAWS.  Except as set forth in Schedule 3.11, EME has
          --------------------                          -------------         
complied in all material respects, and is in compliance in all material
respects, with all federal, state, county, and local laws, rules, regulations
and ordinances currently in effect and applicable to its business.  No claim has
been made or threatened by any governmental authority against EME to the effect
that the business conducted by EME fails to comply, in any respect, with any
law, rule, regulation, or ordinance.

     3.12 INSURANCE.  Attached hereto as Schedule 3.12 is a list of all
          ---------                      -------------                 
policies of fire, liability, business interruption, and other forms of insurance
and all fidelity bonds held by or applicable to EME at any time since January 1,
1995, which schedule sets forth in respect of each such policy the policy name,
policy number, carrier, term, type of coverage, deductible amount or self-
insured retention amount, limits of coverage, and annual premium.  No event has
occurred which will result in a retroactive upward adjustment of premiums under
any such policies or

                                      24
<PAGE>
 
which is likely to result in any prospective upward adjustment in such premiums.
There has been no material change in the type of insurance coverage maintained
by EME during the past five (5) years, including without limitation any change
which has resulted in there being any period during such five (5) years in which
EME has had no insurance coverage. Excluding insurance policies which have
expired and been replaced, no insurance policy of EME has been canceled within
the last three (3) years. The Sellers have made all necessary arrangements to
maintain "tail" insurance for professional and general liability coverage, for
claims, acts or omissions occurring prior to the Closing Date, of the same
types, and to the same extent, as was maintained prior to the Effective Time;
and such "tail" insurance coverage shall be maintained in place for a period of
three (3) years after the Closing. Sun Medical or EME will reimburse Sellers at
the Closing for the actual out-of-pocket costs incurred in maintaining insurance
coverage for EME during the period between the Effective Time and the Closing
Date.

     3.13 EMPLOYEE BENEFIT MATTERS. EME does not maintain or contribute to,
          ------------------------                                           
nor is it required to contribute to, any "employee welfare benefit plan" (as
defined in section 3(1) of the Employee Retirement Income Security Act of 1974
(and any sections of the Code amended by it) and all regulations promulgated
thereunder, as the same have from time to time been amended ("ERISA") or any
"employee pension benefit plan" (as defined in section 3(2) of ERISA and not
exempted under section 4(b) or 201 of ERISA). EME does not presently maintain or
has ever maintained, or had any obligation of any nature to contribute to, a
"defined benefit plan" within the meaning of section 414(j) of the Code, without
regard to whether such defined benefit plan met the requirements of section
401(a) of the Code.



                                      25
<PAGE>
 
     3.14 CONTRACTS AND AGREEMENTS.  Attached hereto as Schedule 3.14 is a
          ------------------------                      -------------     
list of all written or oral contracts, commitments, leases, and other agreements
(including, without limitation, promissory notes, loan agreements, and other
evidences of indebtedness) to which EME is a party or by which EME or its
properties are bound, pursuant to which the obligations thereunder of either
party thereto are, or are contemplated as being, in respect of any such
individual contracts, commitments, leases, or other agreements during any year
during the term thereof, $5,000 or greater, or which are otherwise material to
the business of EME (including, without limitation, all mortgages, deeds of
trust, security agreements, pledge agreements, lithotripsy service agreements,
and similar agreements and instruments and all confidentiality agreements).
Neither EME nor, to the knowledge of the Sellers, any of the other parties
thereto is in default (and no event has occurred which, with the passage of time
or the giving of notice, or both, would constitute a default by EME or, to the
knowledge of the Sellers, by any other party thereto) under any such contracts,
commitments, leases, or other agreements, except where such defaults,
individually or in the aggregate, would not be material. EME has not waived any
material right under any such contracts, commitments, leases, or other
agreements, and no consents or approvals (other than consents or approvals that
have been obtained in writing and delivered to Sun Medical prior to Closing) is
required thereunder in connection with the consummation of the sale of the
Shares or other transactions contemplated hereby. EME has not guaranteed any
obligation of any other person or entity.

     3.15 CLAIMS AND PROCEEDINGS.  Attached hereto as Schedule 3.15 is a list
          ----------------------                      -------------          
and description of all claims, actions, suits, proceedings, and investigations
pending or, to the



                                      26
<PAGE>
 
knowledge of such Seller, threatened against EME, or affecting any of their
properties or assets, at law or in equity, or before or by any court, municipal
or other governmental department, commission, board, agency, or instrumentality.
Except as set forth on Schedule 3.15 attached hereto, none of such claims,
                       -------------
actions, suits, proceedings, or investigations will result in any liability or
loss to EME which (individually or in the aggregate) is material, and EME has
not been, or is now, subject to any order, judgment, decree, stipulation, or
consent of any court, governmental body, or agency. No inquiry, action, or
proceeding has been asserted, instituted, or, to the knowledge of such Seller,
threatened against EME to restrain or prohibit the carrying out of the
transactions contemplated by this Agreement or to challenge the validity of such
transactions or any part thereof or seeking damages on account thereof.

     3.16 TAXES.  All federal, foreign, state, county, and local income, gross
          -----                                                                 
receipts, excise, property, franchise, license, sales, use, withholding, and
other tax (collectively, "Taxes") returns, reports, and declarations of
estimated tax (collectively, "Returns") which were required to be filed by EME
on or before the Closing Date hereof have been filed within the time (including
any applicable extensions) and in the manner (in all material respects) provided
by law, and all such Returns are true and correct in all material respects and
accurately reflect, in all material respects, the Tax liabilities of EME.  All
Taxes, assessments, penalties, and interest which have become due pursuant to
such Returns have been paid or adequately accrued in the EME Financial
Statements.  The provisions for Taxes reflected on the balance sheet contained
in the EME Financial Statements are adequate to cover all of EME's Tax
liabilities for the respective periods then ended and all prior periods.  As of
the Closing, EME will not owe any federal income Taxes for any period prior to
the Effective Time. EME has not executed any presently


                                      27
<PAGE>
 
effective waiver or extension of any statute of limitations against assessments
and collection of Taxes. There are no pending or threatened claims, assessments,
notices, proposals to assess, deficiencies, or audits against EME with respect
to any Taxes owed or allegedly owed by EME. No federal income tax return of EME
has been audited. There are no tax liens on any of the assets of EME. Proper and
accurate amounts have been withheld and remitted by EME from and in respect of
all persons from whom it is required by applicable law to withhold for all
periods in compliance with the tax withholding provisions of all applicable laws
and regulations. EME is not a party to any tax sharing agreement with any other
person. EME utilizes the accrual method of accounting for federal income tax
purposes.


     3.17 PERSONNEL.  Attached hereto as Schedule 3.17 is a list of names and
          ---------                      -------------                       
annual rates of compensation of the employees of EME whose rates of
compensation, on an annualized basis, during the fiscal year ended December 31,
1996 (including base salary, bonus, commissions, and incentive pay) exceeded
$20,000, or whose compensation is expected to exceed $20,000 for the fiscal year
ending December 31, 1997.  Schedule 3.17 attached hereto also contains a brief
                           -------------                                      
description of all material terms of employment agreements and confidentiality
agreements to which EME is a party and all severance benefits which any
director, officer, employee, agent or sales representative of EME is or may be
entitled to receive.  The Sellers have delivered to Sun Medical accurate and
complete copies of all such employment agreements, confidentiality agreements,
and all other agreements, plans, and other instruments to which EME is a party
and under which its employees are entitled to receive benefits of any nature.
The employee relations of EME are good and there is no pending or, to such
Seller's knowledge, threatened labor dispute or union organization campaign
relating to EME.  None of the employees of EME are



                                      28
<PAGE>
 
represented by any labor union or organization. There is no unfair labor
practice claim against EME before the National Labor Relations Board or any
strike, labor dispute, work slowdown, or work stoppage pending or, to the
Sellers' knowledge, threatened against or involving EME.

     3.18 BUSINESS RELATIONS.  Sellers have no reason to believe that any
          ------------------                                              
supplier or customer of EME will cease or refuse to do business with EME in the
same manner as previously conducted as a result of or soon after the
consummation of the transactions contemplated hereby (subject to the expiration
of any service agreements of EME in accordance with their terms). EME has not
received any notice of any disruption (including delayed deliveries or
allocations by suppliers) in the availability of the materials or products used
by EME.

     3.19 ACCOUNTS RECEIVABLE.  All of the accounts, notes, and loans
          -------------------                                          
receivable that have been recorded on the books of EME are bona fide and
represent amounts validly due subject to no defenses.

     3.20 AGENTS.  Except as set forth in Schedule 3.20, EME has not
          ------                          -------------             
designated or appointed any person or other entity to act for it or on its
behalf pursuant to any power of attorney or any agency which is presently in
effect.

     3.21 INDEBTEDNESS TO AND FROM PARTNERS AND EMPLOYEES.  Except as set
          -----------------------------------------------                  
forth in Schedule 3.21, EME does not owe any indebtedness to any of the Sellers
         -------------                                                         
or its partners, members, shareholders, officers, directors or employees and,
EME does not have any indebtedness owed to it from any of the Sellers or its
partners, members, shareholders, officers,



                                      29
<PAGE>
 
directors or employees, excluding indebtedness for travel advances or similar
advances for expenses incurred on behalf of and in its ordinary course of
business and consistent with its past practices.

     3.22 COMMISSION SALES CONTRACTS.  Except as set forth in Schedule 3.22,
          --------------------------                          ------------- 
EME does not employ or have any relationship with any individual, corporation,
partnership, or other entity whose compensation from such entity is in whole or
in part determined on a commission basis.

     3.23 CERTAIN CONSENTS.  There are no material consents, waivers, or
          ----------------                                                
approvals required to be executed and/or obtained by EME or any Seller in
connection with the execution, delivery, and performance of this Agreement.

     3.24 BROKERS.  Neither EME nor any Seller has engaged, or caused any
          -------                                                          
liability to be incurred to, any finder, broker, or sales agent (or has paid, or
will pay, any finder's fee or similar fee or commission to any person, other
than a Seller) in connection with the execution, delivery, or performance of
this Agreement or the transactions contemplated hereby.

     3.25 INTEREST IN COMPETITORS, SUPPLIERS, AND CUSTOMERS.  Neither the
          -------------------------------------------------                
Sellers nor any of their immediate family members or affiliates have any
ownership interest in any competitor, customer or supplier of EME or any
property used in the operation of the business of EME.  Furthermore, no officer
or director of EME, or to the knowledge of Sellers, any employee of EME, has any
such ownership interest.



                                      30
<PAGE>
 
     3.26 WARRANTIES.  Attached hereto as Schedule 3.26 is a list and brief
          ----------                      -------------                    
description of all warranties and guarantees made by EME to third parties with
respect to any products sold or services rendered by it.  Except as set forth on
                                                                                
Schedule 3.26 attached hereto, no claims for breach of product or service
- -------------                                                            
warranties have been made against EME since January 1, 1995.

     3.27 EXTINGUISHMENT OF INDEBTEDNESS.  As of the Closing, all indebtedness
          ------------------------------                                        
and liabilities of EME and all subsidiaries of EME, as of the Effective Time,
including without limitation trade payables and accrued expenses (except accrued
vacation time expense as set forth on Schedule 3.27), will have been paid-off or
                                      -------------                             
otherwise extinguished, and there will be no liens, claims or encumbrances
whatsoever on any of the Shares or any Assets or properties of EME.  None of the
debts or obligations of EME, including without limitation any convertible
indebtedness, was forgiven or otherwise extinguished prior to the Closing such
that any taxable income or gain would be incurred by EME, any of the Sellers or
their other equity owners after the Closing.  With respect to the accrued
vacation time expense for employees of EME as set forth on Schedule 3.27, and
                                                           -------------     
only to the extent set forth on Schedule 3.27, such accrued expense obligation
                                -------------                                 
shall be retained by EME at the Closing, and Sun Medical shall deduct the amount
so retained from amounts due Sellers at the Closing, allocated ratably amongst
the Sellers in accordance with their Ownership Percentages.

     3.28 NO KNOWN BREACHES.  None of the Sellers has knowledge of any breach
          -----------------                                                    
or default by any of the other Sellers of their respective representations and
warranties, covenants or other agreements made in this Agreement.


                                      31
<PAGE>
 
                                  ARTICLE IV

                           COVENANTS AND AGREEMENTS
                           ------------------------
                                        
     4.1 COOPERATION RELATING TO FINANCIAL STATEMENTS.  Each Seller agrees to
         --------------------------------------------                         
reasonably cooperate with Sun Medical in the preparation of any financial
statements of EME for any period prior to the Closing, which Sun Medical or its
affiliates may be required by any applicable law to prepare.  Sun Medical and
its affiliates will have no obligation to compensate Sellers for such
cooperation, or to reimburse any expenses incurred by Sellers unless such
expenses are preapproved in writing by Sun Medical.  However, this Section 4.1
shall not obligate any of the Sellers to incur any out-of-pocket expenses.

     4.2 STRIP-OUT TRANSACTIONS.  Prior to the Closing, the Sellers may cause
         ----------------------                                                
EME (the "Strip-Out Transferor") to enter into the transactions described
specifically on Schedule 4.2 attached hereto (the "Strip-Out Transactions") in
                ------------                                                  
order that the assets (the "Retained Assets") listed on Schedule 4.2 attached
                                                        ------------         
hereto, shall be conveyed out of the Strip-Out Transferor and to one or more
Sellers, or into VJJ, Inc., a California corporation ("Newco") which is owned by
the Sellers; provided that the Sellers hereby agree to assume and be fully
liable for any and all debts, liabilities, costs or other expenses (the
"Retained Asset Liabilities") associated with the Retained Assets including
without limitation those listed on Schedule 4.2 attached hereto. Furthermore,
                                   ------------                              
Sellers may cause EME to distribute cash to Sellers prior to the Closing so long
as no cash is distributed from revenues received by EME after the Effective
Time.


                                      32
<PAGE>
 
     4.3 GUARANTY OF PRIME.  Prime hereby unconditionally and irrevocably
         -----------------                                                 
guarantees the timely performance of, and promises timely to perform, each of
the obligations of Sun Medical hereunder.  Without limiting the foregoing, Prime
agrees that if Sun Medical shall for any reason fail to pay to Sellers (or any
Seller) any amount then due and payable by Sun Medical to Sellers (or any
Seller) under ARTICLE I or ARTICLE VII hereunder, Prime shall immediately pay
such amount to the Sellers (or the applicable Seller).  Prime hereby agrees not
to require any Seller to proceed against Sun Medical or any other person or to
pursue any other remedy before proceeding against Prime under this guaranty.
Prime hereby represents and warrants to each Seller that each of the
representations and warranties in Section 2.1, 2.2 and 2.3 are true and correct
(mutatis mutandis) as if made by Prime with respect to its obligations under
 ----------------                                                           
this Section; except that Prime is a Delaware corporation.

     4.4 CONDUCT OF EME POST-CLOSING.  Following the Closing, Sun Medical
         ---------------------------                                       
shall cause EME (or EME's successors or assigns) to (a) comply in all material
respects with all laws, permits and instruments applicable to EME's business or
the Assets; (b) timely perform in all material respects all commitments or
obligations of EME under each of the contracts and agreements described in
Sections 1.3 and 3.14 and (c) use commercially reasonable efforts to renew the
Class A Contracts, the Class B Contracts and the Class D Contracts.

     4.5 QUALIFICATION IN WASHINGTON AND OREGON.  The parties acknowledge
         --------------------------------------                            
that, as of the Effective Time and the Closing Date, EME was not qualified to do
business in the states of Washington and Oregon, may need new or revised
registrations, licenses, certificates, certificates

                                      34
<PAGE>
 
of need or permits for the business conducted in Washington and Oregon as of the
Closing Date. The parties agree that, after the Closing, EME will qualify to do
business in, and will obtain the necessary new or revised registration,
licenses, certificates, certificates of need or permits for the business
conducted by EME as of the Closing Date in, Washington and Oregon. Sellers,
jointly and severally, agree to reimburse EME or Sun Medical, on demand, for any
and all reasonable out-of-pocket costs incurred by EME or Sun Medical in
accomplishing the matters described in the preceding sentence. Sun Medical's and
Prime's offset rights described in Section 6.2 shall also extend to any amounts
not promptly reimbursed as required in this Section.

                                   ARTICLE V

                              CLOSING OBLIGATIONS
                              -------------------
                                        
     5.1  SUN MEDICAL'S CLOSING OBLIGATIONS.  At the Closing, Sun Medical
          ---------------------------------                              
shall:

          (a)  pay the Closing Payment portion of the Purchase Price and the
prepaid expense amount described in Section 1.2, less the accrued vacation
expense deduction as described in Section 3.27; and

          (b)  deliver such good standing certificates, officer certificates,
and similar documents and certificates as counsel for the Sellers may reasonably
require.


                                      34
<PAGE>
 
     5.2  THE SELLERS' CLOSING OBLIGATIONS.  At the Closing, the Sellers shall:
          --------------------------------

          (a)  deliver the original certificates representing the Shares to Sun
Medical, and execute and deliver an assignment of the Shares and blank stock
power (the "Assignment and Stock Power") to Sun Medical in the form attached
hereto as Exhibit B and such other documents as Sun Medical may request in order
          ---------                                                             
to transfer to Sun Medical the ownership of the Shares on the books of EME;

          (b)  deliver such good standing certificates, officer, manager and/or
partnership certificates, and similar documents and certificates as counsel for
Sun Medical may reasonably require; and

          (c)  cause every director and officer of EME and every director and
officer of any other entities which EME has authority to elect or cause to be
elected, to tender to Sun Medical written resignations from such positions which
are effective as of the Effective Time and which contain releases of all claims,
known or unknown, which such former directors and officers have or might have
against EME or any such other entities.


                                      35
<PAGE>
 
                                  ARTICLE VI

                        INDEMNIFICATION OF SUN MEDICAL
                        ------------------------------
                                        
     6.1  SURVIVAL OF REPRESENTATIONS; TIME LIMITS; KNOWLEDGE.
          ---------------------------------------------------

          (a)  All representations and warranties of the Sellers hereunder shall
survive the Closing and shall terminate on the third anniversary thereof (the
"Termination Date").

          (b)  No Sun Medical Indemnified Party (as defined in Section 6.2
below) shall be entitled to indemnification from any Seller under this ARTICLE
VI (or otherwise) unless the Sun Medical Indemnified Party seeking such
indemnification gives the party from which such indemnification is sought
written notice of a claim for indemnification (which shall set forth in
reasonable detail the basis for such claim) on or before the Termination Date;
provided that this Section 6.1(b) shall not apply to a claim for indemnification
- --------                  
based on a breach by a Seller of his obligations under ARTICLE VIII.

          (c)  No Sun Medical Indemnified Party (or any person claiming through
such party) shall be entitled to indemnification from any Seller based on any
inaccuracy, falsity or misrepresentation of any representation or warranty made
by such other hereunder if the Sun Medical Indemnified Party or Sun Medical had
actual knowledge of such inaccuracy, falsity or


                                      36
<PAGE>
 
misrepresentation prior to the Closing and elected to proceed with the Closing,
unless the election to proceed with the Closing was an accommodation to the
Sellers as set forth in a separate written agreement executed by the parties
hereto at or prior to the Closing.

     6.2 INDEMNIFICATION OF SUN MEDICAL.  Each Seller, jointly and severally,
         ------------------------------                                        
agrees to indemnify and hold harmless Sun Medical and each officer, director,
employee, and affiliate (including without limitation, EME) of Sun Medical
(collectively, the "Sun Medical Indemnified Parties") from and against any and
all damages, losses, claims, liabilities, demands, charges, suits, penalties,
costs, and expenses (including court costs and attorneys' fees and expenses
incurred in investigating and preparing for any litigation or proceeding)
(collectively, "Indemnified Costs") in connection with the commencement or
assertion of any action, proceeding, demand, or claim by a third party
(collectively, a "third-party action") which any of the Sun Medical Indemnified
Parties may sustain, arising out of or relating to (a) any breach or default by
any Seller of any of their representations, warranties, covenants or agreements
contained in this Agreement or in any agreement or document executed in
connection herewith (including, without limitation, the agreement to extinguish
all liabilities of EME as of the Effective Time and to assume the Retained Asset
Liabilities), or (b) any obligation or liability, direct or contingent, known or
unknown, of EME not reflected in the Schedules to this Agreement in violation of
any representation, warranty, covenant or other provision contained in this
Agreement, or (c) the Strip-Out Transactions, or the sale, liquidation or other
disposition by EME, at, before or after the Closing, of the Retained Assets or
any business lines, subsidiaries, divisions or other business units or assets,
and any Taxes arising from any of such transactions, or (d) any liability,
direct or contingent, known or unknown, of EME which arises from or is


                                      37
<PAGE>
 
based on facts, acts or omissions occurring at or prior to the Closing Date,
other than trade payables on open account to unaffiliated entities incurred
after the Effective Time in the ordinary course of its Lithotripsy Operations
and accrued expenses related to expenses incurred in the ordinary course of its
Lithotripsy Operations after the Effective Time, or (e) any claims asserted
against EME based on allegations against, or acts or omissions of, Executive
Medical Enterprises I, Inc. ("EME-I"), or any other entity in which any Seller
has an interest and whose name or trade name is similar to EME's, or (f) any
taxes, fines, levies, fees or assessments asserted against any Sun Medical
Indemnified Party attributable to EME's failure to be qualified in Washington or
Oregon, and to have all necessary registrations, licenses, certificates,
certificates of need or permits for the business conducted in Washington and
Oregon as of the Closing Date. Notwithstanding the foregoing, (i) no Seller
shall have any indemnity obligation under clause (e) above with respect to EME-
I, or any other entity whose name or trade name is similar to EME's, for any
period during which such Seller has, or had, no equity interest in such
corporation or other entity, (ii) the indemnity obligations of the Sellers shall
not be joint and several with respect to any violations by a Seller of any of
the covenants in ARTICLE VIII, each Seller shall be solely responsible for any
indemnity obligations arising from a violation of ARTICLE VIII by that Seller,
and no Seller will have any indemnity obligation arising from a violation of
ARTICLE VIII by another Seller, and (iii) no Seller will have an indemnity
obligation under clause (f) above to the extent Indemnified Costs result from
EME failing to apply for (and thereafter diligently pursue the obtaining of)
qualification to do business in Washington and Oregon and any necessary
registrations, licenses or permits for the business conducted in Washington and
Oregon as of the Closing Date, within ninety (90) days after the

                                      38
<PAGE>
 
Closing Date. Fazio represents and warrants that neither of Gordon or Pecora has
had any interest in EME-I at any time on or prior to the Closing Date; and Sun
Medical and EME agree that no Sun Medical Indemnified Parties will assert an
indemnity claim against Gordon or Pecora under clause (e) above with respect to
EME-I related allegations, acts or omissions on or prior to the Closing Date.
Sun Medical and Prime shall be entitled to credit and offset any indemnity
payments or advances to which any Sun Medical Indemnified Party is entitled
pursuant hereto against any amounts which Sun Medical or EME may owe to the
Sellers, including the Earn-Out Adjustments.

     6.3  DEFENSE OF THIRD-PARTY CLAIMS.  A Sun Medical Indemnified Party shall
          -----------------------------   
give prompt written notice to the Sellers of the commencement or assertion of
any third party action in respect of which such Sun Medical Indemnified Party
shall seek indemnification hereunder.  Any failure so to notify the Sellers
shall not relieve the Sellers from any liability that it may have to such Sun
Medical Indemnified Party under this ARTICLE unless the failure to give such
notice materially and adversely prejudices the Sellers.  The Sellers shall have
the right to assume control of the defense of, settle, or otherwise dispose of
such third-party action on such terms as they deem appropriate; provided,
however, that:

          (a)  The Sun Medical Indemnified Party shall be entitled, at his, her,
or its own expense, to participate in the defense of such third-party action;


                                      39
<PAGE>
 
          (b) The Sellers shall obtain the prior written approval of the Sun
Medical Indemnified Party, which approval shall not be unreasonably withheld or
delayed, before entering into or making any settlement, compromise, admission,
or acknowledgment of the validity of such third-party action or any liability in
respect thereof if, pursuant to or as a result of such settlement, compromise,
admission, or acknowledgment, injunctive or other equitable relief would be
imposed against the Sun Medical Indemnified Party or if, in the reasonable
opinion of the Sun Medical Indemnified Party, such settlement, compromise,
admission, or acknowledgment would have a material adverse effect on its
business or, in the case of a Sun Medical Indemnified Party who is a natural
person, on his or her assets or interests;

          (c) The Sellers shall not consent to the entry of any judgment or
enter into any settlement that does not include as an unconditional term thereof
the giving by each claimant or plaintiff to each Sun Medical Indemnified Party
of a release from all liability in respect of such third-party action; and

          (d) The Sellers shall not be entitled to control (but shall be
entitled to participate at their own expense in the defense of), and the Sun
Medical Indemnified Party shall be entitled to have sole control over, the
defense or settlement, compromise, admission, or acknowledgment of any third-
party action (i) as to which the Sellers fail to assume the defense within a
reasonable length of time or (ii) to the extent the third-party action seeks an
order, injunction, or other equitable relief against the Sun Medical Indemnified
Party which, if successful, would materially adversely affect the business,
operations, assets, or financial


                                      40
<PAGE>
 
condition of the Sun Medical Indemnified Party; provided, however, that the Sun
                                                --------  -------
Medical Indemnified Party shall make no settlement, compromise, admission, or
acknowledgment which would give rise to liability on the part of the Sellers
without the prior written consent of the Sellers.

          (e)  The Sellers shall make payments of all amounts required to be
made pursuant to the foregoing provisions of this Section to or for the account
of the Sun Medical Indemnified Party from time to time promptly upon receipt of
bills or invoices relating thereto or when otherwise due and payable, provided
that the Sun Medical Indemnified Party has agreed in writing to reimburse the
Sellers for the full amount of such payments if the Sun Medical Indemnified
Party is ultimately determined not to be entitled to such indemnification.

          (f)  The parties hereto shall extend reasonable cooperation in
connection with the defense of any third-party action pursuant to this ARTICLE
and, in connection  therewith, shall furnish such records, information, and
testimony and attend such conferences, discovery proceedings, hearings, trials,
and appeals as may be reasonably requested.

     6.4  LIMITATIONS.  Notwithstanding anything in this ARTICLE VI to the
          -----------                                                        
contrary:

          (a)  In the absence of fraud or intentional misrepresentation, no
Seller shall have any liability or obligation to any Sun Medical Indemnified
Party (or any other person) under ARTICLE VI, or otherwise with respect to any
of the matters set forth herein, in an amount that


                                      41
<PAGE>
 
exceeds, in the aggregate, the aggregate Purchase Price (including the Earn-Out
Adjustments) under ARTICLE I.

          (b)  The obligations of any Seller to defend, indemnify and hold
harmless any Sun Medical Indemnified Party (or any other person) under ARTICLE
VI, or otherwise with respect to any of the matters set forth herein, shall
apply only to the extent that the total amount of all Indemnified Costs for
which all Sun Medical Indemnified Parties  (or other persons) are entitled to
indemnification exceeds $25,000.

                                  ARTICLE VII

                        INDEMNIFICATION OF THE SELLERS
                        ------------------------------
                                        
     7.1  SURVIVAL OF REPRESENTATIONS; TIME LIMITS; KNOWLEDGE.
          ---------------------------------------------------   

          (a)  All representations and warranties of Sun Medical hereunder shall
survive the Closing and shall terminate on the Termination Date.

          (b)  No Seller shall be entitled to indemnification from Sun Medical,
or Prime, under this ARTICLE VII (or otherwise) unless the Seller seeking such
indemnification gives the party from which such indemnification is sought
written notice of a claim for indemnification (which shall set forth in
reasonable detail the basis for such claim) on or before the Termination Date.



                                      42
<PAGE>
 
          (c)  No Seller (or any person claiming through such party) shall be
entitled to indemnification from Sun Medical or Prime based on any inaccuracy,
falsity or misrepresentation of any representation or warranty made hereunder if
any Seller had actual knowledge of such inaccuracy, falsity or misrepresentation
prior to the Closing and elected to proceed with the Closing.

     7.2  INDEMNIFICATION OF THE SELLERS.  Sun Medical agrees to indemnify and
          ------------------------------                                        
hold harmless each of the Sellers from and against any and all Indemnified Costs
in connection with the commencement or assertion of any third party action which
any of the Sellers may sustain, arising out of or relating to (a) any breach or
default by Sun Medical of any of the representations, warranties, covenants or
agreements contained in this Agreement or any agreement or document executed in
connection herewith, or (b) any liability, direct or contingent, known or
unknown, of EME or Sun Medical which arises from or is based on facts, acts or
omissions occurring after the Closing Date.

     7.3  DEFENSE OF THIRD-PARTY CLAIMS.  A Seller shall give prompt written
          -----------------------------                                     
notice to Sun Medical of the commencement or assertion of any third party action
in respect of which such Seller shall seek indemnification hereunder.  Any
failure to so notify Sun Medical shall not relieve Sun Medical from any
liability that it may have to such Seller under this ARTICLE unless the failure
to give such notice materially and adversely prejudices Sun Medical.  Sun
Medical


                                      43
<PAGE>
 
shall have the right to assume control of the defense of, settle, or otherwise
dispose of such third-party action on such terms as it deems appropriate;
provided, however, that:

          (a) The Seller shall be entitled, at his, her, or its own expense, to
participate in the defense of such third-party action;

          (b) Sun Medical shall obtain the prior written approval of the Seller,
which approval shall not be unreasonably withheld or delayed, before entering
into or making any settlement, compromise, admission, or acknowledgment of the
validity of such third-party action or any liability in respect thereof if,
pursuant to or as a result of such settlement, compromise, admission, or
acknowledgment, injunctive or other equitable relief would be imposed against
the Seller or if, in the reasonable opinion of the Seller, such settlement,
compromise, admission, or acknowledgment would have a material adverse effect on
its business;

          (c) Sun Medical shall not consent to the entry of any judgment or
enter into any settlement that does not include as an unconditional term thereof
the giving by each claimant or plaintiff to each Seller of a release from all
liability in respect of such third-party action; and

          (d) Sun Medical shall not be entitled to control (but shall be
entitled to participate at its own expense in the defense of), and the Seller
shall be entitled to have sole control over, the defense or settlement,
compromise, admission, or acknowledgment of any third-party action (i) as to
which Sun Medical fails to assume the defense within a reasonable

                                      44
<PAGE>
 
length of time or (ii) to the extent the third-party action seeks an order,
injunction, or other equitable relief against the Seller which, if successful,
would materially adversely affect the business, operations, assets, or financial
condition of the Seller; provided, however, that the Seller shall make no
                         --------  -------
settlement, compromise, admission, or acknowledgment which would give rise to
liability on the part of Sun Medical without the prior written consent of Sun
Medical.

          (e)  Sun Medical shall make payments of all amounts required to be
made pursuant to the foregoing provisions of this Section to or for the account
of the Seller from time to time promptly upon receipt of bills or invoices
relating thereto or when otherwise due and payable, provided that the Seller has
agreed in writing to reimburse Sun Medical for the full amount of such payments
if the Seller is ultimately determined not to be entitled to such
indemnification.

          (f)  The parties hereto shall extend reasonable cooperation in
connection with the defense of any third-party action pursuant to this ARTICLE
and, in connection therewith, shall furnish such records, information, and
testimony and attend such conferences, discovery proceedings, hearings, trials,
and appeals as may be reasonably requested.

     7.4  LIMITATIONS.  Notwithstanding anything in this ARTICLE VII to the
          -----------                                                        
contrary:

          (a)  In the absence of fraud or intentional misrepresentation, neither
Sun Medical nor Prime shall have any liability or obligation to any Seller (or
any other person or


                                      45
<PAGE>
 
entity) under ARTICLE VII, or otherwise with respect to any of the matters set
forth herein, in an amount that exceeds, in the aggregate, the Aggregate
Purchase Price (including the Earn-Out Adjustments) under ARTICLE I.

          (b) The obligations of Sun Medical or Prime to defend, indemnify and
hold harmless any Seller (or any other person) under ARTICLE VII, or otherwise
with respect to any of the matters set forth herein, shall apply only to the
extent that the total amount of all Indemnified Costs for which all Sellers (or
other persons) are entitled to indemnification exceeds $25,000; provided,
however, this $25,000 requirement shall not apply to claims for payment of any
Earn-Out Adjustments.



                                      46
<PAGE>
 
                                  ARTICLE VIII

                                NON-COMPETITION
                                ---------------
                                        
     Each of the Sellers hereby agrees that until the fifth anniversary of the
Closing Date, he will not directly or indirectly (through Newco or otherwise),
either through any kind of ownership (other than ownership of securities of a
publicly held corporation of which it owns less than five percent (5%) of any
class of outstanding securities), or as a principal, agent, employer, employee,
advisor, consultant, co-partner or in any individual or representative capacity
whatever, either for its own benefit or for the benefit of any other person,
firm or corporation, without the prior written consent of Sun Medical, commit
any of the following acts, which acts shall be considered violations of this
covenant not to compete:

          (a)  Directly or indirectly provide lithotripsy services, including
without limitation, lithotripsy patient services, lithoptripsy management
services, lithotripter leasing (except leases to Sun Medical pursuant to this
Agreement), or similar services, anywhere within the States of California,
Oregon or Washington;

          (b)  Directly or indirectly utilize the Retained Assets for
lithotripsy services, as defined in (a) above, anywhere within the States of
California, Oregon or Washington, or sell, lease or otherwise convey any of the
Retained Assets, or any interest therein, to any third party who provides, or
intends to provide during the period ending on the fifth anniversary of the
Closing Date, lithotripsy services (as defined in (a) above) anywhere within the
States of

                                      47
<PAGE>
 
California, Oregon or Washington; it being understood and agreed that if any
sale by Sellers or Newco of any of the Retained Assets is to a person or entity
whose primary business with respect to such types of assets is to acquire them
for resale to unrelated parties, then in such case only, the Sellers shall only
be required to use their best efforts to determine where the Retained Assets
sold to such reseller would be resold and used, and to not sell any Retained
Assets to any such reseller who any Seller concludes, based on such best efforts
determination, may (more likely than not) resell any Retained Assets in, or for
use in, any of the States of California, Oregon or Washington prior to the fifth
anniversary of the Closing Date;

          (c) Directly or indirectly request or advise any patient or physician
or any other person, firm, corporation or other entity having a business
relationship with Sun Medical, EME or any affiliate or entity related to any of
them, to withdraw, curtail, or cancel its business with Sun Medical, EME or such
affiliate or related entity; or

          (d) Directly or indirectly solicit for employment or employ any
employee (other than any employee related to a Seller) of Sun Medical, EME or
any affiliate or entity related to any of them, or induce or attempt to
influence any employee (other than any employee related to a Seller) of Sun
Medical, EME or any such affiliate or related entity to terminate his or her
employment with Sun Medical, EME or any such affiliate or related entity.

     Each of the Sellers has reviewed and carefully considered the provisions of
this ARTICLE and, having done so, each agrees that the restrictions set forth
herein (a) are fair and


                                      48
<PAGE>
 
reasonable with respect to time, geographic area and scope, (b) are not unduly
burdensome to any of the Sellers, and (c) are reasonably required for the
protection of the interests of Sun Medical, EME and their affiliates.

     Each of the Sellers agrees that a violation on its part of any covenant
contained in this ARTICLE will cause Sun Medical and EME irreparable damage for
which remedies at law may be insufficient, and for that reason, each of the
Sellers agrees that Sun Medical and EME shall be entitled as a matter of right
to equitable remedies, including specific performance and injunctive relief,
therefor.  The right to specific performance and injunctive relief shall be
cumulative and in addition to whatever other remedies, at law or in equity, that
Sun Medical or EME may have, including, specifically, recovery of additional
damages.

     Of the Purchase Price, $10,000, $10,000 and $5,000 shall be allocated to
the agreements of Messrs. Gordon, Pecora and Fazio, respectively, under this
ARTICLE VIII.

                                  ARTICLE IX

                            POST CLOSING AGREEMENTS
                            -----------------------
                                        
     Each of the Sellers agrees to reasonably cooperate with Sun Medical and EME
in transitioning the business conducted, and business relationships maintained
by EME prior to the Closing to the operations established by Sun Medical after
the Closing for so long as any Earn-Out Adjustments are, or may be, due; and
each of the Sellers agrees not to take any action or

                                      49
<PAGE>
 
make any disclosure, including disclosures related to the transactions
contemplated by this Agreement, which might alter or impair any relationship
with any patient, customer, or other service recipient which did business with
EME prior to the Closing. Sun Medical, EME and their affiliates will have no
obligation to compensate Sellers for such cooperation, or to reimburse any
expenses incurred by Sellers unless such expenses are preapproved in writing by
Sun Medical. However, this ARTICLE IX shall not obligate any of the Sellers to
incur any out-of-pocket expenses. Each of the Sellers agrees to promptly remit
to EME (through Sun Medical) any payments received by such Seller, for services
provided by EME. Furthermore, each of the Sellers agrees to deposit any such
payments received directly to a deposit account designated and controlled by Sun
Medical or to take such other action as may be requested by Sun Medical to
implement and maintain a system for remitting payments due EME which come into
the possession or control of any of the Sellers.

                                   ARTICLE X

                                 MISCELLANEOUS
                                 -------------
                                        
     10.1 COLLATERAL AGREEMENTS, AMENDMENTS, AND WAIVERS.  This Agreement
          ----------------------------------------------                   
(together with the documents delivered pursuant hereto) supersedes all prior
documents, understandings, and agreements, oral or written, relating to this
transaction and constitutes the entire understanding among the parties with
respect to the subject matter hereof.  Any modification or amendment to, or
waiver of, any provision of this Agreement (or any document delivered pursuant
to this Agreement unless otherwise expressly provided therein) may be made only
by an instrument in writing executed by each party thereto.


                                      50
<PAGE>
 
     10.2 SUCCESSORS AND ASSIGNS.  Neither Sun Medical's nor any of the
          ----------------------                                         
Sellers' rights or obligations under this Agreement may be assigned without the
prior written consent of all parties hereto, except that (i) Sun Medical may
assign its rights and obligations hereunder to any entity, one hundred percent
(100%) of the voting equity ownership interests of which is at the time owned,
directly or indirectly, by Sun Medical or Prime and (ii) any Seller may assign,
in writing, its rights to receive any amounts under Section 1.3 hereof upon
written notice to Sun Medical, provided the amounts so assigned shall remain
fully subject to the offset rights of Sun Medical and Prime hereunder and, as a
condition of such assignment, the assignor shall obtain the written consent and
acknowledgment thereof from the assignee and provide a copy thereof to Sun
Medical.  Any assignment in violation of the foregoing shall be null and void.
Subject to the preceding sentences of this Section, the provisions of this
Agreement (and, unless otherwise expressly provided therein, of any document
delivered pursuant to this Agreement) shall be binding upon and inure to the
benefit of the parties hereto and their respective heirs, legal representatives,
successors, and permitted assigns.

     10.3 EXPENSES.  Regardless of whether the transactions contemplated
          --------                                                        
hereby are consummated, each party hereto shall pay all of its costs and
expenses incurred by it in connection with this Agreement, including the fees
and disbursements of its counsel.

     10.4 INVALID PROVISIONS.  If any provision of this Agreement is held to
          ------------------                                                  
be illegal, invalid, or unenforceable under present or future laws, such
provision shall be fully severable, this Agreement shall be construed and
enforced as if such illegal, invalid, or unenforceable


                                      51
<PAGE>
 
provision had never comprised a part of this Agreement, and the remaining
provisions of this Agreement shall remain in full force and effect and shall not
be affected by the illegal, invalid, or unenforceable provision or by its
severance from this Agreement.

     10.5 INFORMATION AND CONFIDENTIALITY.  Each party hereto agrees that such
          -------------------------------                                       
party shall hold in strict confidence all information and documents received
from any other party hereto, and if the Closing does not occur, each such party
shall return to the other parties hereto all such documents then in such
receiving party's possession without retaining copies; provided, however, that
each party's obligations under this Section shall not apply to (a) any
information or document required to be disclosed by law, (b) any information or
document in the public domain, or (c) any information or document that Sun
Medical discloses to any potential lender to or investor in Sun Medical or any
of its affiliates.

     10.6 WAIVER.  No failure or delay on the part of any party in exercising
          ------                                                               
any right, power, or privilege hereunder or under any of the documents delivered
in connection with this Agreement shall operate as a waiver of such right,
power, or privilege; nor shall any single or partial exercise of any such right,
power, or privilege preclude any other or future exercise thereof or the
exercise of any other right, power or privilege.

     10.7 NOTICES.  Any notices required or permitted to be given under this
          -------                                                             
Agreement (and, unless otherwise expressly provided therein, under any document
delivered pursuant to this Agreement) shall be given in writing and shall be
deemed received (a) when personally delivered to the relevant party at its
address as set forth below or (b) if sent by mail, on the third day

                                      52
<PAGE>
 
following the date when deposited in the United States mail, certified or
registered mail, postage prepaid, to the relevant party at its address indicated
below:

     Sun Medical:       Sun Medical Technologies, Inc.
                        1301 Capital of Texas Highway
                        Austin, Texas  78746
                        Attention:  President

     with a copy to:    Mr. Timothy L. LaFrey
                        Akin, Gump, Strauss, Hauer & Feld, L.L.P.
                        816 Congress Avenue, Suite 1900
                        Austin, Texas  78701

     Sellers:           Joseph Fazio
                        2609 Fletcher Avenue
                        Fort Lee, New Jersey  07024

                        Vernon Gordon
                        610 Commerce Drive, Suite A
                        Roseville, California  95768

                        John Pecora
                        710 West Napa Street, Suite 3
                        Sonoma, California  95476


Each party may change its address for purposes of this Section by proper notice
to the other parties.

     10.8 SURVIVAL OF REPRESENTATIONS, WARRANTIES, AND COVENANTS.  Regardless
          ------------------------------------------------------               
of any investigation at any time made by or on behalf of any party hereto or of
any information any party may have in respect thereof, all covenants,
agreements, representations, and warranties made hereunder or pursuant hereto or
in connection with the transactions contemplated hereby shall

                                      53
<PAGE>
 
survive the Closing until the Termination Date. The provisions of ARTICLE VIII
shall terminate or expire as provided therein, and not on the Termination Date.

     10.9 FURTHER ASSURANCES.  At, and from time to time after, the Closing,
          ------------------                                                  
each party shall, at the request of another party, but without further
consideration, execute and deliver such other instruments of conveyance,
assignment, assumption, transfer and delivery and take such other action as such
party may reasonably request in order more effectively to consummate the
transactions contemplated hereby.

     10.10 CONSTRUCTION.  This Agreement and any documents or instruments
           ------------                                                    
delivered pursuant hereto or in connection herewith shall be construed without
regard to the identity of the person who drafted the various provisions of the
same.  Each and every provision of this Agreement and such other documents and
instruments shall be construed as though all of the parties participated equally
in the drafting of the same.  Consequently, the parties acknowledge and agree
that any rule of construction that a document is to be construed against the
drafting party shall not be applicable either to this Agreement or such other
documents and instruments.

     10.11 ARBITRATION.  Except as set forth in ARTICLE VIII, any controversy
           -----------                                                         
between the parties regarding this Agreement and any claims arising out of this
Agreement or its breach shall be submitted to arbitration by either party.  The
arbitration proceedings shall be conducted by a single arbitrator pursuant to
the Commercial Arbitration Rules of the American Arbitration Association.  The
arbitration shall be conducted in San Francisco, California and the arbitrator

                                      54
<PAGE>
 
shall have the right to award actual damages and attorney fees and costs, but
shall not have the right to award punitive, exemplary or consequential damages
against either party.


     10.12 GOVERNING LAW.  This Agreement shall be governed by and construed
           -------------                                                      
in accordance with the laws of the State of Texas.

     10.13 COUNTERPARTS.  This Agreement may be executed in several
           ------------                                              
counterparts, each of which shall constitute an original and all of which
together shall constitute one and the same instrument.  Any party hereto may
execute this Agreement by signing any one counterpart.

     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as
of the day and year first above written.


                                      55
<PAGE>
 
                      SIGNATURE PAGE TO EXECUTIVE MEDICAL
                                        
                  ENTERPRISES, INC. STOCK PURCHASE AGREEMENT


SUN MEDICAL:                          SUN MEDICAL TECHNOLOGIES, INC.


                                      By: /s/ Cheryl Williams
                                        ---------------------------------------
                                        Cheryl Williams, Assistant Secretary


PRIME:                                   PRIME MEDICAL SERVICES, INC.


                                      By: /s/ Cheryl Williams
                                        ---------------------------------------
                                        Cheryl Williams, Vice President-Finance


EME:                                  EXECUTIVE MEDICAL ENTERPRISES, INC.


 
                                      By:
                                         --------------------------------------
                                      Printed Name:                           
                                                   ----------------------------
                                      Title:
                                            -----------------------------------
FAZIO:

                                      /s/ Joseph Fazio
                                      -----------------------------------------
                                      Joseph Fazio

GORDON:

                                      /s/ Vernon Gordon
                                      -----------------------------------------
                                      Vernon Gordon


PECORA:

                                      /s/ John Pecora 
                                      -----------------------------------------
                                      John Pecora

<PAGE>
 
                            CONTRIBUTION AGREEMENT


                                     Among


                              AK ASSOCIATES, INC.


                                ROBERT BACHMAN,

                              LAWRENCE SODOMIRE,

                      PRIME KIDNEY STONE TREATMENT, INC.,


                                      And


                             AK ASSOCIATES, L.L.C.



                             ____________________

                            Dated September 1, 1997

                             _____________________


- --------------------------------------------------------------------------------
<PAGE>
 
                             CONTRIBUTION AGREEMENT


     This Contribution Agreement (this "Agreement") is entered into to be
effective as of September 1, 1997 (the "Effective Time"), among Prime Kidney
Stone Treatment, Inc., a New Jersey corporation ("Prime"), AK Associates, Inc.,
an Illinois corporation ("AK"), Robert Bachman ("Bachman"), Lawrence Sodomire
("Sodomire"), and AK Associates, L.L.C., a Texas limited liability company
("Newco").  AK, Bachman and Sodomire are also sometimes referred to collectively
herein as the "Sellers" and individually as a "Seller".

     The parties hereto agree as follows:


                                   ARTICLE I

                        AGREEMENT OF PURCHASE AND SALE
                        ------------------------------

     1.1  AGREEMENT.  Upon the basis of the representations and warranties, for
          ---------                                                            
the consideration, and subject to the terms and conditions set forth in this
Agreement, (a) Prime agrees to purchase, as of the Effective Time, from AK an
undivided 75% interest in the Assets (as hereinafter defined) for $4,761,050 in
cash (the "Purchase Price), (b) Prime agrees to contribute to Newco, as of the
Effective Time, the undivided 75% interest in the Assets purchased by Prime, and
will receive a 75% ownership interest in Newco; and (c) AK agrees to contribute,
as of the Effective Time, the remaining undivided 25% interest in the Assets to
Newco and will receive a 25% ownership interest in Newco.  The Purchase Price
will be allocated to the Assets in accordance with Schedule 1.1 attached hereto.
                                                   ------------
Prime and AK agree to
<PAGE>
 
execute the regulations and other organizational documents of Newco, in the form
attached as Exhibit A (the "Organizational Documents").
            ---------

     1.2  CLOSING.  The closing of the transactions contemplated by Section 1.1
          -------                                                              
(the "Closing") shall take place at the offices of Akin, Gump, Strauss, Hauer &
Feld, L.L.P., 1900 Frost Bank Plaza, 816 Congress Avenue, Austin, Texas 78701,
or at such other location as the parties may agree.  The date on which the
Closing occurs is hereinafter referred to as the "Closing Date."

     1.3  ASSETS.  The term "Assets" shall include all of the business and
          ------                                                          
assets, tangible or intangible, wherever situated, of AK, as of the Effective
Time, such assets to include, without limitation:  accounts receivable,
inventory, work in process, prepaid expenses, supplies, vehicles, any cash or
other property or amounts received for services rendered on or after the
Effective Time; all contract rights of AK; all licenses, certificates and
permits;  the telephone number(s) of AK; the name of AK and all trade names and
other intellectual property; deposits; computer software used by AK in its
operations; all of the leasehold improvements, furniture, fixtures, equipment
and other fixed assets owned or leased by AK; all items of personal property
owned or leased by AK; including without limitation all the assets specifically
set out on Schedule 1.3 attached hereto.  Notwithstanding the foregoing, the
           ------------                                                     
following shall not be "Assets" and shall be retained by AK:

          (a) the books of account and record books of AK (complete and accurate
copies of which shall be provided to Prime on or before the Closing Date);

          (b) AK's rights under this Agreement;

          (c) AK's ownership interest in Newco;

                                       2
<PAGE>
 
          (d) all cash balances (excluding all sums received by AK for services
performed by AK on or after the Effective Time); and

          (e) all motor vehicles other than the 1992 Ford van.

     1.4  ASSUMED LIABILITIES.  At the Closing, Newco shall only assume (i) the
          -------------------                                                  
obligations of AK specifically described on Schedule 1.4 hereto, (ii) those
                                            ------------                   
trade payables on open account incurred in the ordinary course of AK's business
since September 1, 1997 from unrelated parties, and (iii) obligations accruing
after the Effective Time under contracts for jobs in progress or not yet begun
(which jobs Newco agrees to complete according to the terms of such contracts).
Such limited assumption shall be pursuant to that certain general conveyance,
assignment and transfer of assets and assumption of liabilities, attached hereto
as Exhibit B (the "Assignment and Assumption Agreement") to be executed by
   ---------                                                              
Newco, Prime and AK at the Closing, effective as of the Effective Time.  With
respect to any lease obligations reflected on Schedule 1.4, and any contracts
                                              ------------                   
described in clause (iii) of the first sentence of this Section 1.4, it is
agreed that Newco will only be assuming obligations thereunder which accrue
after the Effective Time, and will have no responsibility whatsoever for any
breaches or defaults which occurred prior to the Closing Date, or for
obligations accruing prior to the Effective Time. Except for those liabilities
and obligations specifically assumed by Newco as provided above, any and all
debts, liabilities, and obligations of AK, whether known or unknown, absolute,
contingent or otherwise (including, but not limited to, federal, state, and
local taxes, any sales taxes, use taxes and property taxes, any taxes arising
from the transactions contemplated by this Agreement and any liabilities arising
from any litigation or civil, criminal or regulatory proceeding involving or
related to AK or its business) shall remain the sole responsibility of AK and AK
covenants to pay promptly all such

                                       3
<PAGE>
 
debts and liabilities and to fulfill all such obligations as and when the same
become due. Notwithstanding the foregoing, if there should be any controversy
regarding any debt or liability, AK shall not be required to pay promptly such
debt or liability and shall instead indemnify and hold harmless Newco and Prime
from any liability for such debt or liability.

     1.5  ADDITIONAL PAYMENT. In addition to the Purchase Price provided in
          ------------------                                               
Section 1.1 above, AK shall be entitled to receive an additional payment from
Prime, on the terms and subject to the conditions of this Section, based on the
Adjusted Net Income (as hereinafter defined) of Newco for the calendar year
1998.

     For purposes of this Agreement, the "Adjusted Net Income" of Newco shall be
defined as the net income of Newco, before any provision for Federal income
taxes, for calendar year 1998, determined in accordance with generally accepted
accounting principles ("GAAP"), but adjusted as necessary to eliminate any Prime
Contribution to Income (as herein defined). The parties agree that for purposes
of calculating Adjusted Net Income of Newco, the completed contract method of
accounting will be utilized such that income will not be recognized until
projects are completed and delivered, and the percentage of completion method of
accounting previously utilized by AK will no longer be utilized.

     The parties agree that in applying the completed contract method of
accounting to the measurement of Adjusted Net Income, if a project is
substantially complete at the end of calendar year 1998, and the only reason for
such project not being completed during calendar year 1998 is due to delays by
third parties beyond the control of Newco, such as failure to pay for a
completed project and take delivery thereof (in the absence of bankruptcy,
insolvency, contract disputes or other similar performance issues), or failure
of a third party to provide necessary equipment to

                                       4
<PAGE>
 
complete a project, then the parties will evaluate such cases, on a case-by-case
basis and engage in good faith negotiations as to whether, and to what extent,
to include the projected income therefrom in the determination of Adjusted Net
Income of Newco.

     For purposes of this Agreement, the "Prime Contribution to Income" shall be
deemed to mean all revenue, less only total associated cost of sales (including
associated indirect cost of sales), attributable to any business done by Newco
with or for Prime Medical Services, Inc., a Delaware corporation ("Prime
Medical") or any corporation, partnership, limited liability company or other
entity, any of the voting equity interests of which are owned or controlled,
directly or indirectly, by Prime Medical. For purposes of calculating Prime
Contribution to Income, no allocation or deduction of overhead, fixed costs or
indirect costs (other than associated indirect costs properly included in cost
of sales) of Newco will be taken into consideration. The parties acknowledge and
agree that AK has, prior to the Effective Time, been allocating certain
variable, direct costs to general and administrative expenses, and that such
costs would be more appropriately allocated to cost of sales for purposes of
calculating both Adjusted Net Income and Prime Contribution to Income, in
accordance with GAAP. A description of such previously misclassified variable
direct costs is set forth on Schedule 1.5 hereto, and the parties agree that,
                             ------------                                    
notwithstanding the inconsistency with methodology previously utilized by AK,
such items will be included in variable direct costs attributable to specific
projects for purposes of calculating both Adjusted Net Income and Prime
Contribution to Income for purposes of this Agreement. None of the amortization
expense incurred by Newco in 1998 as a result of amortizing any goodwill created
upon the contribution by Prime to Newco of Prime's

                                       5
<PAGE>
 
interest in the Assets will be taken into consideration in calculating the
Adjusted Net Income of Newco for purposes of this Section.

     The parties hereby further agree that the unanimous agreement of the
managers and members of Newco must be obtained prior to Newco undertaking, or
committing to undertake, any transactions during the 1998 calendar year (other
than the GE Certification Project described below) not within the ordinary
course of Newco's business (consistent with such business as conducted by AK
prior to the Effective Time).

     As an exception to the concept in the preceding paragraph, the parties
acknowledge that AK may undertake the development of a new type of trailer for
General Electric (referred to generally herein as the "GE Certification
Project"). The parties agree that the non-recurring capitalizable costs of
obtaining certification by GE of Newco as a vendor for this new type of trailer
                                                            ---                
will be $250,000, of which the parties agree that $50,000 will be amortized in
calendar year 1998. The parties agree that this amortization expense of $50,000
(but not greater than $50,000) will be excluded from the calculation of Adjusted
Net Income of Newco for calendar year 1998 if (i) on December 31, 1998 there is
a written, binding purchase order that has been received and accepted by Newco
for at least two of the GE Certification Project trailers (which may include the
prototype trailer), (ii) the price of the two GE Certification Project trailers
described in (i) would involve a gross profit margin to Newco of at least 10%
for each of the trailers, and (iii) Newco has received a deposit against the
delivery of the two GE Certification Project trailers described in (i) and (ii)
that is comparable to the standard deposit ordinarily received by Newco with
respect to mobile lithotripsy trailer purchase orders. The parties agree that in
the event all requirements of the preceding sentence are met at December 31,

                                       6
<PAGE>
 
1998, then the $50,000 of amortization expense related to the GE certification
(but not any other cost of sales incurred by Newco with respect to the GE
Certification Project), will be excluded for purposes of calculating Adjusted
Net Income under this Section.

     In calculating Adjusted Net Income, any administrative services or
functions previously undertaken by AK which are provided for Newco by Prime
Medical or one of Prime Medical's affiliates during 1998 (such as accounting or
payroll functions) will be charged to Newco by Prime Medical or its applicable
affiliate at the lesser of (i) the fair market value for such services or
functions, or (ii) AK's cost of providing or obtaining such services or
functions prior to the Effective Time; and the amount so determined will be
deducted in calculating Adjusted Net Income for Newco.

     In the event there is a dispute between AK and Prime Medical as to the
calculation of Adjusted Net Income, the parties agree that upon written request
from either party, and at least thirty (30) days advance written notice (during
which the parties agree to undertake to resolve such dispute amongst
themselves), the dispute will be submitted to a determination by a national
accounting firm selected by the mutual agreement of AK and Prime, whose written
decision thereon shall be binding on all parties hereto. In the event Prime and
AK cannot agree on such accounting firm, KPMG Peat Marwick will make the
selection of a firm (other than itself) for such purposes. Newco shall pay the
fees and expenses charged by any such national accounting firm.

     The following table reflects the amounts of additional payments due, if
any, to AK based on Adjusted Net Income. The maximum additional payment which
would ever be due is $1,050,000. The amounts shown in the right hand column
below are not to be added together,

                                       7
<PAGE>
 
but rather are alternative, total additional payment amounts depending on where
Adjusted Net Income, determined in accordance with this Section, falls among the
ranges referenced in the left hand column below. Any additional payment due
which is not in dispute will be payable, in cash or wire transferred funds, to
AK on or before March 31, 1999; provided, in the event of a dispute as to the
determination of Adjusted Net Income, any additional disputed payment ultimately
determined to be due will be paid within thirty (30) days after the dispute is
resolved by the written decision of the national accounting firm as herein
provided.
<TABLE>
<CAPTION>
             1998 ADJUSTED NET INCOME               ADDITIONAL PAYMENT DUE
             ------------------------               ----------------------
<S>                                                  <C>
             Under $950,000                                   None
 
             $950,000 to $1,099,999                       $  262,500
 
             $1,100,000 to $1,249,999                     $  525,000
 
             $1,250,000 to $1,399,999                     $  787,500
 
             $1,400,000 or greater                        $1,050,000
</TABLE>
                                        
     1.6  PAYMENT OF PURCHASE PRICE.  The Purchase Price shall be paid in
          -------------------------
immediately available funds at the Closing.


                                  ARTICLE II

                    REPRESENTATIONS AND WARRANTIES OF PRIME
                    ---------------------------------------

     Prime represents and warrants to AK, Bachman and Sodomire that each of the
following matters is true and correct in all respects as of the Closing (with
the understanding that AK, Bachman and Sodomire are relying materially on such
representations and warranties in entering into and performing this Agreement):

                                       8
<PAGE>
 
     2.1  DUE ORGANIZATION AND PRINCIPAL EXECUTIVE OFFICE.  Prime is a
          -----------------------------------------------             
corporation duly organized, validly existing, and in good standing under the
laws of the State of New Jersey and has full corporate power and authority to
carry on its business as now conducted and as proposed to be conducted.  Prime
is a subsidiary of Prime Medical Services, Inc., a Delaware corporation ("Prime
Medical").  Prime's principal executive offices are located at 1301 Capital of
Texas Highway, Austin, Texas 78746.

     2.2  DUE AUTHORIZATION.  Prime has full corporate power and authority to
          -----------------                                                  
enter into and perform this Agreement and each other agreement, instrument and
document required to be executed by Prime in connection herewith.  This
Agreement and each other agreement, instrument, and document required herein to
be executed by Prime have been duly and validly authorized, executed and
delivered by Prime and constitute the valid and binding obligations of Prime
enforceable against it in accordance with its terms.  The execution, delivery,
and performance of this Agreement and each other agreement, instrument, and
document required herein to be executed by Prime will not (a) violate any
federal, state, county, or local law, rule, or regulation applicable to Prime or
its properties, (b) violate or conflict with, or permit the cancellation of, any
agreement to which Prime is a party or by which it or its properties are bound,
(c) permit the acceleration of the maturity of any indebtedness of, or any
indebtedness secured by the property of, Prime or (d) violate or conflict with
any provision of the certificate of incorporation or bylaws of Prime.  No
action, consent, or approval of, or filing with, any federal, state, county, or
local governmental authority is required by Prime in connection with the
execution, delivery or performance of this Agreement (or any agreement,
instrument or other document executed in connection herewith by Prime).

                                       9
<PAGE>
 
     2.3  BROKERS AND FINDERS.  Prime has not engaged, or caused to be incurred
          -------------------                                                  
any liability to, any finder, broker, or sales agent in connection with the
execution, delivery, or performance of this Agreement or the transactions
contemplated hereby.

     2.4  CLAIMS AND PROCEEDINGS.  Prime is not a party to any claims, actions,
          ----------------------                                               
suits, proceedings, or investigations, at law or in equity, before or by any
court, municipal or other governmental department, commission, board, agency, or
instrumentality which seeks to restrain or prohibit the carrying out of the
transactions contemplated by this Agreement or to challenge the validity of such
transactions or any part thereof or seeking damages on account thereof; and, to
the knowledge of Prime, no such claim, action, suit, proceeding or investigation
is threatened.

                                  ARTICLE III

           REPRESENTATIONS AND WARRANTIES OF AK, BACHMAN AND SODOMIRE
           ----------------------------------------------------------

     AK, Bachman and Sodomire each, jointly and severally, hereby represent and
warrant to Prime that each of the following matters is true and correct in all
respects as of the Closing (with the understanding that Prime is relying
materially on each such representation and warranty in entering into and
performing this Agreement):

     3.1  DUE ORGANIZATION.  AK is a corporation duly organized, validly
          ----------------                                              
existing, and in good standing under the laws of the State of Illinois and has
full power and authority to carry on its business as now conducted and as
proposed to be conducted.  Bachman and Sodomire are the only shareholders of AK.
Complete and correct copies of the Articles of Incorporation and bylaws of AK,
and all amendments thereto, have been delivered to Prime.  AK is qualified to do
business and is in good standing in the states set forth on Schedule 3.1
                                                            ------------
attached hereto, which

                                      10
<PAGE>
 
states represent every jurisdiction where such qualification is required for the
conduct of AK's business as conducted on the Closing Date.

     3.2  SUBSIDIARIES.  AK does not directly or indirectly have (or possess any
          ------------                                                          
options or other rights to acquire) any subsidiaries or any direct or indirect
ownership interests in any person, business, corporation, partnership,
association, joint venture, trust, or other entity.

     3.3  DUE AUTHORIZATION.  The Sellers have full power and authority to enter
          -----------------                                                     
into and perform this Agreement and each other agreement, instrument, and
document required to be executed by them in connection herewith.  The execution,
delivery, and performance of this Agreement and such other agreements,
instruments, and documents have been duly authorized by all necessary corporate
action of AK.  This Agreement has been duly and validly executed and delivered
by the Sellers and constitutes a valid and binding obligation of the Sellers
enforceable against them in accordance with its terms.  The execution, delivery,
and performance of this Agreement, and each other agreement, instrument and
document required herein to be executed by the Sellers will not (a) violate any
federal, state, county, or local law, rule, or regulation applicable to the
Sellers or the Assets, (b) violate or conflict with, or permit the cancellation
of, any agreement to which any of the Sellers is a party, or by which any Seller
or its properties are bound, or result in the creation of any lien, security
interest, charge, or encumbrance upon any of such properties, (c) permit the
acceleration of the maturity of any indebtedness of, or any indebtedness secured
by the property of, AK, or (d) violate or conflict with any provision of the
Articles of Incorporation or bylaws of AK.  No action, consent, or approval of,
or filing with, any federal, state, county or local governmental authority is
required by any of the Sellers in

                                      11
<PAGE>
 
connection with the execution, delivery, or performance of this Agreement (or
any agreement or other document executed in connection herewith).

     3.4  FINANCIAL STATEMENTS.  The unaudited balance sheet and income
          --------------------                                         
statement of AK as of and for the six (6) months ended June 30, 1997, and the AK
prepared internal financial statements as of and for the eight (8) months ended
August 31, 1997 (collectively, the "Financial Statements") are attached hereto
as Exhibit C.  The June 30, 1997 Financial Statements have been prepared in
   ---------                                                               
accordance with the Statements on Standards for Accounting and Review Services
issued by the American Institute of Certified Public Accountants, and are
materially accurate. The August 31, 1997 Financial Statements are AK prepared
internal financial statements and are materially accurate. The Financial
Statements were prepared using the accrual method of accounting and the
percentage of completion method of recognizing income from work in process.
Except for the lease obligations disclosed on Schedule 1.4 and except to the
                                              ------------                  
extent reflected or provided for in the Financial Statements (including the
notes thereto), AK had no liabilities of a type that would be required to be
reflected as such in the Financial Statements (including the notes thereto).
Except as set forth in Schedule 3.4 hereto, and except for increases in cost of
                       ------------                                            
sales and expenses resulting from the operations of AK in the ordinary course of
its business consistent with past practice, since August 31, 1997 there has been
no material adverse change in the financial position, assets, results of
operations, or business of AK.

     3.5  CONDUCT OF BUSINESS; CERTAIN ACTIONS.  Except as set forth on Schedule
          ------------------------------------                          --------
3.5 attached hereto, since August 31, 1997, AK has conducted its business and
- ---                                                                          
operations in the ordinary course and consistent with its past practices and has
not (a) increased the compensation of any of the Sellers, or, except for wage
and salary increases made in the ordinary course of 

                                      12
<PAGE>
 
business and consistent with the past practices of AK, increased the
compensation of any other employees of AK, (b) made capital expenditures
exceeding $5,000 individually or $20,000 in the aggregate, (c) sold any asset
(or any group of related assets) in any transaction (or series of related
transactions) in which the purchase price for such asset (or group of related
assets) exceeded $20,000 (other than sales of inventory in the ordinary course
of business), (d) discharged or satisfied any lien or encumbrance or paid any
obligation or liability, absolute or contingent, other than current liabilities
incurred and paid in the ordinary course of business, (e) made or guaranteed any
loans or advances to any party whatsoever, (f) suffered or permitted any lien,
security interest, claim, charge, or other encumbrance to arise or be granted or
created against or upon any of the assets of AK, real or personal, tangible or
intangible, (g) canceled, waived, or released any of AK's debts, rights, or
claims against third parties, (h) amended the Articles of Incorporation or
bylaws of AK, (i) made or paid any severance or termination payment to any
employee or consultant in excess of $5,000, (j) made any change in the method of
accounting of AK, (k) made any investment or commitment therefor in any person,
business, corporation, association, partnership, joint venture, trust, or other
entity, (l) except as set forth on Schedule 3.11 and Schedule 3.15, made,
                                   -------------     -------------
entered into, amended, or terminated any written employment contract, created,
made, amended, or terminated any bonus, stock option, pension, retirement,
profit sharing, or other employee benefit plan or arrangement, or withdrawn from
any "multi-employer plan" (as defined in the Internal Revenue Code of 1986, as
amended (the "Code")) so as to create any liability under ERISA (as hereinafter
defined) to any entity, (m) amended, terminated or experienced a termination of
any material contract, agreement, lease, franchise, or license to which AK is a
party, (n) entered into any other material transactions

                                      13
<PAGE>
 
except in the ordinary course of business, (o) entered into any contract,
commitment, agreement, or understanding to do any acts described in the
foregoing clauses (a)-(n) of this Section, (p) suffered any material damage,
destruction, or loss (whether or not covered by insurance) to any assets, (q)
experienced any strike, slowdown, or demand for recognition by a labor
organization by or with respect to any of the employees of AK, or (r)
experienced or effected any shutdown, slow-down, or cessation of any operations
conducted by, or constituting part of, AK.

     3.6  OWNERSHIP OF ASSETS:  LICENSES, PERMITS, ETC.  AK has good and
          --------------------------------------------                  
marketable title to all of the Assets subject only to the liens, security
interests, claims and encumbrances specifically described on Schedule 3.6.  AK
                                                             ------------     
has such property and assets, real, personal and mixed, tangible and intangible,
including leases and other contracts, which are required for, or used in
connection with, the operation of AK as currently conducted.  The Assets are in
good operating condition and repair, subject to ordinary wear and tear, taking
into account the respective ages of the properties involved and are adequate for
the conduct of AK's business.  Attached hereto as Schedule 3.6 is a list of all
                                                  ------------                 
federal, state, county, and local governmental licenses, certificates and
permits held or applied for by AK.  AK has complied in all material respects,
and AK is in compliance in all material respects, with the terms and conditions
of any such licenses, certificates and permits.  No additional license,
certificate, or permit is required from any federal, state, county, or local
governmental agency or body thereof in connection with the conduct of the
business of AK.  No claim has been made by any governmental authority (and, to
the knowledge of Sellers, no such claim has been threatened) to the effect that
a license, permit, certificate, or order not possessed by AK is necessary in
respect of the business

                                      14
<PAGE>
 
conducted by AK. All of the licenses, permits, and certificates noted on the
attached Schedule 3.6 are freely assignable to Newco.
         ------------

     3.7  ENVIRONMENTAL ISSUES.
          -------------------- 

          (a) For purposes of this Agreement, the term "environmental laws"
shall mean all laws relating to the manufacture, processing, distribution, use,
treatment, storage, disposal, transport, or handling, or the emission,
discharge, or release, of any pollutant, contaminant, chemical, or industrial
toxic or hazardous substance or waste and any order related thereto.

          (b) AK has complied in all material respects with and obtained all
authorizations and made all filings required by all applicable environmental
laws.  The properties occupied or used by AK have not been contaminated with any
hazardous wastes, hazardous substances, or other hazardous or toxic materials in
violation of any applicable environmental law, the violation of which could have
a material adverse impact on the business or financial position of AK.

          (c) AK has not received any notice from the United States
Environmental Protection Agency that it is a potentially responsible party under
the Comprehensive Environmental Response, Compensation and Liability Act
("Superfund Notice"), any citation from any federal, state or local governmental
authority for non-compliance with its requirements with respect to air, water or
environmental pollution, or the improper storage, use or discharge of any
hazardous waste, other waste or other substance or other material pertaining to
its business ("Citations") or any written notice from any private party alleging
any such non-compliance; and there are no pending or unresolved Superfund
Notices, Citations or written notices from private parties alleging any such
non-compliance.

                                      15
<PAGE>
 
     3.8  INTELLECTUAL PROPERTY RIGHTS.  There are no patents, trademarks,
          ----------------------------                                    
tradenames, or copyrights, and no applications therefor, owned by or registered
in the name of AK or in which AK has any right, license, or interest.  AK is not
a party to any license agreements, either as licensor or licensee, with respect
to any patents, trademarks, tradenames, or copyrights.  AK has not received any
notice that it is infringing any patent, trademark, tradename, or copyright of
others.

     3.9  COMPLIANCE WITH LAWS.  AK has complied in all material respects, and
          --------------------                                                
AK is in compliance in all material respects, with all federal, state, county,
and local laws, rules, regulations, and ordinances currently in effect and
applicable to its business.  No claim has been made by any governmental
authority (and, to the knowledge of Sellers, no such claim has been threatened)
against AK to the effect that the business conducted by AK fails to comply with
any law, rule, regulation, or ordinance.

     3.10  INSURANCE.  Attached hereto as Schedule 3.10 is a list of all
           ---------                      -------------                 
policies of fire, liability, business interruption, and other forms of insurance
and all fidelity bonds held by or applicable to AK at any time within the past
three (3) years, which schedule sets forth in respect of each such policy the
policy name, policy number, carrier, term, type of coverage, deductible amount
or self-insured retention amount, limits of coverage, and annual premium.  To
the knowledge of Sellers, no event directly relating to AK has occurred which
will result in a retroactive upward adjustment of premiums under any such
policies or which is likely to result in any prospective upward adjustment in
such premiums.  There have been no material changes in the type of insurance
coverage maintained by AK during the past three (3) years, including without
limitation any change which has resulted in any period during which AK had no

                                      16
<PAGE>
 
insurance coverage.  Excluding insurance policies which have expired and been
replaced, no insurance policy of AK has been canceled within the last three (3)
years and, to the knowledge of Sellers, no threat has been made to cancel any
insurance policy of AK within such period.

     3.11  EMPLOYEE BENEFIT MATTERS.  Except as set forth on Schedule 3.11, AK
           ------------------------                          -------------    
does not maintain nor does it contribute nor is it required to contribute to any
"employee welfare benefit plan" (as defined in section 3(1) of the Employee
Retirement Income Security Act of 1974 (and any sections of the Code amended by
it) and all regulations promulgated thereunder, as the same have from time to
time been amended ("ERISA")) or any "employee pension benefit plan" (as defined
in ERISA).  AK does not presently maintain and has never maintained, or had any
obligation of any nature to contribute to, a "defined benefit plan" within the
meaning of the Code.

     3.12  CONTRACTS AND AGREEMENTS.  Attached hereto as Schedule 3.12 is a list
           ------------------------                      -------------          
of all written or oral contracts, commitments, leases, and other agreements
(including, without limitation, promissory notes, loan agreements, and other
evidences of indebtedness) to which AK is a party or by which AK or its
properties are bound, pursuant to which the obligations thereunder of any party
thereto are, or are contemplated as being, in respect of any such individual
contracts, commitments, leases, or other agreements during any year during the
term thereof, $10,000 or greater, or which are otherwise material to the
business of AK (including, without limitation, all mortgages, deeds of trust,
security agreements, pledge agreements, service agreements, and similar
agreements and instruments and all confidentiality agreements).  AK is not and,
to the best knowledge of Sellers, no other party thereto is in default (and no
event has occurred which, with the passage of time or the giving of notice, or
both, would constitute a default by AK or, to the best knowledge of Sellers, by
any other party thereto) under any such contracts, commitments, leases, or other
agreements.  AK has not waived any material right under any such

                                      17
<PAGE>
 
contracts, commitments, leases, or other agreements. AK has not guaranteed any
obligations of any other person.

     3.13  CLAIMS AND PROCEEDINGS.  Attached hereto as Schedule 3.13 is a list
           ----------------------                      -------------          
and description of all claims, actions, suits, proceedings, and investigations
pending or, to the knowledge of Sellers, threatened against AK or affecting any
of its properties or assets, at law or in equity, or before or by any court,
municipal or other governmental department, commission, board, agency, or
instrumentality.  Except as set forth on Schedule 3.13 attached hereto, none of
                                         -------------                         
such claims, actions, suits, proceedings, or investigations will result in any
liability or loss to AK which (individually or in the aggregate) is material,
and AK has not been, and AK is not now, subject to any order, judgment, decree,
stipulation, or consent of any court, governmental body, or agency.  No inquiry,
action, or proceeding has been asserted, instituted, or, to the best knowledge
of Sellers, threatened against AK to restrain or prohibit the carrying out of
the transactions contemplated by this Agreement or to challenge the validity of
such transactions or any part thereof or seeking damages on account thereof.

     3.14  TAXES.  AK has been filing its tax returns as a subchapter S
           -----                                                       
corporation under the Internal Revenue Code. All federal, foreign, state,
county, and local income, gross receipts, excise, property, franchise, license,
sales, use, withholding, and other tax (collectively, "Taxes") returns, reports,
and declarations of estimated tax (collectively, "Returns") which were required
to be filed by AK on or before the date hereof have been filed within the time
(including any applicable extensions) and in the manner provided by law, and all
such Returns are true and correct in all material respects and accurately
reflect the Tax liabilities of AK.  All Taxes,

                                      18
<PAGE>
 
assessments, penalties, and interest which have become due pursuant to such
Returns have been paid or adequately accrued in the Financial Statements. The
provisions for Taxes reflected on the balance sheet contained in the Financial
Statements are adequate to cover all of AK's estimated Tax liabilities for the
respective periods then ended and all prior periods. As of the Closing Date, AK
will not owe any Taxes for any period prior to the Closing which are not
reflected on the Financial Statements, except for Taxes attributable to the
operations of AK between the Effective Time and the Closing Date. AK has not
executed any presently effective waiver or extension of any statute of
limitations against assessments and collection of Taxes. There are no pending
or, to the best knowledge of Sellers, threatened claims, assessments, notices,
proposals to assess, deficiencies, or audits, other than an excise tax audit
being conducted as disclosed on Schedule 3.13, (collectively, "Tax Actions")
against AK with respect to any Taxes owed or allegedly owed by AK. Otherwise,
AK's Returns have not been audited. There are no tax liens on any of the assets
of AK. Proper and accurate amounts have been withheld and remitted by AK from
and in respect of all persons from whom it is required by applicable law to
withhold for all periods in compliance with the tax withholding provisions of
all applicable laws and regulations. AK is not a party to any tax sharing
agreement.

     3.15  PERSONNEL.  Attached hereto as Schedule 3.15 is a list of names and
           ---------                      -------------                       
current annual rates of compensation of the employees of AK whose rates of
compensation, on an annualized basis, during calendar year 1997 (including base
salary, bonus, commissions, and incentive pay) are expected to exceed $20,000.
Except as set forth on Schedule 3.15, there are no bonus, profit sharing,
                       -------------                                     
percentage compensation, company automobile, club membership, and other like
benefits, if any, paid or payable by AK to such employees from December 31, 1996
through the

                                      19
<PAGE>
 
Closing Date. Schedule 3.15 attached hereto also contains a brief description of
              -------------
all material terms of employment agreements and confidentiality agreements to
which AK is a party and all severance benefits which any director, officer,
employee, agent or sales representative of AK is or may be entitled to receive.
AK has delivered to Prime accurate and complete copies of all such employment
agreements, confidentiality agreements, and all other agreements, plans, and
other instruments to which AK is a party and under which its employees are
entitled to receive benefits of any nature. There is no pending or, to the best
knowledge of Sellers, threatened (i) labor dispute or union organization
campaign relating to AK, (ii) claims against AK or the Sellers by any employees
of AK (other than those certain Workers' Compensation claims specifically
described on Schedule 3.13), or (iii) terminations, resignations or retirements
             -------------
of any employees of AK. None of the employees of AK are represented by any labor
union or organization. There is no unfair labor practice claim against AK before
the National Labor Relations Board or any strike, labor dispute, work slowdown,
or work stoppage pending or, to the best knowledge of Sellers, threatened
against or involving AK.

     3.16  BUSINESS RELATIONS.  Sellers have not been notified that any supplier
           ------------------                                                   
or customer of AK (other than American Kidney Stone Management, Ltd. of
Columbus, Ohio who attributed a decision not to purchase from AK because of the
relationship with Prime contemplated herein, which has been communicated to
Prime) will cease or refuse to do business with AK or Newco in the same manner
as previously conducted with AK as a result of or within a year after the
consummation of the transactions contemplated hereby.  AK has not received any
notice of any disruption (including delayed deliveries or allocations by
suppliers) in the availability of the materials or products used by AK.

                                      20
<PAGE>
 
     3.17  ACCOUNTS RECEIVABLE.  Except as set forth on Schedule 3.17 attached
           -------------------                          -------------         
hereto, all of the accounts, notes, and loans receivable that have been recorded
on the books of AK are bona fide and represent amounts validly due.

     3.18  AGENTS.  Except as set forth on Schedule 3.18 attached hereto, AK has
           ------                          -------------                        
not designated or appointed any person (other than AK's employees, officers and
directors) or other entity to act for it or on its behalf pursuant to any power
of attorney or any agency which is presently in effect.

     3.19  INDEBTEDNESS TO AND FROM SHAREHOLDERS, DIRECTORS AND EMPLOYEES.
           --------------------------------------------------------------  
Except as set forth on Schedule 3.19 attached hereto, AK does not owe any
                       -------------                                     
indebtedness to any of its shareholders, directors or employees or have
indebtedness owed to it from any of its shareholders, directors or employees,
excluding indebtedness for travel advances or similar advances for expenses
incurred on behalf of and in the ordinary course of business of AK and
consistent with AK's past practices.  As of the Effective Time and the Closing
Date all amounts due AK from any shareholder, director, officer or employee of
AK (or any of their family members) shall have been repaid in full.

     3.20  COMMISSION SALES CONTRACTS.  Except as disclosed in Schedule 3.20
           --------------------------                          -------------
attached hereto, AK does not employ or have any relationship with any
individual, corporation, partnership, or other entity whose compensation from AK
is in whole or in part determined on a commission basis.

     3.21  CERTAIN CONSENTS.  Except as set forth on Schedule 3.21 attached
           ----------------                          -------------         
hereto, there are no consents, waivers, or approvals required to be executed
and/or obtained by any Sellers from

                                      21
<PAGE>
 
third parties (including, without limitation, the spouses of Bachman and
Sodomire) in connection with the execution, delivery, and performance of this
Agreement.

     3.22  BROKERS.  No Seller has engaged, or caused any liability to be
           -------                                                       
incurred to, any finder, broker, or sales agent in connection with the
execution, delivery, or performance of this Agreement or the transactions
contemplated hereby.

     3.23  INTEREST IN COMPETITORS, SUPPLIERS, AND CUSTOMERS.  Except as set
           -------------------------------------------------                
forth on Schedule 3.23 attached hereto, no Seller or any affiliate of any
         -------------                                                   
Seller, and to the knowledge of Sellers no employee of AK or any affiliate of
any employee of AK, has any ownership interest in any competitor, customer or
supplier of AK or any property used in the operation of the business of AK.

     3.24  WARRANTIES. Except as set forth on Schedule 3.24, AK has not made any
           ----------                         -------------                     
warranties or guarantees to third parties with respect to any products sold or
services rendered by it.  Except as set forth on Schedule 3.24 attached hereto,
                                                 -------------                 
no claims for breach of product or service warranties have been made against AK
since January 1, 1996.

     3.25  NO DEFAULTS.  No Seller is aware of any breach or default by any
           -----------                                                     
other Seller of any of the representations, warranties, covenants or agreements
contained herein.

                                   ARTICLE IV

                                   COVENANTS
                                   ---------

     4.1  NAME CHANGE.  The Sellers agree that at, or within thirty (30) days
          -----------                                                        
after, the Closing Date, AK will change its name to a name that does not contain
the letters "AK" in combination, or the word "Associates".

                                      22
<PAGE>
 
     4.2  COOPERATION RELATING TO FINANCIAL STATEMENTS.  Sellers agree to
          --------------------------------------------                   
cooperate with Prime in the preparation of any financial statements of AK and/or
Newco which Prime or its affiliates may be required by any applicable law to
prepare.

     4.3  SHAREHOLDER AND DIRECTOR ACTION.  Each of Bachman and Sodomire agree
          -------------------------------                                     
to vote their shares in AK, and to take such actions as may be necessary in
their capacity as directors of AK, to authorize and direct AK to perform all of
its obligations under this Agreement and under the Organizational Documents.
Furthermore, Bachman and Sodomire each agree that, until such time as neither
Bachman nor Sodomire is an employee of Newco, they will not authorize the
issuance of any additional capital stock of AK to any third party, or cause or
allow any additional directors to be elected to the board of directors of AK.

     4.4  CAPITAL CONTRIBUTIONS.  The parties acknowledge and agree that initial
          ---------------------                                                 
cash working capital of $400,000 is required for the successful operations of
Newco after the Closing. Accordingly, at the Closing, Prime and AK agree to
contribute cash or immediately available funds to Newco in the amount of
$300,000 and $100,000, respectively. Thereafter, any capital contributions to
Newco shall be governed by the Organizational Documents.

                                   ARTICLE V

                             Conditions to Closing
                             ---------------------

     5.1  PRIME'S CLOSING OBLIGATIONS.  At the Closing, Prime shall:
          ---------------------------  
                             
          (a)  pay the Purchase Price to AK;

          (b) execute and deliver the Assignment and Assumption Agreement and
     the Organizational Documents;

                                      23
<PAGE>
 
          (c) deliver such good standing certificates, officer certificates, and
similar documents and certificates as counsel for AK may reasonably require;

          (d) cause Prime Medical to execute and deliver a Closing Certificate
to AK in the form attached hereto as Exhibit K; and
                                     ---------     
          (e) make the capital contributions to Newco required pursuant to
Section 4.4 above.

     5.2  AK'S CLOSING OBLIGATIONS.  At the Closing, AK shall:
          ------------------------                            
          (a) execute and deliver the Assignment and Assumption Agreement and
the Organizational Documents;

          (b) deliver such good standing certificates, officer and/or
partnership certificates, and similar documents and certificates as counsel for
Prime may reasonably require; and

          (c) make the capital contributions to Newco required pursuant to
Section 4.4 above.

     5.3  NEWCO'S CLOSING OBLIGATIONS.  At the Closing, Newco shall execute and
          ---------------------------                                          
deliver the Assignment and Assumption Agreement.


                                   ARTICLE VI

                       INDEMNIFICATION OF PRIME AND NEWCO
                       ----------------------------------

     6.1  INDEMNIFICATION OF PRIME AND NEWCO.  The Sellers, each jointly and
          ----------------------------------                                
severally, agree to indemnify and hold harmless Prime and, following the
Closing, Newco and each officer, director, employee, and affiliate of Prime and,
following the Closing, Newco (collectively, the

                                      24
<PAGE>
 
"Prime Indemnified Parties") from and against any and all damages, losses,
claims, liabilities, demands, charges, suits, penalties, costs, and expenses
(including court costs and attorneys' fees and expenses incurred in
investigating and preparing for any litigation or proceeding) (collectively,
"Indemnified Costs") in connection with the commencement or assertion of any
action, proceeding, demand, or claim by a third party (collectively, a "third-
party action") which any of the Prime Indemnified Parties may sustain, arising
out of (a) any breach or default by any Seller of any of the representations,
warranties, covenants or agreements contained in this Agreement or any agreement
or document executed in connection herewith (including, without limitation, the
Organizational Documents), (b) any obligation or liability of AK not assumed by
Newco pursuant to the Assignment and Assumption Agreement, or (c) any
obligations or liabilities with respect to any claims arising out of events that
occurred prior to the Closing.

     6.2  DEFENSE OF THIRD-PARTY CLAIMS.  A Prime Indemnified Party shall give
          -----------------------------                                       
prompt written notice to Sellers of the commencement or assertion of any third
party action in respect of which such Prime Indemnified Party shall seek
indemnification hereunder.  Any failure so to notify Sellers shall not relieve
Sellers from any liability that they may have to such Prime Indemnified Party
under this ARTICLE unless the failure to give such notice materially and
adversely prejudices Sellers.  Sellers shall have the right to assume control of
the defense of, settle, or otherwise dispose of such third-party action on such
terms as it deems appropriate; provided, however, that:

          (a) The Prime Indemnified Party shall be entitled, at his, her, or its
own expense, to participate in the defense of such third-party action;

                                      25
<PAGE>
 
          (b) Sellers shall obtain the prior written approval of the Prime
Indemnified Party, which approval shall not be unreasonably withheld, before
entering into or making any settlement, compromise, admission, or acknowledgment
of the validity of such third-party action or any liability in respect thereof
if, pursuant to or as a result of such settlement, compromise, admission, or
acknowledgment, injunctive or other equitable relief would be imposed against
the Prime Indemnified Party;

          (c) Sellers shall not consent to the entry of any judgment or enter
into any settlement that does not include as an unconditional term thereof the
execution and delivery of a release from all liability in respect of such third-
party action by each claimant or plaintiff to, and in favor of, each Prime
Indemnified Party; and

          (d) Sellers shall not be entitled to control (but shall be entitled to
participate at their own expense in the defense of), and the Prime Indemnified
Party shall be entitled to have sole control over, the defense or settlement,
compromise, admission, or acknowledgment of any third-party action as to which
Sellers fail to assume the defense within thirty (30) days; provided, however,
                                                            --------  ------- 
that the Prime Indemnified Party shall make no settlement, compromise,
admission, or acknowledgment which would give rise to liability (other than
liability to Prime Indemnified Parties under this Agreement) on the part of
Sellers or AK,  without the prior written consent of Sellers.

          (e) Sellers shall make payments of all amounts required to be made
pursuant to the foregoing provisions of this ARTICLE to or for the account of
the Prime Indemnified Party from time to time promptly upon receipt of bills or
invoices relating thereto or when otherwise due and payable, provided that the
Prime Indemnified Party has agreed in writing to reimburse

                                      26
<PAGE>
 
Sellers for the full amount of such payments if the Prime Indemnified Party is
ultimately determined not to be entitled to such indemnification.

          (f) The parties hereto shall extend reasonable cooperation in
connection with the defense of any third-party action pursuant to this ARTICLE
and, in connection  therewith, shall furnish such records, information, and
testimony and attend such conferences, discovery proceedings, hearings, trials,
and appeals as may be reasonably requested.


                                  ARTICLE VII

                           INDEMNIFICATION OF SELLERS
                           --------------------------

     7.1  INDEMNIFICATION OF SELLERS.  Prime agrees to indemnify and hold
          --------------------------                                     
harmless Sellers (collectively, the "Seller Indemnified Parties") from and
against any and all Indemnified Costs in connection with the commencement or
assertion of any third party action which any of Seller Indemnified Parties may
sustain, arising out of any breach or default by Prime of any of the
representations, warranties, covenants or agreements contained in this Agreement
or any agreement or document executed in connection herewith (including, without
limitation, the Organizational Documents).

     7.2  DEFENSE OF THIRD-PARTY CLAIMS.  A Seller Indemnified Party shall give
          -----------------------------                                        
prompt written notice to Prime of the commencement or assertion of any third
party action in respect of which such Seller Indemnified Party shall seek
indemnification hereunder.  Any failure so to notify Prime shall not relieve
Prime from any liability that it may have to such Seller Indemnified Party under
this ARTICLE unless the failure to give such notice materially and adversely
prejudices Prime.  Prime shall have the right to assume control of the defense
of, settle, or

                                      27
<PAGE>
 
otherwise dispose of such third-party action on such terms as it deems
appropriate; provided, however, that:

          (a) The Seller Indemnified Party shall be entitled, at his or its own
expense, to participate in the defense of such third-party action;

          (b) Prime shall obtain the prior written approval of the Seller
Indemnified Party, which approval shall not be unreasonably withheld, before
entering into or making any settlement, compromise, admission, or acknowledgment
of the validity of such third-party action or any liability in respect thereof
if, pursuant to or as a result of such settlement, compromise, admission, or
acknowledgment, injunctive or other equitable relief would be imposed against
the Seller Indemnified Party;

          (c) Prime shall not consent to the entry of any judgment or enter into
any settlement that does not include as an unconditional term thereof the
execution and delivery of a release from all liability in respect of such third-
party action by each claimant or plaintiff to, and in favor of, each Seller
Indemnified Party; and

          (d) Prime shall not be entitled to control (but shall be entitled to
participate at its own expense in the defense of), and the Seller Indemnified
Party shall be entitled to have sole control over, the defense or settlement,
compromise, admission, or acknowledgment of any third-party action as to which
Prime fails to assume the defense within thirty (30) days; provided, however,
                                                           --------  ------- 
that the Seller Indemnified Party shall make no settlement, compromise,
admission, or acknowledgment which would give rise to liability (other than
liability to Seller Indemnified Parties under this Agreement) on the part of
Prime without the prior written consent of Prime.

                                      28
<PAGE>
 
          (e) Prime shall make payments of all amounts required to be made
pursuant to the foregoing provisions of this ARTICLE to or for the account of
the Seller Indemnified Party from time to time promptly upon receipt of bills or
invoices relating thereto or when otherwise due and payable, provided that the
Seller Indemnified Party has agreed in writing to reimburse Prime for the full
amount of such payments if the Seller Indemnified Party is ultimately determined
not to be entitled to such indemnification.

          (f) The parties hereto shall extend reasonable cooperation in
connection with the defense of any third-party action pursuant to this ARTICLE
and, in connection therewith, shall furnish such records, information, and
testimony and attend such conferences, discovery proceedings, hearings, trials,
and appeals as may be reasonably requested.


                                  ARTICLE VIII

                           NONCOMPETITION AGREEMENTS
                           -------------------------

     8.1  AGREEMENT OF SELLERS.  Each of the Sellers hereby agrees that, until
          --------------------                                                
the later of (i) the fifth (5th) anniversary of the Closing Date, or (ii) two
(2) years after the termination of the employment with Newco of Bachman (for
Bachman) or Sodomire (for Sodomire) or both Bachman and Sodomire (for AK); such
Seller will not directly or indirectly, either through any kind of ownership
(other than ownership of securities of a publicly held corporation of which it
owns less than five percent (5%) of any class of outstanding securities), or as
a principal, shareholder, agent, employer, advisor, consultant, co-partner or in
any individual or representative capacity whatever, either for its own benefit
or for the benefit of any other person,

                                      29
<PAGE>
 
corporation or other entity, without the prior written consent of Prime, commit
any of the following acts, which acts shall be considered violations of this
covenant not to compete:

          (a) Directly or indirectly, anywhere within the continental United
States,  engage in, or provide any services related to, (i) the manufacture,
maintenance, refurbishing, repair, sale, or leasing, of mobile trailers or
coaches for medical service providers, including without limitation mobile
lithotripsy units, trailers or coaches, or mobile prostatherapy units, trailers
or coaches, or (ii) the manufacturing, design, installation, repair,
maintenance, servicing, upgrading, sale or leasing of fixed site or mobile
diagnostic imaging equipment, or (iii) provide any management services, training
or consulting services related to any of the activities described in (i) or
(ii);

          (b) Directly or indirectly provide lithotripsy or prostatherapy
services, including without limitation, lithotripsy or prostatherapy patient
services, lithotripsy or prostatherapy management services, lithotripter or
prostatron leasing or marketing services, or similar services, anywhere within
the continental United States.

          (c) Directly or indirectly request or advise any person, firm,
physician, corporation or other entity having a business relationship with
Prime, Newco, or any affiliate or related entity of either of them, to withdraw,
curtail, or cancel its business with Prime, Newco, or such affiliate or related
entity; or

          (d) Directly or indirectly hire any employee of Prime, Newco, or any
affiliate or related entity of either of them, or induce or attempt to influence
any employee of Prime, Newco, or any such affiliate or related entity to
terminate his or her employment with Prime, Newco, or any such affiliate or
related entity.

                                      30
<PAGE>
 
     8.2  AGREEMENT BY PRIME. Prime agrees that it will not, including through
          ------------------                                                  
its parent, Prime Medical, a subsidiary, affiliate or otherwise (except through
Newco or except as otherwise provided below), directly or indirectly, acquire or
develop any business that engages in, or provides any services to third parties
related to (i) the manufacture, maintenance, refurbishing, repair or sale of
mobile trailers or coaches for medical service providers, including without
limitation mobile lithotripsy units, trailers or coaches, or mobile
prostatherapy units, trailers or coaches, or (ii) the manufacture, design,
installation, repair, and maintenance, servicing, upgrading or sale of fixed
site or mobile diagnostic imaging equipment, or (iii) the providing of
management services, training or consulting services related to any of the
activities described in (i) or (ii).

     Notwithstanding anything contained above or otherwise elsewhere herein to
the contrary, neither Prime, Prime Medical nor any of their subsidiaries or
affiliates (referred to hereinafter in this paragraph as "Prime Acquiring
Entity") shall be prohibited from acquiring any assets, businesses, corporations
or other entities, the acquisition and operation of which would otherwise
constitute a violation of the foregoing provisions of this Section 8.2 provided
either Prime or Prime Medical has provided Newco and the Sellers written notice
of its intent to entertain such acquisition, together with a reasonably detailed
description of the then contemplated terms and conditions of such acquisition,
and has offered Newco the right of first refusal to engage in such acquisition.
Newco shall have forty-five (45) days from the giving of such notice in which to
exercise its right of first refusal, and upon the expiration of such forty-five
(45) day period Newco shall be deemed to have elected not to exercise its right
of first refusal if it has failed for any reason to close, or be fully prepared
to immediately close, the acquisition on the same terms

                                      31
<PAGE>
 
as would be applicable to the Prime Acquiring Entity. If Newco elects to
exercise its right of first refusal, it must participate in the acquisition as
to all (but not less than all) of the rights and obligations that would
otherwise have been acquired and undertaken by the Prime Acquiring Entity and
any other affiliate of Prime or Prime Medical. Neither Prime, Prime Medical nor
any other affiliate of Prime or Prime Medical will be required to arrange any
financing, provide any payment security or otherwise assist Newco (through
concessions, contractual obligations or otherwise) in making such acquisition in
order to allow Newco to exercise its right of first refusal; provided that Prime
will agree to make its pro rata amount (in accordance with its percentage
membership interest) of capital contributions to Newco, along with Newco's other
members, as necessary to fund such acquisition, if additional equity capital
infusions into Newco are necessary in connection with such acquisition and if
all the members (other than Prime) agree to make, and make, their pro rata
capital contributions.

     Notwithstanding anything contained herein to the contrary, it shall not be
a violation of this Agreement for Prime, Prime Medical or any of their
subsidiaries or affiliates, to utilize employees or other contract maintenance
personnel to perform routine maintenance and/or repairs with respect to any
vehicles or equipment owned or operated by Prime, Prime Medical or any of their
respective subsidiaries or affiliates, including without limitation any mobile
trailers or coaches for medical service providers, mobile lithotripsy units,
trailers or coaches, mobile prostatherapy units, trailers or coaches, or any
diagnostic imaging equipment, units, trailers or coaches.

     The provisions of this Section 8.2 shall be binding and in effect until the
earlier to occur of (i) the date on which none of the Sellers or any entity, all
of whose equity ownership interests

                                      32
<PAGE>
 
are owned by one or both of the Sellers, owns a membership interest in Newco, or
(ii) the date on which any of the Sellers ceases to be bound by the agreements
and restrictions contained in Section 8.1 hereof.

     8.3  AGREEMENT OF THE PARTIES.  Each party hereto has reviewed and
          ------------------------                                     
carefully considered the provisions of this ARTICLE and, having done so, agrees
that the restrictions applicable to them as set forth herein (a) are fair and
reasonable with respect to time, geographic area and scope, (b) are not unduly
burdensome to them, and (c) are reasonably required for the protection of the
interests of the other parties hereto for whose benefit such restrictions were
agreed upon.

          Each party hereto agrees that a violation on its part of any
applicable covenant contained in this ARTICLE will cause the other parties
hereto for whose benefit such restrictions were agreed upon irreparable damage
for which remedies at law may be insufficient, and for that reason, each party
hereto agrees that the other parties shall be entitled as a matter of right to
equitable remedies, including specific performance and injunctive relief,
therefor.  The right to specific performance and injunctive relief shall be
cumulative and in addition to whatever other remedies, at law or in equity, that
the other parties may have, including, specifically, recovery of additional
damages.


                                   ARTICLE IX

                            POST CLOSING AGREEMENTS
                            -----------------------

     9.1  TRANSITION OF BUSINESS.  Each Seller agrees to cooperate fully with
          ----------------------                                             
Prime and Newco in transitioning the business conducted, and business
relationships maintained by AK

                                      33
<PAGE>
 
prior to the Closing, to Newco after the Closing; and each Seller agrees not to
take any action or make any disclosure, including disclosures related to the
transactions contemplated by this Agreement, which might alter or impair any
relationship with any customer, or other service recipient, person or entity
which did business with AK prior to the Closing. Each Seller agrees to promptly
remit to Newco any payments received by AK or any Seller for services provided
by AK after the Effective Time or by Newco after the Closing. Furthermore,
Sellers agree to deposit any such payments received directly to a deposit
account designated and controlled by Newco or to take such other action as may
be requested by Prime to implement and maintain a system for remitting payments
due Newco which come into the possession or control of AK or any Seller.

     9.2  RATIFICATION BY NEWCO.  Prime and AK agree that by executing this
          ---------------------                                            
Agreement they are deemed to be voting their ownership interests in Newco to
authorize Newco to enter into and perform this Agreement as it relates to Newco.
Prime and AK agree to execute such resolutions and written consents, and take
such other actions, in their capacities as members of Newco, as either shall
reasonably require after the Closing to have Newco ratify and adopt this
Agreement as it relates to Newco, notwithstanding the official date of Newco's
creation.

     9.3  EMPLOYMENT WITH NEWCO.  Bachman and Sodomire each agree to work full-
          ---------------------                                               
time for Newco for the two (2) year period after the Closing Date, and to enter
into Employment Agreements in the form attached hereto as Exhibit-D at the
                                                          ---------       
Closing.  Bachman and Sodomire agree not to terminate such Employment
Agreements, or their employment with Newco thereunder, during such two (2) year
period unless Newco defaults in its obligations under the Employment Agreements,
or this Agreement.

                                      34
<PAGE>
 
                                   ARTICLE X

                                 MISCELLANEOUS
                                 -------------

     10.1  COLLATERAL AGREEMENTS, AMENDMENTS, AND WAIVERS.  This Agreement
           ----------------------------------------------                 
(together with the documents delivered pursuant hereto) supersedes all prior
documents, understandings, and agreements, oral or written, relating to this
transaction and constitutes the entire understanding among the parties with
respect to the subject matter hereof.  Any modification or amendment to, or
waiver of, any provision of this Agreement (or any document delivered pursuant
to this Agreement unless otherwise expressly provided therein) may be made only
by an instrument in writing executed by each party thereto.

     10.2  SUCCESSORS AND ASSIGNS.  No party's rights or obligations under this
           ----------------------                                              
Agreement may be assigned without the prior written consent of all parties
hereto, except that Prime may assign its rights and obligations hereunder to any
entity, more than 50% of the voting equity ownership interests of which is at
the time owned, directly or indirectly, by Prime Medical Services, Inc., a
Delaware corporation.  Furthermore, AK may, upon written notice to Prime, assign
its rights hereunder to Bachman and/or Sodomire or to any entity, all of whose
equity ownership interests are owned by AK, Bachman and/or Sodomire; provided
that in the event of an assignment to any such entity AK, Bachman and Sodomire
must first agree in writing with Prime, in form and substance reasonably
acceptable to Prime, not to transfer or issue any equity ownership interests
therein to any person or entity other than AK, Bachman or Sodomire for so long
as any provisions of this Agreement remain binding and enforceable on any party
hereto. Upon any such permitted assignment, AK and the assignee shall thereafter
be jointly and

                                      35
<PAGE>
 
severally responsible for the obligations of AK hereunder. Furthermore, no
assignment, of any type, of rights or obligations under this Agreement shall in
any way limit, modify or otherwise affect the obligations of Bachman, Sodomire
or AK pursuant to the provisions of Sections 8.1, 9.1 and 9.3 of this Agreement,
which the parties hereto acknowledge and agree to be the personal obligations of
Bachman, Sodomire and AK not subject to assignment, transfer, modification or
amendment without the express written consent of Prime in each instance. Any
assignment in violation of the foregoing shall be null and void. Subject to the
preceding sentences of this Section, the provisions of this Agreement (and,
unless otherwise expressly provided therein, of any document delivered pursuant
to this Agreement) shall be binding upon and inure to the benefit of the parties
hereto and their respective heirs, legal representatives, successors, and
assigns.

     10.3  EXPENSES.  Except as set forth in the following sentence, regardless
           --------                                                            
of whether the transactions contemplated hereby are consummated, each party
hereto shall pay all of its costs and expenses incurred by it in connection with
this Agreement, including the fees and disbursements of its counsel. The costs
and expenses associated specifically with the formation and documentation of
Newco, including legal fees and expenses for drafting the Organizational
Documents, shall be paid or reimbursed by Newco.

     10.4  INVALID PROVISIONS.  If any provision of this Agreement is held to be
           ------------------                                                   
illegal, invalid, or unenforceable under present or future laws, such provision
shall be fully severable, this Agreement shall be construed and enforced as if
such illegal, invalid, or unenforceable provision had never comprised a part of
this Agreement, and the remaining provisions of this

                                      36
<PAGE>
 
Agreement shall remain in full force and effect and shall not be affected by the
illegal, invalid, or unenforceable provision or by its severance from this
Agreement.

     10.5  WAIVER.  No failure or delay on the part of any party in exercising
           ------                                                             
any right, power, or privilege hereunder or under any of the documents delivered
in connection with this Agreement shall operate as a waiver of such right,
power, or privilege; nor shall any single or partial exercise of any such right,
power, or privilege preclude any other or future exercise thereof or the
exercise of any other right, power or privilege.

     10.6  NOTICES.  Any notices required or permitted to be given under this
           -------                                                           
Agreement (and, unless otherwise expressly provided therein, under any document
delivered pursuant to this Agreement) shall be given in writing and shall be
deemed received (a) when delivered personally or by courier service to the
relevant party at its address as set forth below or (b) if sent by mail, on the
third day following the date when deposited in the United States mail, certified
or registered mail, postage prepaid, to the relevant party at its address
indicated below:

Prime and Newco:    Prime Kidney Stone Treatment, Inc.
                    1301 Capital of Texas Highway
                    Suite C-300
                    Austin, Texas  78746
                    Attention:  President

with a copy to:     Mr. Timothy L. LaFrey
                    Akin, Gump, Strauss, Hauer & Feld, L.L.P.
                    816 Congress Avenue, Suite 1900
                    Austin, Texas  78701

Sellers:            Mr. Robert Bachman, Mr. Lawrence Sodomire, and
                    AK Associates, Inc.
                    19701 South 97th Avenue
                    Mokena, Illinois  60448

with a copy to:     Mr. Michael P. Mullen
                    Mullen & Foster
                    33 North Dearborn Street, Suite 1500

                                      37
<PAGE>
 
                    Chicago, Illinois  60602

     Each party may change its address for purposes of this Section by proper
notice to the other parties.

     10.7  SURVIVAL OF REPRESENTATIONS, WARRANTIES, AND COVENANTS.  Regardless
           ------------------------------------------------------             
of any investigation at any time made by or on behalf of any party hereto or of
any information any party may have in respect thereof, all covenants,
agreements, representations, and warranties made hereunder or pursuant hereto or
in connection with the transactions contemplated hereby shall survive the
Closing.

     10.8  FURTHER ASSURANCES.  At, and from time to time after, the Closing,
           ------------------                                                
each party shall, at the request of another party, but without further
consideration, execute and deliver such other instruments of conveyance,
assignment, assumption, transfer and delivery and take such other action as such
party may reasonably request in order more effectively to consummate the
transactions contemplated hereby.

     10.09  CONSTRUCTION AND KNOWLEDGE.  This Agreement and any documents or
            --------------------------                                      
instruments delivered pursuant hereto or in connection herewith shall be
construed without regard to the identity of the person who drafted the various
provisions of the same.  Each and every provision of this Agreement and such
other documents and instruments shall be construed as though all of the parties
participated equally in the drafting of the same.  Consequently, the parties
acknowledge and agree that any rule of construction that a document is to be
construed against the drafting party shall not be applicable either to this
Agreement or such other documents and instruments.

                                      38
<PAGE>
 
     10.10  GOVERNING LAW.  This Agreement shall be governed by and construed in
            -------------                                                       
accordance with the laws of the State of Texas.

     10.11  COUNTERPARTS.  This Agreement may be executed in several
            ------------                                            
counterparts, each of which shall constitute an original and all of which
together shall constitute one and the same instrument.  Any party hereto may
execute this Agreement by signing any one counterpart.

     10.12  POST EFFECTIVE TIME ADJUSTMENTS.   The parties acknowledge and agree
            -------------------------------                                     
that AK has, prior to the Closing Date, been receiving revenues, making
disbursements and incurring payables and receivables pursuant to the operations
of AK in the ordinary course since September 1, 1997, including without
limitation paying payroll, payroll taxes, trade vendors and other expenses. AK
will promptly account for all such activity and the parties agree that Newco or
AK, as applicable, will reimburse the other for any net amounts due with respect
to such post-Effective Time activity.

     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as
of the day and year first above written.

                                      39
<PAGE>
 
                               SIGNATURE PAGE TO
                             CONTRIBUTION AGREEMENT
                                        

PRIME:                         PRIME KIDNEY STONE TREATMENT, INC.



                               By: /s/ Michael S. Madler
                                  --------------------------------------------
                                  Michael S. Madler, President


AK:                            AK ASSOCIATES, INC.

 
                               By: /s/ Robert Bachman
                                  --------------------------------------------
                               Printed Name: Robert Bachman
                                            ----------------------------------
                               Title: Vice President
                                     -----------------------------------------


NEWCO:                         AK ASSOCIATES, L.L.C.

                               By:  AK ASSOCIATES, INC. -- Member


                                    By: /s/ Lawrence Sodomire
                                       ---------------------------------------

                                    Printed Name: Lawrence Sodomire
                                                 -----------------------------
                                    Title: Vice President
                                          ------------------------------------


                               By:  PRIME KIDNEY STONE TREATMENT,      
                                    INC. -- Member                     


                                    By: /s/ Michael S. Madler
                                       ---------------------------------------
                                       Michael S. Madler, President


BACHMAN:                        /s/ Robert Bachman
                               -----------------------------------------------
                               Robert Bachman
<PAGE>
 
SODOMIRE:                       /s/ Lawrence Sodomire
                               -----------------------------------------------
                               Lawrence Sodomire



                    GUARANTY OF PRIME MEDICAL SERVICES, INC.

Prime Medical Services, Inc., a Delaware corporation, hereby agrees to guarantee
the performance of all obligations of Prime Kidney Stone Treatment, Inc., a New
Jersey corporation, under this Agreement, and by execution hereof below,
acknowledges its authority to execute this written guaranty.

                               PRIME MEDICAL SERVICES, INC.


                               By: /s/ Michael Madler
                                  -----------------------------------

                               Printed: Michael Madler
                                       ------------------------------

                               Title: Sr. VP - Operations
                                     --------------------------------
<PAGE>
 
                                   EXHIBIT-A
                                        


                                REGULATIONS OF
                             AK ASSOCIATES, L.L.C.

            Organized under the Texas Limited Liability Company Act


                                  ARTICLE I.
                               NAME AND LOCATION
                               -----------------
                                        
     Section 1.1.  Name.  The name of this limited liability company is AK
                   ----                                                   
ASSOCIATES, L.L.C. (the "Company").

     Section 1.2.  Members.  The initial members of the Company shall be Prime
                   -------                                                    
Kidney Stone Treatment, Inc., a New Jersey corporation, and AK Associates, Inc.,
a Illinois corporation. For purposes of these Regulations, the "Members" shall
include such initial members and any new members admitted pursuant to the terms
of these Regulations, but does not include any person or entity who has ceased
to be a member in the Company.

     Section 1.3.  Principal Office.  The principal office of the Company shall
                   ----------------                                            
be located in Austin, Texas, or such other location as may be selected by the
Members.

     Section 1.4.  Registered Agent and Address.  The name of the registered
                   -----------------------------                            
agent and the address of the registered office of the Company as set forth in
the Articles of Organization of the Company are:

                         1301 Capital of Texas Highway
                         Suite C-300
                         Austin, TX  78746
                         Attn:  Michael S. Madler

     Section 1.5.  Other Offices.  Other offices and other facilities for the
                   -------------                                             
transaction of business shall be located at such places as the Managers may from
time to time determine.


                                  ARTICLE II.
                                  MEMBERSHIP
                                  ----------

     Section 2.1.  Members' Interests.  The "Membership Interest" of each Member
                   ------------------                                           
is set forth on Exhibit A.
                --------- 
<PAGE>
 
     Section 2.2.  Admission to Membership.  The admission of new Members shall
                   -----------------------                                     
be only by the unanimous vote of the Members.  If new members are admitted,
these Regulations shall be amended to reflect each Member's revised Membership
Interest.

     Section 2.3.  Property Rights.  No Member shall have any right, title, or
                   ---------------                                            
interest in any of the property or assets of the Company.

     Section 2.4.  Liability of Members.  No Member of the Company shall be
                   --------------------                                    
personally liable for any debts, liabilities, or obligations of the Company,
including under a judgment decree, or order of court.

     Section 2.5.  Transferability of Membership.  Except as provided below,
                   -----------------------------                            
Membership Interests in the Company are transferable only with the unanimous
written consent of all Members.  If such unanimous written consent is not
obtained when required, the transferee shall be entitled to receive only the
share of profits or other compensation by way of income and the return of
contributions to which the transferor Member otherwise would be entitled.
Notwithstanding the foregoing, the Membership Interests of Prime Kidney Stone
Treatment, Inc. ("Prime") may be freely transferred, without consent, to any
entity that is then owned or controlled, directly or indirectly, by Prime
Medical Services, Inc., a Delaware corporation ("Prime Medical"). Furthermore,
the Membership Interest of AK Associates, Inc. ("AK") may be freely transferred,
without consent, to any entity all of whose equity ownership interests are owned
by Robert Bachman ("Bachman") and/or Lawrence Sodomire ("Sodomire"), the sole
shareholders of AK. However, any transfer of any of the equity ownership
interests of AK, or of any such permitted transferee of AK, to any persons other
than Bachman or Sodomire, or to any other entity all of whose equity ownership
interests are not at all times owned by Bachman and/or Sodomire, shall be deemed
a transfer of Membership Interest requiring unanimous written consent of all
Members as provided above.

     Section 2.6.  Resignation of Members.  A Member may not withdraw from the
                   ----------------------                                     
Company except on the unanimous consent of the remaining Members.  The terms of
the Members withdrawal shall be determined by agreement between the remaining
Members and the withdrawing Member.


                                 ARTICLE III.
                               MEMBERS' MEETINGS
                               -----------------

     Section 3.1.  Time and Place of Meeting.  All meetings of the Members shall
                   -------------------------                                    
be held at such time and at such place within or without the State of Texas as
shall be determined by the Managers.

     Section 3.2.  Annual Meetings.  In the absence of an earlier meeting at
                   ---------------                                          
such time and place as the Managers shall specify, annual meetings of the
Members shall be held at the principal office of the Company on the date which
is thirty (30) days after the end of the Company's fiscal year if not a legal
holiday, and if a legal holiday, then on the next full business

                                       2
<PAGE>
 
day following, at 10:00 a.m., at which meeting the Members may transact such
business as may properly be brought before the meeting.

     Section 3.3.  Special Meetings.  Special meetings of the Members may be
                   ----------------                                         
called at any time by any Member.  Business transacted at special meetings shall
be confined to the purposes stated in the notice of the meeting.

     Section 3.4.  Notice.  Written or printed notice stating the place, day and
                   ------                                                       
hour of any Members' meeting, and, in the case of a special meeting, the purpose
or purposes for which the meeting is called, shall be delivered not less than
ten (10) days nor more than thirty (30) days before the date of the special
meeting, either personally or by mail, by or at the direction of the person
calling the meeting, to each Member entitled to vote at such meeting.  If
mailed, such notice shall be deemed to be delivered three (3) days after it is
deposited in the United States mail, postage prepaid, to the Member at his
address as it appears on the records of the Company at the time of mailing.

     Section 3.5.  Quorum.  Members present in person or represented by proxy,
                   ------                                                     
holding more than fifty percent (50%) of the total votes which may be cast at
any meeting shall constitute a quorum at all meetings of the Members for the
transaction of business.  If, however, such quorum shall not be present or
represented at any meeting of the Members, the Members entitled to vote, present
in person or represented by proxy, shall have power to adjourn the meeting from
time to time, without notice other than announcement at the meeting, until a
quorum shall be present or represented.  When any adjourned meeting is
reconvened and a quorum shall be present or represented, any business may be
transacted which might have been transacted at the meeting as originally
noticed.  Once a quorum is constituted, the Members present or represented by
proxy at a meeting may continue to transact business until adjournment,
notwithstanding the subsequent withdrawal therefrom of such number of Members as
to leave less than a quorum.

     Section 3.6.  Voting.  When a quorum is present at any meeting, the vote of
                   ------                                                       
the Members, whether present or represented by proxy at such meeting, holding
more than fifty percent (50%) of the total votes which may be cast at any
meeting shall be the act of the Members, unless the vote of a different number
is required by the Texas Limited Liability Company Act (the "Act"), the Articles
of Organization or these Regulations.  Each Member shall be entitled to one vote
for each percentage point represented by their Membership Interest.  Fractional
percentage point interests shall be entitled to a corresponding fractional vote.

     Section 3.7.  Proxy.  Every proxy must be executed in writing by the Member
                   -----                                                        
or by his duly authorized attorney-in-fact, and shall be filed with the
Secretary of the Company prior to or at the time of the meeting.  No proxy shall
be valid after eleven (11) months from the date of its execution unless
otherwise provided therein.  Each proxy shall be revocable unless expressly
provided therein to be irrevocable and unless otherwise made irrevocable by law.

     Section 3.8.  Action by Written Consent.  Any action required or permitted
                   -------------------------                                   
to be taken at any meeting of the Members may be taken without a meeting if a
consent in writing, setting forth the action so taken, shall be signed by all of
the Members entitled to vote with respect to the

                                       3
<PAGE>
 
subject matter thereof, and such consent shall have the same force and effect as
a unanimous vote of Members.

     Section 3.9.  Meetings by Conference Telephone.  Members may participate in
                   --------------------------------                             
and hold meetings of Members by means of conference telephone or similar
communications equipment by means of which all persons participating in the
meeting can hear each other, and participation in such a meeting shall
constitute presence in person at such meeting, except where a person
participates in the meeting for the express purpose of objecting to the
transaction of any business on the ground that the meeting is not lawfully
called or convened.


                                  ARTICLE IV.
                       MEMBERSHIP CAPITAL CONTRIBUTIONS
                        --------------------------------

     Section 4.1.  Capital Contributions.  The initial capital contribution of
                   ---------------------                                      
each Member shall be as set forth in that certain Contribution Agreement dated
effective September 1, 1997, by and among Prime, AK Associates, Inc., Lawrence
Sodomire, Robert Bachman and the Company.

     Section 4.2.  Additional Contributions.  No additional capital
                   ------------------------                        
contributions shall be required of any Member without the approval of all the
Members to raise additional capital proportionately as to each Member.

     Section 4.3.  Loans from Members.  If, in the reasonable discretion of the
                   ------------------                                          
Managers, additional funds are needed for the operations of the Company, and the
unanimous approval required by Section 4.2 cannot be obtained, upon the approval
of the Managers, any Member may (but shall not be obligated to) advance funds in
the form of a temporary loan to the Company due upon demand.  All Members' loans
shall bear interest at a variable, per annum rate equal to the Prime rate (as
quoted in The Wall Street Journal, Southwest edition, from time-to-time), plus
                                                                          ----
three percent (3%), compounded annually, but in no event in excess of the
maximum rate of interest allowable under applicable law.


                                  ARTICLE V.
                            DISTRIBUTION TO MEMBERS
                            -----------------------

     The Managers shall determine, in their sole discretion, the amount and
timing of all distributions from the Company. Notwithstanding the foregoing, the
Members agree that any available cash accumulated by the Company in excess of a
reserve equal to the reasonably projected cash operating needs of the Company
for six (6) months, shall be distributed to the Members no less frequently than
the end of each calendar quarter. Distributions shall be divided among the
Members in accordance with their Membership Interests.  Distributions in kind
shall be made on the basis of agreed value as determined by the Members.
Notwithstanding the foregoing, the Company may not make a distribution to its
Members to the extent that, immediately after giving effect to the distribution,
all liabilities of the Company, other than liabilities to the Members with
respect to their interests and liabilities for which the recourse of

                                       4
<PAGE>
 
creditors is limited to specified property of the Company, exceed the fair value
of the Company assets; except that the fair value of property that is subject to
liability for which recourse of creditors is limited, shall be included in the
Company assets only to the extent that the fair value of the property exceeds
that liability.


                                  ARTICLE VI.
             ALLOCATION OF NET PROFITS AND LOSSES FOR TAX PURPOSES
             -----------------------------------------------------
                                        
     For accounting and income tax purposes, all items of income, gain, loss,
deduction, and credit of the Company for any taxable year shall be allocated
among the Members in accordance with their respective Membership Interests,
except as may be otherwise required by the Internal Revenue Code of 1986, as
amended. However, any amortization expense incurred by the Company as a result
of amortizing any goodwill created upon the initial contribution by Prime of
assets to the Company at the inception of the Company shall be allocated solely
to Prime.


                                 ARTICLE VII.
                          DISSOLUTION AND WINDING UP
                          --------------------------

     Section 7.1.  Dissolution.  The Company shall be dissolved upon the first
                   -----------                                                
of the following to occur:

     (a) Forty (40) years from the date of filing the Articles of Organization
of the Company;

     (b) Written consent of all Members to dissolution;

     (c) The bankruptcy of a Member, unless there is at least one remaining
Member and such Member or, if more than one remaining Member, all remaining
Members agree to continue the Company and its business.

     Section 7.2.  Winding Up.  Unless the Company is continued pursuant to
                   ----------                                              
Section 1(c) of this Article VII., in the event of dissolution of the Company,
the Managers shall wind up the Company's affairs as soon as reasonably
practicable.  On the winding up of the Company, the Managers shall pay and/or
transfer the assets of the Company in the following order:

     (a) In discharging liabilities (including loans from Members) and the
expenses of concluding the Company's affairs;

     (b) The balance, if any, shall be divided between the Members in accordance
with the Members' Membership Interests.

                                       5
<PAGE>
 
                                 ARTICLE VIII.
                                   MANAGERS
                                   --------
                                        
     Section 8.1.  Selection of Managers.  Management of the Company shall be
                   ---------------------                                     
vested in the Managers.  Initially, the Company shall have five (5) Managers,
being Michael S. Madler, Vincent Prendergast, Cheryl Williams (as the initial
Manager designees of Prime), Bachman and Sodomire (as the initial Manager
designees of AK). Thereafter, for so long as there are five (5) Managers, Prime
shall be entitled to designate three (3) of the Managers and AK shall be
entitled to designate the remaining two (2) of the Managers. Each of the Members
agrees to vote its respective Membership Interests to elect those persons as
Managers who the other Member designates as their Manager designees, and to
remove any Manager designees of the other Member which the other Member
indicates it wishes to have removed as Managers. However, the Members may, by
unanimous vote of all Members, from time to time, change the number of Managers
of the Company and remove or add Managers accordingly.  A Manager shall serve as
a Manager until removed pursuant to Section 2 or 3 of this Article VIII.
Managers need not be residents of the State of Texas or Members of the Company.

     Section 8.2.  Resignations.  Each Manager shall have the right to resign at
                   ------------                                                 
any time upon written notice of such resignation to the Members.  Unless
otherwise specified in such written notice, the resignation shall take effect
upon the receipt thereof, and acceptance of such resignation shall not be
necessary to make same effective.

     Section 8.3.  Removal of Managers.  Any Manager may be removed, for or
                   -------------------                                     
without cause, though his term may not have expired, by the unanimous vote of
all Members; provided each Member agrees to vote its respective Membership
Interests for the removal of any of the Manager designees of the other Member
upon the request of the other Member that such Manager designee be removed.

     Section 8.4.  General Powers.  The business of the Company shall be managed
                   --------------                                               
by its Managers, which may each exercise any and all powers of the Company and
do any and all such lawful acts and things as are not by the Act, the Articles
of Organization or by these Regulations directed or required to be exercised or
done by the Members, including, but not limited to, contracting for or incurring
on behalf of the Company debts, liabilities and other obligations, without the
consent of any other person, except as otherwise provided herein.

     Section 8.5.  Place of Meetings.  The Managers of the Company may hold
                   -----------------                                       
their meetings, both regular and special, either within or without the State of
Texas.

     Section 8.6.  Annual Meetings.  The annual meeting of the Managers shall be
                   ---------------                                              
held without further notice immediately following the annual meeting of the
Members, and at the same place, unless by unanimous consent of the Managers that
such time or place shall be changed.

     Section 8.7.  Regular Meetings.  Regular meetings of the Managers may be
                   ----------------                                          
held without notice at such time and place as shall from time to time be
determined by the Managers.

                                       6
<PAGE>
 
     Section 8.8.  Special Meetings.  Special meetings of the Mangers may be
                   ----------------                                         
called by any Manager on seven (7) days notice to each Manager, with such notice
to be given personally, by mail or by telecopy, telegraph or mailgram.

     Section 8.9.  Quorum and Voting.  At all meetings of the Managers the
                   -----------------                                      
presence of at least a majority of the number of Managers shall be necessary and
sufficient to constitute a quorum for the transaction of business, and the
affirmative vote of at least a majority of the Managers present at any meeting
at which there is a quorum shall be the act of the Managers, except as may be
otherwise specifically provided by the Act, the Articles of Organization or
these Regulations.  If a quorum shall not be present at any meeting of Managers,
the Managers present there may adjourn the meeting from time to time without
notice other than announcement at the meeting, until a quorum shall be present.

     Section 8.10.  Committees.  The Managers may, by resolution passed by a
                    ----------                                              
majority of the Managers, designate committees, each committee to consist of one
or more Managers, which committees shall have such power and authority and shall
perform such functions as may be provided in such resolution.  Such committee or
committees shall have such name or names as may be designated by the Managers
and shall keep regular minutes of their proceedings and report the same to the
Managers when required.

     Section 8.11.  Compensation of Managers.  The Members shall have the
                    ------------------------                             
authority to fix the compensation of Managers and such compensation may include
expenses.

     Section 8.12.  Action by Written Consent.  Any action required or permitted
                    -------------------------                                   
to be taken at any meeting of the Managers or of any committee designated by the
Managers may be taken without a meeting if written consent, setting forth the
action so taken, is signed by all the Managers or of such committee, and such
consent shall have the same force and effect as a unanimous vote at a meeting.

     Section 8.13.  Meetings by Conference Telephone.  Managers or members of
                    --------------------------------                         
any committee designated by the Managers may participate in and hold a meeting
of the Managers or such committee by means of conference telephone or similar
communications equipment by means of which all persons participating in the
meeting can hear each other, and participation in such a meeting shall
constitute presence in person at such meeting, except where a person
participates in the meeting for the express purpose of objecting to the
transaction of any business on the ground that the meeting is not lawfully
called or convened.

     Section 8.14.  Liability of Managers.  No Manager of the Company shall be
                    ---------------------                                     
personally liable for any debts, liabilities, or obligations of the Company,
including under a judgment, decree, or order of the court.

     Section 8.15.  Specific Power of Managers.  The Managers shall have the
                    --------------------------                              
authority to enter into and execute all documents in relation to the formation
of the Company including, but not limited to, issuance of the Articles of
Organization and these Regulations.

                                       7
<PAGE>
 
                                  ARTICLE IX.
                                    NOTICES
                                    -------

     Section 9.1.  Form of Notice.  Whenever under the provisions of the Act,
                   --------------                                            
the Articles of Organization or these Regulations notice is required to be given
to any Manager or Member, and no provision is made as to how such notice shall
be given, notice shall not be construed to mean personal notice only, but any
such notice may also be given in writing, by mail, postage prepaid, addressed to
such Manager or Member at such address as appears on the books of the Company,
or by telecopy, telegraph or mailgram.  Any notice required or permitted to be
given by mail shall be deemed to be given three (3) days after it is deposited,
postage prepaid, in the United States mail as aforesaid.

     Section 9.2.  Waiver.  Whenever any notice is required to be given to any
                   ------                                                     
Manager or Member of the Company under the provision of the Act, the Articles of
Organization or these Regulations, a waiver thereof in writing signed by the
person or persons entitled to such notice, whether signed before or after the
time stated in such waiver, shall be deemed equivalent to the giving of such
notice.


                                  ARTICLE X.
                                   OFFICERS
                                   --------

     All Managers are officers of the Company.  The Managers may designate one
or more persons who are not Managers of the Company to serve as officers and may
designate the titles of all officers. The initial officers of the Company shall
be:  Michael S. Madler, President; Cheryl Williams, Secretary and Chief
Financial Officer; Robert Bachman, Vice President; and Lawrence Sodomire, Vice
President. Unless otherwise provided in a resolution of the Members or Managers
the officers of the Company shall have the powers designated with respect to
such offices under the Texas Business Corporation Act, and any successor
statute, as amended from time-to-time.


                                  ARTICLE XI.
                                   INDEMNITY
                                   ---------

     Section 11.1.  Indemnification.  The Company shall indemnify its Managers,
                    ---------------                                            
officers, employees, agents and others as fully as, and to the same extent, a
corporation may indemnify its directors, officers, employees and agents under
the Texas Business Corporation Act, now in effect or hereafter amended.  The
Company shall have the power to purchase and maintain liability insurance
coverage for those persons as, and to the fullest extent, permitted by the Act,
as presently in effect and as may be hereafter amended.

                                       8
<PAGE>
 
     Section 11.2.  Indemnification Not Exclusive.  The rights of
                    -----------------------------                
indemnification and reimbursement provided for in Section 11.1 of this Article
XI. shall not be deemed exclusive of any other rights to which any such Manager,
officer, employee or agent may be entitled under the Articles of Organization,
any Regulations, agreement or vote of Members, or as a matter of law or
otherwise.


                                 ARTICLE XII.
                                 MISCELLANEOUS
                                 -------------

     Section 12.1.  Fiscal Year.  The fiscal year of the Company shall be fixed
                    -----------                                                
by resolution of the Managers.

     Section 12.2.  Records.  At the expense of the Company, the Managers shall
                    -------                                                    
maintain records and accounts of all operations of the Company.  At a minimum,
the Company shall keep at its principal place of business the following records:

     (a) A current list of the name and last known mailing address of each
Member;

     (b) A current list of each Member's Membership Interest;

     (c) A copy of the Articles of Organization and Regulations of the Company,
and all amendments thereto, together with executed copies of any powers of
attorney;

     (d) Copies of the Federal, state, and local income tax returns and reports
for the Company's six most recent tax years; and

     (e) Correct and complete books and records of account of the Company.

     Section 12.3.  Seal.  The Company may by resolution of the Managers adopt
                    ----                                                      
and have a seal, and said seal may be used by causing it or a facsimile thereof
to be impressed or affixed or in any manner reproduced.  Any officer of the
Company shall have authority to affix the seal to any document requiring it.

     Section 12.4.  Agents.  Every Manager and Officer is an agent of the
                    ------                                               
Company for the purpose of the business.  The act of a Manager or Officer,
including the execution in the name of the Company of any instrument for
carrying on in the usual way the business of the Company, binds the Company.

     Section 12.5.  Checks.  All checks, drafts and orders for the payment of
                    ------                                                   
money, notes and other evidences of indebtedness issued in the name of the
Company shall be signed by such officer, officers, agent or agents of the
Company and in such manner as shall from time to time be determined by
resolution of the Managers.  In the absence of such determination by the
Mangers, such instruments shall be signed by the Treasurer or the Secretary and
countersigned by the President or a Vice President of the Company, if the
Company has such officers.

                                       9
<PAGE>
 
     Section 12.6.  Deposits.  All funds of the Company shall be deposited from
                    --------                                                   
time to time to the credit of the Company in such banks, trust companies or
other depositories as the Mangers may select.

     Section 12.7.  Annual Statement.  The Managers shall present at each annual
                    ----------------                                            
meeting, and, when called for by vote of the Members, at any special meeting of
the Members, a full and clear statement of the business and condition of the
Company.

     Section 12.8.  Financial Statements.  As soon as practicable after the end
                    --------------------                                       
of each fiscal year of the Company, a balance sheet as at the end of such fiscal
year, and a profit and loss statement for the period ended, shall be distributed
to the Members, along with such tax information (including all information
returns) as may be necessary for the preparation of each Member of its Federal,
state and local income tax returns.  The balance sheet and profit and loss
statement referred to in the previous sentence may be as shown on the Company's
federal income tax return. Any Member shall be entitled to receive, upon written
request and after the Company is provided with a reasonable period to comply,
any financial statements of the Company as of and for the period ended on any
month, calendar quarter or annual period; and the Members shall have access,
upon request and reasonable advance written notice, to all books, records and
accounts of the Company and all information and documents related thereto.


                                 ARTICLE XIII.
                                  AMENDMENTS
                                  ----------

     Section 13.1.  Amendments.  These Regulations may be altered, amended or
                    ----------                                               
repealed and new Regulations may be adopted by the vote of a majority of the
Membership Interests of the Members, at any regular meeting or at any special
meeting called for that purpose.

     Section 13.2.  When Regulations Silent.  It is expressly recognized that
                    -----------------------                                  
when the Regulations are silent or in conflict with the requirements of the Act
as to the manner of performing any Company function, the provisions of the Act
shall control.

                                       10
<PAGE>
 
                               SIGNATURE PAGE TO
                                  REGULATIONS
                                        

     IN WITNESS WHEREOF, the undersigned Members hereby adopt these Regulations
as the Regulations of the Company, effective as of the 1st day of September,
1997.



                              PRIME KIDNEY STONE TREATMENT, INC.


                              By: /s/ Michael S. Madler
                                 ---------------------------------------------
                                 Michael S. Madler, President


                              AK ASSOCIATES, INC.


                              By: /s/ Robert Bachman
                                 ---------------------------------------------
                              Printed Name: Robert Bachman
                                           -----------------------------------
                              Title: Vice President                      
                                     -----------------------------------------

                                       11
<PAGE>
 
                                   EXHIBIT A



                              OWNERSHIP INTERESTS
                              -------------------

 
               NAME                                    OWNERSHIP PERCENTAGE
               ----                                    --------------------  
 
Prime Kidney Stone Treatment, Inc.                              75%
 
AK Associates, Inc.                                             25%








                                      A-1
<PAGE>
 
                                   EXHIBIT-B
                                        



                      ASSIGNMENT AND ASSUMPTION AGREEMENT
                                        


     This Assignment and Assumption Agreement (this "Assignment") is made and
entered into effective the 1st day of September, 1997 between and among AK
Associates, Inc., an Illinois corporation ("AK"), Prime Kidney Stone Treatment,
Inc., a New Jersey corporation ("Prime"), and AK Associates, L.L.C., a Texas
limited liability company ("Newco").

     For good and valuable consideration, and pursuant to and in accordance with
the terms of that certain Contribution Agreement (the "Contribution Agreement")
made and entered into effective the 1st day of September, 1997, between and
among AK, Prime, Robert Bachman, Lawrence Sodomire, and Newco, the parties
hereto agree as follows:

     1.  AK hereby assigns, transfers and sets over to Newco all of AK's right,
title and interest in and to all of AK's undivided twenty-five percent (25%)
interest in the Assets (as defined in the Contribution Agreement), and Newco
hereby accepts such assignment and transfer.

     2.  Prime hereby assigns, transfers and sets over to Newco all of Prime's
right, title and interest in and to all of Prime's undivided seventy-five
percent (75%) interest in the Assets (as defined in the Contribution Agreement),
and Newco hereby accepts such assignment and transfer.

     3.  Newco hereby assumes, accepts and agrees to discharge and perform (i)
the obligations of AK specifically described on Exhibit-A hereto which accrue on
or after September 1, 1997, (ii) those certain trade payables on open account
incurred in the ordinary course of AK's business since September 1, 1997 from
unrelated parties, and (iii) obligations accruing after September 1, 1997 under
contracts for jobs in progress or not yet begun (which jobs Newco agrees to
complete according to the terms of such contracts). With respect to any lease
obligations reflected on Exhibit-A, and any contracts described in clause (iii)
of the preceding sentence, it is agreed that Newco will only be assuming
obligations thereunder which accrue on or after September 1, 1997, and Newco
will have no responsibility whatsoever for any breaches or defaults which
occurred prior to the Closing Date (as defined in the Contribution Agreement),
or for obligations accruing prior to September 1, 1997.

     4.  Except for those certain obligations specifically assumed by Newco
pursuant to paragraph 3 above, no party hereto is assuming any debts,
liabilities or obligations of any other party, person or entity whatsoever
pursuant to this Assignment, and any and all debts, liabilities and obligations
of AK, whether known or unknown, absolute, contingent or otherwise (including,
<PAGE>
 
but not limited to, federal, state, and local taxes, any sales taxes, use taxes
and property taxes, any taxes arising from the transactions contemplated by the
Contribution Agreement and any liabilities arising from any litigation or civil,
criminal or regulatory proceeding involving or related to AK or its business)
shall remain the sole responsibility of AK.


     5.  This Assignment has been executed pursuant to, and in connection with,
the Contribution Agreement and the Closing (as defined therein) of the
transactions contemplated thereby and should be construed consistently
therewith.  In the event of any conflict between the terms of this Assignment
and the Contribution Agreement, the terms of the Contribution Agreement shall
control.

                                       2
<PAGE>
 
                               SIGNATURE PAGE TO
                      ASSIGNMENT AND ASSUMPTION AGREEMENT



     IN WITNESS WHEREOF, the parties have caused this Assignment to be executed
by their duly authorized representatives effective September 1, 1997.


AK:                                            AK ASSOCIATES, INC.


                                               By: /s/ Robert Bachman
                                                  ------------------------------

                                               Printed Name: Robert Bachman
                                                            --------------------
                                               Title: Vice President
                                                     ----------------------


PRIME:                                         PRIME KIDNEY STONE TREATMENT
                                                INC.


                                               By: /s/ Michael S. Madler
                                                  ------------------------------
                                                  Michael S. Madler, President


NEWCO:                                         AK ASSOCIATES, L.L.C.


                                               By: /s/ Michael S. Madler
                                                  ------------------------------

                                                  Michael S. Madler, President

                                                                  and


                                               By: /s/ Robert Bachman
                                                  ------------------------------
                                                  Robert Bachman, Vice President
                                       

                                       3
<PAGE>
 
                           ARTICLES OF ORGANIZATION
                                      OF
                             AK ASSOCIATES, L.L.C.
                                        
     The undersigned natural person of the age of eighteen years or more, acting
as the sole organizer of a limited liability company (the "Company") under the
Texas Limited Liability Company Act, does hereby adopt the following Articles of
Organization for such limited liability company:

                                  ARTICLE I.

     The name of the Company is AK Associates, L.L.C.

                                  ARTICLE II.

     The period of its duration is forty (40) years from the date of the filing
of these Articles of Organization with the Secretary of State of Texas.

                                 ARTICLE III.

     The purpose for which the Company is organized is to transact any and all
lawful business for which limited liability companies may be organized under the
Texas Limited Liability Company Act.

                                  ARTICLE IV.

     The street address of the Company's initial registered office is 1301
Capital of Texas Highway, Suite C-300, Austin, Texas 78746, and the name of its
initial registered agent at such address is Michael S. Madler.
<PAGE>
 
                                  ARTICLE V.

     The Company is to be managed by managers.  The names and addresses of the
persons who are to serve as managers until the first annual meeting of the
members or until their successors are elected and qualified are:


Michael S. Madler                1301 Capital of Texas Hwy.
                                 Suite C-300
                                 Austin, Texas  78746

Vincent Prendergrast             1301 Capital of Texas Hwy.
                                 Suite C-300
                                 Austin, Texas  78746

Cheryl Williams                  1301 Capital of Texas Hwy.
                                 Suite C-300
                                 Austin, Texas  78746

Robert Bachman                   19701 South 97th Avenue
                                 Mokena, Illinois  60448

Lawrence Sodomire                19701 South 97th Avenue
                                 Mokena, Illinois  60448

                                  ARTICLE VI.

     No manager shall be liable to the Company or its members for monetary
damages for an act or omission in the manager's capacity as a manager, except
that this Article does not eliminate or limit the liability of a manager to the
extent the manager is found liable for:

     (1) a breach of the manager's duty of loyalty to the Company or its
members;

     (2) an act or omission not in good faith that constitutes a breach of duty
of such manager to the Company

                                       2
<PAGE>
 
     (3) an act or omission not in good faith that constitutes a breach of duty
of the manager to the Company or an act or omission that involves intentional
misconduct or a knowing violation of the law;

     (4) a transaction from which the manager received an improper benefit,
whether or not the benefit resulted from an action taken within the scope of the
manager's office; or

     (5) an act or omission for which the liability of the manager is expressly
provided by an applicable statute.

     Any repeal or modification of this Article by the members of the Company
shall be prospective only and shall not adversely affect any limitation on the
liability of a manager of the Company existing at the time of such repeal or
modification.

                                  ARTICLE VII.

     The name and address of the organizer are:

        Name                               Address
        ----                               --------                      
        Tim LaFrey                         816 Congress Avenue
                                           Suite 1900
                                           Austin, Texas  78701


     EXECUTED BY THE UNDERSIGNED ORGANIZER on this 3rd day of October, 1997.



                                           /s/ Tim LaFrey
                                           ---------------------------------
                                           Tim LaFrey

                                       3

  
                        AGREEMENT OF LIMITED PARTNERSHIP
                                       OF
                       PACIFIC MEDICAL LIMITED PARTNERSHIP

<PAGE>

                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                       PACIFIC MEDICAL LIMITED PARTNERSHIP

                                TABLE OF CONTENTS

         Article Heading                                           Page

         1.       FORMATION..........................................1

         2.       NAME...............................................1

         3.       OFFICES............................................2

         4.       PURPOSE............................................2

         5.       TERM...............................................2

         6.       CERTAIN DEFINED TERMS..............................2

         7.       CAPITAL CONTRIBUTIONS..............................6

         8.       GUARANTIES.........................................7

         9.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE 
                  LIMITED PARTNERS...................................7

         10.      REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                  GENERAL PARTNER....................................7

         11.      ADMISSION OF LIMITED PARTNERS......................8

         12.      CAPITAL ACCOUNTS...................................8

         13.      ALLOCATIONS........................................9

         14.      DISTRIBUTIONS.....................................12

         15.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS........13

         16.      LIMITED LIABILITY.................................13

         17.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS...13

         18.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS 
                  ON CERTAIN EVENTS.................................17

C#0124195.02

<PAGE>




         19.      SALE, ASSIGNMENT OR OTHER TRANSFER OF THE GENERAL
                  PARTNER'S INTEREST................................22

         20.      TERMINATION OF THE SERVICES OF THE 
                  GENERAL PARTNER...................................22

         21.      MANAGEMENT AND OPERATION OF BUSINESS..............23

         22.      RESERVES..........................................25

         23.      INDEMNIFICATION AND EXCULPATION OF THE GENERAL
                  PARTNER...........................................25

         24.      DISSOLUTION OF THE PARTNERSHIP....................26

         25.      DISTRIBUTION UPON DISSOLUTION.....................27

         26.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.............28

         27.      NOTICES...........................................29

         28.      AMENDMENTS........................................29

         29.      LIMITATIONS ON AMENDMENTS.........................29

         30.      MEETINGS, CONSENTS AND VOTING.....................29

         31.      SUBMISSIONS TO THE LIMITED PARTNERS...............30

         32.      ADDITIONAL DOCUMENTS..............................30

         33.      SURVIVAL OF RIGHTS................................30

         34.      INTERPRETATION AND GOVERNING LAW..................30

         35.      SEVERABILITY......................................31

         36.      AGREEMENT IN COUNTERPARTS.........................31

         37.      THIRD PARTIES.....................................31

         38.      POWER OF ATTORNEY.................................31

         39.      ARBITRATION.......................................32

         40.      CREDITORS.........................................32


C#0124195.02

<PAGE>



           Schedule A............... Schedule of Partnership Interests

C#0124195.02

<PAGE>



THE  LIMITED  PARTNERSHIP  INTERESTS  REPRESENTED  BY THIS  LIMITED  PARTNERSHIP
AGREEMENT HAVE NOT BEEN REGISTERED  WITH THE SECURITIES AND EXCHANGE  COMMISSION
UNDER  THE  SECURITIES  ACT OF  1933,  AS  AMENDED,  UNDER  THE  HAWAII  UNIFORM
SECURITIES ACT (MODIFIED),  AS AMENDED, THE ARKANSAS SECURITIES ACT, AS AMENDED,
THE FLORIDA  SECURITIES AND INVESTOR  PROTECTION ACT, AS AMENDED,  THE LOUISIANA
SECURITIES  LAW, AS AMENDED,  THE TEXAS  SECURITIES ACT OF 1957, AS AMENDED,  OR
SIMILAR LAWS OR ACTS OF OTHER  STATES IN RELIANCE  UPON  EXEMPTIONS  UNDER THOSE
ACTS  (THE  "STATE  LAWS").  THE  SALE  OR  OTHER  DISPOSITION  OF  THE  LIMITED
PARTNERSHIP  INTERESTS  IS  RESTRICTED  AS  STATED  IN THE  LIMITED  PARTNERSHIP
AGREEMENT,  AND IN ANY  EVENT  IS  PROHIBITED  UNLESS  THE  LIMITED  PARTNERSHIP
RECEIVES AN OPINION OF COUNSEL  SATISFACTORY TO THE LIMITED  PARTNERSHIP AND ITS
COUNSEL THAT SUCH SALE OR OTHER  DISPOSITION  CAN BE MADE  WITHOUT  REGISTRATION
UNDER THE SECURITIES ACT OF 1933, AS AMENDED,  OR THE APPLICABLE  STATE LAWS. BY
ACQUIRING  THE  LIMITED  PARTNERSHIP   INTERESTS  REPRESENTED  BY  THIS  LIMITED
PARTNERSHIP AGREEMENT, THE LIMITED PARTNERS REPRESENT THAT THEY WILL NOT SELL OR
OTHERWISE  DISPOSE OF THEIR RESPECTIVE  LIMITED  PARTNERSHIP  INTERESTS  WITHOUT
REGISTRATION  OR OTHER  COMPLIANCE  WITH THE  AFORESAID  ACTS AND THE  RULES AND
REGULATIONS ISSUED THEREUNDER.


                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                               OF PACIFIC MEDICAL
                               LIMITED PARTNERSHIP


                  THIS  AGREEMENT OF LIMITED  PARTNERSHIP  is made as of January
23, 1995, by and among LITHOTRIPTERS,  INC., a North Carolina  corporation,  and
the persons listed on Schedule A attached hereto as the Limited Partners.

                  1.       FORMATION.

                  The  Partnership  was  formed  filing  in  the  Office  of the
Secretary  of State of Hawaii on  December  14,  1995 a  Certificate  of Limited
Partnership in accordance with the provisions of the Act.

                  2.       NAME.

                  2.1  The name of the Partnership is "Pacific Medical Limited 
Partnership."

                  2.2 The  Partnership  business  shall be conducted  under such
names as the General  Partner may from time to time deem necessary or advisable,
provided that appropriate amendments to this Agreement and all necessary filings
under  applicable  assumed  or  fictitious  name  statutes  or the Act are first
obtained.


                                                      -1-
C#0124195.02

<PAGE>



                  3.       OFFICES.

                  3.1 The principal  office of the Partnership  shall be at 2008
Litho Place,  Fayetteville,  North Carolina 28304, or at such other place as the
General  Partner  may,  from time to time,  designate  by notice to the  Limited
Partners (the "Records Office").

                  3.2 The Partnership  may have such  additional  offices as the
General Partner may, from time to time, deem necessary or advisable.

                  4.       PURPOSE.

                  The  purpose  and  business  of the  Partnership  shall  be to
operate a LithostarTM extracorporeal shock-wave lithotripter (or any other renal
stone  treatment  equipment)  for  lithotripsy  of renal  stones  primarily in a
designated  service  area  consisting  of the island of Oahu,  Hawaii or in such
other  location(s)  within or outside  such  state as the  General  Partner  may
determine,  in  its  sole  discretion,  to be  in  the  best  interests  of  the
Partnership and to engage in any and all activities incidental or related to the
foregoing,  including  biliary  lithotripsy  if the same is ever approved by the
FDA, upon and subject to the terms and conditions of this Agreement.

                  5.       TERM.

                  The Partnership  shall terminate on December 31, 2040,  unless
sooner terminated as herein provided.

                  6.       CERTAIN DEFINED TERMS.

                  Certain terms used in this Agreement  shall have the following
meanings:

                  Act.  The Act means the  Hawaii  Uniform  Limited  Partnership
Act,  as then in effect.

                  Affiliate.  An  Affiliate  is  (i)  any  person,  partnership,
corporation, association or other legal entity ("person") directly or indirectly
controlling, controlled by or under common control with another person; (ii) any
person owning or controlling 10% or more of the  outstanding  voting interest of
such other person;  (iii) any officer,  director or partner of such person;  and
(iv) if such other  person is an officer,  director  or partner,  any entity for
which such person acts in such capacity.

                  Agreement.  This Agreement of Limited Partnership, as the same
may be amended from time to time.

                  Bank.  First-Citizens Bank & Trust Company.

                  Capital Account.  The Partnership capital account of a Partner
as computed pursuant to Article 12 of this Agreement.


                                       -2-
C#0124195.02

<PAGE>



                  Capital  Contributions.  All capital  contributions  made by a
Partner or his predecessor in interest which shall include,  without limitation,
contributions made pursuant to Article 7 of this Agreement.

                  Capital Transaction.  Any transaction which, were it to 
generate proceeds, would produce Partnership Sales Proceeds or Partnership 
Refinancing Proceeds.

                  Coach. The new or reconditioned  self-propelled mobile vehicle
or tractor-trailer upfitted to house the LithostarTM. The Coach will be acquired
by the  Partnership  with the proceeds of the Loan,  together  with the proceeds
from the sale of the Units in the event the tractor-trailer model is purchased.

                  Code.  The Internal Revenue Code of 1986, as amended, or 
corresponding provisions of subsequent, superseding revenue laws.

                  Equipment.  The  initial  equipment  to  be  acquired  by  the
Partnership  for the operation of the  LithostarTM  Mobile  System.  The initial
equipment to be used in the  operation  of the  LithostarTM  Mobile  System will
include the  LithostarTM,  the Coach and  miscellaneous  medical  equipment  and
supplies.

                  FDA.  The Food and Drug Administration.

                  General Partner.  The General Partner of the Partnership, 
LITHOTRIPTERS, INC., a North Carolina corporation controlled by William R. 
Jordan, M.D.

                  Guaranty.  The  Guaranty  Agreement  pursuant  to  which  each
Limited Partner will guarantee a portion of the Partnership's  obligation to the
Bank under the Loan.  The form of the  Guaranty is included in the  Subscription
Packet accompanying the Memorandum.

                  Initial  Limited  Partner.  Dr.  William R.  Jordan,  a  
resident of North Carolina and the majority  shareholder of the General Partner.
The Initial Limited Partner is to be the only limited partner of the Partnership
until such time as the new Limited Partners are admitted to the Partnership,  at
which time the Initial Limited Partner shall withdraw from the Partnership. 

                  Limited Partners.  The Limited Partners are those investors in
the Units admitted to the  Partnership  and any person  admitted as a substitute
Limited Partner in accordance with the provisions of this Agreement.

                  LithostarTM.   The  new  or  reconditioned  LithostarTM  model
extracorporeal shock wave lithotripter manufactured by Siemens to be acquired by
the Partnership with the proceeds of the Loan.

                  LithostarTM Mobile System.  The Coach with the installed and 
operational LithostarTM.

                  Loan. The loan up to $1,652,014 from the Bank to the 
Partnership.  A portion of the Loan proceeds will be used by the  Partnership to
(i) acquire the LithostarTM  (up to $945,000),  (ii) acquire and upfit the Coach
(up to $390,590),  (iii) pay the Hawaii use tax on the Coach and the LithostarTM
(up to $53,424) and (iv) ship the Coach and the  Lithostar(TM)  to Hawaii (up to
$12,500). The
                                       -3-
C#0124195.02

<PAGE>



remainder  of the Loan  proceeds  will be used as initial  start-up  and working
capital  (up to  $250,000).  The  maximum  amount of the Loan  proceeds  will be
reduced if the Partnership  purchases a reconditioned Coach at a lower cost. The
Loan  will be  secured  by the  LithostarTM  Mobile  System,  the  Partnership's
accounts  receivable and other Partnership assets, the guaranties of the General
Partner (and its shareholders), and the Limited Partner Guaranties.

                  Losses.  The net loss (including Net Losses from Capital
Transactions)  of the Partnership for each Year of the Partnership as determined
for federal income tax purposes.

                  Majority  in Interest  of the  Limited  Partners.  The Limited
Partners who hold more than 50% of the Limited Partner  Percentage  Interests in
the Partnership.

                  Memorandum.  The Confidential Private Placement Memorandum of 
the Partnership dated January 8, 1996, as amended or as supplemented.

                  Net Gains from Capital Transactions. The gains realized by the
Partnership  as a result of or upon any sale,  exchange,  condemnation  or other
disposition of the capital assets of the Partnership (which assets shall include
Code Section 1231 assets) or as a result of or upon the damage or destruction of
such capital assets.

                  Net Losses from Capital  Transactions.  The losses realized by
the Partnership as a result of or upon any sale, exchange, condemnation or other
disposition of the capital assets of the  Partnership  (which shall include Code
Section 1231 assets) or as a result of or upon the damage or destruction of such
capital assets.

                  Nonrecourse  Deductions.  A deduction as set forth in Treasury
Regulations Section  1.704-2(b)(1).  The amount of Nonrecourse  Deductions for a
given Year equals the excess, if any, of the net increase, if any, in the amount
of  Partnership  Minimum Gain during such Year over the aggregate  amount of any
Distributions  during such Year of proceeds of a Nonrecourse  Liability that are
allocable to an increase in Partnership  Minimum Gain,  determined  according to
the provisions of Treasury Regulations Section 1.704-2(h).

                  Nonrecourse  Liability.  Any Partnership liability (or portion
thereof)  for which no Partner  bears the  "economic  risk of loss,"  within the
meaning of Treasury Regulations Section 1.704- 2(i).

                  Partners.  The General Partner and the Limited Partners, 
collectively, where no distinction is required by the context in which the term 
is used herein.

                  Partner Minimum Gain. An amount,  with respect to each Partner
Nonrecourse  Debt,  equal to the  Partnership  Minimum Gain that would result if
such  Partner  Nonrecourse  Debt  were  treated  as  a  Nonrecourse   Liability,
determined in accordance with Treasury Regulations Section 1.704- 2(i).


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                  Partner  Nonrecourse  Debt.  Any  nonrecourse  debt  (for  the
purposes of Treasury  Regulations Section 1.1001-2) of the Partnership for which
any Partner  bears the  "economic  risk of loss," within the meaning of Treasury
Regulations Section 1.752-2.

                  Partner  Nonrecourse  Deductions.  Deductions  as described in
Treasury  Regulations Section  1.704-2(i)(2).  The amount of Partner Nonrecourse
Deductions  with respect to a Partner  Nonrecourse  Debt for any Year equals the
excess,  if any, of the net increase,  if any, in the amount of Partner  Minimum
Gain  attributable  to such Partner  Nonrecourse  Debt during such Year over the
aggregate amount of any Distributions during that Year to the Partner that bears
the economic risk of loss for such Partner  Nonrecourse  Debt to the extent such
Distributions  are from the  proceeds of such Partner  Nonrecourse  Debt and are
allocable to an increase in Partner  Minimum Gain  attributable  to such Partner
Nonrecourse  Debt,  determined in accordance with Treasury  Regulations  Section
1.704- 2(i).

                  Partnership.  Pacific Medical Limited Partnership, a Hawaii 
limited partnership.

                  Partnership  Cash Flow. For the applicable  period the excess,
if any,  of (A) the sum of (i) all  gross  receipts  from  any  source  for such
period,  other than from  Partnership  loans,  Capital  Transactions and Capital
Contributions,  and (ii) any funds released by the  Partnership  from previously
established  reserves,  over  (B) the sum of (i) all cash  expenses  paid by the
Partnership  for such  period;  (ii) the amount of all  payments of principal on
loans to the Partnership;  (iii) capital  expenditures of the  Partnership;  and
(iv) such  reasonable  reserves as the General  Partner shall deem  necessary or
prudent to set aside for future repairs,  improvements or equipment  replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities and contingencies of the Partnership; provided, however, that
the  amounts  referred  to in (B)(i),  (ii) and (iii)  above shall be taken into
account  only to the extent not funded by Capital  Contributions,  loans or paid
out of previously  established reserves.  Such term shall also include all other
funds deemed  available for  distribution  and designated as  "Partnership  Cash
Flow" by the General Partner.

                  Partnership Interest.  The interest of a Partner in the 
Partnership as defined by the Act and this Agreement.

                  Partnership Minimum Gain.  Gain as defined in Treasury 
Regulations Section 1.704-2(d).

                  Partner  Nonrecourse  Deduction.  Deductions  as  described in
Treasury  Regulations Section  1.704-2(i)(2).  The amount of Partner Nonrecourse
Deductions  with respect to a Partner  Nonrecourse  Debt for any Year equals the
excess,  if any, of the net increase,  if any, in the amount of Partner  Minimum
Gain  attributable  to such Partner  Nonrecourse  Debt during such Year over the
aggregate amount of any Distributions during that Year to the Partner that bears
the economic risk of loss for such Partner  Nonrecourse  Debt to the extent such
Distributions  are from the  proceeds of such Partner  Nonrecourse  Debt and are
allocable to an increase in Partner  Minimum Gain  attributable  to such Partner
Nonrecourse  Debt,  determined in accordance with Treasury  Regulations  Section
1.704- 2(i).


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                  Partnership  Refinancing Proceeds.  The cash realized from the
refinancing of Partnership assets after retirement of any secured loans and less
(i) payment of all expenses  relating to the transaction and (ii)  establishment
of such  reasonable  reserves as the General  Partner  shall deem  necessary  or
prudent to set aside for future repairs,  improvements, or equipment replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities or contingencies of the Partnership.

                  Partnership  Sales Proceeds.  The cash realized from the sale,
exchange,  casualty  or other  disposition  of all or a portion  of  Partnership
assets after the retirement of all secured loans and less (i) the payment of all
expenses  related to the transaction and (ii)  establishment  of such reasonable
reserves as the General Partner shall deem necessary or prudent to set aside for
future repairs,  improvements, or equipment replacement or additions, or to meet
working  capital  requirements or foreseen or unforeseen  future  liabilities or
contingencies of the Partnership.

                  Percentage  Interest.  The  interest  of each  Partner  in the
Partnership,  to be determined in the case of a Limited  Partner by reference to
his Unit  ownership  based upon the Limited  Partners  holding an aggregate  80%
Percentage  Interest in the  Partnership,  with each Unit sold  representing  an
initial 1% interest.  The General Partner will own a 20% Percentage  Interest in
the Partnership. The Partners' Percentage Interests in the Partnership as of the
date  hereof  are as set forth in  Schedule A attached  hereto.  The  Percentage
Interest of each Partner shall be adjusted as provided in Article 18.6.3.

                  Profit.  The net income of the Partnership (including Net 
Gains from Capital  Transactions) for each Year of the Partnership as determined
for federal income tax purposes.

                  Pro  Rata  Basis.   In   connection   with  an  allocation  or
distribution,  an allocation  or  distribution  in proportion to the  respective
Percentage Interests of the class of Partners to which reference is made.

                  Qualified  Income  Offset Item. An  adjustment,  allocation or
distribution described in Treasury Regulations Sections 1.704-1(b)(2)(ii)(d)(4),
1.704-1(b)(2)(ii)(d)(5)  or  1.704-1(b)(2)(ii)(d)(6)  unexpectedly received by a
Partner.

                  Sales Commission.  The $270 sales commission paid to Medtech 
Investments, Inc. for each Unit sold, other than Units sold to the General 
Partner and its Affiliates.

                  Service.  The Internal Revenue Service.

                  Siemens.  Siemens Medical Systems, Inc. and its Affiliates.

                  Units.   The  80  equal  limited  partner   interests  in  the
Partnership offered pursuant to the Memorandum for a price per Unit of $2,500 in
cash, plus a personal guaranty of 1% of the Partnership's  obligations under the
Loan (up to a $16,520.14 principal guaranty obligation).

                  Year of the Partnership. An annual accounting period ending on
December 31 of each year during the term of the Partnership.

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                  7.       CAPITAL CONTRIBUTIONS.

                  7.1 On or  before  the  date of this  Agreement,  the  General
Partner  will  contribute  to the capital of the  Partnership  cash in an amount
equal to $__________.

                  7.2 Each Limited Partner hereby agrees to contribute and shall
contribute to the capital of the Partnership on the date of his admission to the
Partnership the amount set forth opposite his name on Schedule A attached hereto
in cash.

                  7.3 Except as otherwise  provided herein, no interest shall be
paid on any contribution to the capital of the Partnership.

                  8.       GUARANTIES.

                  Each Partner agrees to execute and deliver to the  Partnership
on the date of his  admission  to the  Partnership  a Guaranty  agreement in the
amount set forth opposite his or her name on Schedule A attached hereto.

                  9.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF
                           THE LIMITED PARTNERS.

                  The  obligations of the Limited  Partners to make cash Capital
Contributions  hereunder are subject to the condition that the  representations,
warranties, agreements and covenants of the General Partner set forth in Article
10 of this  Agreement  are and shall be true and  correct  or have been and will
have been  complied  with in all  material  respects  on the date  such  Capital
Contributions  are  required  to be made,  except  to the  extent  that any such
representation or warranty expressly pertains to an earlier date.

                  10.      REPRESENTATIONS, WARRANTIES AND COVENANTS OF
                           THE GENERAL PARTNER.

                  10.1     The General Partner hereby represents and warrants to
the Limited Partners that:

                  (a)  The  Partnership  is  a  limited  partnership  formed  in
         accordance  with  and  validly  existing  under  the Act and the  other
         applicable laws of the State of Hawaii;

                  (b) The interests in the  Partnership of the Limited  Partners
         will have been duly  authorized  or created and validly  issued and the
         Limited  Partners shall have no personal  liability to contribute money
         to the  Partnership  other than the amounts agreed to be contributed by
         them in the  manner  and on the  terms  set  forth  in this  Agreement,
         subject, however, to such limitations as may be imposed under the Act;

                  (c) No material  breach or default  adverse to the Partnership
         exists under the terms of any other  material  agreement  affecting the
         Partnership;


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                  (d) No  material  claim or  litigation  is pending  or, to the
         knowledge and belief of the General Partner,  is threatened against the
         General   Partner  or  the   Partnership  in  any  court,   commission,
         administrative   body  or  other  authority,   which  could  materially
         adversely affect the Partnership, or the ability of the General Partner
         to  perform  any of its  obligations  contemplated  by this  Agreement,
         except as may be fully covered by liability insurance; and

                  (e) The General Partner is a North Carolina corporation formed
         and existing under the laws of the State of North Carolina.

                  10.2 The  General  Partner  hereby  covenants  to the  Limited
Partners that:

                  (a) It  will  at all  times  act in a  fiduciary  manner  with
         respect  to the  Partnership,  the  LithostarTM  Mobile  System and the
         Limited Partners;

                  (b) Except as  provided  in  Article  19, it will serve as the
         General Partner of the Partnership  until the Partnership is terminated
         without reconstitution;

                  (c) It will cause the  Partnership  to carry  adequate  public
         liability,  property  damage and other insurance as is customary in the
         business to be engaged in by the Partnership; and

                  (d) It will use its best  efforts to assure  that it meets all
         net  worth  requirements  which,  in the  opinion  of  counsel  for the
         Partnership,  may,  from time to time,  be necessary to assure that the
         Partnership  is  classified  as a  partnership  for Federal  income tax
         purposes.

                  11.      ADMISSION OF LIMITED PARTNERS.

                  The General Partner may permit the offer and sale of the Units
on the terms and  conditions  provided in the  Memorandum  and may admit persons
subscribing  for Units as Limited  Partners in the  Partnership on the terms and
conditions set forth in this Article 11.

                  (a) The General  Partner  shall have approved of the admission
         of said person in writing on such terms and  conditions  as the General
         Partner shall determine;

                  (b)  Said  person  shall  have  executed  such   documents  or
         instruments  as the General  Partner may deem necessary or desirable to
         effect his admission as a Limited Partner;

                  (c) Said  person  shall have  accepted  and adopted all of the
         terms and provisions of this Agreement, as then amended;

                  (d)  Said  person  (if a  corporation)  shall  deliver  to the
         General  Partner  a  certified  copy of a  resolution  of its  Board of
         Directors  authorizing  it to become a Limited  Partner under the terms
         and conditions of this Agreement; and

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                  (e)  Said  person  upon  request  shall  pay  such  reasonable
         expenses as may be  incurred  in  connection  with its  admission  as a
         Limited Partner.

                  12.      CAPITAL ACCOUNTS.

                  A capital  account shall be  established  for each Partner and
shall at all  times be  determined  and  maintained  as  provided  by the  Final
Treasury  Regulations  under  Section  704(b)  of the  Code,  as the same may be
amended.  A Partner  shall not be entitled  to withdraw  any part of his capital
account or to receive any distribution from the Partnership,  except as provided
in Articles 14 and 25.

                  (a)      Each Partners' capital account shall be increased by:

                           (i)The amount of his Capital Contribution pursuant 
                  to Article 7; and

                           (ii)The amount of Profits allocated to him pursuant
                  to Article 13; and

                           (iii) The Partner's pro rata share (determined in the
                  same  manner as such  Partner's  share of  Profits  and Losses
                  allocated pursuant to Article 13 hereof) of any income or gain
                  exempt from tax; and

                  (b) Each Partner's capital account shall be decreased by:

                           (i)      The amount of Losses allocated to him 
                  pursuant to Article 13; and

                           (ii) The amount of Partnership Cash Flow, Partnership
                  Sales   Proceeds   and   Partnership    Refinancing   Proceeds
                  distributed to him pursuant to Article 14; and

                           (iii)  The  Partner's  pro rata  share  of any  other
                  expenditures  of the  Partnership  which are not deductible in
                  computing  Partnership  Profits  or  Losses  and which are not
                  added to the tax basis of any Partnership property, including,
                  without   limitation,   expenditures   described   in  Section
                  705(a)(2)(B) of the Code. The Partner's pro rata share of such
                  expenditures,  other  than  the  Sales  Commission,  shall  be
                  determined  in the  same  manner  as such  Partner's  share of
                  Profits  and Losses  allocated  pursuant  to  Article  13. The
                  Partner's share of the Sales  Commission  shall be that amount
                  allocated to him pursuant to Article 13.





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                  13.      ALLOCATIONS

                  (a)      Nonrecourse Deductions.  Nonrecourse Deductions shall
          be allocated 20% to the General Partner and 80% to the Limited 
          Partners on a Pro Rata Basis.

                  (b) Partner  Nonrecourse  Deductions.  Any Partner Nonrecourse
         Deductions  shall be  specially  allocated to the Partner who bears the
         economic risk of loss with respect to the Partner  Nonrecourse  Debt to
         which  such  Partner   Nonrecourse   Deductions  are   attributable  in
         accordance with Treasury Regulation Section 1.704-2(i).

                  (c)      Profits and Losses.

                  (i)  The  Profits  and  Losses  of the  Partnership  shall  be
         allocated 20% to the General Partner and 80% to the Limited Partners on
         a Pro Rata Basis.  In  allocating  Profits  and  Losses,  Net Gains and
         Losses from Capital  Transactions  (a part of Profits and  Losses),  if
         any, shall be allocated first.

                  (ii) In no event shall Losses be allocated  under this Article
         13(c) to a Limited  Partner if and to the extent  that such  allocation
         would cause,  as of the end of the Year,  the negative  balance in such
         Limited  Partner's  Capital  Account to exceed such  Limited  Partner's
         share of Partnership Minimum Gain plus such Limited Partner's share, if
         any, of Partner Minimum Gain. Any Losses which are not allocated to the
         Limited Partner by virtue of the application of the preceding  sentence
         shall be allocated to the General Partner. For purposes of this Article
         13(c),  a  Partner's  Capital  Account  shall be  treated as reduced by
         Qualified  Income Offset Items as provided in Article  13(d)(iii).  All
         items of income,  gain, loss,  deduction,  or credit shall be allocated
         among  the  Partners  proportionately.   Further,  notwithstanding  the
         foregoing,  after giving effect to the special  allocations  in Article
         13(d), the General Partner shall be allocated at least 20% of all items
         of income, gain, loss, deduction or credit.

                  (d) Special  Allocations.  The following  special  allocations
shall be made:

                  (i) Minimum  Gain  Chargeback.  If there is a net  decrease in
         Partnership  Minimum  Gain  during  any  Year,  each  Partner  shall be
         specially  allocated items of Partnership income and gain for such Year
         (and,  if  necessary,  subsequent  Years)  in an  amount  equal to such
         Partner's  share  of the net  decrease  in  Partnership  Minimum  Gain,
         determined   in   accordance   with   Treasury    Regulations   Section
         1.704-2(g)(2).  Allocations  pursuant to the previous sentence shall be
         made in proportion to the respective  amounts  required to be allocated
         to each  Partner.  The items to be so allocated  shall be determined in
         accordance with Treasury  Regulations Section 1.704- 2(f). This Article
         13(d)(i)  is  intended  to  comply  with the  minimum  gain  chargeback
         requirement in such Section of the Regulations and shall be interpreted
         consistently therewith.


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                  (ii) Partner  Minimum  Gain  Chargeback.  Notwithstanding  any
         other provision of this Article 13 except Article 13(d)(i), if there is
         a net  decrease  in  Partner  Minimum  Gain  attributable  to a Partner
         Nonrecourse  Debt during any Year,  each Partner who has a share of the
         Partner  Minimum Gain  attributable to such Partner  Nonrecourse  Debt,
         determined in accordance with Treasury  Regulations Section 1.704-2(f),
         shall be specially  allocated items of Partnership  income and gain for
         such Year (and, if necessary,  subsequent  Years) in an amount equal to
         such  Partner's  share of the net  decrease  in  Partner  Minimum  Gain
         attributable to such Partner  Nonrecourse  Debt, to the extent required
         by and  determined in  accordance  with  Treasury  Regulations  Section
         1.704-2(i)(4).  Allocations  pursuant to the previous sentence shall be
         made in proportion to the respective  amounts  required to be allocated
         to each Partner pursuant thereto. The items to be so allocated shall be
         determined   in   accordance   with   Treasury    Regulations   Section
         1.704-2(i)(4).  This  Article  13(d)(ii) is intended to comply with the
         minimum gain chargeback  requirement in such Section of the Regulations
         and shall be interpreted consistently therewith.

                  (iii)  Qualified  Income Offset.  If any Partner  unexpectedly
         receives  any  adjustment,  allocation  or  distribution  described  in
         Treasury Regulations Section 1.704- 1(b)(2)(ii)(d)(4) through (6) which
         causes or increases a deficit balance in such Partner's Capital Account
         (adjusted  for  this  purpose  in  the  manner   provided  in  Treasury
         Regulations Section 1.704-1(b)(2)(ii)(d)),  items of Partnership income
         and gain shall be specially allocated to each such Partner in an amount
         and manner  sufficient  to  eliminate,  to the extent  required  by the
         Regulations,  the deficit Capital Account of such Partner as quickly as
         possible,   provided  that  an  allocation  pursuant  to  this  Article
         13(d)(iii)  shall be made if and only to the extent  that such  Partner
         would  have a deficit  Capital  Account  after  all  other  allocations
         provided for in this  Article  13(d) have been  tentatively  made as if
         this Article  13(d)(iii)  were not in the Agreement.  This provision is
         intended  to be a  "qualified  income  offset,"  as defined in Treasury
         Regulations  Section   1.704-1(b)(2)(ii)(d),   such  Regulations  being
         specifically incorporated herein by reference.

                  (iv) Sales Commission. The Sales Commission shall be allocated
         to the  Units  which  are  not  held  by the  General  Partner  and its
         Affiliates  in  proportion to their  respective  Capital  Contributions
         represented  by such Units (i.e.,  $270 in Sales  Commissions  per each
         such Unit).  The purpose of this  Article  13(d)(iv) is to allocate the
         Sales  Commission  to those  Partners who  actually  bore the burden of
         paying the Sales Commission.

                  (e) Ordering Provision. In applying the provisions of Articles
         13 and 14 with respect to distributions and allocations,  the following
         ordering of priorities shall apply:

                  (i)  Capital  Accounts  shall  be  deemed  to  be  reduced  by
         Qualified Income Offset Items.


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                  (ii) Capital  Accounts  shall be reduced by  Distributions  of
         Partnership Cash Flow under Article 14(a).

                  (iii) Capital  Accounts shall be reduced by  Distributions  of
         Partnership Sales Proceeds and Partnership  Refinancing  Proceeds under
         Article 14(b).

                  (iv) Capital  Accounts  shall be increased by any Minimum Gain
         Chargeback under Articles 13(d)(i) and (ii).

                  (v)  Capital  Accounts  shall be  increased  by any  Qualified
         Income Offset under Article 13(d)(iii).

                  (vi)  Capital  Accounts  shall be  reduced by  allocations  of
         Nonrecourse Deductions under Article 13(a).

                  (vii)  Capital  Accounts  shall be reduced by  allocations  of
         Partner Nonrecourse Deductions under Article 13(b).

                  (viii)  Capital  Accounts shall be increased by allocations of
         Profits under Article 13(c).

                  (ix)  Capital  Accounts  shall be  reduced by  allocations  of
         Losses under Article 13(c).

                  To the maximum extent permitted under the Code, allocations of
         Profits  and Losses  shall be modified  so that the  Partners'  Capital
         Accounts  reflect the amount they would have  reflected if  adjustments
         required by Articles 13(d)(i), (ii) and (iii) had not occurred.

                  (f)  Allocations  Between  Transferor and  Transferee.  In the
         event of the  transfer of all or any part of a Partner's  interest  (in
         accordance with the provisions of this Agreement) in the Partnership at
         any time other  than at the end of a Year,  or the  admission  of a new
         Partner  (in  accordance  with  the  terms  of  this  Agreement),   the
         transferring  Partner  or new  Partner's  share  of  the  Partnership's
         income,  gain,  loss,  deductions  and  credits,  as computed  both for
         accounting  purposes  and for  Federal  income tax  purposes,  shall be
         allocated between the transferor Partner and the transferee Partner (or
         Partners),  or the new Partner and the other Partners,  as the case may
         be, in the same  ratio as the  number of days in such Year  before  and
         after the date of the transfer or admission; provided, however, that if
         there  has  been a sale  or  other  disposition  of the  assets  of the
         Partnership  (or any part  thereof)  during  such  Year,  then upon the
         mutual agreement of all the Partners (excluding the new Partner and the
         transferring  Partner),  the Partnership shall treat the periods before
         and after the date of the transfer or  admission as separate  Years and
         allocate the Partnership's net income,  gain, net loss,  deductions and
         credits for each of such deemed  separate  Years.  Notwithstanding  the
         foregoing, the Partnership's "allocable cash basis items," as that

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<PAGE>



         term is used in Section 706(d)(2)(B) of the Code, shall be allocated as
         required  by  Section   706(d)(2)  of  the  Code  and  the  regulations
         thereunder.

                  (g) Tax  Withholding.  The Partnership  shall be authorized to
         pay, on behalf of any  Partner,  any amounts to any  federal,  state or
         local taxing  authority,  as may be necessary  for the  Partnership  to
         comply with tax withholding  provisions of the Code or the other income
         tax or  revenue  laws  of any  taxing  authority.  To  the  extent  the
         Partnership  pays any such  amounts  that it may be  required to pay on
         behalf  of  a  Partner,  such  amounts  shall  be  treated  as  a  cash
         Distribution  to such  Partner  and shall  reduce the amount  otherwise
         distributable to such Partner.

                  14.      DISTRIBUTIONS.

                  (a)  Distribution of Partnership  Cash Flow.  Partnership Cash
         Flow shall be distributed to the Partners  within 60 days after the end
         of each Year of the  Partnership,  or earlier in the  discretion of the
         General  Partner,  20% to the  General  Partner  and 80% to the Limited
         Partners on a Pro Rata Basis.

                  (b)  Distribution  of  Partnership  Refinancing  Proceeds  and
         Partnership  Sales  Proceeds.   Partnership  Refinancing  Proceeds  and
         Partnership  Sales Proceeds shall be distributed to the Partners within
         60 days of the Capital  Transaction  giving rise to such  proceeds,  or
         earlier in the  discretion of the General  Partner,  20% to the General
         Partner and 80% to the Limited Partners on a Pro Rata Basis.

                  (c)  Distribution  in  Liquidation.  Upon  liquidation  of the
         Partnership,  all of the  Partnership's  property  shall  be  sold  and
         Profits and Losses allocated accordingly. Proceeds from the liquidation
         of the Partnership shall be distributed in accordance with Article 25.

                  15.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS.

                  15.1  Management.  The Limited Partners shall not take part in
the management of the business,  nor transact any business for the  Partnership,
nor shall they have power to sign for or to bind the  Partnership.  The  General
Partner may,  however,  contract with one or more Limited Partners to act as the
local manager of the LithostarTM  Mobile System. No Limited Partner may withdraw
from the Partnership except as expressly permitted herein.

                  15.2  Operation  of  LithostarTM  Mobile  System.  The Limited
Partners  shall not  operate or utilize the  LithostarTM  Mobile  System  except
pursuant to (i) an Agreement with the Partnership; or (ii) any other arrangement
specifically approved by the General Partner.

                  16.      LIMITED LIABILITY.

                  No Limited Partner shall be required to make any  contribution
to the  capital of the  Partnership  except as set forth in Article 7, nor shall
any Limited  Partner in his capacity as such, be bound by, or personally  liable
for, any expense, liability or obligation of the Partnership except to the

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extent of his (i) interest in the  Partnership;  (ii)  Guaranties of Partnership
obligations;  and (iii)  obligation  to return  distributions  made to him under
certain circumstances as required by the Act.

                  17.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS.

                  17.1     Transferability.

                  (a) The  term  "transfer"  when  used in this  Agreement  with
         respect to a Partnership  Interest includes a sale,  assignment,  gift,
         pledge, exchange, or any other disposition.

                  (b) Except as otherwise  provided herein,  the General Partner
         shall not at any time  transfer or assign its interest or obligation as
         General  Partner,  except  that the  General  Partner  may  cause to be
         admitted to the  Partnership  additional  General  Partners in order to
         comply with Article 10.2(d).

                  (c) The Partnership  Interest of any Limited Partner shall not
         be  transferred,  in whole or in part,  except in  accordance  with the
         conditions and limitations set forth in Articles 17.2 or 18.

                  (d) The  transferee of a Partnership  Interest by  assignment,
         operation of law or otherwise,  shall have only the rights,  powers and
         privileges  enumerated in Article 17.3 or otherwise provided by law and
         may not be admitted to the  Partnership as a Limited  Partner except as
         provided in Article 17.4 or as a General  Partner except as provided in
         Article 17.5

                  (e) Notwithstanding any provision herein to the contrary,  the
         Partnership  Agreement  shall  in  no  way  restrict  the  issuance  or
         transfers of the stock of the General Partner.

                  17.2     Restrictions on Transfers by Limited Partners.

                  (a) All or part of a Partnership  Interest may be  transferred
         by a  Limited  Partner  only  with the prior  written  approval  of the
         General  Partner,  which  approval may be granted or denied in the sole
         discretion of the General  Partner.  Units may only be  transferred  in
         increments of one Unit unless all Units or portions  thereof owned by a
         Limited  Partner are being  transferred.  In no event may a Partnership
         Interest be  transferred  if such  transfer  would  result in a default
         under the  Guaranties or a termination  of the  Partnership  under Code
         Section  708,  nor  may a  Partnership  Interest  be  transferred  to a
         "tax-exempt  entity" (as defined in Code  Section  168(h))  which would
         affect the  method or manner in which the  Partnership  may  depreciate
         Partnership assets.

                  (b) The General  Partner  shall not approve any  transfer of a
         Partnership   Interest  unless  the  proposed   transferee  shall  have
         furnished the General Partner with a sworn statement that:

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                           (i)      proposes to acquire his Partnership Interest
                  as a principal, for investment and not with a view to resale 
                  or distribution;

                           (ii) the proposed  transferee meets such requirements
                  regarding sophistication,  income and net worth as required by
                  applicable state and Federal securities laws;

                           (iii) the proposed  transferee has met such net worth
                  and income  suitability  standards as have been established by
                  the General Partner;

                           (iv)  the   proposed   transferee   recognizes   that
                  investment in the Partnership  involves  certain risks and has
                  taken  full  cognizance  of and  understands  all of the  risk
                  factors related to the purchase of a Partnership Interest; and

                           (v)  the  proposed   transferee  has  met  all  other
                  requirements of the General Partner for the proposed transfer.

                  (c) A transfer of a Partnership  Interest may be made only if,
         prior to the date thereof,  the  Partnership  upon request  receives an
         opinion of counsel,  satisfactory  in form and substance to the General
         Partner,  that  neither the offering  nor the  proposed  transfer  will
         violate any Federal or applicable  state  securities law or regulations
         or any of the provisions of Article  17.2(b)  hereof,  will prevent the
         Partnership from being entitled to use any method of depreciation which
         the  Partnership  might otherwise be entitled to use, or will adversely
         affect the  status of the  Partnership  as a  partnership  for  Federal
         income tax purposes.

                  17.3     Rights of Transferee.

                  Unless  admitted to the Partnership in accordance with Article
17.4, the  transferee of a Partnership  Interest or a part thereof or any right,
title or interest therein shall not be entitled to any of the rights, powers, or
privileges of his  predecessor in interest,  except that he shall be entitled to
receive and be credited or debited with his  proportionate  share of Partnership
income, gains, Profits, Losses, deductions, credits or Distributions.

                  17.4     Admission of Limited Partners.

                  A General  Partner,  or the  transferee  of all or part of the
Partnership  Interest of either a General Partner or a Limited  Partner,  may be
admitted to the  Partnership as a Limited Partner upon furnishing to the General
Partner all of the following:

                  (a) the written  approval of a Majority in Interest all of the
         Limited Partners except the assignor  Partner,  or the assignor Partner
         alone,  which approval may be granted or denied in the sole  discretion
         of such Partners or Partner (as the case may be);

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                  (b)  the  written  approval  of  the  General  Partner,  which
         approval may be granted or denied in the sole discretion of the General
         Partner;

                  (c) acceptance, in a form satisfactory to the General Partner,
         of all the  terms  and  conditions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d)      a power of attorney substantially identical to that 
         contained in Article 38;

                  (e) such other  documents or instruments as may be required in
         order to effect his admission as a Limited Partner; and

                  (f) payment of such reasonable  expenses as may be incurred in
         connection with his admission as a Limited Partner.

                  17.5     Admission of General Partners.

                  A Limited  Partner,  or the  transferee  of all or part of the
Partnership  Interest of the General Partner, may be admitted to the Partnership
as a  general  partner  upon  furnishing  to  the  General  Partner  all  of the
following:

                  (a) the written  approval  of both the  General  Partner and a
         Majority in Interest of the Limited  Partners,  which  approval  may be
         granted or denied in the sole discretion of the Partners;

                  (b) such financial statements,  guarantees or other assurances
         as the General  Partner  may require  with regard to the ability of the
         proposed  general  partner to fulfill the  financial  obligations  of a
         general partner hereunder;

                  (c) acceptance,  in form  satisfactory to the General Partner,
         of all the  terms  and  provisions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d) a certified copy of a resolution of its Board of Directors
         (if it is a  corporation)  authorizing  it to become a general  partner
         under the terms and conditions of this Agreement;

                  (e)      a power of attorney substantially identical to that 
         contained in Article 38;

                  (f) such other  documents or instruments as may be required in
         order to effect its admission as a general partner; and


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                  (g) payment of such reasonable  expenses as may be incurred in
         connection with its admission as a general partner.

                  Notwithstanding  the above,  a transferee  that controls or is
controlled by the General Partner or one or more of its Affiliates that receives
all or part of the  Partnership  Interest of the General Partner may be admitted
to the  Partnership as a general  partner upon complying with all the provisions
of Article 17.5 except for  subparagraph  17.5(a).  As long as the transferee is
controlled by the General Partner or one or more of its  Affiliates,  no Limited
Partner  consents will be required to admit such transferee as a General Partner
to the Partnership.

                  17.6     Amendment of Certificate of Limited Partnership and
                           Qualification.

                  The  General  Partner  shall  take  all  steps  necessary  and
appropriate to prepare and record any  amendments to the  Certificate of Limited
Partnership, as may be necessary or appropriate from time to time to comply with
the requirements of the Act, including,  without limitation,  upon the admission
to the Partnership of any general partner  pursuant to the provisions of Article
17.5, and may for this purpose  exercise the power of attorney  delivered to the
General Partner pursuant to Article 17.5 or 38. In addition, the General Partner
shall take all steps necessary and appropriate to prepare and record any and all
documents  necessary to qualify the Partnership to do business in  jurisdictions
where the Partnership is doing business,  and may for this purpose  exercise the
power of attorney  delivered to the General  Partner  pursuant to Articles 17.4,
17.5 or 38.

                  17.7     Withdrawal of Initial Limited Partner.

                  Upon the date the first  Limited  Partner is  admitted  to the
Partnership in accordance with Article 11 of this Agreement, the Initial Limited
Partner  shall  withdraw  from  the  Partnership,   and  thereupon  his  Capital
Contribution shall be returned and his Partnership Interest shall be reallocated
to the Limited Partners.

                  18.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP
                           INTERESTS ON CERTAIN EVENTS.

                  18.1     Death.

                  18.1.1  Upon the  death of a  Limited  Partner,  the  deceased
         Limited Partner's executor,  administrator,  or other legal or personal
         representative  shall give  written  notice of that fact to the General
         Partner.  In such event, the executor,  administrator or other legal or
         personal  representative  of the deceased  Limited Partner shall have a
         period of ninety (90) days  following the date of death (the  "Response
         Period") within which to locate a qualified investor approved of by the
         General  Partner,  which  approval can be granted or denied in the sole
         discretion of the General Partner (a "Qualified Investor"), to purchase
         the entire Partnership Interest of the deceased Limited Partner. In the
         event  the  executor,   administrator   or  other   personal  or  legal
         representative  of the  deceased  Limited  Partner  locates a Qualified
         Investor who is willing to purchase the entire Partnership  Interest of
         the deceased Limited Partner, he

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<PAGE>



         shall give notice of that fact in writing to the General Partner, which
         notice  shall  state  the  name of the  proposed  transferee  Qualified
         Investor.  Provided  the  requirements  of  Articles  17.2 and 17.4 (b)
         through (f) are satisfied, the executor,  administrator, or other legal
         or personal  representative  of the deceased  Limited  Partner may then
         transfer the  Partnership  Interest of the deceased  Limited Partner to
         the  Qualified  Investor  specified  in the notice free of the purchase
         options  granted in Article  18.1.2.  If such conditions are satisfied,
         the transferee Qualified Investor shall have the rights of a transferee
         Limited  Partner as set forth in Article 17.3 and shall become  subject
         to all obligations connected with the Partnership interest transferred.
         The deceased Limited  Partner's  Guaranty shall remain an obligation of
         his  estate,  unless  the Bank  agrees to release  the estate  from the
         Guaranty in substitution of a like Guaranty from any transferee Limited
         Partner.

                  18.1.2 In the event the requirements of Articles 17.2 and 17.4
         (b) through (f) are not satisfied with respect to a proposed transferee
         Qualified  Investor,  or the executor,  administrator or other legal or
         personal representative of the deceased Limited Partner fails to locate
         a Qualified  Investor to purchase the deceased Limited Partner's entire
         Partnership  Interest within the Response  Period,  the General Partner
         shall have the option to purchase at the Closing (as defined below) the
         Partnership  Interest of the deceased  Limited Partner (whose executor,
         administrator  or other  legal or  personal  representative  shall then
         become  obligated  to sell  such  Partnership  Interest)  at the  price
         determined in the manner provided in Article 18.5 of this Agreement and
         on the terms and conditions provided in Article 18.6 of this Agreement.
         The General  Partner shall have a period of thirty (30) days  following
         the date of the close of the  Response  Period  (the  "Option  Period")
         within  which to notify  in  writing  the  deceased  Limited  Partner's
         executor,  administrator  or other  legal or  personal  representative,
         whether the General  Partner wishes to purchase all or a portion of the
         Partnership  Interest of the deceased Limited  Partner.  If the General
         Partner does not elect to purchase the entire  Partnership  Interest of
         the deceased Limited Partner before the expiration of the Option Period
         and in the manner  provided  herein,  the  portion  of the  Partnership
         Interest not purchased shall be held by the deceased Limited  Partner's
         executor,  administrator, or other legal representative pursuant to the
         terms of this Agreement.

                  18.2     Bankruptcy, Insolvency or Assignment for
                           Benefit of Creditors of a Limited Partner.

                  18.2.1  In  the  event  that  an   involuntary   or  voluntary
         proceeding under the Federal Bankruptcy Code, as amended,  is filed for
         or against any Limited Partner, or if any Limited Partner shall make an
         assignment for the benefit of his creditors,  or if any Limited Partner
         has a receiver or custodian  appointed  for his assets,  or any Limited
         Partner  generally  fails to pay his  debts  when  due,  the  insolvent
         Limited Partner shall give written notice to the General Partner of the
         commencement  of any such  proceeding  or the  occurrence of such event
         within  five days of the first  notice to him of such  commencement  or
         occurrence of such event. The insolvent Limited Partner or his trustee,
         custodian, receiver or representative shall have a period of

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<PAGE>



         ninety (90) days  following  the date of the  occurrence of one of such
         events  (the  "Response  Period")  within  which to locate a  Qualified
         Investor to purchase the entire  Partnership  Interest of the insolvent
         Limited  Partner.  In the event the  insolvent  Limited  Partner or his
         trustee, custodian,  receiver or other legal or personal representative
         locates a  Qualified  Investor  who is willing to  purchase  the entire
         Partnership  Interest of the insolvent  Limited Partner,  he shall give
         notice of that fact in writing to the  General  Partner,  which  notice
         shall state the name of the  proposed  transferee  Qualified  Investor.
         Provided the requirements of Articles 17.2 and 17.4 (b) through (f) are
         satisfied,  the insolvent  Limited  Partner or his trustee,  custodian,
         receiver or representative  may then transfer the Partnership  Interest
         of the insolvent Limited Partner to the Qualified Investor specified in
         the notice free of the purchase  options granted in Article 18.2.2.  If
         such conditions are satisfied,  the transferee Qualified Investor shall
         have the rights of a transferee Limited Partner as set forth in Article
         17.3 and shall become  subject to all  obligations  connected  with the
         Partnership Interest  transferred.  The insolvent Limited Partner shall
         remain  personally  liable on his  Guaranty,  unless the Bank agrees to
         release such Limited  Partner  from his Guaranty in  substitution  of a
         like Guaranty from any transferee Limited Partner.

                  18.2.2 In the event the requirements of Articles 17.2 and 17.4
         (b) through (f) are not satisfied with respect to a proposed transferee
         Qualified  Investor,  or the insolvent  Limited  Partner,  his trustee,
         custodian,  receiver or other legal or personal representative fails to
         locate a Qualified Investor to purchase the insolvent Limited Partner's
         Partnership  Interest within the Response  Period,  the General Partner
         shall have the option to purchase at the Closing (as defined below) the
         Partnership  Interest of the insolvent Limited Partner (which insolvent
         Limited Partner or his trustee,  custodian,  receiver or other personal
         or  legal  representative,  as the  case  may  be,  shall  then  become
         obligated to sell such Partnership Interest) at the price determined in
         the manner  provided in Article 18.5 of this Agreement and on the terms
         and conditions provided in Article 18.6 of this Agreement.  The General
         Partner  shall have a period of thirty (30) days  following the date of
         the close of the Response Period (the "Option  Period") within which to
         notify  in  writing  the  insolvent  Limited  Partner  or his  trustee,
         custodian, receiver, or other legal or personal representative, whether
         the  General  Partner  wishes  to  purchase  all  or a  portion  of the
         Partnership  Interest of the insolvent Limited Partner.  If the General
         Partner does not elect to purchase the entire  Partnership  Interest of
         the  insolvent  Limited  Partner  before the  expiration  of the Option
         Period  and  in  the  manner  provided  herein,   the  portion  of  the
         Partnership  Interest  not  purchased  shall  be held by the  insolvent
         Partner,  his trustee,  custodian,  receiver or other legal or personal
         representative pursuant to the terms of this Agreement.

                  18.3  Default  under  Guaranties.  Notwithstanding  any  other
provision in this Article 18 to the contrary,  if any of the events  outlined in
Articles  18.1 or 18.2 or any other  defaulting  event  outlined in the Guaranty
(the  "Defaulting  Events")  should occur with respect to a Limited Partner (the
"Defaulting  Limited Partner"),  and the General Partner determines (in its sole
discretion)  that  such  event may  result in  default  and  acceleration  of an
obligation  secured by the Guaranty unless another  guarantor  acceptable to the
Lender can be substituted in the place of the Defaulting Limited Partner,

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<PAGE>



then the General  Partner shall have the right to immediately  take the steps as
outlined in this Article 18.3 to prevent such default.  Upon the General Partner
receiving  notice of a Defaulting  Event as provided above, the General Partner,
in its sole discretion,  shall immediately have the right to either (i) sell the
entire  Partnership  Interest of the Defaulting  Limited  Partner to an investor
approved of by the General Partner, (ii) purchase for its own account the entire
Partnership Interest of the Defaulting Limited Partner, or (iii) sell the entire
Partnership  Interest of the  Defaulting  Limited  Partner to one or more of the
other  Limited  Partners.   The  Defaulting   Limited  Partner  shall  sell  his
Partnership  Interest to the purchaser at the purchase  price  determined in the
manner as provided in Article 18.5 and on the terms and  conditions  as provided
in Article 18.6. The transfer of the  Partnership  Interest,  the payment of the
purchase  price,  and  the  assumption  of  the  Defaulting   Limited  Partner's
obligations  under his Guaranty (as provided in Article 18.5),  shall be made at
such time as determined by the General Partner in order to avoid the default and
acceleration  of the obligation  secured by the Guaranty.  Each Limited  Partner
hereby makes,  constitutes and appoints the General Partner,  with full power of
substitution,  his true and lawful  attorney-in-fact,  to take such  actions and
execute such  documents on his behalf to effect the transfer of his  Partnership
Interest as provided in this Article  18.3,  in the event such  Limited  Partner
becomes a Defaulting Limited Partner.

                  18.4 Divestiture  Option.  If state or federal  regulations or
laws are enacted or applied, or if any other legal developments occur, which, in
the opinion of the General Partner,  adversely affect (or potentially  adversely
affect) the operation of the Partnership or the business of the Partnership in a
manner deemed  substantial by the General Partner in its sole discretion  (e.g.,
exclusion from any  governmental  health care program or any provider  ownership
prohibition),  the General Partner shall promptly either, in its discretion, (i)
take the steps  outlined in this Article 18.4 to divest the Limited  Partners of
their  Partnership  Interests,  or (ii) dissolve the  Partnership as provided in
Article  24.1(d).  If the General Partner chooses option (i), it shall deliver a
written  notice to all of the Limited  Partners (the "Notice of  Election")  and
either sell the entire  Partnership  Interests of all of the Limited Partners to
one or more investors selected by it (including, without limitation,  Affiliates
of the General Partner),  and/or purchase such Partnership Interests for its own
account.  In such  event,  the  Limited  Partners  shall sell their  Partnership
Interests to the purchaser or purchasers at the purchase price determined in the
manner  as  provided  in  Article  18.5 and be on the terms  and  conditions  as
provided in Article 18.6. The transfer of the Partnership Interests, the payment
of the purchase prices, and the assumption of the Limited Partners'  obligations
under their respective Guaranties (as provided in Article 18.5) shall be made at
such time as  determined by the General  Partner to be in the best  interests of
the Partnership and its Limited Partners.  If the General Partner chooses option
(ii), it shall proceed with reasonable  promptness to dissolve and liquidate the
Partnership  and no vote of the  Limited  Partners  shall  be  required  in that
connection.  Each Limited  Partner  hereby makes,  constitutes  and appoints the
General  Partner,  with  full  power  of  substitution,   his  true  and  lawful
attorney-in-fact,  to take such actions and execute such documents on his behalf
to effect the transfer of his  Partnership  Interest or the  dissolution  of the
Partnership, as the case may be, as provided in this Article 18.4.

                  18.5  Purchase  Price.  The purchase  price to be paid for the
Partnership  Interest of any Limited  Partner whose interest is being  purchased
(the "Retiring Limited Partner")  pursuant to the provisions of Articles 18.1.2,
18.2.2,  18.3 or 18.4 shall be an amount equal to the Retiring Limited Partner's
share of the Partnership's  book value, if any, (prorated in the event that only
a portion of his  Partnership  Interest is being  purchased) as reflected by the
Capital Account of the Retiring Limited Partner (unadjusted for any appreciation
in Partnership assets and as reduced by

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<PAGE>



depreciation  deductions  claimed  by the  Partnership  for tax  purposes).  The
determination of the Retiring Limited Partner's Capital Account on the Valuation
Date (as defined  below)  shall be made by the  Partnership's  firm of certified
public  accountants  (the  "Partnership   Accountant")  upon  a  review  of  the
Partnership  books of  account,  and a formal  audit is  expressly  waived.  The
statement of the  Partnership  Accountant with respect to the Capital Account of
the  Retiring  Limited  Partner  on the  Valuation  Date  shall be  binding  and
conclusive upon the Partnership,  the purchaser and the Retiring Limited Partner
and his  representative.  The Valuation  Date shall be the last day of the month
next preceding the month in which occurs: (i) the death of a Limited Partner, in
the case of a purchase by reason of death;  (ii) the bankruptcy or insolvency of
a Limited  Partner,  in the case of a purchase by reason of such  bankruptcy  or
insolvency;  (iii) the notice of a Defaulting Event as provided in Article 18.3,
in the case of a purchase occurring by reason of one of such events; or (iv) the
Notice of Election as  provided  in Article  18.4,  in the case of a purchase by
reason  thereof.  The purchase price shall be paid at the Closing in cash (or by
certified  or  cashier's  check).  If as of the date of the Closing the Retiring
Limited Partner still has an outstanding  personal obligation under the Guaranty
(the "Obligation"),  the purchaser shall assume the portion of the Obligation as
is equal to the portion of the Partnership  Interest being purchased,  indemnify
the Retiring Limited Partner from such portion of the Obligation,  and take such
steps  deemed  necessary  by  the  General  Partner  to  formally  evidence  the
assumption  of such portion of the  Obligation,  including  without  limitation,
executing such  documents and providing  such financial  information to the Bank
(as  the  case  may be) to  evidence  the  assumption  of  such  portion  of the
Obligation,  and obtain if possible,  the release of the  Retiring  Partner from
such portion of the Obligation.

                  18.6     Closing.

                  18.6.1  Closing  of  Purchase  and Sale.  The  Closing  of any
         purchase and sale of a Partnership Interest pursuant to Articles 18.1.2
         or 18.2.2 of this Agreement shall take place at the principal office of
         the Partnership, or such other place designated by the General Partner,
         on the date determined as follows (the "Closing"):

                  (a) In the case of a purchase and sale  occurring by reason of
         the death of a Limited  Partner as provided  in Article  18.1.2 of this
         Agreement,  the Closing  shall be held on the thirtieth day (or if such
         thirtieth  day is not a business  day, the next  business day following
         the thirtieth day) next following the last to occur of:

                           (i)      Qualification of the executor or personal 
                  administrator of the deceased Limited Partner's estate;

                           (ii) The date on which any necessary determination of
                  the purchase price of the Partnership Interest to be purchased
                  has been made, or

                           (iii) The date that  coincides  with the close of the
                  Option Period.

                  (b) In the case of a purchase and sale  occurring by reason of
         the  bankruptcy  or  insolvency  of a Limited  Partner as  provided  in
         Article 18.2.2 of this

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         Agreement,  the Closing  shall be held on the thirtieth day (of if such
         thirtieth  day is not a business  day, the next  business day following
         the thirtieth day) next following the later to occur of:

                           (i) The date on which any necessary determination of 
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (ii) The date  that  coincides  with the close of the
                  Option Period.

         At the Closing, the Limited Partner whose Partnership Interest is being
         purchased (the  "Transferring  Partner") shall concurrently with tender
         and receipt of the applicable purchase price,  deliver to the purchaser
         duly executed  instruments of transfer and  assignment,  assigning good
         and  marketable  title to the portion or  portions of the  Transferring
         Partner's entire  Partnership  Interest thus purchased,  free and clear
         from any liens or  encumbrances or rights of other therein (except with
         respect to liens or rights  associated with the Guaranties as otherwise
         provided herein).

                  18.6.2  Terms and  Conditions  of  Purchase.  The  Partnership
         Interest of a Limited  Partner shall not be  transferred to any Partner
         unless the  requirements  of Articles 17.2 and 17.4 (b) through (f) are
         satisfied  with  respect to it. The  purchaser  shall be liable for all
         obligations  and  liabilities   connected  with  that  portion  of  the
         Partnership  Interest  transferred  to it  unless  otherwise  agreed in
         writing.

                  18.6.3 Percentage Interests.  The Percentage Interests of each
         Partner who purchases all or a portion of the Partnership Interest of a
         Limited  Partner  pursuant to the provisions of Article 18.3,  shall be
         increased by the Percentage Interest represented by that portion of the
         Partnership Interest purchased by such Partner.

                  19.      SALE,  ASSIGNMENT  OR OTHER  TRANSFER  OF THE GENERAL
                           PARTNER'S INTEREST.

                  19.1  The   General   Partner   may  not   mortgage,   pledge,
hypothecate,  transfer,  sell, assign or otherwise dispose of all or any part of
its interest in the  Partnership,  whether  voluntarily,  by operation of law or
otherwise (the foregoing  actions being  hereafter  collectively  referred to as
"Transfers" or singularly as a "Transfer") except as permitted by this Article.

                  19.2 If the  General  Partner  makes a Transfer of its general
partner interest in the Partnership pursuant to this Article, it shall be liable
for all obligations and liabilities incurred by it as the General Partner of the
Partnership on or before the effective  date of such Transfer,  but shall not be
liable for any obligations or liabilities of the  Partnership  arising after the
effective date of the Transfer.




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                  19.3     No Transfer by the General Partner shall be permitted
 unless:

                  (a) The certified public  accountant for the Partnership shall
         have  delivered  to the  Partnership  an opinion  that the new  general
         partner of the  Partnership has sufficient net worth (if necessary) and
         meets all other published  requirements of the Internal Revenue Service
         necessary to assure that the Partnership will continue to be classified
         as a partnership for Federal income tax purposes;

                  (b) Counsel for the Partnership shall have rendered an opinion
         that none of the actions  taken in  connection  with such Transfer will
         cause the Partnership to be classified  other than as a partnership for
         Federal income tax purpose or will cause the termination or dissolution
         of the Partnership and

                  (c) Such  documents  or  instruments,  in form  and  substance
         satisfactory to counsel for the  Partnership,  shall have been executed
         and  delivered  as may be  required  in the  opinion of counsel for the
         Partnership to effect fully any such Transfer.

                  20.      TERMINATION OF THE SERVICES OF THE GENERAL
                           PARTNER.

                  If the General Partner shall be finally adjudged by a court of
competent  jurisdiction to be liable to the Limited  Partners or the Partnership
for any act of gross negligence or willful  misconduct in the performance of its
duties under the terms of this Agreement, the General Partner may be removed and
another  substituted  with the  consent  of all of the  Limited  Partners.  Such
consent  shall be evidenced  by a  certificate  of removal  signed by all of the
Limited Partners. In the event of removal, the new general partner shall succeed
to all of the powers, privileges and obligations of the General Partner, and the
General  Partner's  interest in the  Partnership  shall become that of a Limited
Partner,  and the General Partner shall maintain its same Percentage Interest in
the Partnership  notwithstanding  anything contained in the Act to the contrary.
In addition,  in the event of removal,  the new general  partner  shall take all
steps  necessary  and  appropriate  to prepare  and record an  amendment  to the
Certificate of Limited Partnership to reflect the removal of the General Partner
and the admission of such new general partner.

                  21.      MANAGEMENT AND OPERATION OF BUSINESS.

                  21.1 All  decisions  with  respect  to the  management  of the
business and affairs of the Partnership shall be made by the General Partner.

                  21.2 The General  Partner shall be under no duty to devote all
of its time to the business of the Partnership,  but shall devote only such time
as it deems  necessary  to conduct the  Partnership  business and to operate and
manage the Partnership in an efficient manner.

                  21.3 The  General  Partner may charge to the  Partnership  all
ordinary and necessary costs and expenses, direct and indirect,  attributable to
the activities,  conduct and management of the business of the Partnership.  The
costs and expenses to be borne by the  Partnership  shall  include,  but are not
limited to, all expenditures  incurred in acquiring and financing the Equipment,
legal and

                                      -23-
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accounting  fees  and  expenses,  salaries  of  employees  of  the  Partnership,
insurance premiums and interest.

                  21.4 In addition to, and not in limitation  of, any rights and
powers  covenanted by law or other  provisions of this agreement,  and except as
limited,  restricted or prohibited by the express  provisions of this Agreement,
the General Partner shall have any may exercise on behalf of the Partnership all
powers and rights necessary,  proper,  convenient or advisable to effectuate and
carry out the purposes, business and objectives of the Partnership.  Such powers
shall include, without limitation, the following:

                  (a)      To acquire a LithostarTM Mobile System;

                  (b) To acquire (i) a second  LithostarTM  system,  or (ii) any
         other  assets  related  to  the  provisions  of  lithotripsy   services
         (collectively,  the  "Additional  Assets"),  at such  times and at such
         price and upon such terms,  as the General  Partner  deems to be in the
         best interest of the Partnership.

                  (c) To purchase,  hold, manage,  lease, license and dispose of
         Partnership assets (including the LithostarTM Mobile System), including
         the purchase,  exchange,  trade or sale of the Partnership's  assets at
         such price, or amount, for cash,  securities or other property and upon
         such terms,  as the General Partner deems to be in the best interest of
         the  Partnership;  provided,  that  should  the  Partnership  assets be
         exchanged or traded for securities or other property (the  "Replacement
         Property")  the General  Partner shall have the same powers with regard
         to the Replacement Property as it does towards the traded property;

                  (d) To determine the travel  itinerary and site  locations for
         the LithostarTM Mobile System;

                  (e) To borrow money for any Partnership purpose (including the
         acquisition  of the  Additional  Assets)  and,  if security is required
         therefor, to subject to any security device any portion of the property
         for the  Partnership,  to obtain  replacements  of any  other  security
         device, to prepay, in whole or in part,  refinance,  increase,  modify,
         consolidate or extend any encumbrance or other security device;

                  (f) To deposit,  withdraw,  invest, pay, retain (including the
         establishment  of reserves in order to acquire the  Additional  Assets)
         and distribute the  Partnership's  funds in any manner  consistent with
         the provisions of this Agreement;

                  (g)      To institute and defend actions at law or in equity;

                  (h) To enter into and carry out contracts and  agreements  and
         any or all documents and  instruments  and to do any and all such other
         things as may be in furtherance of Partnership purposes or necessary or
         appropriate to the conduct of the Partnership activities;


                                      -24-
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                  (i)  To   execute,   acknowledge   and  deliver  any  and  all
         instruments  which may be deemed  necessary or convenient to effect the
         foregoing;

                  (j) To form a new  limited  partnership  made up of  qualified
         investors to treat  gallstone  patients  (if the FDA ever  approves the
         LithostarTM  for  such  purpose),  and to  contract  on  behalf  of the
         Partnership  with the new limited  partnership for the use for a fee of
         the  LithostarTM  for the  treatment  of the new limited  partnership's
         gallstone patients; and

                  (k) To engage or retain one or more persons to perform acts or
         provide  materials  as  may be  required  by  the  Partnership,  at the
         Partnership's  expense,  and to compensate  such person or persons at a
         rate to be set by the General  Partner,  provided that the compensation
         is at the then  prevailing  rate for the type of services and materials
         provided,  or both.  Any person,  whether a Partner,  an Affiliate of a
         Partner or otherwise, including without limitation the General Partner,
         may be  employed  or engaged  by the  Partnership  to render  services,
         including,  but  not  limited  to,  management  services,  professional
         lithotripsy  services,  accounting  services  and  legal  services,  or
         provide materials; and if such person is a Partner or an Affiliate of a
         Partner,  he shall be entitled to, and shall be paid  compensation  for
         said services or materials,  anything in this Agreement to the contrary
         notwithstanding, provided that the compensation to be received for such
         services  or  materials  is  competitive  in price and terms  with then
         prevailing rate for the type of services and/or materials provided. The
         Partnership,  pursuant  to the terms of a  Management  Agreement,  will
         contract with the General  Partner with respect to the  supervision and
         coordination  of the  management and  administration  of the day-to-day
         operations of the LithostarTM  Mobile System for a monthly fee equal to
         the  greater of 7.5% of  Partnership  Cash Flow per month or $8,000 per
         month.  All costs  incurred by the General  Partner except the costs of
         employing one or more local  physicians to supervise the management and
         administration of the LithostarTM  Mobile System,  shall be paid by the
         Partnership directly. The Partnership will also contract with qualified
         physicians  desiring  to use  the  LithostarTM  for  the  treatment  of
         patients.  Owning  an  interest  in  the  Partnership  shall  not  be a
         condition  to  using  the  LithostarTM.  The  General  Partner  and its
         Affiliates  may  engage in or  possess an  interest  in other  business
         ventures of any nature and  description  independently  or with others,
         including,  but not limited to, the  operation of a mobile  lithotripsy
         unit  similar to the  LithostarTM  Mobile  System,  whether or not such
         business  ventures  are in  direct  or  indirect  competition  with the
         Partnership,  and neither the  Partnership  nor the Partners shall have
         any  right  by  virtue  of this  Agreement  in and to said  independent
         ventures or to the income or profits derived therefrom.

                  21.5  In  addition  to  other  acts  expressly  prohibited  or
restricted  by this  Agreement  or by law,  the  General  Partner  shall have no
authority to act on behalf of the Partnership in:

                  (a)    Doing any act in contravention of this Agreement or its
          Certificate of Limited Partnership;


                                      -25-
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                  (b) Doing any act which would make it  impossible  to carry on
         the ordinary business of the Partnership;

                  (c) Possessing or in any manner dealing with the Partnership's
         property  or   assigning   the  rights  of  the   Partnership   in  the
         Partnership's property for other than Partnership purposes;

                  (d)  Admitting  a person  as a  Limited  Partner  or a General
         Partner except as provided in this Agreement; or

                  (e)  Performing  any act (other  than an act  required by this
         Agreement  or any act  taken  in good  faith  reliance  upon  counsel's
         opinion)  which  would,  at the time  such act  occurred,  subject  any
         Limited Partner to liability as a general partner in any jurisdiction.

                  22.      RESERVES.

                  The  General  Partner  may cause the  Partnership  to create a
reserve account to be used exclusively for repairs and acquisition of Additional
Assets and for any other valid Partnership  purpose.  The General Partner shall,
in its sole discretion, determine the amount of payments to such reserve.

                  23.      INDEMNIFICATION AND EXCULPATION OF THE
                           GENERAL PARTNER.

                  23.1 The General  Partner is accountable to the Partnership as
a fiduciary and consequently  must exercise good faith and integrity in handling
Partnership  affairs.  This is a rapidly developing and changing area of the law
and Limited  Partners who have  questions  concerning  the duties of the General
Partner  should  consult  with  their  counsel.  The  General  Partner  and  its
Affiliates  shall have no liability to the  Partnership  which arises out of any
action or  inaction  of the  General  Partner or its  Affiliates  if the General
Partner or its Affiliates, in good faith, determined that such course of conduct
was in the best interest of the  Partnership  and such course of conduct did not
constitute gross negligence or willful  misconduct of the General Partner or its
Affiliates.  The General Partner and its Affiliates  shall be indemnified by the
Partnership  against any losses,  judgments,  liabilities,  expenses and amounts
paid in  settlement  of any  claims  sustained  by them in  connection  with the
Partnership,  provided that the same were not the result of gross  negligence or
willful misconduct on the part of the General Partner or its Affiliates.

                  23.2 The General Partner shall not be liable for the return of
the Capital Contributions of the Limited Partners, and upon dissolution, Limited
Partners shall look solely to the assets of the Partnership.

                  24.      DISSOLUTION OF THE PARTNERSHIP.

                  24.1 The Partnership shall be dissolved and terminated and its
business wound up upon the occurrence of any one of the following events:

                                      -26-
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                  (a)      The expiration of its term on December 31, 2040;

                  (b) The  filing  by, on  behalf  of, or  against  the  General
         Partner of any  petition or  pleading,  voluntary  or  involuntary,  to
         declare the General  Partner  bankrupt under any bankruptcy law or act,
         or the  commencement  in any  court  of any  proceeding,  voluntary  or
         involuntary,  to declare the General Partner insolvent or unable to pay
         its debts, or the appointment by any court or supervisory  authority of
         a  receiver,  trustee or other  custodian  of the  property,  assets or
         business of the General  Partner or the  assignment by it of all or any
         part of its  property or assets for the benefit of  creditors,  if said
         action,  proceeding  or  appointment  is  not  dismissed,   vacated  or
         otherwise terminated within ninety (90) days of its commencement;

                  (c) The  joint  determination  of the  General  Partner  and a
         Majority  in  Interest of the  Limited  Partners  that the  Partnership
         should be dissolved;

                  (d) The  election  of the  General  Partner  to  dissolve  the
         Partnership  following the occurrence of an event  described in Article
         18.4;

                  (e)  The  sale,  exchange  or  other  disposition  of  all  or
         substantially  all of the property of the  Partnership  without  making
         provision for the replacement thereof; and

                  (f)   The   dissolution,   retirement,   resignation,   death,
         disability  or legal  incapacity  of a general  partner,  and any other
         event  resulting in the  dissolution or termination of the  Partnership
         under  the  laws of the  State of  Hawaii;  provided,  that the  events
         described  in  Sections  425D-402(4)  and (5) of the Act or any similar
         provisions of any successor  statute,  shall not work a dissolution  of
         the Partnership except as expressly provided in (b) above.

                  24.2  Notwithstanding  the  provisions  of Article  24.1,  the
Partnership   shall  not  be  dissolved  and  terminated  upon  the  retirement,
resignation,  bankruptcy,  assignment for the benefit of creditors, dissolution,
death,  disability or legal  incapacity of a general  partner,  and its business
shall continue  pursuant to the terms and conditions of this  Agreement,  if any
general partner or general partners remain  following such event;  provided that
such  remaining  general  partner or general  partners  are hereby  obligated to
continue the business of the  Partnership.  If no general  partner remains after
the  occurrence of such event,  the business of the  Partnership  shall continue
pursuant to the terms and conditions of this  Agreement,  if, within ninety (90)
days after the occurrence of such event, the Limited Partners  unanimously agree
in writing to continue the business of the  Partnership,  and, if necessary,  to
the  appointment  of one or more  persons or entities to be  substituted  as the
general  partner.  In the event  the  Limited  Partners  agree to  continue  the
business of the  Partnership,  the new general partner or general partners shall
succeed to all of the powers, privileges and obligations of the General Partner,
and the General  Partner's  interest in the  Partnership  shall become a Limited
Partner's  interest  hereunder.  Furthermore,  in the event a remaining  general
partner or the  Limited  Partners,  as the case may be,  agree to  continue  the
business of the Partnership as provided herein, the remaining general partner or
the newly  appointed  general partner or general  partners,  as the case may be,
shall  take all  steps  necessary  and  appropriate  to  prepare  and  record an
amendment to the Certificate of

                                                      -27-
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Limited  Partnership  to  reflect  the  continuation  of  the  business  of  the
Partnership and the admission of a new general partner or general  partners,  if
any.

                  25.      DISTRIBUTION UPON DISSOLUTION.

                  Upon the dissolution and termination of the  Partnership,  the
General Partner or, if there is none, a representative  of the Limited Partners,
shall  cause  the  cancellation  of the  Partnership's  Certificate  of  Limited
Partnership,  shall liquidate the assets of the Partnership, and shall apply and
distribute the proceeds of such liquidation in the following order of priority:

                  (a)      First, to the payment of the debts and liabilities of
         the Partnership, and the expenses of liquidation;

                  (b) Second,  to the creation of any reserves which the General
         Partner  (or the  representatives  of the  Limited  Partners)  may deem
         reasonably  necessary  for the payment of any  contingent or unforeseen
         liabilities or obligations of the Partnership or of the General Partner
         arising out of or in connection  with the business and operation of the
         Partnership; and

                  (c) Third,  the balance,  if any,  shall be distributed to the
         Partners in accordance  with the  Partners'  positive  Capital  Account
         balances  after such  capital  accounts  are  adjusted  as  provided by
         Article 13, and any other  adjustments  required by the Final  Treasury
         Regulations  under Section 704(b) of the Code. Any General Partner with
         a negative  Capital Account  following the  distribution of liquidation
         proceeds or the  liquidation  of its interest  must  contribute  to the
         Partnership  an amount  equal to such  negative  Capital  Account on or
         before the end of the Partnership's  taxable year (or, if later, within
         ninety days after the date of liquidation).  Any capital so contributed
         shall  be (i)  distributed  to those  Partners  with  positive  Capital
         Accounts until such Capital  Accounts are reduced to zero,  and/or (ii)
         used to discharge recourse liabilities.

                  26.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.

                  26.1 Proper and complete records and books of account shall be
kept by the General  Partner in which shall be entered fully and  accurately all
transactions  and such other matters relating to the  Partnership's  business as
are usually  entered  into  records and books of account  maintained  by persons
engaged  in  businesses  of a like  character.  The  books  and  records  of the
Partnership  shall be prepared  according to the accounting method determined to
be in  the  best  interest  of  the  Partnership  by the  General  Partner.  The
Partnership's  fiscal  year shall be the  calendar  year.  The books and records
shall at all times be maintained at the  Partnership's  Records Office and shall
be open to the reasonable  inspection  and  examination of the Partners or their
duly authorized representatives during reasonable business hours.

                  26.2 Within ninety (90) days after the end of each Year of the
Partnership,  the  General  Partner  shall send to each person who was a Limited
Partner at any time during such year such tax  information,  including,  without
limitation, Federal tax Schedule K-1, as shall be reasonably necessary

                                      -28-
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for the preparation by such person of his Federal income tax return. The General
Partner will also make available to the Limited  Partners any other  information
required by the Act.

                  26.3 The General  Partner shall maintain at the  Partnership's
Records  Office  copies of the  Partnership's  original  Certificate  of Limited
Partnership   and  any  certificate  of  amendment,   restated   certificate  or
certificate of cancellation with respect thereto and such other documents as the
Act shall require.  The General Partner will furnish to any Limited Partner upon
request a copy of the Partnership's  original Certificate of Limited Partnership
and any  certificate  of amendment,  restated  certificate,  or  certificate  of
cancellation, if any.

                  26.4 The General Partner shall, in its sole  discretion,  make
for the  Partnership  any and all  elections  for  federal,  state and local tax
purposes including, without limitation, any election, if permitted by applicable
law, to adjust the basis of the Partnership's  property pursuant to Code Section
754,  734(b) and  743(b),  or  comparable  provisions  of state or local law, in
connection  with  transfers  of  interests in the  Partnership  and  Partnership
Distributions.

                  26.5 The  General  Partner is  designated  as the Tax  Matters
Partner  (as  defined  in  Section  6231 of the Code) and to act in any  similar
capacity  under  state or local law,  and is  authorized  (at the  Partnership's
expense):   (i)  to  represent  the   Partnership  and  Partners  before  taxing
authorities  or courts of competent  jurisdiction  in tax matters  affecting the
Partnership  or  Partners  in their  capacity  as  Partners;  (ii) to extend the
statute of limitations for assessment of tax deficiencies  against Partners with
respect to adjustments to the Partnership's federal, state or local tax returns;
(iii) to execute any agreements or other documents relating to or affecting such
tax matters, including agreements or other documents that bind the Partners with
respect to such tax matters or  otherwise  affect the rights of the  Partnership
and Partners; and (iv) to expend Partnership funds for professional services and
costs  associated  therewith.  The General partner is authorized and required to
notify the federal,  state or local tax  authorities of the appointment of a Tax
Matters  Partner  in  the  manner  provided  in  Treasury   Regulations  Section
301.6231(a)(7)-IT, as modified from time to time. In its capacity as Tax Matters
Partner,  the General  Partner shall oversee the  Partnership tax affairs in the
manner which, in its best judgment, are in the interests of the Partners.

                  27.      NOTICES.

                  All notices under this Agreement shall be in writing and shall
be deemed to have been given when delivered  personally,  or mailed by certified
or registered mail, postage prepaid,  return receipt  requested.  Notices to the
General  Partner  shall be  delivered  at, or mailed to, its  principal  office.
Notices to the  Partnership  shall be delivered  at, or mailed to, its principal
office with a copy to each of its business offices.  Notice to a Limited Partner
shall be  delivered  to such  Limited  Partner,  or mailed  to the last  address
furnished  by him for such  purposes to the General  Partner.  Limited  Partners
shall give  notice of a change of address to the  General  Partner in the manner
provided in this Article.

                  28.      AMENDMENTS.

                  Subject to the  provisions  of Article 29, this  Agreement  is
subject to  amendment  only by  written  consent of the  General  Partner  and a
Majority in Interest of the Limited Partners; provided,

                                      -29-
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however,  the  consent of the  Limited  Partners  shall not be  required if such
amendments  are  ministerial  in nature and do not  contravene the provisions of
Article 29.

                  29.      LIMITATIONS ON AMENDMENTS.

                  Notwithstanding  the provisions of Article 28, no amendment to
this Agreement shall:

                  (a)  Enlarge  the   obligations  of  any  Partner  under  this
         Agreement  or convert the  interest in the  Partnership  of any Limited
         Partner  into the  interest of a general  partner or modify the limited
         liability of any Limited Partner, without the consent of such Partner;

                  (b) Amend the provisions of Articles 13, 14, 16 and 25 without
         the approval of the Partners  representing  two-thirds of the aggregate
         Percentage Interests in the Partnership;  provided,  however,  that the
         General Partner may at any time amend such Articles without the consent
         of the Limited Partners in order to permit the Partnership  allocations
         to be  sustained  for  Federal  income tax  purposes,  but only if such
         amendments  do  not   materially   affect   adversely  the  rights  and
         obligations of the Limited Partners,  in which case such amendments may
         only be made as provided in this Article 29(c); or

                  (c) Amend this Article 29 without the consent of all Partners.

                  30.      MEETINGS, CONSENTS AND VOTING.

                  30.1 A meeting of the  Partnership to consider any matter with
respect to which the  Partners  may vote as set forth in this  Agreement  may be
called  by the  General  Partner  or by  Limited  Partners  who hold  more  than
twenty-five  percent (25%) of the aggregate interests in the Partnership held by
all the Limited Partners.  Upon receipt of a notice requesting a meeting by such
Partner or Partners and stating the purpose of the meeting,  the General Partner
shall, within ten (10) days thereafter, give notice to the Partners of a meeting
of the  Partnership  to be held at a time and place  convenient  to the  Limited
Partners  on a date not  earlier  than  fifteen  (15) days after  receipt by the
General  Partner of the notice  requesting a meeting.  The notice of the meeting
shall set forth the time, date, location and purpose of the meeting.

                  30.2 Any consent of a Partner  required by this  Agreement may
be given as follows:

                  (a) By a written  consent given by the consenting  Partner and
         received by the General  Partner at or prior to the doing of the act or
         thing for which the consent is solicited, or

                  (b) By the affirmative  vote by the consenting  Partner to the
         doing of the act or thing for which the  consent  is  solicited  at any
         meeting  called  pursuant to this Article to consider the doing of such
         act or thing.


                                      -30-
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                  30.3 When exercising voting rights expressly granted under the
Articles of this  Agreement,  each Partner shall have that number of votes as is
equal to the  Percentage  Interest  of such  Partner  at the  time of the  vote,
multiplied by 100.

                  31.      SUBMISSIONS TO THE LIMITED PARTNERS.

                  The General Partner shall give the Limited  Partners notice of
any proposal or other matter  required by any provision of this  Agreement or by
law to be submitted for consideration and approval of the Limited Partners. Such
notice shall include any  information  required by the relevant  provision or by
law.

                  32.      ADDITIONAL DOCUMENTS.

                  Each  party  hereto  agrees to  execute  and  acknowledge  all
documents and writings which the General Partner may deem necessary or expedient
in the creation of this Partnership and the achievement of its purpose.

                  33.      SURVIVAL OF RIGHTS.

                  Except as herein  otherwise  provided  to the  contrary,  this
Agreement  shall be binding upon and inure to the benefit of the parties hereto,
their successor and assigns.

                  34.      INTERPRETATION AND GOVERNING LAW.

                  When the  context  in which  words are used in this  Agreement
indicates  that such is the intent,  words in the singular  number shall include
the plural and vise versa; in addition,  the masculine  gender shall include the
feminine and neuter  counterparts.  The Article headings or titles and the table
of  contents  shall not define,  limit,  extend or  interpret  the scope of this
Agreement  or any  particular  Article.  This  Agreement  shall be governed  and
construed  in  accordance  with the laws of the State of Hawaii  without  giving
effect to the conflicts of laws provisions thereof.

                  35.      SEVERABILITY.

                  If any provision,  sentence,  phrase or word of this Agreement
or the application  thereof to any person or circumstance shall be held invalid,
the remainder of this Agreement, or the application of such provision, sentence,
phrase, or word to persons or circumstances,  other than those as to which it is
held invalid, shall not be affected thereby.

                  36.      AGREEMENT IN COUNTERPARTS.

                  This Agreement may be executed in several  counterparts,  each
of which shall be deemed an original,  but all of which shall constitute one and
the same  instrument.  In  addition,  this  Agreement  may contain more than one
counterpart  of the  signature  page and this  Agreement  may be executed by the
affixing of the  signatures  of each of the Partners to one of such  counterpart
signature  pages;  all of such signature  pages shall be read as though one, and
they  shall have the same  force and  effect as though  all of the  signers  had
signed a single signature page.

                                                      -31-
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                  37.      THIRD PARTIES.

                  The agreements, covenants and representations contained herein
are for the benefit of the parties  hereto  inter se and are not for the benefit
of any  third  parties  including,  without  limitation,  any  creditors  of the
Partnership.

                  38.      POWER OF ATTORNEY.

                  Each Limited  Partner hereby makes,  constitutes  and appoints
Dr. William R. Jordan,  Dr.  Franklin S. Clark and Dr. Dan A. Myers,  severally,
with full power of substitution, his true and lawful attorneys-in-fact,  for him
and in his  name,  place  and  stead  and for his use and  benefit  to sign  and
acknowledge,  file and record,  any amendments hereto among the Partners for the
further purpose of executing and filing on behalf of each Limited  Partner,  any
and all  certificates  of limited  partnership or other  documents  necessary to
constitute the Partnership or to effect the continuation of the Partnership, the
admission  or  withdrawal  of a  general  partner  or  a  limited  partner,  the
qualification of the Partnership in a foreign jurisdiction (or amendment to such
qualification),  the admission of substitute Limited Partners or the dissolution
or  termination  of the  Partnership,  provided  such  continuation,  admission,
withdrawal, qualification, or dissolution and termination are in accordance with
the terms of this Agreement.

                  The foregoing power of attorney is a special power of attorney
coupled with an interest,  is  irrevocable  and shall survive the death or legal
incapacity  of each  Limited  Partner.  It may be  exercised  by any one of said
attorneys by listing all of the Limited  Partners  executing any instrument over
the  signature  of the  attorney-in-fact  acting  for all of them.  The power of
attorney shall survive the delivery of an assignment by a Limited Partner of the
whole or any portion of his Unit.  In those cases in which the  assignee  of, or
the  successor  to, a Limited  Partner  owning a Unit has been  approved  by the
Partners for admission to the Partnership as a substitute  Limited Partner,  the
power of attorney  shall  survive for the sole  purpose of enabling  the General
Partner to execute, acknowledge and file any instrument necessary to effect such
substitution.

                  This power of attorney shall not be affected by the subsequent
incapacity or mental incompetence of any Limited Partner.

                  39.      ARBITRATION.

                  Any  dispute  arising  out  of  or  in  connection  with  this
Agreement or the breach  thereof  shall be decided by  arbitration  in Honolulu,
Hawaii in accordance with the then effective commercial arbitration rules of the
American  Arbitration  Association,  and judgment  thereof may be entered in any
court having jurisdiction thereof.

                  40.      CREDITORS.

                  None of the  provisions  of this  Agreement  shall  be for the
benefit of or enforceable by any creditors of the Partnership.


                                      -32-
C#0124195.02

<PAGE>



                  IN WITNESS  WHEREOF,  the parties have executed this Agreement
of Limited Partnership as of the day and year first above written.

                               GENERAL PARTNER:

                               LITHOTRIPTERS, INC., a North Carolina corporation


                               By:      /s/ Joseph Jenkins
                                        -----------------------------
                                        Joseph Jenkins, M.D.,
                                        President
ATTEST:
Anthony Rand
- --------------------------
Secretary

[CORPORATE SEAL]

                            INITIAL LIMITED PARTNER:

                                        William R. Jordan
                                        ---------------------------------------
                                        William R. Jordan, M.D.




                                      -33-
C#0124195.02

<PAGE>



STATE OF NORTH CAROLINA )
                                         )
COUNTY OF CUMBERLAND    )


     On this 1st day of April, 1996, before me, the undersigned Notary Public in
and for the County of Cumberland in the State of North Carolina, personally came
Joseph Jenkins,  M.D., who, being by me duly sworn, said that he is President of
Lithotripters, Inc., the General Partner of Pacific Medical Limited Partnership,
that the seal affixed to the  foregoing  instrument  in writing is the corporate
seal of the corporation,  and that said writing was signed, sworn to, and sealed
by him in behalf of said  corporation by its authority duly given.  And the said
Joseph Jenkins,  M.D. further certified that the facts set forth in said writing
are true and correct, and acknowledged said instrument to be the act and deed of
said corporation.

                  WITNESS my hand and notarial seal.

                                    /s/ Ricarda Kelly
                                    -------------------------------------------

                                             Notary Public

My commission expires:

1-8-97
- ---------------------------


STATE OF NORTH CAROLINA )
                                         )
COUNTY OF CUMBERLAND   )


     I,  Ricarda  Kelly,  a notary  public,  do hereby  certify  that William R.
Jordan,  M.D.,  personally  appeared  before me this 1st day of April,  1996 and
acknowledged and swore to the due execution of the foregoing Limited Partnership
Agreement in his capacity as the initial limited partner.


                                    /s/ Ricarda Kelly
                                    -------------------------------------------

                                              Notary Public

My commission expires:

1-8-97
- ---------------------------


                                      -34-
C#0124195.02

<PAGE>



                           COUNTERPART SIGNATURE PAGE


                  By signing this  Counterpart  Signature  Page, the undersigned
acknowledges  his or  her  acceptance  of  that  certain  Agreement  of  Limited
Partnership of Pacific Medical Limited Partnership,  and his or her intention to
be legally bound thereby.

                  Dated this 1st day of April, 1996.

                                   /s/ Philip J. Gallina
                                  ---------------------------------------------

                                       Signature

                                   Lithotripters, Inc
                                   by Philip J. Gallina, VP and Treasurer
                                  --------------------------------------------

                                              Printed Name




STATE OF NORTH CAROLINA        )
                                
COUNTY OF CUMBERLAND )


                  BEFORE ME, the undersigned  Notary Public in and for the State
and County set forth  above,  on the  1ST day of  APRIL,  1996,
personally  appeared  ___________________,  and,  being by me first duly  sworn,
stated that (s)he  signed this  Counterpart  Signature  Page for the purpose set
forth above and that the statements contained therein are true.
                                   /s/ Ricarda Kelly
                                   -------------------------------------------

                                            Signature of Notary Public

                                   Ricarda Kelly
                                   -------------------------------------------

                                              Printed Name of Notary

My Commission Expires:
1-8-97
- ---------------------------

[SEAL]

                                      -35-
C#0124195.02

<PAGE>



                                                                    SCHEDULE A


                        Schedule of Partnership Interests

                       PACIFIC MEDICAL LIMITED PARTNERSHIP

           CONTRIBUTIONS OF CAPITAL TO THE PARTNERSHIP AND GUARANTIES


                           Cash              Percentage
General Partner         Contribution          Interest

Lithotripters, Inc.      $47,688                  20%

Limited Partners
- -----------------
Lithotripters, Inc.      $47,250                  21
Antonio Tan               10,000                   4
Robert Carlile            10,000                   4
Herbert Chinn             10,000                   4
Rick Davis                10,000                   4
Terry Yee                  5,000                   2
William Flanagan           2,250                   1
Keith Mooney               2,500                   1
Franklin Clark             2,250                   1 
Thomas Jordan              2,250                   1
William Jordan             2,250                   1
Philip Gallina             2,250                   1
William Grine              2,250                   1
Jack Cassell               2,500                   1
Marilyn Hata              10,000                   4
David Kychenbecker        10,000                   4
Douglas Gary Lattimer     10,000                   4
William Yarbrough         10,000                   4
Dan Myers                  2,250                   1
Jim Brady                  2,250                   1
Tom Mobley                 2,250                   1
Timothy Quillen            2,250                   1
James Monroe               2,250                   1
J. Ronald Smith            2,250                   1
David M Coussens           2,500                   1
Denis E. Healey            2,500                   1
Lewis F. Russell           2,500                   1
Alan Terry                 2,250                   1
Anthony Rand               2,250                   1
Joseph Jenkins             2,250                   1
Rena Sepulveda             2,500                   1
Robert McAlpine            2,250                   1
Lance Templeton            2,500                   1
Lelan C. Byrd              2,500                   1
Donald A. Steward          2,500                   1

                        ---------               ----

            TOTAL:      $238,438                100%
                        =========               ====





<PAGE>



                        AGREEMENT OF LIMITED PARTNERSHIP

                                       OF

                 CALIFORNIA I PROSTATHERAPY LIMITED PARTNERSHIP

<PAGE>

                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                 CALIFORNIA I PROSTATHERAPY LIMITED PARTNERSHIP

                                TABLE OF CONTENTS

         Article Heading                                                 Page

         1.       FORMATION.................................................1

         2.       NAME......................................................1

         3.       OFFICES...................................................1

         4.       PURPOSE...................................................1

         5.       TERM......................................................2

         6.       CERTAIN DEFINED TERMS.....................................2

         7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS..............5

         8.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE LIMITED
                       PARTNERS.............................................6

         9.       REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                      GENERAL PARTNER.......................................6

         10.      ADMISSION OF LIMITED PARTNERS.............................7

         11.      CAPITAL ACCOUNTS..........................................7

         12.      ALLOCATIONS...............................................8

         13.      DISTRIBUTIONS.............................................9

         14.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS...............10

         15.      LIMITED LIABILITY........................................10

         16.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS..........10

         17.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON
                    CERTAIN EVENTS.........................................14




<PAGE>



         18.      SALE, ASSIGNMENT OR OTHER TRANSFER OF THE GENERAL

                    PARTNER'S INTEREST.....................................18

         19.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER.......19

         20.      MANAGEMENT AND OPERATION OF BUSINESS.....................19

         21.      RESERVES.................................................21

         22.      INDEMNIFICATION AND EXCULPATION OF THE GENERAL
                    PARTNER................................................21

         23.      DISSOLUTION OF THE PARTNERSHIP...........................22

         24.      DISTRIBUTION UPON DISSOLUTION............................23

         25.      BOOKS OF ACCOUNT, RECORDS AND REPORTS....................23

         26.      NOTICES..................................................24

         27.      AMENDMENTS...............................................25

         28.      LIMITATIONS ON AMENDMENTS................................25

         29.      MEETINGS, CONSENTS AND VOTING............................25

         30.      SUBMISSIONS TO THE LIMITED PARTNERS......................26

         31.      ADDITIONAL DOCUMENTS.....................................26

         32.      SURVIVAL OF RIGHTS.......................................26

         33.      INTERPRETATION AND GOVERNING LAW.........................26

         34.      SEVERABILITY.............................................26

         35.      AGREEMENT IN COUNTERPARTS................................26

         36.      THIRD PARTIES............................................27

         37.      POWER OF ATTORNEY........................................27

         38.      ARBITRATION..............................................27

         39.      CREDITORS................................................27

                  Schedule A...............  Schedule of Partnership Interests



<PAGE>



THE  LIMITED  PARTNERSHIP  INTERESTS  REPRESENTED  BY THIS  LIMITED  PARTNERSHIP
AGREEMENT HAVE NOT BEEN REGISTERED  WITH THE SECURITIES AND EXCHANGE  COMMISSION
UNDER THE  SECURITIES  ACT OF 1933,  AS  AMENDED,  QUALIFIED  UNDER THE  GENERAL
STATUTES OF CALIFORNIA, OR REGISTERED UNDER SIMILAR LAWS OR ACTS OF OTHER STATES
IN RELIANCE UPON EXEMPTIONS UNDER SUCH LAWS.


                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                          OF CALIFORNIA I PROSTATHERAPY
                               LIMITED PARTNERSHIP


                  THIS AGREEMENT OF LIMITED  PARTNERSHIP  (the  "Agreement")  is
made  as of  June 12th,  1997,  by and  among  PROSTATHERAPIES,  INC.,  a
Delaware corporation (the "General Partner"), and the persons listed on Schedule
A attached hereto as the Limited Partners.

                  1.       FORMATION.

                  The  Partnership was formed pursuant to a filing in the Office
of the  Secretary of State of  California  on March 12, 1997, a  Certificate  of
Limited Partnership in accordance with the provisions of the Act.

                  2.       NAME.

                  2.1      The name of the Partnership is "California I 
Prostatherapy Limited Partnership."

                  2.2 The  Partnership  business  shall be conducted  under such
names as the General  Partner may from time to time deem necessary or advisable,
provided that appropriate amendments to this Agreement and all necessary filings
under  applicable  assumed  or  fictitious  name  statutes  or the Act are first
obtained.

                  3.       OFFICES.

                  3.1 The principal  office of the Partnership  shall be at 2008
Litho Place,  Fayetteville,  North Carolina 28304, or at such other place as the
General  Partner  may,  from time to time,  designate  by notice to the  Limited
Partners (the "Records Office").

                  3.2 The Partnership  may have such  additional  offices as the
General Partner may, from time to time, deem necessary or advisable.

                  4.       PURPOSE.

                  The purpose and business of the  Partnership  shall be: (i) to
operate one or more Prostatron(R)  microwave thermotherapy devices (or any other
BPH treatment equipment) for the transurethral  treatment of the symptoms of BPH
primarily in Central and Southern California, or in such

                                       -1-


<PAGE>



other location(s) as the General Partner may determine,  in its sole discretion,
to be in the best interests of the  Partnership,  (ii) to acquire and operate in
the future any other urological  device or equipment that as of the date of this
Agreement  either  has not  been  invented  or has not  received  FDA  premarket
approval, as long as such device has such approval at the time it is acquired by
the Partnership; (iii) to acquire an interest in any business entity, including,
without  limitation,  a  limited  partnership,   limited  liability  company  or
corporation,  that engages in any business activity described in this Article 4;
and (iv) to  engage  in any and all  activities  incidental  or  related  to the
foregoing, upon and subject to the terms and conditions of this Agreement.

                  5.       TERM.

                  The  Partnership  shall  terminate on January 1, 2047,  unless
sooner terminated as herein provided.

                  6.       CERTAIN DEFINED TERMS.

                  Certain terms used in this Agreement  shall have the following
meanings:

                  Act.  The Act means the California Revised Limited Partnership
Act, as then in effect.

                  Affiliate.  An  Affiliate  is  (i)  any  person,  partnership,
corporation, association or other legal entity ("person") directly or indirectly
controlling, controlled by or under common control with another person; (ii) any
person owning or controlling 10% or more of the  outstanding  voting interest of
such other person;  (iii) any officer,  director or partner of such person;  and
(iv) if such other  person is an officer,  director  or partner,  any entity for
which such person acts in such capacity.

                  Agreement.  This Agreement of Limited Partnership, as the same
may be amended from time to time.

                  BPH.  Benign Prostatic Hyperplasia, common enlargement of the 
prostate.

                  Capital Account.  The Partnership capital account of a Partner
as computed pursuant to Article 11 of this Agreement.

                  Capital  Contributions.  All capital  contributions  made by a
Partner or his predecessor in interest which shall include,  without limitation,
contributions made pursuant to Article 7 of this Agreement.

                  Capital Transaction.  Any transaction which, were it to 
generate proceeds, would produce Partnership Sales Proceeds or Partnership 
Refinancing Proceeds.

                  Code.  The Internal Revenue Code of 1986, as amended, or 
corresponding provisions of subsequent, superseding revenue laws.

                  Dilution  Offering.   As  provided  in  Section  7.4  of  this
Agreement,  the future offering of additional limited  partnership  interests in
the Partnership by the General Partner.  Any successful  Dilution  Offering will
proportionately  reduce the  Percentage  Interests of the then  current  Limited
Partners in the Partnership.

                                       -2-


<PAGE>



                  Domestic Proceeding.  Any divorce, annulment, separation or 
similar domestic proceeding between a married couple.

                  Equipment.  The  initial  equipment  to  be  acquired  by  the
Partnership for the operation of the  Prostatron(R)  Mobile System.  The initial
equipment to be used in the  operation of the  Prostatron(R)  Mobile System will
include the Trailer,  a tractor truck, the  Prostatron(R),  an ultrasound system
and miscellaneous medical equipment and supplies.

                  FDA.  The United States Food and Drug Administration.

                  General Partner.  The General Partner of the Partnership, 
Prostatherapies, Inc., a Delaware corporation.

                  Initial  Limited  Partner.  Dan A. Myers,  M.D., a resident of
North Carolina. The Initial Limited Partner is to be the only limited partner of
the Partnership  until such time as the new Limited Partners are admitted to the
Partnership,  at which time the Initial  Limited Partner shall withdraw from the
Partnership.

                  Limited Partners.  The Limited Partners are those investors in
the Units  admitted  to the  Partnership  and any person  admitted  as a Limited
Partner in accordance with the provisions of this Agreement.

                  Losses.  The net loss (including Net Losses from Capital 
Transactions) of the Partnership for each Year of the Partnership as determined
for federal income tax purposes.

                  Majority  in Interest  of the  Limited  Partners.  The Limited
Partners who hold more than 50% of the Limited Partner  Percentage  Interests in
the Partnership.

                  Net Gains from Capital Transactions. The gains realized by the
Partnership  as a result of or upon any sale,  exchange,  condemnation  or other
disposition of the capital assets of the Partnership (which assets shall include
Code Section 1231 assets) or as a result of or upon the damage or destruction of
such capital assets.

                  Net Losses from Capital  Transactions.  The losses realized by
the Partnership as a result of or upon any sale, exchange, condemnation or other
disposition of the capital assets of the  Partnership  (which shall include Code
Section 1231 assets) or as a result of or upon the damage or destruction of such
capital assets.

                  Partners.  The General Partner and the Limited Partners, 
collectively, where no distinction is required by the context in which the term 
is used herein.

                  Partnership.  California I Prostatherapy Limited Partnership, 
a California limited partnership.

                  Partnership  Cash Flow. For the applicable  period the excess,
if any,  of (A) the sum of (i) all  gross  receipts  from  any  source  for such
period,  other than from  Partnership  loans,  Capital  Transactions and Capital
Contributions, and (ii) any funds released by the Partnership from previously

                                       -3-
<PAGE>



established  reserves,  over  (B) the sum of (i) all cash  expenses  paid by the
Partnership  for such  period;  (ii) the amount of all  payments of principal on
loans to the Partnership;  (iii) capital  expenditures of the  Partnership;  and
(iv) such  reasonable  reserves as the General  Partner shall deem  necessary or
prudent to set aside for future repairs,  improvements or equipment  replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities and contingencies of the Partnership; provided, however, that
the  amounts  referred  to in (B)(i),  (ii) and (iii)  above shall be taken into
account  only to the extent not funded by Capital  Contributions,  loans or paid
out of previously  established reserves.  Such term shall also include all other
funds deemed  available for  distribution  and designated as  "Partnership  Cash
Flow" by the General Partner.

                  Partnership Interest.  The interest of a Partner in the 
Partnership as defined by the Act and this Agreement.

                  Partnership  Refinancing Proceeds.  The cash realized from the
refinancing of Partnership assets after retirement of any secured loans and less
(i) payment of all expenses  relating to the transaction and (ii)  establishment
of such  reasonable  reserves as the General  Partner  shall deem  necessary  or
prudent to set aside for future repairs,  improvements, or equipment replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities or contingencies of the Partnership.

                  Partnership  Sales Proceeds.  The cash realized from the sale,
exchange,  casualty  or other  disposition  of all or a portion  of  Partnership
assets after the retirement of all secured loans and less (i) the payment of all
expenses  related to the transaction and (ii)  establishment  of such reasonable
reserves as the General Partner shall deem necessary or prudent to set aside for
future repairs,  improvements, or equipment replacement or additions, or to meet
working  capital  requirements or foreseen or unforeseen  future  liabilities or
contingencies of the Partnership.

                  Percentage  Interest.  The  interest  of each  Partner  in the
Partnership,  to be  determined  initially  in the case of a Limited  Partner by
reference  to his Unit  ownership  based upon the  Limited  Partners  holding an
aggregate 80%  Percentage  Interest in the  Partnership,  with each initial Unit
sold representing an initial 0.25% interest.  The General Partner initially will
own a 20%  Percentage  Interest  in  the  Partnership.  A  Partner's  Percentage
Interest may be reduced by a future Dilution Offering.  The Partners' Percentage
Interests in the  Partnership as of the date hereof are as set forth in Schedule
A attached hereto. Any future adjustments in the Partners' Percentage Interests,
due to future Dilution Offerings or otherwise, will be reflected by revisions to
Schedule A.

                  Profit.  The net income of the Partnership (including Net 
Gains from Capital  Transactions) for each Year of the Partnership as determined
for federal income tax purposes.

                  Pro  Rata  Basis.   In   connection   with  an  allocation  or
distribution,  an allocation  or  distribution  in proportion to the  respective
Percentage Interests of the class of Partners to which reference is made.

                  Prostatron(R).   The  Prostatron(R)   microwave  thermotherapy
device  manufactured by EDAP Technomed and to be utilized by the Partnership for
the treatment of the symptoms of BPH.

                  Prostatron(R) Mobile System.  The Trailer with the installed 
and operational Prostatron(R) and ultrasound system, and tractor truck.

                                       -4-


<PAGE>



                  Sales Agency  Agreement.  The sales agency  agreement  through
which  MedTech  Investments,  Inc.,  an Affiliate  of the General  Partner and a
broker-dealer company registered with the Securities and Exchange commission and
a member of the National Association of Securities Dealers, Inc. shall offer and
sell  the  limited  partnership  interest  of the  Partnership  pursuant  to the
Summary.

                  Sales Commission.  The $112.50 sales commission paid to 
MedTech Investments, Inc. for each Unit sold.

                  Service.  The Internal Revenue Service.

                  Summary.  The Confidential Summary of the Offering of the 
Partnership dated March 24, 1997, as amended or as supplemented.

                  Trailer.  The new mobile trailer manufactured and upfitted by 
AK Associates, Inc. to house the Prostatron(R).

                  Units.  The 320 equal limited partner interests in the 
Partnership offered pursuant to the Summary for a price per Unit of $2,600 in 
cash.

                  Year.  An annual accounting period ending on December 31 of 
each year during the term of the Partnership.

                  7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS.

                  7.1  General  Partner  Contribution.  On or before the date of
this  Agreement,  the  General  Partner  will  contribute  to the capital of the
Partnership  cash in an amount  equal to 20% (up to  $208,000) of the total cash
contributed to the  Partnership by the Partners in the offering made pursuant to
the Summary.

                  7.2 Limited Partner Contribution.  Each Limited Partner hereby
agrees to contribute and shall  contribute to the capital of the  Partnership on
the date of his admission to the  Partnership the cash amount set forth opposite
his name on Schedule A attached hereto.

                  7.3      No Interest.  Except as otherwise provided herein, no
interest shall be paid on any contribution to the capital of the Partnership.

                  7.4 Dilution  Offerings.  If the General Partner,  in its sole
discretion,  determines that it is in the best interest of the Partnership,  the
General Partner may, from time to time, issue, offer and sell additional limited
partnership  interests  in the  Partnership  (a  "Dilution  Offering")  to local
urologists who are not already Limited  Partners  ("Qualified  Investors").  The
primary  purpose  of any  Dilution  Offering  would be (i) to  raise  additional
capital for any  legitimate  Partnership  purpose as set forth in Article 4, and
(ii) to assure  the  highest  quality  of patient  care by  admitting  Qualified
Investors to the  Partnership  who would be dedicated and motivated as owners to
follow  the  Partnership's  treatment  protocol,  and  comply  with its  quality
assurance  and outcome  analysis  programs.  Any limited  partnership  interests
offered by the  Partnership  in a Dilution  Offering shall be sold in the manner
and  according to the terms  prescribed  in the sole  discretion  of the General
Partner;  provided,  however,  that any additional limited partnership interests
offered  in a  Dilution  Offering  will be sold for a price  no  lower  than the
highest price for which

                                       -5-


<PAGE>



proportionate  limited  partnership  interests  in  the  Partnership  have  been
previously sold by the Partnership.  Any sale of additional limited  partnership
interests  will  result  in  the  proportionate   dilution  of  the  Partnership
Percentage Interests of the existing Partners. Notwithstanding the above, in the
event of a Dilution  Offering,  the General  Partner  and/or its  Affiliates may
elect, in their sole discretion, to prevent dilution of the Percentage Interests
of  the  General  Partner  and/or  its  Affiliates  by  either   contributing  a
proportionate  amount of  additional  capital to the  Partnership  or purchasing
additional  limited  partnership  interests  in any Dilution  Offering.  Limited
Partners will have no right to purchase additional limited partnership interests
in any Dilution Offering.  Any investor acquiring a limited partnership interest
in a Dilution  Offering shall agree to be bound by the terms of this  Agreement,
and shall be automatically admitted as a Limited Partner of the Partnership. Any
adjustment  in the  Partners'  Percentage  Interests  resulting  from a Dilution
Offering shall be set forth on Schedule A attached hereto.

                  8.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE
                           LIMITED PARTNERS.

                  The  obligations of the Limited  Partners to make cash Capital
Contributions  hereunder are subject to the condition that the  representations,
warranties, agreements and covenants of the General Partner set forth in Article
9 of this Agreement are and shall be true and correct or have been and will have
been  complied  with  in  all  material   respects  on  the  date  such  Capital
Contributions  are  required  to be made,  except  to the  extent  that any such
representation or warranty expressly pertains to an earlier date.

                  9.       REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                           GENERAL PARTNER.

                  9.1 The General Partner hereby  represents and warrants to the
Limited Partners that:

                  (a)  The  Partnership  is  a  limited  partnership  formed  in
         accordance  with  and  validly  existing  under  the Act and the  other
         applicable laws of the State of California;

                  (b) The interests in the  Partnership of the Limited  Partners
         will have been duly  authorized  or created and validly  issued and the
         Limited  Partners shall have no personal  liability to contribute money
         to the  Partnership  other than the amounts agreed to be contributed by
         them in the  manner  and on the  terms  set  forth  in this  Agreement,
         subject, however, to such limitations as may be imposed under the Act;

                  (c) No material  breach or default  adverse to the Partnership
         exists under the terms of any other  material  agreement  affecting the
         Partnership; and

                  (d) The General Partner is a Delaware  corporation  formed and
         existing under the laws of the State of Delaware.

                  9.2  The  General  Partner  hereby  covenants  to the  Limited
Partners that:

                  (a)      It will at all times act in a fiduciary manner with 
         respect to the Partnership and the Limited Partners;


                                       -6-


<PAGE>



                  (b) Except as  provided  in  Article  18, it will serve as the
         General Partner of the Partnership  until the Partnership is terminated
         without reconstitution; and

                  (c) It will cause the  Partnership  to carry  adequate  public
         liability,  property  damage and other insurance as is customary in the
         business to be engaged in by the Partnership.

                  10.      ADMISSION OF LIMITED PARTNERS.

                  The  General  Partner may permit the offer and sale of limited
partnership  interests  on the terms and  conditions  provided in the Summary or
future  Dilution  Offering and may admit  persons  subscribing  for interests as
Limited  Partners in the  Partnership  on the terms and  conditions set forth in
this Article 10.

                  (a) The General  Partner  shall have approved of the admission
         of said person in writing on such terms and  conditions  as the General
         Partner shall determine;

                  (b)  Said  person  shall  have  executed  such   documents  or
         instruments  as the General  Partner may deem necessary or desirable to
         effect his admission as a Limited Partner;

                  (c) Said  person  shall have  accepted  and adopted all of the
         terms and provisions of this Agreement, as then amended;

                  (d)  Said  person  (if a  corporation)  shall  deliver  to the
         General  Partner  a  certified  copy of a  resolution  of its  Board of
         Directors  authorizing  it to become a Limited  Partner under the terms
         and conditions of this Agreement; and

                  (e) Said person,  upon request by the General  Partner,  shall
         pay such reasonable  expenses as may be incurred in connection with its
         admission as a Limited Partner.

                  11.      CAPITAL ACCOUNTS.

                  A capital  account shall be  established  for each Partner and
shall at all  times be  determined  and  maintained  as  provided  by the  Final
Treasury  Regulations  under  Section  704(b)  of the  Code,  as the same may be
amended.  A Partner  shall not be entitled  to withdraw  any part of his capital
account or to receive any distribution from the Partnership,  except as provided
in Articles 13 and 24.

                  (a)      Each Partners' capital account shall be increased by:

                           (i)  The amount of his Capital Contribution pursuant 
                  to Article 7; and

                           (ii) The amount of Profits allocated to him pursuant 
                  to Article 12; and


                                       -7-


<PAGE>



                           (iii) The Partner's pro rata share (determined in the
                  same  manner as such  Partner's  share of  Profits  and Losses
                  allocated pursuant to Article 12 hereof) of any income or gain
                  exempt from tax.

                  (b) Each Partner's capital account shall be decreased by:

                           (i)      The amount of Losses allocated to him 
                  pursuant to Article 12; and

                           (ii) The amount of Partnership Cash Flow, Partnership
                  Sales   Proceeds   and   Partnership    Refinancing   Proceeds
                  distributed to him pursuant to Article 13; and

                           (iii)  The  Partner's  pro rata  share  of any  other
                  expenditures  of the  Partnership  which are not deductible in
                  computing  Partnership  Profits  or  Losses  and which are not
                  added to the tax basis of any Partnership property, including,
                  without   limitation,   expenditures   described   in  Section
                  705(a)(2)(B) of the Code. The Partner's pro rata share of such
                  expenditures  shall be  determined  in the same manner as such
                  Partner's  share of Profits and Losses  allocated  pursuant to
                  Article 12.

                  12.      ALLOCATIONS

                  (a)  Profits  and  Losses.  The  Profits  and  Losses  of  the
         Partnership  shall be allocated  among the Partners in accordance  with
         their  respective  Percentage  Interests.  In  allocating  Profits  and
         Losses,  Net Gains and  Losses  from  Capital  Transactions  (a part of
         Profits and Losses), if any, shall be allocated first.

                  (b)  Qualified  Income  Offset.  If any  Partner  unexpectedly
         receives  any  adjustment,  allocation  or  distribution  described  in
         Treasury Regulations Section 1.704- 1(b)(2)(ii)(d)(4) through (6) which
         causes or increases a deficit balance in such Partner's Capital Account
         (adjusted  for  this  purpose  in  the  manner   provided  in  Treasury
         Regulations Section 1.704-1(b)(2)(ii)(d)),  items of Partnership income
         and gain shall be specially allocated to each such Partner in an amount
         and manner  sufficient  to  eliminate,  to the extent  required  by the
         Regulations,  the deficit Capital Account of such Partner as quickly as
         possible,   provided  that  an  allocation  pursuant  to  this  Article
         12(d)(iii)  shall be made if and only to the extent  that such  Partner
         would  have a deficit  Capital  Account  after  all  other  allocations
         provided for in this  Article  12(d) have been  tentatively  made as if
         this Article  12(d)(iii)  were not in the Agreement.  This provision is
         intended  to be a  "qualified  income  offset,"  as defined in Treasury
         Regulations   Section   1.704-1(b)(2)(ii)(d),   such  Regulation  being
         specifically incorporated herein by reference.

                  (c) Sales Commission.  The Sales Commission shall be allocated
         to the  Units  which  are  not  held  by the  General  Partner  and its
         Affiliates  in  proportion to their  respective  capital  contributions
         represented by such Units (i.e.,  $112.50 in Sales Commissions per each
         such Unit).  The purpose of Article  12(d)(iv) is to allocate the Sales
         Commission to those Partners who actually bore the burden of paying the
         Sales Commission.

                                       -8-


<PAGE>




                  (d)  Allocations  Between  Transferor and  Transferee.  In the
         event of the transfer (other than the pledges of the General  Partner's
         interest  permitted  by Article 18 or  Permitted  Pledges  described in
         Article  16.2(b))  of all or  any  part  of a  Partner's  interest  (in
         accordance with the provisions of this Agreement) in the Partnership at
         any time other  than at the end of a Year,  or the  admission  of a new
         Partner  (in  accordance  with  the  terms  of  this  Agreement),   the
         transferring  Partner  or new  Partner's  share  of  the  Partnership's
         income,  gain,  loss,  deductions  and  credits,  as computed  both for
         accounting  purposes  and for  Federal  income tax  purposes,  shall be
         allocated between the transferor Partner and the transferee Partner (or
         Partners),  or the new Partner and the other Partners,  as the case may
         be, in the same  ratio as the  number of days in such Year  before  and
         after the date of the transfer or admission; provided, however, that if
         there  has  been a sale  or  other  disposition  of the  assets  of the
         Partnership  (or any part thereof)  during such Year,  then the General
         Partner may elect, in its sole discretion,  to treat the periods before
         and after the date of the transfer or  admission as separate  Years and
         allocate the Partnership's net income,  gain, net loss,  deductions and
         credits for each of such deemed  separate  Years.  Notwithstanding  the
         foregoing, the Partnership's "allocable cash basis items," as that term
         is used in Section  706(d)(2)(B)  of the Code,  shall be  allocated  as
         required  by  Section   706(d)(2)  of  the  Code  and  the  regulations
         thereunder.

                  (e) Tax  Withholding.  The Partnership  shall be authorized to
         pay, on behalf of any  Partner,  any amounts to any  federal,  state or
         local taxing  authority,  as may be necessary  for the  Partnership  to
         comply with tax withholding  provisions of the Code or the other income
         tax or  revenue  laws  of any  taxing  authority.  To  the  extent  the
         Partnership  pays any such  amounts  that it may be  required to pay on
         behalf  of  a  Partner,  such  amounts  shall  be  treated  as  a  cash
         Distribution  to such  Partner  and shall  reduce the amount  otherwise
         distributable to such Partner.

                  13.      DISTRIBUTIONS.

                  (a)  Distribution of Partnership  Cash Flow.  Partnership Cash
         Flow shall be distributed to the Partners  within 60 days after the end
         of each Year, or earlier in the discretion of the General  Partner,  in
         proportion  to their  respective  Percentage  Interests  at the time of
         distribution.

                  (b)  Distribution  of  Partnership  Refinancing  Proceeds  and
         Partnership  Sales  Proceeds.   Partnership  Refinancing  Proceeds  and
         Partnership  Sales Proceeds shall be distributed to the Partners within
         60 days of the Capital  Transaction  giving rise to such  proceeds,  or
         earlier in the  discretion  of the General  Partner,  in  proportion to
         their respective Percentage Interests at the time of distribution.

                  (c)  Distribution  in  Liquidation.  Upon  liquidation  of the
         Partnership,  all of the  Partnership's  property  shall  be  sold  and
         Profits and Losses allocated accordingly. Proceeds from the liquidation
         of the Partnership shall be distributed in accordance with Article 24.


                                       -9-


<PAGE>



                  14.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS.

                  14.1  Management.  The Limited Partners shall not take part in
the management of the business,  nor transact any business for the  Partnership,
nor  shall  they  have  power  to  sign  for or to  bind  the  Partnership.  The
Partnership may,  however,  contract with one or more Limited Partners to act as
the local Medical Director and Quality Assessment Director for the Prostatron(R)
Mobile System.  No Limited Partner may withdraw from the  Partnership  except as
expressly permitted herein.

                  14.2 Operation of  Prostatron(R)  Mobile  System.  The Limited
Partners shall not operate or utilize the  Prostatron(R)  Mobile System or other
Partnership  equipment except pursuant to (i) an Agreement with the Partnership;
or (ii) any other arrangement specifically approved by the General Partner.

                  14.3 Outside  Activities.  A Limited  Partner  (that is not an
Affiliate of the General Partner) shall not directly or indirectly own, lease or
sublease  a  Prostatron(R)  (or  similar  equipment  used  for  treating  benign
prostatic   hyperplasia)  or  any  other  therapeutic  device  acquired  by  the
Partnership.  Prohibited  indirect ownership of a competing device shall include
the ownership of any interest in a business  venture  (through stock  ownership,
partnership  interest  ownership,   or  as  otherwise  determined  in  the  sole
discretion of the General  Partner)  involving  the  ownership,  purchase,  use,
lease,  sublease or operation of a Prostatron(R)  (or similar equipment used for
treating BPH) or other competing device or equipment, unless the General Partner
determines  that such activity by the Limited  Partner is not detrimental to the
best interest of the Partnership. In the event of breach of this Article 14.3 as
determined  by the General  Partner,  the  Partnership  shall be entitled to any
remedy  at law or  equity  with  respect  to  such  breach,  including,  without
limitation,  an injunction or suit for damages. In addition, the General Partner
shall also be entitled to enforce the purchase  rights  provided in Article 17.3
without effecting its other remedies as provided above.

                  15.      LIMITED LIABILITY.

                  No Limited Partner shall be required to make any  contribution
to the  capital of the  Partnership  except as set forth in Article 7, nor shall
any Limited  Partner in his capacity as such, be bound by, or personally  liable
for,  any expense,  liability or  obligation  of the  Partnership  except to the
extent of his or her (i) interest in the  Partnership;  and (ii)  obligation  to
return distributions made to him or her under certain  circumstances as required
by the Act.

                  16.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS.

                  16.1     Transferability.

                  (a) The  term  "transfer"  when  used in this  Agreement  with
         respect to a Partnership  Interest includes a sale,  assignment,  gift,
         pledge,  exchange,  or any other  disposition (but does not include the
         issuance of new Partnership Interests pursuant to a Dilution Offering);

                  (b) Except as otherwise  provided herein,  the General Partner
         shall not at any time  transfer or assign its interest or obligation as
         General Partner;


                                      -10-


<PAGE>



                  (c) The Partnership  Interest of any Limited Partner shall not
         be  transferred,  in whole or in part,  except in  accordance  with the
         conditions and limitations set forth in Articles 16.2 or 17;

                  (d) The  transferee of a Partnership  Interest by  assignment,
         operation of law or otherwise,  shall have only the rights,  powers and
         privileges  enumerated in Article 16.3 or otherwise provided by law and
         may not be admitted to the  Partnership as a Limited  Partner except as
         provided in Article 16.4 or as a General  Partner except as provided in
         Article 16.5;

                  (e) Notwithstanding any provision herein to the contrary,  the
         Partnership  Agreement  shall  in  no  way  restrict  the  issuance  or
         transfers of stock of the General Partner; and

                  (f) Notwithstanding any provision herein to the contrary,  the
         issuance of Partnership  Interests  pursuant to a Dilution Offering and
         the admission of new Limited Partners  pursuant to a Dilution  Offering
         shall be governed by the provisions of Section 7.4 of this Agreement.

                  16.2     Restrictions on Transfers by Limited Partners.

                  (a) All or part of a Partnership  Interest may be  transferred
         by a  Limited  Partner  only  with the prior  written  approval  of the
         General  Partner,  which  approval may be granted or denied in the sole
         discretion of the General Partner.

                  (b) The General  Partner  shall not approve any  transfer of a
         Partnership  Interest,  except a pledge of any Partnership  Interest by
         the General Partner to any bank,  insurance  company or other financial
         institution to secure payment of indebtedness  (a "Permitted  Pledge"),
         or otherwise  unless the proposed  transferee  shall have furnished the
         General Partner with a sworn statement that:

                           (i) The proposed  transferee  proposes to acquire his
                  Partnership  Interest as a principal,  for  investment and not
                  with a view to resale or distribution;

                           (ii) The proposed  transferee meets such requirements
                  regarding sophistication,  income and net worth as required by
                  applicable state and Federal securities laws;

                           (iii) The proposed  transferee has met such net worth
                  and income  suitability  standards as have been established by
                  the General Partner;

                           (iv)  The   proposed   transferee   recognizes   that
                  investment in the Partnership  involves  certain risks and has
                  taken  full  cognizance  of and  understands  all of the  risk
                  factors related to the purchase of a Partnership Interest; and

                                      -11-


<PAGE>



                           (v)  The  proposed   transferee  has  met  all  other
                  requirements of the General Partner for the proposed transfer.

                  (c) Other than in the case of a Permitted  Pledge,  a transfer
         of a  Partnership  Interest  may be made  only  if,  prior  to the date
         thereof,  the Partnership  upon request receives an opinion of counsel,
         satisfactory in form and substance to the General Partner, that neither
         the offering nor the proposed transfer will require  registration under
         Federal or applicable state securities laws or regulations.

                  16.3     Rights of Transferee.

                  Unless  admitted to the Partnership in accordance with Article
16.4, the  transferee of a Partnership  Interest or a part thereof or any right,
title or interest therein shall not be entitled to any of the rights, powers, or
privileges of his  predecessor in interest,  except that he shall be entitled to
receive and be credited or debited with his  proportionate  share of Partnership
income, gains, Profits, Losses, deductions, credits or Distributions.

                  16.4     Admission of Limited Partners.

                  Except as  otherwise  provided  in  Article  17,  the  General
Partner, or the transferee of all or part of the Partnership  Interest of either
a General Partner or a Limited Partner,  may be admitted to the Partnership as a
Limited Partner upon furnishing to the General Partner all of the following:

                  (a) The  written  approval of a Majority in Interest of all of
         the Limited  Partners  except the  assignor  Partner,  or the  assignor
         Partner  alone,  which  approval  may be  granted or denied in the sole
         discretion of such Partners or Partner (as the case may be);

                  (b)  The  written  approval  of  the  General  Partner,  which
         approval may be granted or denied in the sole discretion of the General
         Partner;

                  (c) Acceptance, in a form satisfactory to the General Partner,
         of all the  terms  and  conditions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d)  A  properly  executed  power  of  attorney  substantially
         identical to that contained in Article 37;

                  (e) Such other  documents or instruments as may be required in
         order to effect his admission as a Limited Partner; and

                  (f) Payment of such reasonable  expenses as may be incurred in
         connection with his or her admission as a Limited Partner.


                                      -12-


<PAGE>



                  16.5     Admission of General Partners.

                  A Limited  Partner,  or the  transferee  of all or part of the
Partnership  Interest of the General Partner, may be admitted to the Partnership
as a  general  partner  upon  furnishing  to  the  General  Partner  all  of the
following:

                  (a) The  written  consent of both the  General  Partner  and a
         Majority  in Interest of the  Limited  Partners,  which  consent may be
         granted or denied in the sole discretion of the Partners;

                  (b) Such financial statements,  guarantees or other assurances
         as the General  Partner  may require  with regard to the ability of the
         proposed  general  partner to fulfill the  financial  obligations  of a
         general partner hereunder;

                  (c) Acceptance,  in form  satisfactory to the General Partner,
         of all the  terms  and  provisions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d) A certified copy of a resolution of its Board of Directors
         (if it is a  corporation)  authorizing  it to become a general  partner
         under the terms and conditions of this Agreement;

                  (e)      A power of attorney substantially identical to that 
         contained in Article 37;

                  (f) Such other  documents or instruments as may be required in
         order to effect its admission as a general partner; and

                  (g) Payment of such reasonable  expenses as may be incurred in
         connection with its admission as a general partner.

                  Notwithstanding  the above,  a transferee  that controls or is
controlled by the General Partner or one or more of its Affiliates that receives
all or part of the  Partnership  Interest of the General Partner may be admitted
to the  Partnership as a general  partner upon complying with all the provisions
of Article  16.5  except for  subparagraph  16.5(a).  As long as the  transferee
either  controls or is controlled  by the General  Partner or one or more of its
Affiliates,  no  Limited  Partner  consents  will  be  required  to  admit  such
transferee as a General Partner to the Partnership.

                  16.6     Amendment of Certificate of Limited Partnership and 
Qualification.

                  The  General  Partner  shall  take  all  steps  necessary  and
appropriate to prepare and record any  amendments to the  Certificate of Limited
Partnership, as may be necessary or appropriate from time to time to comply with
the requirements of the Act, including,  without limitation,  upon the admission
to the Partnership of any general partner  pursuant to the provisions of Article
16.5, and may for this purpose  exercise the power of attorney  delivered to the
General Partner pursuant to Article 16.5 or 37. In addition, the General Partner
shall take all steps necessary and appropriate to prepare and record any and all
documents  necessary to qualify the Partnership to do business in  jurisdictions
where the Partnership is

                                      -13-


<PAGE>



doing  business,  and may for  this  purpose  exercise  the  power  of  attorney
delivered to the General Partner pursuant to Articles 16.4, 16.5 or 37.

                  16.7     Fundamental Changes.

                  In the  event  a plan  is  approved  by  the  General  Partner
providing for the merger or consolidation of the Partnership with another person
or entity, or the sale of all or substantially all of the Partnership Interests,
including  without  limitation the exchange of Partnership  Interests for equity
interests  in  another  person or entity or for cash or other  consideration  or
combination  thereof,  then and in such  event,  the Limited  Partners  shall be
obligated to take or refrain  from  taking,  as the case may be, such actions as
the  plan  may  provide,   including,   without   limitations,   executing  such
instruments,  and  providing  such  information  as the  General  Partner  shall
reasonably  request.  Any plan described in this Article 16.7 may also effect an
amendment to the  Partnership  Agreement  or the  adoption of a new  partnership
agreement in connection with the merger of the  Partnership  with another person
or  entity as  provided  in  Section  15678.2(e)  of the Act.  The plan may also
provide  that the General  Partner and its  Affiliates  shall  receive  fees for
services  rendered in connection  with the operation of the  Partnership  or any
successor entity following the consummation of the transactions described in the
plan,  and  neither the  Partnership  nor the  Partners  shall have any right by
virtue of this  Agreement in the income  derived  therefrom.  Any  securities or
other consideration to be distributed to the Partners pursuant to the plan shall
be  distributed  in the  manner  set  forth  in  Article  24(c)  as  though  the
Partnership were being liquidated.  For this purpose only, the fair market value
of the  securities or other  consideration  to be received  pursuant to the plan
shall be treated as "Profits" and the capital  accounts of the Partners shall be
increased  in the manner  provided  in Article  11(a)(ii).  No Partner  shall be
entitled  to  any  appraisal  or  similar  rights  in  connection  with  a  plan
contemplated by this Article 16.7.

                  16.8     Withdrawal of Initial Limited Partner.

                  Upon the date the first  Limited  Partner is  admitted  to the
Partnership in accordance with Article 10 of this Agreement, the Initial Limited
Partner  shall  withdraw  from  the  Partnership,   and  thereupon  his  Capital
Contribution shall be returned and his Partnership Interest shall be reallocated
to the Limited Partners.

                  17.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON
                           CERTAIN EVENTS.

                  17.1     Death.

                  Upon the  death of a Limited  Partner,  the  deceased  Limited
Partner's  executor,  administrator,  or other legal or personal  representative
shall give  written  notice of that fact to the  General  Partner.  The  General
Partner shall have the option to purchase at the Closing (as defined  below) the
Partnership   Interest  of  the  deceased   Limited  Partner  (whose   executor,
administrator  or other  legal or  personal  representative  shall  then  become
obligated  to sell such  Partnership  Interest) at the price  determined  in the
manner  provided  in  Article  17.6  of  this  Agreement  and on the  terms  and
conditions provided in Article 17.7 of this Agreement. The General Partner shall
have a period of thirty (30) days  following  the date of notice of the death of
the Limited Partner (the "Option  Period") within which to notify in writing the
deceased Limited  Partner's  executor,  administrator or other legal or personal
representative,  whether the General Partner wishes to purchase all or a portion
of the Partnership Interest of the deceased

                                      -14-


<PAGE>



Limited  Partner.  If the General  Partner does not elect to purchase the entire
Partnership  Interest of the deceased  Limited  Partner before the expiration of
the  Option  Period  and in the  manner  provided  herein,  the  portion  of the
Partnership  Interest  not  purchased  shall  be  held by the  deceased  Limited
Partner's executor, administrator, or other legal representative pursuant to the
terms of this Agreement. The General Partner, in its sole discretion,  may elect
to assign its rights to purchase the Partnership  Interest of a deceased Limited
Partner  under this  Section  17.1 to the  Partnership  and,  in such case,  the
Partnership shall have the same rights as provided for the General Partner under
this Section 17.1.

                  17.2     Bankruptcy, Insolvency or Assignment for Benefit of 
                           Creditors of a Limited Partner.

                   In the event  that an  involuntary  or  voluntary  proceeding
under the  Federal  Bankruptcy  Code,  as  amended,  is filed for or against any
Limited  Partner,  or if any Limited  Partner shall make an  assignment  for the
benefit of his creditors,  or if any Limited Partner has a receiver or custodian
appointed  for his assets,  or any Limited  Partner  generally  fails to pay his
debts when due, the insolvent  Limited  Partner  shall give written  notice (the
"Notice of Insolvency")  to the General Partner of the  commencement of any such
proceeding or the  occurrence of such event within five days of the first notice
to him of such  commencement  or occurrence of such event.  The General  Partner
shall  have the  option to  purchase  at the  Closing  (as  defined  below)  the
Partnership  Interest of the insolvent  Limited Partner (which insolvent Limited
Partner  or  his  trustee,  custodian,  receiver  or  other  personal  or  legal
representative,  as the case may be,  shall then become  obligated  to sell such
Partnership  Interest) at the price determined in the manner provided in Article
17.6 of this Agreement and on the terms and conditions  provided in Article 17.7
of this  Agreement.  The General Partner shall have a period of thirty (30) days
following  the date of the Notice of  Insolvency  (the "Option  Period")  within
which to notify  in  writing  the  insolvent  Limited  Partner  or his  trustee,
custodian,  receiver,  or other  legal or personal  representative,  whether the
General Partner wishes to purchase all or a portion of the Partnership  Interest
of the  insolvent  Limited  Partner.  If the General  Partner  does not elect to
purchase the entire Partnership Interest of the insolvent Limited Partner before
the  expiration  of the Option  Period and in the manner  provided  herein,  the
portion of the Partnership Interest not purchased shall be held by the insolvent
Partner,   his  trustee,   custodian,   receiver  or  other  legal  or  personal
representative pursuant to the terms of this Agreement.  The General Partner, in
its sole discretion,  may elect to assign its rights to purchase the Partnership
Interest  of an  insolvent  Limited  Partner  under  this  Section  17.2  to the
Partnership  and, in such case,  the  Partnership  shall have the same rights as
provided for the General Partner under this Section 17.2.

                  17.3     Breach of Article 14.3.

                  In the  event  a  Limited  Partner  (the  "Defaulting  Limited
Partner")  breaches  the  provisions  of  Article  14.3  of this  Agreement,  as
determined in the sole  discretion of the General  Partner,  the General Partner
may elect, in its sole  discretion,  to treat such event as a default under this
Agreement  and enforce  the  provisions  of this  Article  17.3.  If the General
Partner  elects to enforce the  provisions  of this  Article  17.3,  the General
Partner shall give written  notice of such election (the "Notice of Default") to
the Defaulting  Limited  Partner within 180 days of the date the General Partner
first received  notice of the defaulting  event.  The General Partner shall have
the option to  purchase  at the  Closing  (as  defined  below)  the  Partnership
Interest of the Defaulting  Limited  Partner (which  Defaulting  Limited Partner
shall then become  obligated  to sell such  Partnership  Interest)  at the price
determined in the manner  provided in Article 17.6 of this  Agreement and on the
terms and  conditions  provided in Article 17.7 of this  Agreement.  The General
Partner shall have a period of thirty (30) days  following the date of the close
of the date of the

                                      -15-


<PAGE>



Notice of Default (the "First Option  Period") within which to notify in writing
the Defaulting  Limited Partner,  whether the General Partner wishes to purchase
all or a portion of the Partnership  Interest of the Defaulting Limited Partner.
If the  General  Partner  does not  elect to  purchase  the  entire  Partnership
Interest of the Defaulting  Limited  Partner before the expiration of the Option
Period  and in the  manner  provided  herein,  the  portion  of the  Partnership
Interest not purchased shall be held by the Defaulting  Limited Partner pursuant
to the terms of this Agreement. The General Partner, in its sole discretion, may
elect to assign its rights to purchase the Partnership  Interest of a Defaulting
Limited  Partner under this Section 17.3 to the  Partnership  and, in such case,
the  Partnership  shall have the same rights as provided for the General Partner
under this Section 17.3.

                  17.4  Domestic  Proceeding.  In the  event  that a spouse of a
Limited Partner  commences  against a Limited  Partner,  or a Limited Partner is
named in, a Domestic  Proceeding,  the Limited Partner shall give written notice
(the "Notice of Domestic Proceeding") to the General Partner of the commencement
of any such  proceeding  within  five  days of the  first  notice to him of such
commencement.  The  General  Partner  shall have the option to  purchase  at the
Closing  (as defined  below) the  Partnership  Interest  of the Limited  Partner
involved in the Domestic  Proceeding  (which  Limited  Partner shall then become
obligated to sell such  Partnership  Interest),  at the price  determined in the
manner  provided  in  Article  17.6  of  this  Agreement  and on the  terms  and
conditions provided in Article 17.7 of this Agreement.

 The General  Partner shall have a period of thirty (30) days following the date
of the Notice of Domestic  Proceeding  (the  "Option  Period")  within  which to
notify in writing  the Limited  Partner  involved  in the  Domestic  Proceeding,
whether  the  General  Partner  wishes  to  purchase  all  or a  portion  of the
Partnership  Interest of such Limited  Partner.  If the General Partner does not
elect to purchase the Partnership  Interest of the Limited  Partner  involved in
the Domestic  Proceeding  before the  expiration of the Option Period and in the
manner provided  herein,  the portion of the Partnership  Interest not purchased
shall be held by such Limited  Partner  pursuant to the terms of this Agreement.
The General Partner,  in its sole discretion,  may elect to assign its rights to
purchase  the  Partnership  Interest  of the  Limited  Partner  involved  in the
Domestic  Proceeding  under this  Section 17.4 to the  Partnership  and, in such
case,  the  Partnership  shall have the same rights as provided  for the General
Partner under this Section 17.4.

                  17.5 Divestiture  Option.  If state or federal  regulations or
laws are enacted or applied, or if any other legal developments occur, which, in
the opinion of the General Partner  adversely  affect (or potentially  adversely
affect) the operation of the Partnership  (e.g., the enactment or application of
prohibitory physician  self-referral  legislation against the Partnership or its
Partners),  the General Partner shall promptly  either,  in its discretion,  (i)
take the steps  outlined in this Article 17.5 to divest the Limited  Partners of
their  Partnership  Interests,  or (ii) dissolve the  Partnership as provided in
Article  23.1(d).  If the General Partner chooses option (i), it shall deliver a
written  notice to all of the Limited  Partners (the "Notice of  Election")  and
purchase such Partnership  Interests for its own account.  The purchase price to
be paid for each  Partnership  Interest  shall be  determined  in the  manner as
provided in Article 17.6 and shall be on the terms and conditions as provided in
Article 17.7. The transfer of the  Partnership  Interests and the payment of the
purchase  price (as  provided  in  Article  17.6)  shall be made at such time as
determined by the General Partner to be in the best interests of the Partnership
and its Limited  Partners.  Each Limited  Partner hereby makes,  constitutes and
appoints  the General  Partner,  with full power of  substitution,  his true and
lawful attorney-in-fact,  to take such actions and execute such documents on his
behalf to effect the  transfer of his  Partnership  Interest as provided in this
Article 17.5.

                  17.6     Purchase Price.  The purchase price to be paid for 
the  Partnership  Interest  of any  Limited  Partner  whose  interest  is  being
purchased pursuant to the provisions of Articles 17.1, 17.2, 17.3,

                                      -16-


<PAGE>



17.4 or 17.5 (the "Retiring  Limited  Partner")  shall be an amount equal to the
Retiring  Limited  Partner's  share of the  Partnership's  book  value,  if any,
(prorated in the event that only a portion of his Partnership  Interest is being
purchased) as reflected by the Capital  Account of the Retiring  Limited Partner
(unadjusted  for any  appreciation  in  Partnership  assets  and as  reduced  by
depreciation  deductions  claimed  by the  Partnership  for tax  purposes).  The
determination of the Retiring Limited Partner's Capital Account on the Valuation
Date (as defined below) shall be made by the Partnership's  internal  accountant
(the  "Partnership  Accountant")  upon a  review  of the  Partnership  books  of
account,  and  a  formal  audit  is  expressly  waived.  The  statement  of  the
Partnership  Accountant  with  respect to the  Capital  Account of the  Retiring
Limited  Partner on the Valuation Date shall be binding and conclusive  upon the
Partnership,   the   purchaser  and  the  Retiring   Limited   Partner  and  his
representative.  The  Valuation  Date  shall be the last day of the  month  next
preceding the month in which occurs: (i) the death of a Limited Partner,  in the
case of a purchase by reason of death;  (ii) the  bankruptcy  or insolvency of a
Limited  Partner,  in the case of a  purchase  by reason of such  bankruptcy  or
insolvency;  (iii) the Notice of Default as provided in Article 17.3 in the case
of a  purchase  by  reason  thereof;  (iv)  the  commencement  of  the  Domestic
Proceeding,  in the case of a purchase by reason  thereof;  or (v) the Notice of
Election  as  provided  in Article  17.5,  in the case of a  purchase  by reason
thereof. Any Limited Partner whose Partnership Interest is purchased pursuant to
the provisions of Article 17.1,  17.2, 17.3, 17.4 or 17.5 shall be entitled only
to the  purchase  price  which  shall  be paid  at the  Closing  in cash  (or by
certified  or  cashier's  check) and shall not be  entitled  to any  Partnership
distributions  made after the  Valuation  Date.  The  transfer of a  Partnership
Interest  of a  Retiring  Limited  Partner  shall be  deemed  to occur as of the
Valuation  Date and the Retiring  Limited  Partner shall have no voting or other
rights as a Limited  Partner after such date. The purchaser shall be entitled to
any distributions  attributable to the transferred  interest after the Valuation
Date and shall  have the right to deduct  the  amount of any such  distributions
made to the Retiring Limited Partner from the purchase price.

                  17.7     Closing.

                  17.7.1  Closing  of  Purchase  and Sale.  The  Closing  of any
         purchase and sale of a Partnership  Interest  pursuant to Article 17.1,
         17.2,  17.3,  17.4 or 17.5 of this  Agreement  shall  take place at the
         principal office of the Partnership,  or such other place designated by
         the General Partner, on the date determined as follows (the "Closing"):

                  (a) In the case of a purchase and sale  occurring by reason of
         the death of a Limited  Partner as  provided  in  Article  17.1 of this
         Agreement,  the Closing  shall be held on the thirtieth day (or if such
         thirtieth  day is not a business  day, the next  business day following
         the thirtieth day) next following the last to occur of:

                           (i)      Qualification of the executor or personal 
                  administrator of the deceased Limited Partner's estate;

                           (ii) The date on which any necessary determination of
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (iii) The date that  coincides  with the close of the
                  Option Period.


                                      -17-


<PAGE>



                  (b) In the case of a purchase and sale  occurring by reason of
         the  occurrence of one of the events  described in Article 17.2,  17.3,
         17.4 or  17.5  of this  Agreement,  the  Closing  shall  be held on the
         thirtieth day (or if such thirtieth day is not a business day, the next
         business day following the thirtieth  day) next  following the later to
         occur of:

                           (i)  The date on which any necessary determination of
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (ii) The date  that  coincides  with the close of the
                  Option Period.

         At the Closing,  although not  necessary  to effect the  transfer,  the
         Retiring Limited Partner shall  concurrently with tender and receipt of
         the applicable  purchase price,  deliver to the purchaser duly executed
         instruments of transfer and  assignment,  assigning good and marketable
         title to the  portion or  portions of the  Retiring  Limited  Partner's
         entire  Partnership  Interest thus  purchased,  free and clear from any
         liens  or  encumbrances  or  rights  of  others  therein.  The  parties
         acknowledge  that occurrence of any of the triggering  events described
         in Article 17.1,  17.2,  17.3, 17.4 or 17.5 and compliance with all the
         Articles  of this  Agreement,  except  the  execution  of the  transfer
         documents  by the  Retiring  Partner as provided  above in this Article
         17.7.1,  are sufficient to effect the complete transfer of the Retiring
         Limited  Partner's  interest and the Retiring  Limited Partner shall be
         deemed to  consent  to  admission  of the  transferee  as a  substitute
         Limited Partner.  Notwithstanding  the date of the Closing or whether a
         Closing is successfully held, the transfer of a Partnership Interest of
         a Retiring Limited Partner shall be deemed to occur as of the Valuation
         Date as defined in Article  17.6.  The  deemed  transfer  is  effective
         regardless of whether the Retiring  Limited Partner performs the duties
         set forth in this Article 17.7.1.

                  17.7.2  Terms and  Conditions  of  Purchase.  The  Partnership
         Interest of a Limited  Partner shall not be  transferred to any Partner
         unless the  requirements  of Articles 16.2 and 16.4 (b) through (f) are
         satisfied  with  respect to it. The  purchaser  shall be liable for all
         obligations  and  liabilities   connected  with  that  portion  of  the
         Partnership  Interest  transferred  to it  unless  otherwise  agreed in
         writing.

                  18.      SALE,  ASSIGNMENT  OR OTHER  TRANSFER  OF THE GENERAL
                           PARTNER'S INTEREST.

                  18.1  The   General   Partner   may  not   mortgage,   pledge,
hypothecate,  transfer,  sell, assign or otherwise dispose of all or any part of
its interest in the  Partnership,  whether  voluntarily,  by operation of law or
otherwise (the foregoing  actions being  hereafter  collectively  referred to as
"Transfers" or singularly as a "Transfer") except as permitted by this Article.

                  18.2 If the  General  Partner  makes a Transfer  (other than a
mortgage,  pledge or  hypothecation)  of its  general  partner  interest  in the
Partnership pursuant to this Article, it shall be liable for all obligations and
liabilities  incurred  by it as the  General  Partner of the  Partnership  on or
before the

                                      -18-


<PAGE>



effective date of such Transfer,  but shall not be liable for any obligations or
liabilities of the Partnership arising after the effective date of the Transfer.

                  18.3     No Transfer by the General Partner shall be permitted
unless:

                  (a) Counsel for the Partnership shall have rendered an opinion
         that none of the actions  taken in  connection  with such Transfer will
         cause the Partnership to be classified  other than as a partnership for
         Federal income tax purpose or will cause the termination or dissolution
         of the Partnership under state law; and

                  (b) Such  documents  or  instruments,  in form  and  substance
         satisfactory to counsel for the  Partnership,  shall have been executed
         and  delivered  as may be  required  in the  opinion of counsel for the
         Partnership to effect fully any such Transfer.

                  Notwithstanding the foregoing provisions of this Article 18.3,
the General  Partner may pledge its  interest  in the  Partnership  to any bank,
insurance   company  or  other  financial   institution  to  secure  payment  of
indebtedness.

                  19.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER.

                  If the General Partner shall be finally adjudged by a court of
competent  jurisdiction to be liable to the Limited  Partners or the Partnership
for any act of gross negligence or willful  misconduct in the performance of its
duties under the terms of this Agreement, the General Partner may be removed and
another  substituted  with the  consent  of all of the  Limited  Partners.  Such
consent  shall be evidenced  by a  certificate  of removal  signed by all of the
Limited Partners. In the event of removal, the new general partner shall succeed
to all of the powers, privileges and obligations of the General Partner, and the
General  Partner's  interest in the  Partnership  shall become that of a Limited
Partner,  and the General Partner shall maintain its same Percentage Interest in
the Partnership  notwithstanding  anything contained in the Act to the contrary.
In addition,  in the event of removal,  the new general  partner  shall take all
steps  necessary  and  appropriate  to prepare  and record an  amendment  to the
Certificate of Limited Partnership to reflect the removal of the General Partner
and the admission of such new general partner.

                  20.      MANAGEMENT AND OPERATION OF BUSINESS.

                  20.1 All  decisions  with  respect  to the  management  of the
business and affairs of the Partnership shall be made by the General Partner.

                  20.2 The General  Partner shall be under no duty to devote all
of its time to the business of the Partnership,  but shall devote only such time
as it deems  necessary  to conduct the  Partnership  business and to operate and
manage the Partnership in an efficient manner.

                  20.3 The  General  Partner may charge to the  Partnership  all
ordinary and necessary costs and expenses, direct and indirect,  attributable to
the activities,  conduct and management of the business of the Partnership.  The
costs and expenses to be borne by the  Partnership  shall  include,  but are not
limited to, all  expenditures  incurred in acquiring and financing the Equipment
or other Partnership property, legal and accounting fees and expenses,  salaries
of employees of the Partnership,  consulting and quality  assurance fees paid to
independent contractors, insurance premiums and interest.

                                      -19-


<PAGE>



                  20.4 In addition to, and not in limitation  of, any rights and
powers  covenanted by law or other  provisions of this agreement,  and except as
limited,  restricted or prohibited by the express  provisions of this Agreement,
the General Partner shall have and may exercise on behalf of the Partnership all
powers and rights necessary,  proper,  convenient or advisable to effectuate and
carry out the purposes, business and objectives of the Partnership.  Such powers
shall include, without limitation, the following:

                  (a)      To acquire a Prostatron(R) Mobile System;

                  (b) To acquire (i) additional  Prostatron(R)  Mobile  Systems,
         (ii) any other  assets  related to the  provision  of benign  prostatic
         hyperplasia  treatment services, or (iii) any other assets or equipment
         or an interest in another  entity  consistent  with the purposes of the
         Partnership  as provided in Article 4  (collectively,  the  "Additional
         Assets"),  at such times and at such price and upon such terms,  as the
         General Partner deems to be in the best interest of the Partnership;

                  (c) To purchase,  hold, manage,  lease, license and dispose of
         Partnership   assets  (including  the  Prostatron(R)   Mobile  System),
         including the purchase,  exchange,  trade or sale of the  Partnership's
         assets at such price, or amount, for cash, securities or other property
         and upon such  terms,  as the General  Partner  deems to be in the best
         interest of the  Partnership;  provided,  that  should the  Partnership
         assets be exchanged or traded for  securities  or other  property  (the
         "Replacement  Property") the General Partner shall have the same powers
         with regard to the  Replacement  Property as it does towards the traded
         property;

                  (d) To  exercise  the  option of the  General  Partner  or the
         Partnership  to  purchase  a  Limited  Partner's  Partnership  Interest
         pursuant to Article 17;

                  (e) To determine the travel  itinerary and site  locations for
         the Prostatron(R) Mobile System or other Partnership technology;

                  (f) To borrow money for any Partnership purpose (including the
         acquisition  of the  Additional  Assets)  and,  if security is required
         therefor, to subject to any security device any portion of the property
         for the  Partnership,  to obtain  replacements  of any  other  security
         device, to prepay, in whole or in part,  refinance,  increase,  modify,
         consolidate or extend any encumbrance or other security device;

                  (g) To deposit,  withdraw,  invest, pay, retain (including the
         establishment  of reserves in order to acquire the  Additional  Assets)
         and distribute the  Partnership's  funds in any manner  consistent with
         the provisions of this Agreement;

                  (h)      To institute and defend actions at law or in equity;

                  (i) To enter into and carry out contracts and  agreements  and
         any or all documents and  instruments  and to do any and all such other
         things as may be in furtherance of Partnership purposes or necessary or
         appropriate to the conduct of the Partnership activities;


                                      -20-


<PAGE>



                  (j)  To   execute,   acknowledge   and  deliver  any  and  all
         instruments  which may be deemed  necessary or convenient to effect the
         foregoing; and

                  (k) To engage or retain one or more persons to perform acts or
         provide  materials  as  may be  required  by  the  Partnership,  at the
         Partnership's  expense,  and to compensate  such person or persons at a
         rate to be set by the General  Partner,  provided that the compensation
         is at the then  prevailing  rate for the type of services and materials
         provided,  or both.  Any person,  whether a Partner,  an Affiliate of a
         Partner or otherwise, including without limitation the General Partner,
         may be employed or engaged by the  Partnership  to render  services and
         provide materials,  including, but not limited to, management services,
         professional   services,   accounting   services,   quality  assessment
         services, legal services,  marketing services,  maintenance services or
         provide materials; and if such person is a Partner or an Affiliate of a
         Partner,  he shall be entitled to, and shall be paid  compensation  for
         said services or materials,  anything in this Agreement to the contrary
         notwithstanding, provided that the compensation to be received for such
         services  or  materials  is  competitive  in price and terms  with then
         prevailing rate for the type of services and/or materials provided. The
         Partnership,  pursuant  to the terms of a  Management  Agreement,  will
         contract with Lithotripters,  Inc., a North Carolina corporation and an
         Affiliate of the General  Partner,  with respect to the supervision and
         coordination  of the  management and  administration  of the day-to-day
         operations of the  Prostatron(R)  Mobile System for a monthly fee equal
         to the greater of 7.5% of Partnership Cash Flow per month or $8,000 per
         month. All costs incurred by the General  Partner,  excluding the costs
         of employing one or more local physicians to act as a Medical Director,
         shall be paid by the  Partnership  directly.  The  Partnership may also
         contract with qualified  physicians  desiring to use the  Prostatron(R)
         Mobile System for the treatment of patients.  Owning an interest in the
         Partnership shall not be a condition to using the Prostatron(R)  Mobile
         System. The General Partner and its Affiliates may engage in or possess
         an interest in other  business  ventures of any nature and  description
         independently  or with  others,  including,  but not  limited  to,  the
         operation  of a mobile  benign  prostatic  hyperplasia  treatment  unit
         similar  to the  Prostatron(R)  Mobile  System,  whether  or  not  such
         business  ventures  are in  direct  or  indirect  competition  with the
         Partnership,  and neither the  Partnership  nor the Partners shall have
         any  right  by  virtue  of this  Agreement  in and to said  independent
         ventures or to the income or profits derived therefrom.

                  21.      RESERVES.

                  The  General  Partner  may cause the  Partnership  to create a
reserve account to be used exclusively for repairs and acquisition of Additional
Assets and for any other valid Partnership  purpose.  The General Partner shall,
in its sole discretion, determine the amount of payments to such reserve.

                  22.      INDEMNIFICATION AND EXCULPATION OF THE
                           GENERAL PARTNER.

                  22.1 The General  Partner is accountable to the Partnership as
a fiduciary and consequently  must exercise good faith and integrity in handling
Partnership  affairs.  This is a rapidly developing and changing area of the law
and Limited  Partners who have  questions  concerning  the duties of the General
Partner  should  consult  with  their  counsel.  The  General  Partner  and  its
Affiliates shall have

                                      -21-


<PAGE>



no  liability to the  Partnership  which arises out of any action or inaction of
the General  Partner or its Affiliates if the General Partner or its Affiliates,
in good faith,  determined  that such course of conduct was in the best interest
of the  Partnership  and  such  course  of  conduct  did  not  constitute  gross
negligence or willful  misconduct of the General Partner or its Affiliates.  The
General  Partner and its  Affiliates  shall be  indemnified  by the  Partnership
against  any  losses,  judgments,  liabilities,  expenses  and  amounts  paid in
settlement of any claims  sustained by them in connection with the  Partnership,
provided  that the same  were not the  result  of gross  negligence  or  willful
misconduct on the part of the General Partner or its Affiliates.

                  22.2 The General Partner shall not be liable for the return of
the Capital Contributions of the Limited Partners, and upon dissolution, Limited
Partners shall look solely to the assets of the Partnership.

                  23.      DISSOLUTION OF THE PARTNERSHIP.

                  23.1 The Partnership shall be dissolved and terminated and its
business wound up upon the occurrence of any one of the following events:

                  (a)      The expiration of its term on January 1, 2047;

                  (b) The  filing  by, on  behalf  of, or  against  the  General
         Partner of any  petition or  pleading,  voluntary  or  involuntary,  to
         declare the General  Partner  bankrupt under any bankruptcy law or act,
         or the  commencement  in any  court  of any  proceeding,  voluntary  or
         involuntary,  to declare the General Partner insolvent or unable to pay
         its debts, or the appointment by any court or supervisory  authority of
         a  receiver,  trustee or other  custodian  of the  property,  assets or
         business of the General  Partner or the  assignment by it of all or any
         part of its  property or assets for the benefit of  creditors,  if said
         action,  proceeding  or  appointment  is  not  dismissed,   vacated  or
         otherwise terminated within ninety (90) days of its commencement;

                  (c) The determination of the General Partner that the 
         Partnership should be dissolved;

                  (d) The  election  of the  General  Partner  to  dissolve  the
         Partnership  following the occurrence of an event  described in Article
         17.5;

                  (e)  The  sale,  exchange  or  other  disposition  of  all  or
         substantially  all of the property of the  Partnership  without  making
         provision for the replacement thereof; and

                  (f)   The   dissolution,   retirement,   resignation,   death,
         disability  or legal  incapacity  of a general  partner,  and any other
         event  resulting in the  dissolution or termination of the  Partnership
         under the laws of the State of California.

                  23.2  Notwithstanding  the  provisions  of Article  23.1,  the
Partnership   shall  not  be  dissolved  and  terminated  upon  the  retirement,
resignation,  bankruptcy,  assignment for the benefit of creditors, dissolution,
death,  disability or legal  incapacity of a general  partner,  and its business
shall continue  pursuant to the terms and conditions of this  Agreement,  if any
general partner or general partners remain  following such event;  provided that
such remaining general partner or general partners are hereby obligated to

                                      -22-


<PAGE>



continue the business of the  Partnership.  If no general  partner remains after
the  occurrence of such event,  the business of the  Partnership  shall continue
pursuant to the terms and conditions of this  Agreement,  if, within ninety (90)
days after the occurrence of such event, the Limited Partners  unanimously agree
in writing to continue the business of the  Partnership,  and, if necessary,  to
the  appointment  of one or more  persons or entities to be  substituted  as the
general  partner.  In the event  the  Limited  Partners  agree to  continue  the
business of the  Partnership,  the new general partner or general partners shall
succeed to all of the powers, privileges and obligations of the General Partner,
and the General  Partner's  interest in the  Partnership  shall become a Limited
Partner's  interest  hereunder.  Furthermore,  in the event a remaining  general
partner or the  Limited  Partners,  as the case may be,  agree to  continue  the
business of the Partnership as provided herein, the remaining general partner or
the newly  appointed  general partner or general  partners,  as the case may be,
shall  take all  steps  necessary  and  appropriate  to  prepare  and  record an
amendment to the Certificate of Limited  Partnership to reflect the continuation
of the business of the Partnership and the admission of a new general partner or
general partners, if any.

                  24.      DISTRIBUTION UPON DISSOLUTION.

                  Upon the dissolution and termination of the  Partnership,  the
General Partner or, if there is none, a representative  of the Limited Partners,
shall  cause  the  cancellation  of the  Partnership's  Certificate  of  Limited
Partnership,  shall liquidate the assets of the Partnership, and shall apply and
distribute the proceeds of such liquidation in the following order of priority:

                  (a) First, to the payment of the debts and liabilities of the 
         Partnership, and the expenses of liquidation;

                  (b) Second,  to the creation of any reserves which the General
         Partner  (or the  representatives  of the  Limited  Partners)  may deem
         reasonably  necessary  for the payment of any  contingent or unforeseen
         liabilities or obligations of the Partnership or of the General Partner
         arising out of or in connection  with the business and operation of the
         Partnership; and

                  (c) Third,  the balance,  if any,  shall be distributed to the
         Partners in accordance  with the  Partners'  positive  Capital  Account
         balances  after such  capital  accounts  are  adjusted  as  provided by
         Article 13, and any other  adjustments  required by the Final  Treasury
         Regulations  under Section 704(b) of the Code. Any general partner with
         a negative  Capital Account  following the  distribution of liquidation
         proceeds or the  liquidation  of its interest  must  contribute  to the
         Partnership  an amount  equal to such  negative  Capital  Account on or
         before the end of the Partnership's  taxable year (or, if later, within
         ninety days after the date of liquidation).  Any capital so contributed
         shall  be (i)  distributed  to those  Partners  with  positive  Capital
         Accounts until such Capital  Accounts are reduced to zero,  and/or (ii)
         used to discharge recourse liabilities.

                  25.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.

                  25.1 Proper and complete records and books of account shall be
kept by the General  Partner in which shall be entered fully and  accurately all
transactions  and such other matters relating to the  Partnership's  business as
are usually  entered  into  records and books of account  maintained  by persons
engaged  in  businesses  of a like  character.  The  books  and  records  of the
Partnership shall be prepared

                                      -23-


<PAGE>



according to the accounting  method determined to be in the best interest of the
Partnership by the General Partner.  The Partnership's  fiscal year shall be the
calendar  year.  The books and records  shall at all times be  maintained at the
Partnership's  Records Office and shall be open to the reasonable inspection and
examination  of the  Partners or their duly  authorized  representatives  during
reasonable business hours.

                  25.2 Within  ninety (90) days after the end of each Year,  the
General  Partner shall send to each person who was a Limited Partner at any time
during such year such tax information,  including,  without limitation,  Federal
tax Schedule K-1, as shall be reasonably  necessary for the  preparation by such
person of his Federal  income tax return.  The  General  Partner  will also make
available to the Limited Partners any other information required by the Act.

                  25.3 The General  Partner shall maintain at the  Partnership's
Records  Office  copies of the  Partnership's  original  Certificate  of Limited
Partnership   and  any  certificate  of  amendment,   restated   certificate  or
certificate of cancellation with respect thereto and such other documents as the
Act shall require.  The General Partner will furnish to any Limited Partner upon
request a copy of the Partnership's  original Certificate of Limited Partnership
and any  certificate  of amendment,  restated  certificate,  or  certificate  of
cancellation, if any.

                  25.4 The General Partner shall, in its sole  discretion,  make
for the  Partnership  any and all  elections  for  federal,  state and local tax
purposes including, without limitation, any election, if permitted by applicable
law, to adjust the basis of the Partnership's property pursuant to Code Sections
754,  734(b) and  743(b),  or  comparable  provisions  of state or local law, in
connection  with  transfers  of  interests in the  Partnership  and  Partnership
Distributions.

                  25.5 The  General  Partner is  designated  as the Tax  Matters
Partner  (as  defined  in  Section  6231 of the Code) and to act in any  similar
capacity  under  state or local law,  and is  authorized  (at the  Partnership's
expense):   (i)  to  represent  the   Partnership  and  Partners  before  taxing
authorities  or courts of competent  jurisdiction  in tax matters  affecting the
Partnership  or  Partners  in their  capacity  as  Partners;  (ii) to extend the
statute of limitations for assessment of tax deficiencies  against Partners with
respect to adjustments to the Partnership's federal, state or local tax returns;
(iii) to execute any agreements or other documents relating to or affecting such
tax matters, including agreements or other documents that bind the Partners with
respect to such tax matters or  otherwise  affect the rights of the  Partnership
and Partners; and (iv) to expend Partnership funds for professional services and
costs  associated  therewith.  The General partner is authorized and required to
notify the federal,  state or local tax  authorities of the appointment of a Tax
Matters  Partner  in  the  manner  provided  in  Treasury   Regulations  Section
301.6231(a)(7)-IT, as modified from time to time. In its capacity as Tax Matters
Partner,  the General  Partner shall oversee the  Partnership tax affairs in the
manner which, in its best judgment, are in the interests of the Partners.

                  26.      NOTICES.

                  All notices under this Agreement shall be in writing and shall
be deemed to have been given when delivered  personally,  or mailed by certified
or registered mail, postage prepaid,  return receipt  requested.  Notices to the
General  Partner  shall be  delivered  at, or mailed to, its  principal  office.
Notices to the  Partnership  shall be delivered  at, or mailed to, its principal
office with a copy to each of its business offices.  Notice to a Limited Partner
shall be  delivered  to such  Limited  Partner,  or mailed  to the last  address
furnished  by him for such  purposes to the General  Partner.  Limited  Partners
shall give  notice of a change of address to the  General  Partner in the manner
provided in this Article.

                                      -24-


<PAGE>



                  27.      AMENDMENTS.

                  Subject to the  provisions  of Article 28, this  Agreement  is
subject to  amendment  only by  written  consent of the  General  Partner  and a
Majority in Interest of the Limited Partners;  provided, however, the consent of
the Limited Partners shall not be required if such amendments are ministerial in
nature and do not contravene the provisions of Article 28.

                  28.      LIMITATIONS ON AMENDMENTS.

                  Notwithstanding  the provisions of Article 27, no amendment to
this Agreement shall:

                  (a)  Enlarge  the   obligations  of  any  Partner  under  this
         Agreement  or convert the  interest in the  Partnership  of any Limited
         Partner  into the  interest of a general  partner or modify the limited
         liability of any Limited Partner, without the consent of such Partner;

                  (b) Amend the  provisions  of Article 12, 13, 15 or 24 without
         the  approval of the General  Partner and a Majority in Interest of the
         Limited Partners;  provided,  however,  that the General Partner may at
         any time  amend  such  Articles  without  the  consent  of the  Limited
         Partners in order to permit the Partnership allocations to be sustained
         for Federal  income tax  purposes,  but only if such  amendments do not
         materially  affect  adversely the rights and obligations of the Limited
         Partners, in which case such amendments may only be made as provided in
         this Article 28(c); or

                  (c) Amend this Article 28 without the consent of all Partners.

                  29.      MEETINGS, CONSENTS AND VOTING.

                  29.1 A meeting of the  Partnership to consider any matter with
respect to which the  Partners  may vote as set forth in this  Agreement  may be
called  by the  General  Partner  or by  Limited  Partners  who hold  more  than
twenty-five  percent (25%) of the aggregate interests in the Partnership held by
all the Limited Partners.  Upon receipt of a notice requesting a meeting by such
Partner or Partners and stating the purpose of the meeting,  the General Partner
shall, within ten (10) days thereafter, give notice to the Partners of a meeting
of the  Partnership  to be held at a time and place  convenient  to the  Limited
Partners  on a date not  earlier  than  fifteen  (15) days after  receipt by the
General  Partner of the notice  requesting a meeting.  The notice of the meeting
shall set forth the time, date, location and purpose of the meeting.

                  29.2 Any consent of a Partner  required by this  Agreement may
be given as follows:

                  (a) By a written  consent given by the consenting  Partner and
         received by the General  Partner at or prior to the doing of the act or
         thing for which the consent is solicited, or

                  (b) By the affirmative  vote by the consenting  Partner to the
         doing of the act or thing for which the  consent  is  solicited  at any
         meeting  called  pursuant to this Article to consider the doing of such
         act or thing.


                                      -25-


<PAGE>



                  29.3 When exercising voting rights expressly granted under the
Articles of this  Agreement,  each Partner shall have that number of votes as is
equal to the  Percentage  Interest  of such  Partner  at the  time of the  vote,
multiplied by 100.

                  30.      SUBMISSIONS TO THE LIMITED PARTNERS.

                  The General Partner shall give the Limited  Partners notice of
any proposal or other matter  required by any provision of this  Agreement or by
law to be submitted for consideration and approval of the Limited Partners. Such
notice shall include any  information  required by the relevant  provision or by
law.

                  31.      ADDITIONAL DOCUMENTS.

                  Each  party  hereto  agrees to  execute  and  acknowledge  all
documents and writings which the General Partner may deem necessary or expedient
in the creation of this Partnership and the achievement of its purpose.

                  32.      SURVIVAL OF RIGHTS.

                  Except as herein  otherwise  provided  to the  contrary,  this
Agreement  shall be binding upon and inure to the benefit of the parties hereto,
their successor and assigns.

                  33.      INTERPRETATION AND GOVERNING LAW.

                  When the  context  in which  words are used in this  Agreement
indicates  that such is the intent,  words in the singular  number shall include
the plural and vise versa; in addition,  the masculine  gender shall include the
feminine and neuter  counterparts.  The Article headings or titles and the table
of  contents  shall not define,  limit,  extend or  interpret  the scope of this
Agreement  or any  particular  Article.  This  Agreement  shall be governed  and
construed in accordance with the laws of the State of California  without giving
effect to the conflicts of laws provisions thereof.

                  34.      SEVERABILITY.

                  If any provision,  sentence,  phrase or word of this Agreement
or the application  thereof to any person or circumstance shall be held invalid,
the remainder of this Agreement, or the application of such provision, sentence,
phrase, or word to persons or circumstances,  other than those as to which it is
held invalid, shall not be affected thereby.

                  35.      AGREEMENT IN COUNTERPARTS.

                  This Agreement may be executed in several  counterparts,  each
of which shall be deemed an original,  but all of which shall constitute one and
the same  instrument.  In  addition,  this  Agreement  may contain more than one
counterpart  of the  signature  page and this  Agreement  may be executed by the
affixing of the  signatures  of each of the Partners to one of such  counterpart
signature  pages;  all of such signature  pages shall be read as though one, and
they  shall have the same  force and  effect as though  all of the  signers  had
signed a single signature page.


                                      -26-


<PAGE>



                  36.      THIRD PARTIES.

                  The agreements, covenants and representations contained herein
are for the benefit of the parties  hereto  inter se and are not for the benefit
of any  third  parties  including,  without  limitation,  any  creditors  of the
Partnership.

                  37.      POWER OF ATTORNEY.

                  Each Limited  Partner hereby makes,  constitutes  and appoints
Dr.  Joseph  Jenkins  and Dr.  Dan A.  Myers,  severally,  with  full  power  of
substitution,  his true and lawful  attorneys-in-fact,  for him and in his name,
place and stead and for his use and  benefit to sign and  acknowledge,  file and
record,  any  amendments  hereto among the  Partners for the further  purpose of
executing and filing on behalf of each Limited Partner, any and all certificates
of  limited   partnership  or  other  documents   necessary  to  constitute  the
Partnership or to effect the continuation of the  Partnership,  the admission or
withdrawal of a general partner or a limited partner,  the  qualification of the
Partnership in a foreign jurisdiction (or amendment to such qualification),  the
admission of substitute  Limited  Partners or the  dissolution or termination of
the   Partnership,   provided   such   continuation,    admission,   withdrawal,
qualification,  or dissolution  and termination are in accordance with the terms
of this Agreement.

                  The foregoing power of attorney is a special power of attorney
coupled with an interest,  is  irrevocable  and shall survive the death or legal
incapacity  of each  Limited  Partner.  It may be  exercised  by any one of said
attorneys by listing all of the Limited  Partners  executing any instrument over
the  signature  of the  attorney-in-fact  acting  for all of them.  The power of
attorney shall survive the delivery of an assignment by a Limited Partner of the
whole or any portion of his Unit.  In those cases in which the  assignee  of, or
the  successor  to, a Limited  Partner  owning a Unit has been  approved  by the
Partners for admission to the Partnership as a substitute  Limited Partner,  the
power of attorney  shall  survive for the sole  purpose of enabling  the General
Partner to execute, acknowledge and file any instrument necessary to effect such
substitution.

                  This power of attorney shall not be affected by the subsequent
incapacity or mental incompetence of any Limited Partner.

                  38.      ARBITRATION.

                  Any  dispute  arising  out  of  or  in  connection  with  this
Agreement  or the breach  thereof  shall be decided by  arbitration  in Raleigh,
North  Carolina in accordance  with the then  effective  commercial  arbitration
rules of the  American  Arbitration  Association,  and  judgment  thereof may be
entered in any court having jurisdiction thereof.

                  39.      CREDITORS.

                  None of the  provisions  of this  Agreement  shall  be for the
benefit of or enforceable by any creditors of the Partnership.



                                      -27-


<PAGE>



                  IN WITNESS  WHEREOF,  the parties have executed this Agreement
of Limited Partnership as of the day and year first above written.

                            GENERAL PARTNER:

                            PROSTATHERAPIES, INC., a Delaware corporation


                            By:      /s/ Dan A. Myers
                                     -----------------------------
                                     Dan A. Myers, M.D., President

ATTEST:

/s/ Philip J. Gallina                                      [CORPORATE SEAL]
- ----------------------
Secretary


                            INITIAL LIMITED PARTNER:

                                        /s/ Dan A. Myers
                                       ---------------------------------------
                                        Dan A. Myers, M.D.


STATE OF NORTH CAROLINA                     )
                                            )
COUNTY OF CUMBERLAND                        )

                  On this  12th  day of  June,  1997,  before  me, the
undersigned  Notary  Public in and for the County of  Cumberland in the State of
North Carolina, personally came Dan A. Myers, M.D., who, being by me duly sworn,
said that he is President of Prostatherapies,  Inc., the sole general partner of
California I  Prostatherapy  Limited  Partnership,  that the seal affixed to the
foregoing  instrument in writing is the corporate seal of the  corporation,  and
that said  writing  was  signed,  sworn to,  and sealed by him in behalf of said
corporation  by its  authority  duly  given.  And the said Dan A.  Myers,  M.D.,
further certified that the facts set forth in said writing are true and correct,
and acknowledged said instrument to be the act and deed of said corporation.

                  WITNESS my hand and notarial seal.

                                   /s/ Lou Ann Barnes
                                   -------------------------------------------

                                    Notary Public
My commission expires:
May 26, 2001
- ---------------------------



                                      -28-


<PAGE>



STATE OF NORTH CAROLINA                     )
                                            )
COUNTY OF CUMBERLAND                        )


                  I, Lou Ann Barnes, a notary public, do hereby
certify that Dan A. Myers, M.D.  personally appeared before me this 12th day of
June, 1997 and acknowledged and swore to the due execution of the foregoing
Limited Partnership Agreement in his capacity as the initial limited partner.



                                     /s/ Lou Ann Barnes
                                    ------------------------------------------

                                    Notary Public

My commission expires:
May 26, 2001
- ---------------------------


                                      -29-


<PAGE>



                           COUNTERPART SIGNATURE PAGE


                  By signing this  Counterpart  Signature  Page, the undersigned
acknowledges  his or  her  acceptance  of  that  certain  Agreement  of  Limited
Partnership of California I Prostatherapy  Limited  Partnership,  and his or her
intention to be legally bound thereby.

                  Dated this 12th day of June, 1997.


                                    /s/ Philip J. Gallina
                                    -------------------------------------------

                                    Signature


                                    Philip J. Gallina, Secretary
                                    Prostatherapies, Inc.
                                    -------------------------------------------

                                    Printed Name




STATE OF NORTH CAROLINA                   )
                                           
COUNTY OF CUMBERLAND                    )


                  BEFORE ME, the undersigned  Notary Public in and for the State
and County set forth  above,  on the  12th day of  June,  1997,
personally  appeared  Philip J. Gallina,  and,  being by me first duly  sworn,
stated that (s)he  signed this  Counterpart  Signature  Page for the purpose set
forth above and that the statements contained therein are true.



                                    /s/ Lou Ann Barnes
                                    -------------------------------------------

                                    Signature of Notary Public


                                    Lou Ann Barnes
                                    -------------------------------------------

                                    Printed Name of Notary

My Commission Expires:
May 26, 2001
- ---------------------------

[SEAL]

                                      -30-


<PAGE>

                                   SCHEDULE A

                       Schedule of Partnership Interests

                 CALIFORNIA I PROSTATHERAPY LIMITED PARTNERSHIP

           CONTRIBUTIONS OF CAPITAL TO THE PARTNERSHIP AND PERCENTAGE
                                   INTERESTS

                                             Cash               Percentage
         General Partner                  Contribution            Interest
 
         Prostatherapies, Inc.             $207,339.06                20%
         2008 Litho Place
         Fayetteville, NC 28304

         Limited Partners

         Roger N. Andrews                    10,400                    1
         Habib Anwar                          1,300                     .125
         Stephen Auerbach                    10,400                    1
         Ruben Baghdassarian                  5,200                     .50
         Alex G. Batta                        2,600                     .25
         Theodore V. Benderev                 5,200                     .50
         Mohamed Bidair                       2,600                     .25
         Kenneth J. Blunt                    10,400                    1
         William E. Bodenstab                10,400                    1
         Philip C. Bosch                     10,400                    1
         Stephen S. Bridge                   10,400                    1
         Paul A. Brower                      10,400                    1
         Bruce W. Bucklew                    10,400                    1
         Philip A. Butler                    10,400                    1
         James A. Cavins                      2,600                     .25
         Richard A. Cerruti                   5,200                     .50
         Stuart A. Chalfin                    5,200                     .50
         Neil O. Chamberlain                  5,200                     .50
         Edward s. Cohen                      5,200                     .50
         David M. Cumes                       2,600                     .25
         Daniel J. Curhan                    10,400                    1
         John W. Davis                       10,400                    1
         Ganesha L. Devendra                  5,200                     .50
         John W. Edwards                      5,200                     .50
         Cedric B. Emery                     10,400                    1
         John A. Emery                        2,600                     .25
         General B. Farrow                    5,200                     .50

<PAGE>
         Stuart L. Feldman                    5,200                     .50
         Vincent J. Flynn                     5,200                     .50
         Bradley L. Frasier                  10,400                    1
         Alan M. Freedman                     2,600                     .25
         William E. Friedel                   2,600                     .25
         Edwin S. Gardiner                   10,400                    1
         Franklin D. Gaylis                   2,600                     .25
         Lawrence S. Greenberg               10,400                    1
         John J. Greisman                    10,400                    1
         Lee B. Harbach                      10,400                    1
         Harry M. Henderson                   5,200                     .50
         William F. Hohn                     10,400                    1
         Daniel B. Hunting                   10,400                    1
         Lawrence W. Jones                    2,600                     .25
         Saad Juma                            2,600                     .25
         Ashok J. Kar                        10,400                    1
         Jeffrey E. Kaufman                   5,200                     .50
         Danny L. Keiller                     2,600                     .25
         Warren O. Kessler                   10,400                    1
         Fred Khonsari                        5,200                     .50
         William T. Klope                     2,600                     .25
         Alec S. Koo                          2,600                     .25
         Alex Koper                          10,400                    1
         Michael A. LaRocque                 10,400                    1
         David J. Laub                        2,600                     .25
         Huey C. Lin                          5,200                     .50
         Morgan P. Lloyd                     10,400                    1
         Howard D. Lowe                      10,400                    1
         Derrick Marinelli                   10,400                    1
         Leonard S. Marks                     7,800                     .75
         John J. Martin                       2,600                     .25
         Arturo G. Martinez                  10,400                    1
         Robert H. Masters                    2,600                     .25
         James P. Meaglia                     7,800                     .75
         Manish Mehta                        10,400                    1
         William G. Moseley                  10,400                    1
         Daniel A. Nachtsheim                 7,800                     .75
         William T. Naftel                    2,600                     .25
         Paul Neustein                        2,600                     .25
         Daniel S. Niku                       5,200                     .50
         Melvyn H. Novegrod                   2,600                     .25
         Thomas G. Ochsner                   10,400                    1
         C. Lowell Parsons                    7,800                     .75
         Joy G. Paul                          2,600                     .25
         Jules M. Perley                     10,400                    1

<PAGE>

         Cu N. Phan                           2,600                      .25
         John R. Piconi                       2,600                      .25
         Raymond S. Pong                      5,200                      .50
         Prostatherapies, Inc.               58,456.25                  5.875
         Robert C. Pugach                     2,600                      .25
         Joseph L. Raffel                    10,400                     1
         Eugene C. Rajaratnam                 7,800                      .75
         Muni Reddy                           5,200                      .50
         Richard R. Reed                      2,600                      .25
         Robert J. Reiner                     2,600                      .25
         William F. Reynolds                  2,600                      .25
         David W. Rhodes                      5,200                      .50
         Donald B. Rhodes                    10,400                     1
         George N. Riffle                     2,600                      .25
         Marianne G. Rochester               10,400                     1
         Lewis Rubin                         10,400                     1
         Steven M. Rudy                      10,400                     1
         Donald E. Sawyer                     3,900                      .375
         Robert A. Schroeder                  5,200                      .50
         Terrence D. Schuhrke                10,400                     1
         Joel R. Sheiner                     10,400                     1
         Igal Silber                         10,400                     1
         Paul D. Silverman                    5,200                      .50
         Robin V. Smith                      10,400                     1
         Ronald S. Solomon                   10,400                     1
         Max M. Stearns                       2,600                      .25
         Marc J. Stratton                    10,400                     1
         Roy I. Sugasawara                    2,600                      .25
         Bradley J. Taylor                   10,400                     1
         Bernard A. Turbow                   10,400                     1
         Carlton T. Valvo                     2,600                      .25
         Barton H. Wachs                      2,600                      .25
         Arthur B. Warshawsky                10,400                     1
         Alan C. Weinberg                    10,400                     1
         Alex J. Weinstein                   10,400                     1
         Martin J. Weissman                  10,400                     1
         Phillip G. Wise                     10,400                     1
         Fredrick N. Wolk                     2,600                      .25
         Alan H. Yamada                       9,100                      .875
         Jay M. Young                        10,400                     1
         Scott K. Yun                         2,600                      .25
         Norman R. Zinner                     2,600                      .25
                  TOTAL                  $1,036,695.31                100%



<PAGE>



                        AGREEMENT OF LIMITED PARTNERSHIP

                                       OF

                   GREAT LAKES LITHOTRIPSY LIMITED PARTNERSHIP



<PAGE>



                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                   GREAT LAKES LITHOTRIPSY LIMITED PARTNERSHIP

                                TABLE OF CONTENTS

         Article Heading                                                 Page

         1.       FORMATION..................................................1

         2.       NAME.......................................................1

         3.       OFFICES....................................................1

         4.       PURPOSE....................................................2

         5.       TERM.......................................................2

         6.       CERTAIN DEFINED TERMS......................................2

         7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS...............6

         8.       GUARANTIES.................................................6

         9.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE LIMITED
                  PARTNERS...................................................7

         10.      REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                  GENERAL PARTNER............................................7

         11.      ADMISSION OF LIMITED PARTNERS..............................7

         12.      CAPITAL ACCOUNTS...........................................8

         13.      ALLOCATIONS................................................9

         14.      DISTRIBUTIONS.............................................10

         15.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS................10

         16.      LIMITED LIABILITY.........................................12

         17.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS...........12

         18.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON CERTAIN
                  EVENTS....................................................16



<PAGE>




         19.      SALE, ASSIGNMENT OR OTHER TRANSFER OF THE GENERAL
                  PARTNER'S INTEREST........................................20

         20.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER........21

         21.      MANAGEMENT AND OPERATION OF BUSINESS......................21

         22.      RESERVES..................................................24

         23.      INDEMNIFICATION AND EXCULPATION OF THE GENERAL
                  PARTNER...................................................24

         24.      DISSOLUTION OF THE PARTNERSHIP............................24

         25.      DISTRIBUTION UPON DISSOLUTION.............................26

         26.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.....................26

         27.      NOTICES...................................................27

         28.      AMENDMENTS................................................27

         29.      LIMITATIONS ON AMENDMENTS.................................27

         30       MEETINGS, CONSENTS AND VOTING.............................28
                  
         31.      SUBMISSIONS TO THE LIMITED PARTNERS.......................28

         32.      ADDITIONAL DOCUMENTS......................................29

         33.      SURVIVAL OF RIGHTS........................................29

         34.      INTERPRETATION AND GOVERNING LAW..........................29

         35.      SEVERABILITY..............................................29

         36.      AGREEMENT IN COUNTERPARTS.................................29

         37.      THIRD PARTIES.............................................29

         38.      POWER OF ATTORNEY.........................................30

         39.      ARBITRATION...............................................30

         40.      CREDITORS.................................................30

                  Schedule A...............  Schedule of Partnership Interests



<PAGE>



THE  LIMITED  PARTNERSHIP  INTERESTS  REPRESENTED  BY THIS  LIMITED  PARTNERSHIP
AGREEMENT HAVE NOT BEEN REGISTERED  WITH THE SECURITIES AND EXCHANGE  COMMISSION
UNDER THE  SECURITIES  ACT OF 1933, AS AMENDED,  UNDER THE WISCONSIN  SECURITIES
LAWS, AS AMENDED, OR UNDER SIMILAR LAWS OR ACTS OF OTHER STATES IN RELIANCE UPON
EXEMPTIONS UNDER SUCH LAWS.


                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                             GREAT LAKES LITHOTRIPSY
                               LIMITED PARTNERSHIP


                  THIS AGREEMENT OF LIMITED  PARTNERSHIP  (the  "Agreement")  is
made as of  October 21,  1997, by and among PRIME KIDNEY STONE  TREATMENT,
INC., a New Jersey corporation (the "General  Partner"),  and the persons listed
on Schedule A attached hereto as the Limited Partners.

                  1.       FORMATION.

                  The Partnership was originally formed under the name Wisconsin
Lithotripsy  Limited  Partnership  I  pursuant  to a filing in the Office of the
Secretary  of State of Wisconsin  on or about May 14, 1997 of a  Certificate  of
Limited  Partnership.  Subsequently,  the name of the Partnership was changed to
Great  Lakes  Lithotripsy  Limited  Partnership  pursuant  to  the  filing  of a
Certificate of Amendment in the Office of the Secretary of State of Wisconsin on
or about May 16, 1997 in accordance with the provisions of the Act.

                  2.       NAME.

                  2.1  The name of the Partnership is "Great Lakes Lithotripsy
Limited Partnership."

                  2.2 The  Partnership  business  shall be conducted  under such
names as the General  Partner may from time to time deem necessary or advisable,
provided that appropriate amendments to this Agreement and all necessary filings
under  applicable  assumed  or  fictitious  name  statutes  or the Act are first
obtained.

                  3.       OFFICES.

                  3.1 The principal  office of the Partnership  shall be at 1301
Capital of Texas Highway,  Suite C-300,  Austin,  Texas 78746,  or at such other
place as the General Partner may, from time to time,  designate by notice to the
Limited Partners (the "Records Office").

                  3.2 The Partnership  may have such  additional  offices as the
General Partner may, from time to time, deem necessary or advisable.


                                       -1-


<PAGE>



                  4.       PURPOSE.

                  The purpose and business of the  Partnership  shall be: (i) to
operate one or more extracorporeal,  shock-wave  lithotripters for the treatment
of renal stones  primarily in northern  Indiana and Wisconsin,  or in such other
location(s) as the General Partner may determine, in its sole discretion,  to be
in the best  interests  of the  Partnership,  (ii) to acquire and operate in the
future  any  other  urological  device  or  equipment  that  as of the  date  of
acquisition by the Partnership has received FDA premarket approval; and (iii) to
engage in any and all activities  incidental or related to the  foregoing,  upon
and subject to the terms and conditions of this Agreement.

                  5.       TERM.

                  The Partnership  shall terminate on May 31, 2047 unless sooner
terminated as herein provided.

                  6.       CERTAIN DEFINED TERMS.

                  Certain terms used in this Agreement  shall have the following
meanings:

                  Act.  The Act means the Wisconsin Uniform Limited Partnership 
Act, as then in effect.

                  Affiliate.  An  Affiliate  is  (i)  any  person,  partnership,
corporation, association or other legal entity ("person") directly or indirectly
controlling, controlled by or under common control with another person; (ii) any
person owning or controlling 10% or more of the  outstanding  voting interest of
such other person;  (iii) any officer,  director or partner of such person;  and
(iv) if such other  person is an officer,  director  or partner,  any entity for
which such person acts in such capacity.

                  Agreement.  This Agreement of Limited Partnership, as the same
may be amended from time to time.

                  Bank.  First Citizens Bank & Trust Company.

                  Capital Account.  The Partnership capital account of a Partner
as computed pursuant to Article 11 of this Agreement.

                  Capital  Contributions.  All capital  contributions  made by a
Partner or his predecessor in interest which shall include,  without limitation,
contributions made pursuant to Article 7 of this Agreement.

                  Capital Transaction.  Any transaction which, were it to 
generate proceeds, would produce Partnership Sales Proceeds or Partnership 
Refinancing Proceeds.

                  Code.  The Internal Revenue Code of 1986, as amended, or 
corresponding provisions of subsequent, superseding revenue laws.


                                       -2-


<PAGE>



                  Dilution  Offering.   As  provided  in  Section  7.4  of  this
Agreement,  the future offering of additional limited  partnership  interests in
the Partnership by the General Partner.  Any successful  Dilution  Offering will
proportionately  reduce the  Percentage  Interests of the then  current  Limited
Partners in the Partnership.

                  Domestic Proceeding.  Any divorce, annulment, separation or
similar domestic proceeding between a married couple.

                  Equipment.  The  initial  equipment  to  be  acquired  by  the
Partnership  for the  operation of the Mobile  Lithotripsy  System.  The initial
equipment  to be used in the  operation  of the Mobile  Lithotripsy  system will
include the  lithotripter,  the Trailer,  the Truck, and  miscellaneous  medical
equipment and supplies.

                  FDA.  The United States Food and Drug Administration.

                  General Partner.  The General Partner of the Partnership, 
Prime Kidney Stone Treatment, Inc., a New Jersey corporation.

                  Guaranty.  The  Guaranty  Agreement  pursuant  to  which  each
Limited Partner will guarantee a portion of the Partnership's  obligation to the
Bank under the Loan.  The form of the  Guaranty  Agreement  is  included  in the
Subscription Packet accompanying the Memorandum.

                  Initial  Limited  Partner.  Dan A. Myers,  M.D., a resident of
North  Carolina  and an Affiliate of the General  Partner.  The Initial  Limited
Partner is to be the only limited partner of the Part nership until such time as
the new Limited  Partners  are  admitted to the  Partnership,  at which time the
Initial Limited Partner shall withdraw from the Partnership.

                  Limited Partners.  The Limited Partners are those investors in
the Units  admitted  to the  Partnership  and any person  admitted  as a Limited
Partner in accordance with the provisions of this Agreement.

                  Loan.  The  loan  of up to  $1,056,000  from  the  Bank to the
Partnership.  Loan  proceeds will be used by the  Partnership  to (i) acquire an
extracorporeal  shock-wave  lithotripter together with options (up to $650,000),
(ii)  acquire  and  upfit a mobile  Trailer  to house  the  lithotripter  (up to
$300,000),  (iii)  acquire  the  Truck  for  hauling  the  Trailer  housing  the
lithotripter (up to $50,000),  and (iv) pay the Wisconsin use tax on the Trailer
and the lithotripter (up to $56,000).

                  Losses.  The net loss (including Net Losses from Capital 
Transactions)  of the Partnership for each Year of the Partnership as determined
for federal income tax purposes.

                  Majority  in Interest  of the  Limited  Partners.  The Limited
Partners who hold more than 50% of the Limited Partner  Percentage  Interests in
the Partnership.

                  Memorandum.  The Confidential Private Placement Memorandum of 
the Partnership dated May 21, 1997, as amended or as supplemented.


                                       -3-


<PAGE>



                  Mobile Lithotripsy System.  The Trailer and Truck with the 
installed and operational lithotripter.

                  Net Gains from Capital Transactions. The gains realized by the
Partnership  as a result of or upon any sale,  exchange,  condemnation  or other
disposition of the capital assets of the Partnership (which assets shall include
Code Section 1231 assets) or as a result of or upon the damage or destruction of
such capital assets.

                  Net Losses from Capital  Transactions.  The losses realized by
the Partnership as a result of or upon any sale, exchange, condemnation or other
disposition of the capital assets of the  Partnership  (which shall include Code
Section 1231 assets) or as a result of or upon the damage or destruction of such
capital assets.

                  Partners.  The General Partner and the Limited Partners, 
collectively, where no distinction is required by the context in which the term 
is used herein.

                  Partnership.  Great Lakes Lithotripsy Limited Partnership, a 
Wisconsin limited partnership.

                  Partnership  Cash Flow. For the applicable  period the excess,
if any,  of (A) the sum of (i) all  gross  receipts  from  any  source  for such
period,  other than from  Partnership  loans,  Capital  Transactions and Capital
Contributions,  and (ii) any funds released by the  Partnership  from previously
established  reserves,  over  (B) the sum of (i) all cash  expenses  paid by the
Partnership  for such  period;  (ii) the amount of all  payments of principal on
loans to the Partnership;  (iii) capital  expenditures of the  Partnership;  and
(iv) such  reasonable  reserves as the General  Partner shall deem  necessary or
prudent to set aside for future repairs,  improvements or equipment  replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities and contingencies of the Partnership; provided, however, that
the  amounts  referred  to in (B)(i),  (ii) and (iii)  above shall be taken into
account  only to the extent not funded by Capital  Contributions,  loans or paid
out of previously  established reserves.  Such term shall also include all other
funds deemed  available for  distribution  and designated as  "Partnership  Cash
Flow" by the General Partner.

                  Partnership Interest.  The interest of a Partner in the 
Partnership as defined by the Act and this Agreement.

                  Partnership  Refinancing Proceeds.  The cash realized from the
refinancing of Partnership assets after retirement of any secured loans and less
(i) payment of all expenses  relating to the transaction and (ii)  establishment
of such  reasonable  reserves as the General  Partner  shall deem  necessary  or
prudent to set aside for future repairs,  improvements, or equipment replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities or contingencies of the Partnership.

                  Partnership  Sales Proceeds.  The cash realized from the sale,
exchange,  casualty  or other  disposition  of all or a portion  of  Partnership
assets after the retirement of all secured loans and less (i) the payment of all
expenses  related to the transaction and (ii)  establishment  of such reasonable
reserves as the General Partner shall deem necessary or prudent to set aside for
future repairs, improvements, or

                                       -4-


<PAGE>



equipment  replacement or additions,  or to meet working capital requirements or
foreseen or unforeseen future liabilities or contingencies of the Partnership.

                  Percentage  Interest.  The  interest  of each  Partner  in the
Partnership,  to be  determined  initially  in the case of a Limited  Partner by
reference to his or her Unit ownership based upon the Limited  Partners  holding
an aggregate 80% Percentage Interest in the Partnership,  with each initial Unit
sold representing an initial 1% interest. The General Partner initially will own
a 20% Percentage  Interest in the Partnership.  A Partner's  Percentage Interest
may be reduced by a future Dilution Offering. The Partners' Percentage Interests
in the Partnership as of the date hereof are as set forth in Schedule A attached
hereto. Any future  adjustments in the Partners'  Percentage  Interests,  due to
future  Dilution  Offerings  or  otherwise,  will be  reflected  by revisions to
Schedule A.

                  PKST.  Prime Kidney Stone Treatment, Inc., a New Jersey 
corporation, and the sole General Partner of the Partnership.

                  Profit.  The net income of the Partnership (including Net 
Gains from Capital  Transactions) for each Year of the Partnership as determined
for federal income tax purposes.

                  Pro  Rata  Basis.   In   connection   with  an  allocation  or
distribution,  an allocation  or  distribution  in proportion to the  respective
Percentage Interests of the class of Partners to which reference is made.

                  Sales Agency  Agreement.  The sales agency  agreement  through
which  MedTech  Investments,  Inc.,  an Affiliate  of the General  Partner and a
broker-dealer company registered with the Securities and Exchange commission and
a member of the National Association of Securities Dealers, Inc. shall offer and
sell  the  limited  partnership  interest  of the  Partnership  pursuant  to the
Memorandum.

                  Sales Commission.  The $250 sales commission paid to MedTech 
Investments, Inc. for each Unit sold.

                  Service.  The Internal Revenue Service.

                  Trailer.  The new or reconditioned mobile Trailer upfitted to 
house the lithotripter.

                  Truck.  The used tractor-trailer truck to be utilized for 
hauling the Trailer.

                  Units.   The  80  equal  limited  partner   interests  in  the
Partnership offered pursuant to the Memorandum for a price per Unit of $2,500 in
cash, plus a personal guaranty of 1% of the Partnership's  obligations under the
Loan (up to a $10,560 principal guaranty obligation).

                  Year.  An annual accounting period ending on December 31 of 
each year during the term of the Partnership.


                                       -5-


<PAGE>



                  7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS.

                  7.1  General  Partner  Contribution.  On or before the date of
this  Agreement,  the  General  Partner  will  contribute  to the capital of the
Partnership  cash in an amount  equal to 20% (up to  $50,000)  of the total cash
contributed to the  Partnership by the Partners in the offering made pursuant to
the Memorandum.

                  7.2 Limited Partner Contribution.  Each Limited Partner hereby
agrees to contribute and shall  contribute to the capital of the  Partnership on
the date of his admission to the  Partnership the cash amount set forth opposite
his name on Schedule A attached hereto.

                  7.3      No Interest.  Except as otherwise provided herein, no
interest shall be paid on any contribution to the capital of the Partnership.

                  7.4 Dilution  Offerings.  If the General Partner,  in its sole
discretion,  determines that it is in the best interest of the Partnership,  the
General Partner may, from time to time, issue, offer and sell additional limited
partnership  interests  in the  Partnership  (a  "Dilution  Offering")  to local
urologists who are not already Limited  Partners  ("Qualified  Investors").  The
primary  purpose  of any  Dilution  Offering  would be (i) to  raise  additional
capital for any  legitimate  Partnership  purpose as set forth in Article 4, and
(ii) to assure  the  highest  quality  of patient  care by  admitting  Qualified
Investors to the  Partnership  who would be dedicated and motivated as owners to
follow  the  Partnership's  treatment  protocol,  and  comply  with its  quality
assurance  and outcome  analysis  programs.  Any limited  partnership  interests
offered by the  Partnership  in a Dilution  Offering shall be sold in the manner
and  according to the terms  prescribed  in the sole  discretion  of the General
Partner;  provided,  however,  that any additional limited partnership interests
offered  in a  Dilution  Offering  will be sold for a price  no  lower  than the
highest  price for which  proportionate  limited  partnership  interests  in the
Partnership have been previously sold by the Partnership. Any sale of additional
limited partnership  interests will result in the proportionate  dilution of the
Partnership  Percentage Interests of the existing Partners.  Notwithstanding the
above,  in the event of a Dilution  Offering,  the  General  Partner  and/or its
Affiliates  may elect,  in their sole  discretion,  to prevent  dilution  of the
Percentage  Interests of the General  Partner  and/or its  Affiliates  by either
contributing a proportionate  amount of additional capital to the Partnership or
purchasing  additional limited  partnership  interests in any Dilution Offering.
Limited Partners will have no right to purchase  additional limited  partnership
interests in any Dilution Offering. Any investor acquiring a limited partnership
interest  in a Dilution  Offering  shall  agree to be bound by the terms of this
Agreement,  and shall be  automatically  admitted  as a Limited  Partner  of the
Partnership. Any adjustment in the Partners' Percentage Interests resulting from
a Dilution Offering shall be set forth on Schedule A attached hereto.

                  8.       GUARANTIES.

                  Each Partner agrees to execute and deliver to the  Partnership
on the date of his or her admission to the  Partnership a Guaranty  agreement in
the amount set forth opposite his or her name on Schedule A attached hereto.


                                       -6-


<PAGE>



                  9.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE
                           LIMITED PARTNERS.

                  The  obligations of the Limited  Partners to make cash Capital
Contributions  hereunder are subject to the condition that the  representations,
warranties, agreements and covenants of the General Partner set forth in Article
10 of this  Agreement  are and shall be true and  correct  or have been and will
have been  complied  with in all  material  respects  on the date  such  Capital
Contributions  are  required  to be made,  except  to the  extent  that any such
representation or warranty expressly pertains to an earlier date.

                  10.      REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                           GENERAL PARTNER.

                  10.1 The General Partner hereby represents and warrants to the
Limited Partners that:

                  (a)  The  Partnership  is  a  limited  partnership  formed  in
         accordance  with  and  validly  existing  under  the Act and the  other
         applicable laws of the State of Wisconsin;

                  (b) The interests in the  Partnership of the Limited  Partners
         will have been duly  authorized  or created and validly  issued and the
         Limited  Partners shall have no personal  liability to contribute money
         to the  Partnership  other than the amounts agreed to be contributed by
         them in the  manner  and on the  terms  set  forth  in this  Agreement,
         subject, however, to such limitations as may be imposed under the Act;

                  (c) No material  breach or default  adverse to the Partnership
         exists under the terms of any other  material  agreement  affecting the
         Partnership; and

                  (d) The General Partner is a New Jersey corporation formed and
         existing under the laws of the State of New Jersey.

                  10.2 The  General  Partner  hereby  covenants  to the  Limited
Partners that:

                  (a) It will at all times act in a fiduciary manner with 
         respect to the Partnership and the Limited Partners;

                  (b) Except as  provided  in  Article  19, it will serve as the
         General Partner of the Partnership  until the Partnership is terminated
         without reconstitution; and

                  (c) It will cause the  Partnership  to carry  adequate  public
         liability,  property  damage and other insurance as is customary in the
         business to be engaged in by the Partnership.

                  11.      ADMISSION OF LIMITED PARTNERS.

                  The  General  Partner may permit the offer and sale of limited
partnership  interests on the terms and conditions provided in the Memorandum or
future Dilution Offering and may admit persons

                                       -7-


<PAGE>



subscribing  for interests as Limited  Partners in the  Partnership on the terms
and conditions set forth in this Article 11.

                  (a) The General  Partner  shall have approved of the admission
         of said person in writing on such terms and  conditions  as the General
         Partner shall determine;

                  (b)  Said  person  shall  have  executed  such   documents  or
         instruments  as the General  Partner may deem necessary or desirable to
         effect his admission as a Limited Partner;

                  (c) Said  person  shall have  accepted  and adopted all of the
         terms and provisions of this Agreement, as then amended;

                  (d)  Said  person  (if a  corporation)  shall  deliver  to the
         General  Partner  a  certified  copy of a  resolution  of its  Board of
         Directors  authorizing  it to become a Limited  Partner under the terms
         and conditions of this Agreement; and

                  (e) Said person,  upon request by the General  Partner,  shall
         pay such reasonable  expenses as may be incurred in connection with its
         admission as a Limited Partner.

                  12.      CAPITAL ACCOUNTS.

                  A capital  account shall be  established  for each Partner and
shall at all  times be  determined  and  maintained  as  provided  by the  Final
Treasury  Regulations  under  Section  704(b)  of the  Code,  as the same may be
amended.  A Partner  shall not be entitled  to withdraw  any part of his capital
account or to receive any distribution from the Partnership,  except as provided
in Articles 14 and 25.

                  (a)      Each Partners' capital account shall be increased by:

                           (i) The amount of his Capital Contribution pursuant 
                  to Article 7; and

                           (ii) The amount of Profits allocated to him pursuant
                  to Article 13; and

                           (iii) The Partner's pro rata share (determined in the
                  same  manner as such  Partner's  share of  Profits  and Losses
                  allocated pursuant to Article 13 hereof) of any income or gain
                  exempt from tax.

                  (b) Each Partner's capital account shall be decreased by:

                           (i) The amount of Losses allocated to him pursuant to
                  Article 13; and


                                       -8-


<PAGE>



                           (ii) The amount of Partnership Cash Flow, Partnership
                  Sales   Proceeds   and   Partnership    Refinancing   Proceeds
                  distributed to him pursuant to Article 14; and

                           (iii)  The  Partner's  pro rata  share  of any  other
                  expenditures  of the  Partnership  which are not deductible in
                  computing  Partnership  Profits  or  Losses  and which are not
                  added to the tax basis of any Partnership property, including,
                  without   limitation,   expenditures   described   in  Section
                  705(a)(2)(B) of the Code. The Partner's pro rata share of such
                  expenditures  shall be  determined  in the same manner as such
                  Partner's  share of Profits and Losses  allocated  pursuant to
                  Article 13.

                  13.      ALLOCATIONS

                  (a)  Profits  and  Losses.  The  Profits  and  Losses  of  the
         Partnership  shall be allocated  among the Partners in accordance  with
         their  respective  Percentage  Interests.  In  allocating  Profits  and
         Losses,  Net Gains and  Losses  from  Capital  Transactions  (a part of
         Profits and Losses), if any, shall be allocated first.

                  (b)  Qualified  Income  Offset.  If any  Partner  unexpectedly
         receives  any  adjustment,  allocation  or  distribution  described  in
         Treasury Regulations Section 1.704- 1(b)(2)(ii)(d)(4) through (6) which
         causes or increases a deficit balance in such Partner's Capital Account
         (adjusted  for  this  purpose  in  the  manner   provided  in  Treasury
         Regulations Section 1.704-1(b)(2)(ii)(d)),  items of Partnership income
         and gain shall be specially allocated to each such Partner in an amount
         and manner  sufficient  to  eliminate,  to the extent  required  by the
         Regulations,  the deficit Capital Account of such Partner as quickly as
         possible,  provided that an  allocation  pursuant to this Article 13(b)
         shall be made if and only to the extent that such Partner  would have a
         deficit  Capital  Account after all other  allocations  provided for in
         this Article 13 have been  tentatively  made as if this  Article  13(b)
         were  not  in  the  Agreement.  This  provision  is  intended  to  be a
         "qualified income offset," as defined in Treasury  Regulations  Section
         1.704- 1(b)(2)(ii)(d),  such Regulation being specifically incorporated
         herein by reference.

                  (c) Sales Commission.  The Sales Commission shall be allocated
         to the  Units  which  are  not  held  by the  General  Partner  and its
         Affiliates  in  proportion to their  respective  capital  contributions
         represented  by such Units (i.e.,  $250 in Sales  Commissions  per each
         such Unit).  The purpose of this Article 13(c) is to allocate the Sales
         Commission to those Partners who actually bore the burden of paying the
         Sales Commission.

                  (d)  Allocations  Between  Transferor and  Transferee.  In the
         event of the transfer (other than the pledges of the General  Partner's
         interest  permitted  by Article 19 or  Permitted  Pledges  described in
         Article  17.2(b))  of all or  any  part  of a  Partner's  interest  (in
         accordance with the provisions of this Agreement) in the Partnership at
         any time other  than at the end of a Year,  or the  admission  of a new
         Partner (in accordance with the

                                       -9-


<PAGE>



         terms of this  Agreement),  the  transferring  Partner or new Partner's
         share of the Partnership's  income, gain, loss, deductions and credits,
         as computed  both for  accounting  purposes and for Federal  income tax
         purposes,  shall be allocated  between the  transferor  Partner and the
         transferee  Partner  (or  Partners),  or the new  Partner and the other
         Partners,  as the case may be, in the same  ratio as the number of days
         in such Year before and after the date of the  transfer  or  admission;
         provided,  however,  that if there has been a sale or other disposition
         of the assets of the  Partnership  (or any part  thereof)  during  such
         Year, then the General Partner may elect,  in its sole  discretion,  to
         treat  the  periods  before  and  after  the  date of the  transfer  or
         admission as separate Years and allocate the  Partnership's net income,
         gain, net loss, deductions and credits for each of such deemed separate
         Years. Notwithstanding the foregoing, the Partnership's "allocable cash
         basis items," as that term is used in Section 706(d)(2)(B) of the Code,
         shall be allocated as required by Section 706(d)(2) of the Code and the
         regulations thereunder.

                  (e) Tax  Withholding.  The Partnership  shall be authorized to
         pay, on behalf of any  Partner,  any amounts to any  federal,  state or
         local taxing  authority,  as may be necessary  for the  Partnership  to
         comply with tax withholding  provisions of the Code or the other income
         tax or  revenue  laws  of any  taxing  authority.  To  the  extent  the
         Partnership  pays any such  amounts  that it may be  required to pay on
         behalf  of  a  Partner,  such  amounts  shall  be  treated  as  a  cash
         Distribution  to such  Partner  and shall  reduce the amount  otherwise
         distributable to such Partner.

                  14.      DISTRIBUTIONS.

                  (a)  Distribution of Partnership  Cash Flow.  Partnership Cash
         Flow shall be distributed to the Partners  within 60 days after the end
         of each Year, or earlier in the discretion of the General  Partner,  in
         proportion  to their  respective  Percentage  Interests  at the time of
         distribution.

                  (b)  Distribution  of  Partnership  Refinancing  Proceeds  and
         Partnership  Sales  Proceeds.   Partnership  Refinancing  Proceeds  and
         Partnership  Sales Proceeds shall be distributed to the Partners within
         60 days of the Capital  Transaction  giving rise to such  proceeds,  or
         earlier in the  discretion  of the General  Partner,  in  proportion to
         their respective Percentage Interests at the time of distribution.

                  (c)  Distribution  in  Liquidation.  Upon  liquidation  of the
         Partnership,  all of the  Partnership's  property  shall  be  sold  and
         Profits and Losses allocated accordingly. Proceeds from the liquidation
         of the Partnership shall be distributed in accordance with Article 25.

                  15.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS.

                  15.1  Management.  The Limited Partners shall not take part in
the management of the business,  nor transact any business for the  Partnership,
nor  shall  they  have  power  to  sign  for or to  bind  the  Partnership.  The
Partnership may,  however,  contract with one or more Limited Partners to act as
the

                                      -10-


<PAGE>



local manager of the Mobile Lithotripsy  System. No Limited Partner may withdraw
from the Partnership except as expressly permitted herein.

                  15.2  Operation  of Mobile  Lithotripsy  System.  The  Limited
Partners  shall not  operate or utilize the Mobile  Lithotripsy  System or other
Partnership  equipment except pursuant to (i) an Agreement with the Partnership;
or (ii) any other arrangement specifically approved by the General Partner.

                  15.3 Outside Activities.  The Limited Partners agree that they
owe a fiduciary  duty to the  Partnership  and, as a  consequence,  each Limited
Partner (that is not an Affiliate of the General  Partner) shall not directly or
indirectly  own,  lease or  sublease a Mobile  Lithotripsy  System  (or  similar
equipment used for lithotripsy of renal stones) or any other therapeutic  device
acquired by the Partnership  while they are Limited  Partners in the Partnership
(collectively,  the "Outside  Activities").  Prohibited  indirect ownership of a
competing  device  shall  include the  ownership  of any  interest in a business
venture  (through  stock  ownership,   partnership  interest  ownership,  or  as
otherwise  determined in the sole discretion of the General  Partner)  involving
the  ownership,  purchase,  use,  lease,  sublease  or  operation  of  a  Mobile
Lithotripsy  System (or similar  equipment used for lithotripsy of renal stones)
or other competing  device or equipment,  unless the General Partner  determines
that  such  activity  by the  Limited  Partner  is not  detrimental  to the best
interest of the Partnership.  In the event a Limited Partner elects to engage in
an Outside  Activity in violation of this Article  15.3,  he or she must provide
written  notice of such intent to the General  Partner prior to engaging in such
activity,  and such election shall be deemed an election by the Limited  Partner
to withdraw  from the  Partnership  (the "Notice of  Withdrawal").  If a Limited
Partner  engages in an Outside  Activity  without  first  notifying  the General
Partner of his or her election to do so, the Limited  Partner shall be deemed to
have given a Notice of Withdrawal on the date the General  Partner first becomes
aware of the  Limited  Partner's  Outside  Activity.  Upon  receiving  a Limited
Partner's Notice of Withdrawal or equivalent  thereof,  the  Partnership's  sole
remedy shall be the purchase rights provided in Article 18.3.

                  15.4  Disclosure  of  Confidential  Information.  Each Limited
Partner acknowledges and agrees that his or her participation in the Partnership
under this Agreement necessarily involves his or her understanding of and access
to certain trade secrets and other  confidential  information  pertaining to the
business of the  Partnership.  Accordingly,  each Limited Partner agrees that at
all  times  during  his or her  participation  in the  Partnership  as a Limited
Partner and thereafter, he or she will not, directly or indirectly,  without the
express written authority of the Partnership, unless required by law or directed
by a applicable  legal authority having  jurisdiction  over the Limited Partner,
disclose  or use for the  benefit of any  person,  corporation  or other  entity
(other than the Partnership),  or himself or herself, (i) any trade,  technical,
operational, management or other secrets, any patient or customer lists or other
confidential  or secret data, or any other  proprietary,  confidential or secret
information of the Partnership or (ii) any confidential  information  concerning
any of the financial  arrangements,  financial positions,  hospital or physician
contracts,  third  party  payor  arrangements,  quality  assurance  and  outcome
analysis programs,  competitive status,  customer or supplier matters,  internal
organizational  matters,  technical  abilities,  or other business affairs of or
relating to the Partnership.  The Limited  Partners  acknowledge that all of the
foregoing constitutes proprietary  information,  which is the exclusive property
of the Partnership. In the event of breach of this Article 15.4 as determined by
the General Partner,  the Partnership  shall be entitled to any remedy at law or
equity with respect to such breach, including without limitation,  an injunction
or suit for damages.

                                      -11-


<PAGE>



                  16.      LIMITED LIABILITY.

                  No Limited Partner shall be required to make any  contribution
to the  capital of the  Partnership  except as set forth in Article 7, nor shall
any Limited  Partner in his or her capacity as such,  be bound by, or personally
liable for, any expense,  liability or obligation of the  Partnership  except to
the extent of his or her (i) interest in the  Partnership;  (ii)  Guaranties  of
Partnership  obligations;  and (iii) obligation to return  distributions made to
him or her under certain circumstances as required by the Act.

                  17.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS.

                  17.1     Transferability.

                  (a) The  term  "transfer"  when  used in this  Agreement  with
         respect to a Partnership  Interest includes a sale,  assignment,  gift,
         pledge,  exchange,  or any other  disposition (but does not include the
         issuance of new Partnership Interests pursuant to a Dilution Offering);

                  (b) Except as otherwise  provided herein,  the General Partner
         shall not at any time  transfer or assign its interest or obligation as
         General Partner;

                  (c) The Partnership  Interest of any Limited Partner shall not
         be  transferred,  in whole or in part,  except in  accordance  with the
         conditions and limitations set forth in Articles 17.2 or 18;

                  (d) The  transferee of a Partnership  Interest by  assignment,
         operation of law or otherwise,  shall have only the rights,  powers and
         privileges  enumerated in Article 17.3 or otherwise provided by law and
         may not be admitted to the  Partnership as a Limited  Partner except as
         provided in Article 17.4 or as a General  Partner except as provided in
         Article 17.5;

                  (e) Notwithstanding any provision herein to the contrary,  the
         Partnership  Agreement  shall  in  no  way  restrict  the  issuance  or
         transfers of stock of the General Partner; and

                  (f) Notwithstanding any provision herein to the contrary,  the
         issuance of Partnership  Interests  pursuant to a Dilution Offering and
         the admission of new Limited Partners  pursuant to a Dilution  Offering
         shall be governed by the provisions of Section 7.4 of this Agreement.

                  17.2     Restrictions on Transfers by Limited Partners.

                  (a) All or part of a Partnership  Interest may be  transferred
         by a  Limited  Partner  only  with the prior  written  approval  of the
         General  Partner,  which  approval may be granted or denied in the sole
         discretion  of the  General  Partner.  In no  event  may a  Partnership
         Interest be  transferred  if such  transfer  would  result in a default
         under the  Guaranties,  unless  otherwise  agreed to in  writing by the
         General Partner.

                                      -12-


<PAGE>



                  (b) The General  Partner  shall not approve any  transfer of a
         Partnership  Interest,  except a pledge of any Partnership  Interest by
         the General Partner to any bank,  insurance  company or other financial
         institution to secure payment of indebtedness  (a "Permitted  Pledge"),
         or otherwise  unless the proposed  transferee  shall have furnished the
         General Partner with a sworn statement that:

                           (i) The proposed  transferee  proposes to acquire his
                  or her Partnership Interest as a principal, for investment and
                  not with a view to resale or distribution;

                           (ii) The proposed  transferee meets such requirements
                  regarding sophistication,  income and net worth as required by
                  applicable state and federal securities laws;

                           (iii) The proposed  transferee has met such net worth
                  and income  suitability  standards as have been established by
                  the General Partner;

                           (iv)  The   proposed   transferee   recognizes   that
                  investment in the Partnership  involves  certain risks and has
                  taken  full  cognizance  of and  understands  all of the  risk
                  factors related to the purchase of a Partnership Interest; and

                           (v)  The  proposed   transferee  has  met  all  other
                  requirements of the General Partner for the proposed transfer.

                  (c) Other than in the case of a Permitted  Pledge,  a transfer
         of a  Partnership  Interest  may be made  only  if,  prior  to the date
         thereof,  the Partnership  upon request receives an opinion of counsel,
         satisfactory in form and substance to the General Partner, that neither
         the offering nor the proposed transfer will require  registration under
         federal or applicable state securities laws or regulations.

                  17.3     Rights of Transferee.

                  Unless  admitted to the Partnership in accordance with Article
17.4, the  transferee of a Partnership  Interest or a part thereof or any right,
title or interest therein shall not be entitled to any of the rights, powers, or
privileges of his  predecessor in interest,  except that he shall be entitled to
receive and be credited or debited with his  proportionate  share of Partnership
income, gains, Profits, Losses, deductions, credits or Distributions.

                  17.4     Admission of Limited Partners.

                  Except as  otherwise  provided  in  Article  18,  the  General
Partner, or the transferee of all or part of the Partnership  Interest of either
a General Partner or a Limited Partner,  may be admitted to the Partnership as a
Limited Partner upon furnishing to the General Partner all of the following:


                                      -13-


<PAGE>



                  (a) The  written  approval of a Majority in Interest of all of
         the Limited  Partners  (except the assignor  Partner),  or the assignor
         Partner  alone,  which  approval  may be  granted or denied in the sole
         discretion of such Partners or Partner (as the case may be);

                  (b)  The  written  approval  of  the  General  Partner,  which
         approval may be granted or denied in the sole discretion of the General
         Partner;

                  (c) Acceptance, in a form satisfactory to the General Partner,
         of all the  terms  and  conditions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d)  A  properly  executed  power  of  attorney  substantially
         identical to that contained in Article 38;

                  (e) Such other  documents or instruments as may be required in
         order to effect his or her admission as a Limited Partner; and

                  (f) Payment of such reasonable  expenses as may be incurred in
         connection with his or her admission as a Limited Partner.

                  17.5     Admission of General Partners.

                  A Limited  Partner,  or the  transferee  of all or part of the
Partnership  Interest of the General Partner, may be admitted to the Partnership
as a  general  partner  upon  furnishing  to  the  General  Partner  all  of the
following:

                  (a) The  written  consent of both the  General  Partner  and a
         Majority  in Interest of the  Limited  Partners,  which  consent may be
         granted or denied in the sole discretion of the Partners;

                  (b) Such financial statements,  guarantees or other assurances
         as the General  Partner  may require  with regard to the ability of the
         proposed  general  partner to fulfill the  financial  obligations  of a
         general partner hereunder;

                  (c) Acceptance,  in form  satisfactory to the General Partner,
         of all the  terms  and  provisions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d) A certified copy of a resolution of its Board of Directors
         (if it is a  corporation)  authorizing  it to become a general  partner
         under the terms and conditions of this Agreement;

                  (e) A power of attorney substantially identical to that 
         contained in Article 38;


                                      -14-


<PAGE>



                  (f) Such other  documents or instruments as may be required in
         order to effect its admission as a general partner; and

                  (g) Payment of such reasonable  expenses as may be incurred in
         connection with its admission as a general partner.

                  Notwithstanding  the above,  a transferee  that controls or is
controlled by the General Partner or one or more of its Affiliates that receives
all or part of the  Partnership  Interest of the General Partner may be admitted
to the  Partnership as a general  partner upon complying with all the provisions
of this Article 17.5 except for subparagraph  17.5(a). As long as the transferee
either  controls or is controlled  by the General  Partner or one or more of its
Affiliates,  no  Limited  Partner  consents  will  be  required  to  admit  such
transferee as a General Partner to the Partnership.

                  17.6     Amendment of Certificate of Limited Partnership and 
Qualification.

                  The  General  Partner  shall  take  all  steps  necessary  and
appropriate to prepare and record any  amendments to the  Certificate of Limited
Partnership, as may be necessary or appropriate from time to time to comply with
the requirements of the Act, including,  without limitation,  upon the admission
to the Partnership of any general partner  pursuant to the provisions of Article
17.5, and may for this purpose  exercise the power of attorney  delivered to the
General Partner pursuant to Article 17.5 or 38. In addition, the General Partner
shall take all steps necessary and appropriate to prepare and record any and all
documents  necessary to qualify the Partnership to do business in  jurisdictions
where the Partnership is doing business,  and may for this purpose  exercise the
power of attorney  delivered to the General  Partner  pursuant to Articles 17.4,
17.5 or 38.

                  17.7     Fundamental Changes.

                  In the  event  a plan  is  approved  by  the  General  Partner
providing for the merger or consolidation of the Partnership with another person
or entity, or the sale of all or substantially all of the Partnership Interests,
including  without  limitation the exchange of Partnership  Interests for equity
interests  in  another  person or entity or for cash or other  consideration  or
combination  thereof,  then and in such  event,  the Limited  Partners  shall be
obligated to take or refrain  from  taking,  as the case may be, such actions as
the  plan  may  provide,   including,   without   limitations,   executing  such
instruments,  and  providing  such  information  as the  General  Partner  shall
reasonably  request.  Any plan described in this Article 17.7 may also effect an
amendment to the  Partnership  Agreement  or the  adoption of a new  partnership
agreement in connection with the merger of the  Partnership  with another person
or entity. The plan may also provide that the General Partner and its Affiliates
shall receive fees for services rendered in connection with the operation of the
Partnership  or  any  successor   entity   following  the  consummation  of  the
transactions described in the plan, and neither the Partnership nor the Partners
shall  have  any  right  by  virtue  of this  Agreement  in the  income  derived
therefrom.  Any  securities  or other  consideration  to be  distributed  to the
Partners  pursuant to the plan shall be  distributed  in the manner set forth in
Article 25(c) as though the Partnership were being liquidated.  For this purpose
only,  the fair market  value of the  securities  or other  consideration  to be
received  pursuant  to the plan shall be treated as  "Profits"  and the  capital
accounts of the Partners  shall be  increased in the manner  provided in Article
12(a)(ii).  No Partner shall be entitled to any  appraisal or similar  rights in
connection with a plan contemplated by this Article 17.7.

                                      -15-


<PAGE>



                  17.8     Withdrawal of Initial Limited Partner.

                  Upon the date the first  Limited  Partner is  admitted  to the
Partnership in accordance with Article 11 of this Agreement, the Initial Limited
Partner  shall  withdraw  from  the  Partnership,   and  thereupon  his  Capital
Contribution shall be returned and his Partnership Interest shall be reallocated
to the Limited Partners.

                  18.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON
                           CERTAIN EVENTS.

                  18.1     Death.

                  Upon the  death of a Limited  Partner,  the  deceased  Limited
Partner's  executor,  administrator,  or other legal or personal  representative
shall give  written  notice of that fact to the  General  Partner.  The  General
Partner shall have the option to purchase at the Closing (as defined  below) the
Partnership   Interest  of  the  deceased   Limited  Partner  (whose   executor,
administrator  or other  legal or  personal  representative  shall  then  become
obligated  to sell such  Partnership  Interest) at the price  determined  in the
manner  provided  in  Article  18.6  of  this  Agreement  and on the  terms  and
conditions provided in Article 18.7 of this Agreement. The General Partner shall
have a period of thirty (30) days  following  the date of notice of the death of
the Limited Partner (the "Option  Period") within which to notify in writing the
deceased Limited  Partner's  executor,  administrator or other legal or personal
representative,  whether the General Partner wishes to purchase all or a portion
of the  Partnership  Interest of the deceased  Limited  Partner.  If the General
Partner  does not elect to  purchase  the  entire  Partnership  Interest  of the
deceased  Limited  Partner before the expiration of the Option Period and in the
manner provided  herein,  the portion of the Partnership  Interest not purchased
shall be held by the deceased  Limited  Partner's  executor,  administrator,  or
other legal representative pursuant to the terms of this Agreement.  The General
Partner, in its sole discretion,  may elect to assign its rights to purchase the
Partnership  Interest of a deceased  Limited  Partner under this Article 18.1 to
the Partnership and, in such case, the Partnership shall have the same rights as
provided for the General Partner under this Article 18.1.

                  18.2     Bankruptcy, Insolvency or Assignment for Benefit of 
                           Creditors of a Limited Partner.

                   In the event  that an  involuntary  or  voluntary  proceeding
under the  Federal  Bankruptcy  Code,  as  amended,  is filed for or against any
Limited  Partner,  or if any Limited  Partner shall make an  assignment  for the
benefit of his creditors,  or if any Limited Partner has a receiver or custodian
appointed  for his assets,  or any Limited  Partner  generally  fails to pay his
debts when due, the insolvent  Limited  Partner  shall give written  notice (the
"Notice of Insolvency")  to the General Partner of the  commencement of any such
proceeding or the  occurrence of such event within five days of the first notice
to him of such  commencement  or occurrence of such event.  The General  Partner
shall  have the  option to  purchase  at the  Closing  (as  defined  below)  the
Partnership  Interest of the insolvent  Limited Partner (which insolvent Limited
Partner  or  his  trustee,  custodian,  receiver  or  other  personal  or  legal
representative,  as the case may be,  shall then become  obligated  to sell such
Partnership  Interest) at the price determined in the manner provided in Article
18.6 of this Agreement and on the terms and conditions  provided in Article 18.7
of this Agreement. The General Partner shall have a period of thirty

                                      -16-


<PAGE>



(30) days following the date of the Notice of Insolvency  (the "Option  Period")
within which to notify in writing the insolvent  Limited Partner or his trustee,
custodian,  receiver,  or other  legal or personal  representative,  whether the
General Partner wishes to purchase all or a portion of the Partnership  Interest
of the  insolvent  Limited  Partner.  If the General  Partner  does not elect to
purchase the entire Partnership Interest of the insolvent Limited Partner before
the  expiration  of the Option  Period and in the manner  provided  herein,  the
portion of the Partnership Interest not purchased shall be held by the insolvent
Partner,   his  trustee,   custodian,   receiver  or  other  legal  or  personal
representative pursuant to the terms of this Agreement.  The General Partner, in
its sole discretion,  may elect to assign its rights to purchase the Partnership
Interest  of an  insolvent  Limited  Partner  under  this  Article  18.2  to the
Partnership  and, in such case,  the  Partnership  shall have the same rights as
provided for the General Partner under this Article 18.2.

                  18.3     Breach of Article 15.3.

                  In the event the  General  Partner  (the  "Defaulting  Limited
Partner")  either receives a Notice of Withdrawal as provided in Article 15.3 or
receives notice of breach of Article 15.3, the General Partner may elect, in its
sole  discretion,  to treat such event as a default  under  this  Agreement  and
enforce the  provisions of this Article 18.3. If the General  Partner  elects to
enforce the  provisions  of this Article  18.3,  the General  Partner shall give
written  notice of such  election  (the "Notice of  Default") to the  Defaulting
Limited  Partner within 180 days of the date the General  Partner first received
the Notice of Withdrawal or notice of the defaulting  event. The General Partner
shall  have the  option to  purchase  at the  Closing  (as  defined  below)  the
Partnership Interest of the Defaulting Limited Partner (which Defaulting Limited
Partner shall then become  obligated to sell such  Partnership  Interest) at the
price determined in the manner provided in Article 18.6 of this Agreement and on
the terms and conditions provided in Article 18.7 of this Agreement. The General
Partner shall have a period of thirty (30) days  following the date of the close
of the date of the Notice of Default (the "First Option Period") within which to
notify in writing the Defaulting  Limited  Partner,  whether the General Partner
wishes  to  purchase  all  or a  portion  of  the  Partnership  Interest  of the
Defaulting  Limited  Partner.  If the General Partner does not elect to purchase
the entire  Partnership  Interest of the Defaulting  Limited  Partner before the
expiration of the Option Period and in the manner provided  herein,  the portion
of the  Partnership  Interest  not  purchased  shall  be held by the  Defaulting
Limited Partner pursuant to the terms of this Agreement. The General Partner, in
its sole discretion,  may elect to assign its rights to purchase the Partnership
Interest  of a  Defaulting  Limited  Partner  under  this  Article  18.3  to the
Partnership  and, in such case,  the  Partnership  shall have the same rights as
provided for the General Partner under this Article 18.3.

                  18.4     Domestic Proceeding.

                  In the  event  that a spouse of a  Limited  Partner  commences
against  a  Limited  Partner,  or a  Limited  Partner  is named  in, a  Domestic
Proceeding,  the Limited  Partner  shall give  written  notice  (the  "Notice of
Domestic  Proceeding")  to the General  Partner of the  commencement of any such
proceeding within five days of the first notice to him of such commencement. The
General  Partner  shall have the option to  purchase  at the Closing (as defined
below) the Partnership  Interest of the Limited Partner involved in the Domestic
Proceeding  (which  Limited  Partner  shall then become  obligated  to sell such
Partnership Interest), at the price determined in the manner provided in Article
18.6 of this Agreement and on the terms and conditions  provided in Article 18.7
of this Agreement. The General Partner shall

                                      -17-


<PAGE>



have a period of thirty (30) days  following  the date of the Notice of Domestic
Proceeding  (the "Option  Period") within which to notify in writing the Limited
Partner involved in the Domestic Proceeding,  whether the General Partner wishes
to  purchase  all or a  portion  of the  Partnership  Interest  of such  Limited
Partner.  If the  General  Partner  does not elect to purchase  the  Partnership
Interest of the Limited Partner involved in the Domestic  Proceeding  before the
expiration of the Option Period and in the manner provided  herein,  the portion
of the Partnership  Interest not purchased shall be held by such Limited Partner
pursuant  to the  terms of this  Agreement.  The  General  Partner,  in its sole
discretion,  may elect to assign its rights to purchase the Partnership Interest
of the Limited Partner  involved in the Domestic  Proceeding  under this Article
18.4 to the Partnership  and, in such case, the Partnership  shall have the same
rights as provided for the General Partner under this Article 18.4.

                  18.5     Divestiture Option.

                  If  state  or  federal  regulations  or laws  are  enacted  or
applied,  or if any other legal developments occur, which, in the opinion of the
General Partner adversely affect (or potentially adversely affect) the operation
of the Partnership (e.g., the enactment or application of prohibitory  physician
self-referral  legislation against the Partnership or its Partners), the General
Partner shall promptly either, in its discretion, (i) take the steps outlined in
this Article 18.5 to divest the Limited Partners of their Partnership Interests,
or (ii) dissolve the Partnership as provided in Article 24.1(d).  If the General
Partner  chooses  option  (i), it shall  deliver a written  notice to all of the
Limited  Partners  (the  "Notice of  Election")  and purchase  such  Partnership
Interests  for  its  own  account.  The  purchase  price  to be  paid  for  each
Partnership  Interest  shall be  determined in the manner as provided in Article
18.6 and shall be on the terms and  conditions as provided in Article 18.7.  The
transfer of the Partnership  Interests and the payment of the purchase price (as
provided  in  Article  18.6)  shall be made at such  time as  determined  by the
General  Partner to be in the best interests of the  Partnership and its Limited
Partners.  Each  Limited  Partner  hereby  makes,  constitutes  and appoints the
General  Partner,  with  full  power  of  substitution,   his  true  and  lawful
attorney-in-fact,  to take such actions and execute such documents on his behalf
to effect the transfer of his  Partnership  Interest as provided in this Article
18.5.

                  18.6     Purchase Price.

                  The purchase price to be paid for the Partnership  Interest of
any Limited Partner whose interest is being purchased pursuant to the provisions
of Articles 18.1,  18.2,  18.3,  18.4 or 18.5 (the "Retiring  Limited  Partner")
shall  be an  amount  equal  to the  Retiring  Limited  Partner's  share  of the
Partnership's  book value, if any, (prorated in the event that only a portion of
his Partnership Interest is being purchased) as reflected by the Capital Account
of the Retiring Limited Partner  (unadjusted for any appreciation in Partnership
assets and as reduced by depreciation  deductions claimed by the Partnership for
tax purposes).  The  determination  of the Retiring  Limited  Partner's  Capital
Account  on  the  Valuation  Date  (as  defined  below)  shall  be  made  by the
Partnership's  internal accountant (the "Partnership  Accountant") upon a review
of the Partnership books of account, and a formal audit is expressly waived. The
statement of the  Partnership  Accountant with respect to the Capital Account of
the  Retiring  Limited  Partner  on the  Valuation  Date  shall be  binding  and
conclusive upon the Partnership,  the purchaser and the Retiring Limited Partner
and his  representative.  The Valuation  Date shall be the last day of the month
immediately  preceding  the  month in which  occurs:  (i) the death of a Limited
Partner,  in the case of a purchase by reason of death;  (ii) the  bankruptcy or
insolvency  of a Limited  Partner,  in the case of a purchase  by reason of such
bankruptcy or insolvency; (iii) the Notice of Default as provided in

                                      -18-


<PAGE>



Article 18.3 in the case of a purchase by reason thereof;  (iv) the commencement
of the Domestic Proceeding,  in the case of a purchase by reason thereof; or (v)
the Notice of Election as provided in Article 18.5, in the case of a purchase by
reason  thereof.  Any Limited  Partner whose  Partnership  Interest is purchased
pursuant to the  provisions of Article 18.1,  18.2,  18.3,  18. or 18.5 shall be
entitled  only to the purchase  price which shall be paid at the Closing in cash
(or  by  certified  or  cashier's  check)  and  shall  not  be  entitled  to any
Partnership  distributions  made after the  Valuation  Date.  Any  distributions
inadvertently made to a Retiring Limited Partner after the Valuation Date may be
applied in  reduction  of the  purchase  price as  determined  pursuant  to this
Article  18.6.  The  transfer of a  Partnership  Interest of a Retiring  Limited
Partner  shall be  deemed  to occur as of the  Valuation  Date and the  Retiring
Limited  Partner shall have no voting or other rights as a Limited Partner after
such date. The purchaser shall be entitled to any distributions  attributable to
the  transferred  interest  after the Valuation Date and shall have the right to
deduct the amount of any such distributions made to the Retiring Limited Partner
from the purchase price.

                  18.7     Closing.

                  18.7.1  Closing  of  Purchase  and Sale.  The  Closing  of any
         purchase and sale of a Partnership  Interest  pursuant to Article 18.1,
         18.2,  18.3,  18.4 or 18.5 of this  Agreement  shall  take place at the
         principal office of the Partnership,  or such other place designated by
         the General Partner, on the date determined as follows (the "Closing"):

                  (a) In the case of a purchase and sale  occurring by reason of
         the death of a Limited  Partner as  provided  in  Article  18.1 of this
         Agreement,  the Closing  shall be held on the thirtieth day (or if such
         thirtieth  day is not a business  day, the next  business day following
         the thirtieth day) next following the last to occur of:

                           (i)      Qualification of the executor or personal 
                  administrator of the deceased Limited Partner's estate;

                           (ii) The date on which any necessary determination of
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (iii) The date that  coincides  with the close of the
                  Option Period.

                  (b) In the case of a purchase and sale  occurring by reason of
         the  occurrence of one of the events  described in Article 18.2,  18.3,
         18.4 or  18.5  of this  Agreement,  the  Closing  shall  be held on the
         thirtieth day (or if such thirtieth day is not a business day, the next
         business day following the thirtieth  day) next  following the later to
         occur of:

                           (i) The date on which any necessary determination of 
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or


                                      -19-


<PAGE>



                           (ii) The date  that  coincides  with the close of the
                  Option Period.

         At the Closing,  although not  necessary  to effect the  transfer,  the
         Retiring Limited Partner shall  concurrently with tender and receipt of
         the applicable  purchase price,  deliver to the purchaser duly executed
         instruments of transfer and  assignment,  assigning good and marketable
         title to the  portion or  portions of the  Retiring  Limited  Partner's
         entire  Partnership  Interest thus  purchased,  free and clear from any
         liens  or  encumbrances  or  rights  of  others  therein.  The  parties
         acknowledge  that occurrence of any of the triggering  events described
         in Article 18.1,  18.2,  18.3, 18.4 or 18.5 and compliance with all the
         Articles  of this  Agreement,  except  the  execution  of the  transfer
         documents  by the  Retiring  Partner as provided  above in this Article
         18.7.1,  are sufficient to effect the complete transfer of the Retiring
         Limited  Partner's  interest and the Retiring  Limited Partner shall be
         deemed to  consent  to  admission  of the  transferee  as a  substitute
         Limited Partner.  Notwithstanding  the date of the Closing or whether a
         Closing is successfully held, the transfer of a Partnership Interest of
         a Retiring Limited Partner shall be deemed to occur as of the Valuation
         Date as defined in Article  18.6.  The  deemed  transfer  is  effective
         regardless of whether the Retiring  Limited Partner performs the duties
         set forth in this Article 18.7.1.

                  18.7.2  Terms and  Conditions  of  Purchase.  The  Partnership
         Interest of a Limited  Partner shall not be  transferred to any Partner
         unless the  requirements  of Articles 17.2 and 17.4 (b) through (f) are
         satisfied  with  respect to it. The  purchaser  shall be liable for all
         obligations  and  liabilities   connected  with  that  portion  of  the
         Partnership  Interest  transferred  to it  unless  otherwise  agreed in
         writing.

                  19.      SALE,  ASSIGNMENT  OR OTHER  TRANSFER  OF THE GENERAL
                           PARTNER'S INTEREST.

                  19.1  The   General   Partner   may  not   mortgage,   pledge,
hypothecate,  transfer,  sell, assign or otherwise dispose of all or any part of
its interest in the  Partnership,  whether  voluntarily,  by operation of law or
otherwise (the foregoing  actions being  hereafter  collectively  referred to as
"Transfers" or singularly as a "Transfer") except as permitted by this Article.

                  19.2 If the  General  Partner  makes a Transfer  (other than a
mortgage,  pledge or  hypothecation)  of its  general  partner  interest  in the
Partnership pursuant to this Article, it shall be liable for all obligations and
liabilities  incurred  by it as the  General  Partner of the  Partnership  on or
before  the  effective  date of such  Transfer,  but shall not be liable for any
obligations or liabilities of the  Partnership  arising after the effective date
of the Transfer.

                  19.3     No Transfer by the General Partner shall be permitted
 unless:

                  (a) Counsel for the Partnership shall have rendered an opinion
         that none of the actions  taken in  connection  with such Transfer will
         cause the Partnership to be classified  other than as a partnership for
         Federal income tax purpose or will cause the termination or dissolution
         of the Partnership under state law; and

                                      -20-


<PAGE>



                  (b) Such  documents  or  instruments,  in form  and  substance
         satisfactory to counsel for the  Partnership,  shall have been executed
         and  delivered  as may be  required  in the  opinion of counsel for the
         Partnership to effect fully any such Transfer.

                  Notwithstanding the foregoing provisions of this Article 19.3,
the General  Partner may pledge its  interest  in the  Partnership  to any bank,
insurance   company  or  other  financial   institution  to  secure  payment  of
indebtedness.

                  20.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER.

                  If the General Partner shall be finally adjudged by a court of
competent  jurisdiction to be liable to the Limited  Partners or the Partnership
for any act of gross negligence or willful  misconduct in the performance of its
duties under the terms of this Agreement, the General Partner may be removed and
another  substituted  with the  consent  of all of the  Limited  Partners.  Such
consent  shall be evidenced  by a  certificate  of removal  signed by all of the
Limited Partners. In the event of removal, the new general partner shall succeed
to all of the powers, privileges and obligations of the General Partner, and the
General  Partner's  interest in the  Partnership  shall become that of a Limited
Partner,  and the General Partner shall maintain its same Percentage Interest in
the Partnership  notwithstanding  anything contained in the Act to the contrary.
In addition,  in the event of removal,  the new general  partner  shall take all
steps  necessary  and  appropriate  to prepare  and record an  amendment  to the
Certificate of Limited Partnership to reflect the removal of the General Partner
and the admission of such new general partner.

                  21.      MANAGEMENT AND OPERATION OF BUSINESS.

                  21.1 All  decisions  with  respect  to the  management  of the
business and affairs of the Partnership shall be made by the General Partner.

                  21.2 The General  Partner shall be under no duty to devote all
of its time to the business of the Partnership,  but shall devote only such time
as it deems  necessary  to conduct the  Partnership  business and to operate and
manage the Partnership in an efficient manner.

                  21.3 The  General  Partner may charge to the  Partnership  all
ordinary and necessary costs and expenses, direct and indirect,  attributable to
the activities,  conduct and management of the business of the Partnership.  The
costs and expenses to be borne by the  Partnership  shall  include,  but are not
limited to, all  expenditures  incurred in acquiring and financing the Equipment
or other Partnership property, legal and accounting fees and expenses,  salaries
of employees of the Partnership,  consulting and quality  assurance fees paid to
independent contractors, insurance premiums and interest.

                  21.4 In addition to, and not in limitation  of, any rights and
powers  covenanted by law or other  provisions of this agreement,  and except as
limited,  restricted or prohibited by the express  provisions of this Agreement,
the General Partner shall have and may exercise on behalf of the Partnership all
powers and rights necessary,  proper,  convenient or advisable to effectuate and
carry out the purposes, business and objectives of the Partnership.  Such powers
shall include, without limitation, the following:

                  (a)      To acquire a Mobile Lithotripsy System;

                                      -21-


<PAGE>



                  (b) To  acquire on behalf of the  Partnership  (i) one or more
         fixed-base or Mobile Lithotripsy Systems, (ii) any other assets related
         to the provision of lithotripsy  services, or (iii) any other assets or
         equipment  consistent  with the purposes of the Partnership as provided
         in Article 4 (collectively, the "Additional Assets"), at such times and
         at such price and upon such terms,  as the General  Partner deems to be
         in the best interest of the Partnership;

                  (c) To purchase,  hold, manage,  lease, license and dispose of
         Partnership assets (including the Mobile Lithotripsy System), including
         the purchase,  exchange,  trade or sale of the Partnership's  assets at
         such price, or amount, for cash,  securities or other property and upon
         such terms,  as the General Partner deems to be in the best interest of
         the  Partnership;  provided,  that  should  the  Partnership  assets be
         exchanged or traded for securities or other property (the  "Replacement
         Property")  the General  Partner shall have the same powers with regard
         to the Replacement Property as it does towards the traded property;

                  (d) To  exercise  the  option of the  General  Partner  or the
         Partnership  to  purchase  a  Limited  Partner's  Partnership  Interest
         pursuant to Article 18;

                  (e) To determine the travel  itinerary and site  locations for
         the Mobile Lithotripsy System or other Partnership technology;

                  (f) To borrow money for any Partnership purpose (including the
         acquisition  of the  Additional  Assets)  and,  if security is required
         therefor, to subject to any security device any portion of the property
         for the  Partnership,  to obtain  replacements  of any  other  security
         device, to prepay, in whole or in part,  refinance,  increase,  modify,
         consolidate or extend any encumbrance or other security device;

                  (g) To deposit,  withdraw,  invest, pay, retain (including the
         establishment  of reserves in order to acquire the  Additional  Assets)
         and distribute the  Partnership's  funds in any manner  consistent with
         the provisions of this Agreement;

                  (h)      To institute and defend actions at law or in equity;

                  (i) To enter into and carry out contracts and  agreements  and
         any or all documents and  instruments  and to do any and all such other
         things as may be in furtherance of Partnership purposes or necessary or
         appropriate to the conduct of the Partnership activities;

                  (j)  To   execute,   acknowledge   and  deliver  any  and  all
         instruments  which may be deemed  necessary or convenient to effect the
         foregoing; and

                  (k) To engage or retain one or more persons to perform acts or
         provide  materials  as  may be  required  by  the  Partnership,  at the
         Partnership's  expense,  and to compensate  such person or persons at a
         rate to be set by the General  Partner,  provided that the compensation
         is at the then prevailing rate for the type of services and materials

                                      -22-


<PAGE>



         provided,  or both.  Any person,  whether a Partner,  an Affiliate of a
         Partner or otherwise, including without limitation the General Partner,
         may be employed or engaged by the  Partnership  to render  services and
         provide materials,  including, but not limited to, management services,
         professional   services,   accounting   services,   quality  assessment
         services, legal services,  marketing services,  maintenance services or
         provide materials; and if such person is a Partner or an Affiliate of a
         Partner,  he shall be entitled to, and shall be paid  compensation  for
         said services or materials,  anything in this Agreement to the contrary
         notwithstanding, provided that the compensation to be received for such
         services  or  materials  is  competitive  in price and terms  with then
         prevailing rate for the type of services and/or materials provided. The
         Partnership,  pursuant  to the terms of a  Management  Agreement,  will
         contract with the General Partner,  with respect to the supervision and
         coordination  of the  management and  administration  of the day-to-day
         operations of the Mobile  Lithotripsy System for a monthly fee equal to
         the  greater of 7.5% of  Partnership  Cash Flow per month or $8,000 per
         month. All costs incurred by the General  Partner,  excluding the costs
         of employing one or more local physicians to act as a Medical Director,
         shall be paid by the  Partnership  directly.  The  Partnership may also
         contract  with  qualified   physicians   desiring  to  use  the  Mobile
         Lithotripsy System for the treatment of patients. Owning an interest in
         the  Partnership   shall  not  be  a  condition  to  using  the  Mobile
         Lithotripsy  System.  The General Partner and its Affiliates may engage
         in or possess an interest in other business  ventures of any nature and
         description  independently or with others,  including,  but not limited
         to, the  operation of a mobile  lithotripsy  unit similar to the Mobile
         Lithotripsy System, whether or not such business ventures are in direct
         or  indirect   competition  with  the  Partnership,   and  neither  the
         Partnership  nor the  Partners  shall  have any right by virtue of this
         Agreement  in and to said  independent  ventures  or to the  income  or
         profits derived  therefrom.  Notwithstanding  the above, if the General
         Partner,  in its sole  discretion,  elects to cause the  Partnership to
         provide  services in the State of  Illinois,  the  General  Partner may
         determine,  in its sole  discretion,  the terms and conditions that the
         Partnership   will  contract  with  PKST  regarding  the  provision  of
         lithotripsy  services to hospitals  already  contracting with PKST, and
         shall determine the fee or other remuneration payable to or retained by
         PKST.

                  21.5  In  addition  to  other  acts  expressly  prohibited  or
restricted  by this  Agreement  or by law,  the  General  Partner  shall have no
authority to act on behalf of the Partnership in:

                  (a) Doing any act in contravention of this Agreement or the 
         Partnership's Certificate of Limited Partnership;

                  (b) Doing any act which would make it  impossible  to carry on
         the ordinary business of the Partnership;

                  (c)   Confessing  a  judgment   against  the   Partnership  in
         connection with any threatened or pending legal action;


                                      -23-


<PAGE>



                  (d) Possessing or in any manner dealing with the Partnership's
         property  or   assigning   the  rights  of  the   Partnership   in  the
         Partnership's property for other than Partnership purposes;

                  (e)  Admitting  a person  as a  Limited  Partner  or a General
         Partner except as provided in this Agreement; or

                  (f)  Performing  any act (other  than an act  required by this
         Agreement  or any act  taken  in good  faith  reliance  upon  counsel's
         opinion)  which  would,  at the time  such act  occurred,  subject  any
         Limited Partner to liability as a general partner in any jurisdiction.

                  22.      RESERVES.

                  The  General  Partner  may cause the  Partnership  to create a
reserve account to be used exclusively for repairs and acquisition of Additional
Assets and for any other valid Partnership  purpose.  The General Partner shall,
in its sole discretion, determine the amount of payments to such reserve.

                  23.      INDEMNIFICATION AND EXCULPATION OF THE GENERAL
                           PARTNER.

                  23.1 The General  Partner is accountable to the Partnership as
a fiduciary and consequently  must exercise good faith and integrity in handling
Partnership  affairs.  The  General  Partner  and its  Affiliates  shall have no
liability to the  Partnership  which arises out of any action or inaction of the
General Partner or its Affiliates if the General  Partner or its Affiliates,  in
good faith,  determined  that such course of conduct was in the best interest of
the Partnership and such course of conduct did not constitute  gross  negligence
or willful  misconduct  of the General  Partner or its  Affiliates.  The General
Partner and its Affiliates  shall be indemnified by the Partnership  against any
losses, judgments,  liabilities,  expenses and amounts paid in settlement of any
claims sustained by them in connection with the  Partnership,  provided that the
same were not the result of gross  negligence or willful  misconduct on the part
of the General Partner or its Affiliates.

                  23.2 The General Partner shall not be liable for the return of
the Capital Contributions of the Limited Partners, and upon dissolution, Limited
Partners shall look solely to the assets of the Partnership.

                  24.      DISSOLUTION OF THE PARTNERSHIP.

                  24.1 The Partnership shall be dissolved and terminated and its
business wound up upon the occurrence of any one of the following events:

                  (a)      The expiration of its term on May 31, 2047;

                  (b) The  filing  by, on  behalf  of, or  against  the  General
         Partner of any  petition or  pleading,  voluntary  or  involuntary,  to
         declare the General  Partner  bankrupt under any bankruptcy law or act,
         or the commencement in any court of any proceeding, voluntary

                                      -24-


<PAGE>



         or involuntary,  to declare the General Partner  insolvent or unable to
         pay its debts, or the appointment by any court or supervisory authority
         of a receiver,  trustee or other  custodian of the property,  assets or
         business of the General  Partner or the  assignment by it of all or any
         part of its  property or assets for the benefit of  creditors,  if said
         action,  proceeding  or  appointment  is  not  dismissed,   vacated  or
         otherwise terminated within ninety (90) days of its commencement;

                  (c)      The determination of the General Partner that the 
         Partnership should be dissolved;

                  (d) The  approval of a plan by the General  Partner  providing
         for the  merger,  consolidation  or sale of  Partnership  Interests  as
         described in Article 17.7;

                  (e) The  election  of the  General  Partner  to  dissolve  the
         Partnership  following the occurrence of an event  described in Article
         18.5;

                  (f)  The  sale,  exchange  or  other  disposition  of  all  or
         substantially  all of the property of the  Partnership  without  making
         provision for the replacement thereof; and

                  (g)   The   dissolution,   retirement,   resignation,   death,
         disability  or legal  incapacity  of a general  partner,  and any other
         event  resulting in the  dissolution or termination of the  Partnership
         under the laws of the State of Wisconsin.

                  24.2  Notwithstanding  the  provisions  of Article  24.1,  the
Partnership   shall  not  be  dissolved  and  terminated  upon  the  retirement,
resignation,  bankruptcy,  assignment for the benefit of creditors, dissolution,
death,  disability or legal  incapacity of a general  partner,  and its business
shall continue  pursuant to the terms and conditions of this  Agreement,  if any
general partner or general partners remain  following such event;  provided that
such  remaining  general  partner or general  partners  are hereby  obligated to
continue the business of the  Partnership.  If no general  partner remains after
the  occurrence of such event,  the business of the  Partnership  shall continue
pursuant to the terms and conditions of this  Agreement,  if, within ninety (90)
days after the  occurrence of such event,  a Majority in Interest of the Limited
Partners agree in writing to continue the business of the  Partnership,  and, if
necessary,  to  the  appointment  of one  or  more  persons  or  entities  to be
substituted as the general  partner.  In the event the Limited Partners agree to
continue the  business of the  Partnership,  the new general  partner or general
partners shall succeed to all of the powers,  privileges and  obligations of the
General Partner,  and the General  Partner's  interest in the Partnership  shall
become a  Limited  Partner's  interest  hereunder.  Furthermore,  in the event a
remaining general partner or the Limited Partners,  as the case may be, agree to
continue the  business of the  Partnership  as provided  herein,  the  remaining
general partner or the newly appointed general partner or general  partners,  as
the case may be, shall take all steps  necessary and  appropriate to prepare and
record an amendment to the  Certificate  of Limited  Partnership  to reflect the
continuation  of the  business of the  Partnership  and the  admission  of a new
general partner or general partners, if any.


                                      -25-


<PAGE>



                  25.      DISTRIBUTION UPON DISSOLUTION.

                  Upon the dissolution and termination of the  Partnership,  the
General Partner or, if there is none, a representative  of the Limited Partners,
shall  cause  the  cancellation  of the  Partnership's  Certificate  of  Limited
Partnership,  shall liquidate the assets of the Partnership, and shall apply and
distribute the proceeds of such liquidation in the following order of priority:

                  (a)      First, to the payment of the debts and liabilities of
         the Partnership, and the expenses of liquidation;

                  (b) Second,  to the creation of any reserves which the General
         Partner  (or the  representatives  of the  Limited  Partners)  may deem
         reasonably  necessary  for the payment of any  contingent or unforeseen
         liabilities or obligations of the Partnership or of the General Partner
         arising out of or in connection  with the business and operation of the
         Partnership; and

                  (c) Third,  the balance,  if any,  shall be distributed to the
         Partners in accordance  with the  Partners'  positive  Capital  Account
         balances  after such  capital  accounts  are  adjusted  as  provided by
         Article 13, and any other  adjustments  required by the Final  Treasury
         Regulations  under Section 704(b) of the Code. Any general partner with
         a negative  Capital Account  following the  distribution of liquidation
         proceeds or the  liquidation  of its interest  must  contribute  to the
         Partnership  an amount  equal to such  negative  Capital  Account on or
         before the end of the Partnership's  taxable year (or, if later, within
         ninety days after the date of liquidation).  Any capital so contributed
         shall  be (i)  distributed  to those  Partners  with  positive  Capital
         Accounts until such Capital  Accounts are reduced to zero,  and/or (ii)
         used to discharge recourse liabilities.

                  26.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.

                  26.1 Proper and complete records and books of account shall be
kept by the General  Partner in which shall be entered fully and  accurately all
transactions  and such other matters relating to the  Partnership's  business as
are usually  entered  into  records and books of account  maintained  by persons
engaged  in  businesses  of a like  character.  The  books  and  records  of the
Partnership  shall be prepared  according to the accounting method determined by
the General Partner.  The Partnership's  fiscal year shall be the calendar year.
The books and  records  shall at all times be  maintained  at the  Partnership's
Records Office and shall be open to the reasonable inspection and examination of
the Partners or their duly authorized representatives during reasonable business
hours.

                  26.2 Within  ninety (90) days after the end of each Year,  the
General  Partner shall send to each person who was a Limited Partner at any time
during such year such tax information,  including,  without limitation,  Federal
tax Schedule K-1, as shall be reasonably  necessary for the  preparation by such
person of his Federal  income tax return.  The  General  Partner  will also make
available to the Limited Partners any other information required by the Act.

                  26.3 The General  Partner shall maintain at the  Partnership's
Records  Office  copies of the  Partnership's  original  Certificate  of Limited
Partnership and any certificate of amendment, restated

                                      -26-


<PAGE>



certificate or certificate of  cancellation  with respect thereto and such other
documents  as the Act shall  require.  The General  Partner  will furnish to any
Limited Partner upon request a copy of the Partnership's original Certificate of
Limited Partnership and any certificate of amendment,  restated certificate,  or
certificate of cancellation, if any.

                  26.4 The General Partner shall, in its sole  discretion,  make
for the  Partnership  any and all  elections  for  federal,  state and local tax
purposes including, without limitation, any election, if permitted by applicable
law, to adjust the basis of the Partnership's property pursuant to Code Sections
754,  734(b) and  743(b),  or  comparable  provisions  of state or local law, in
connection  with  transfers  of  interests in the  Partnership  and  Partnership
Distributions.

                  26.5 The  General  Partner is  designated  as the Tax  Matters
Partner  (as  defined  in  Section  6231 of the Code) and to act in any  similar
capacity  under  state or local law,  and is  authorized  (at the  Partnership's
expense):   (i)  to  represent  the   Partnership  and  Partners  before  taxing
authorities  or courts of competent  jurisdiction  in tax matters  affecting the
Partnership  or  Partners  in their  capacity  as  Partners;  (ii) to extend the
statute of limitations for assessment of tax deficiencies  against Partners with
respect to adjustments to the Partnership's federal, state or local tax returns;
(iii) to execute any agreements or other documents relating to or affecting such
tax matters, including agreements or other documents that bind the Partners with
respect to such tax matters or  otherwise  affect the rights of the  Partnership
and Partners; and (iv) to expend Partnership funds for professional services and
costs  associated  therewith.  The General partner is authorized and required to
notify the federal,  state or local tax  authorities of the appointment of a Tax
Matters  Partner  in  the  manner  provided  in  Treasury   Regulations  Section
301.6231(a)(7)-IT, as modified from time to time. In its capacity as Tax Matters
Partner,  the General  Partner shall oversee the  Partnership tax affairs in the
manner which, in its best judgment, are in the interests of the Partners.

                  27.      NOTICES.

                  All notices under this Agreement shall be in writing and shall
be deemed to have been given when delivered  personally,  or mailed by certified
or registered mail, postage prepaid,  return receipt  requested.  Notices to the
General  Partner  shall be  delivered  at, or mailed to, its  principal  office.
Notices to the  Partnership  shall be delivered  at, or mailed to, its principal
office with a copy to each of its business offices.  Notice to a Limited Partner
shall be  delivered  to such  Limited  Partner,  or mailed  to the last  address
furnished  by him for such  purposes to the General  Partner.  Limited  Partners
shall give  notice of a change of address to the  General  Partner in the manner
provided in this Article.

                  28.      AMENDMENTS.

                  Subject to the  provisions  of Article 29, this  Agreement  is
subject to  amendment  only by  written  consent of the  General  Partner  and a
Majority in Interest of the Limited Partners;  provided, however, the consent of
the Limited Partners shall not be required if such amendments are ministerial in
nature and do not contravene the provisions of Article 29.

                  29.      LIMITATIONS ON AMENDMENTS.

                  Notwithstanding  the provisions of Article 28, no amendment to
this Agreement shall:

                                      -27-


<PAGE>



                  (a)  Enlarge  the   obligations  of  any  Partner  under  this
         Agreement  or convert the  interest in the  Partnership  of any Limited
         Partner  into the  interest of a general  partner or modify the limited
         liability of any Limited Partner, without the consent of such Partner;

                  (b) Amend the  provisions  of Article 13, 14, 16 or 25 without
         the  approval of the General  Partner and a Majority in Interest of the
         Limited Partners;  provided,  however,  that the General Partner may at
         any time  amend  such  Articles  without  the  consent  of the  Limited
         Partners in order to permit the Partnership allocations to be sustained
         for Federal  income tax  purposes,  but only if such  amendments do not
         materially  affect  adversely the rights and obligations of the Limited
         Partners, in which case such amendments may only be made as provided in
         this Article 29(b); or

                  (c) Amend this Article 29 without the consent of all Partners.

                  30       MEETINGS, CONSENTS AND VOTING.

                  30.1 A meeting of the  Partnership to consider any matter with
respect to which the  Partners  may vote as set forth in this  Agreement  may be
called  by the  General  Partner  or by  Limited  Partners  who hold  more  than
twenty-five  percent (25%) of the aggregate interests in the Partnership held by
all the Limited Partners.  Upon receipt of a notice requesting a meeting by such
Partner or Partners and stating the purpose of the meeting,  the General Partner
shall, within ten (10) days thereafter, give notice to the Partners of a meeting
of the  Partnership  to be held at a time and place  convenient  to the  Limited
Partners  on a date not  earlier  than  fifteen  (15) days after  receipt by the
General  Partner of the notice  requesting a meeting.  The notice of the meeting
shall set forth the time, date, location and purpose of the meeting.

                  30.2 Any consent of a Partner  required by this  Agreement may
be given as follows:

                  (a) By a written  consent given by the consenting  Partner and
         received by the General  Partner at or prior to the doing of the act or
         thing for which the consent is solicited, or

                  (b) By the affirmative  vote by the consenting  Partner to the
         doing of the act or thing for which the  consent  is  solicited  at any
         meeting  called  pursuant to this Article to consider the doing of such
         act or thing.

                  30.3 When exercising voting rights expressly granted under the
Articles of this  Agreement,  each Partner shall have that number of votes as is
equal to the  Percentage  Interest  of such  Partner  at the  time of the  vote,
multiplied by 100.

                  31.      SUBMISSIONS TO THE LIMITED PARTNERS.

                  The General Partner shall give the Limited  Partners notice of
any proposal or other matter  required by any provision of this  Agreement or by
law to be submitted for consideration and approval

                                      -28-


<PAGE>



of the Limited Partners.  Such notice shall include any information  required by
the relevant provision or by law.

                  32.      ADDITIONAL DOCUMENTS.

                  Each  party  hereto  agrees to  execute  and  acknowledge  all
documents and writings which the General Partner may deem necessary or expedient
in the creation of this Partnership and the achievement of its purpose.

                  33.      SURVIVAL OF RIGHTS.

                  Except as herein  otherwise  provided  to the  contrary,  this
Agreement  shall be binding upon and inure to the benefit of the parties hereto,
their successor and assigns.

                  34.      INTERPRETATION AND GOVERNING LAW.

                  When the  context  in which  words are used in this  Agreement
indicates  that such is the intent,  words in the singular  number shall include
the plural and vise versa; in addition,  the masculine  gender shall include the
feminine and neuter  counterparts.  The Article headings or titles and the table
of  contents  shall not define,  limit,  extend or  interpret  the scope of this
Agreement  or any  particular  Article.  This  Agreement  shall be governed  and
construed in accordance  with the laws of the State of Wisconsin  without giving
effect to the conflicts of laws provisions thereof.

                  35.      SEVERABILITY.

                  If any provision,  sentence,  phrase or word of this Agreement
or the application  thereof to any person or circumstance shall be held invalid,
the remainder of this Agreement, or the application of such provision, sentence,
phrase, or word to persons or circumstances,  other than those as to which it is
held invalid, shall not be affected thereby.

                  36.      AGREEMENT IN COUNTERPARTS.

                  This Agreement may be executed in several  counterparts,  each
of which shall be deemed an original,  but all of which shall constitute one and
the same  instrument.  In  addition,  this  Agreement  may contain more than one
counterpart  of the  signature  page and this  Agreement  may be executed by the
affixing of the  signatures  of each of the Partners to one of such  counterpart
signature  pages;  all of such signature  pages shall be read as though one, and
they  shall have the same  force and  effect as though  all of the  signers  had
signed a single signature page.

                  37.      THIRD PARTIES.

                  The agreements, covenants and representations contained herein
are for the benefit of the parties  hereto  inter se and are not for the benefit
of any  third  parties  including,  without  limitation,  any  creditors  of the
Partnership.


                                      -29-


<PAGE>



                  38.      POWER OF ATTORNEY.

                  Each Limited  Partner hereby makes,  constitutes  and appoints
Michael Madler and Philip Gallina,  severally,  with full power of substitution,
his true and lawful attorneys-in-fact,  for him and in his name, place and stead
and for his use and  benefit  to sign  and  acknowledge,  file and  record,  any
amendments  hereto among the Partners for the further  purpose of executing  and
filing on behalf of each Limited  Partner,  any and all  certificates of limited
partnership or other  documents  necessary to constitute  the  Partnership or to
effect the  continuation  of the  Partnership,  the admission or withdrawal of a
general partner or a limited partner,  the qualification of the Partnership in a
foreign  jurisdiction  (or  amendment to such  qualification),  the admission of
substitute   Limited   Partners  or  the   dissolution  or  termination  of  the
Partnership, provided such continuation,  admission, withdrawal,  qualification,
or  dissolution  and  termination  are in  accordance  with  the  terms  of this
Agreement.

                  The foregoing power of attorney is a special power of attorney
coupled with an interest,  is  irrevocable  and shall survive the death or legal
incapacity  of each  Limited  Partner.  It may be  exercised  by any one of said
attorneys by listing all of the Limited  Partners  executing any instrument over
the  signature  of the  attorney-in-fact  acting  for all of them.  The power of
attorney shall survive the delivery of an assignment by a Limited Partner of the
whole or any portion of his Unit.  In those cases in which the  assignee  of, or
the  successor  to, a Limited  Partner  owning a Unit has been  approved  by the
Partners for admission to the Partnership as a substitute  Limited Partner,  the
power of attorney  shall  survive for the sole  purpose of enabling  the General
Partner to execute, acknowledge and file any instrument necessary to effect such
substitution.

                  This power of attorney shall not be affected by the subsequent
incapacity or mental incompetence of any Limited Partner.

                  39.      ARBITRATION.

                  Any  dispute  arising  out  of  or  in  connection  with  this
Agreement  or the breach  thereof  shall be decided by  arbitration  in Raleigh,
North  Carolina in accordance  with the then  effective  commercial  arbitration
rules of the  American  Arbitration  Association,  and  judgment  thereof may be
entered in any court having jurisdiction thereof.

                  40.      CREDITORS.

                  None of the  provisions  of this  Agreement  shall  be for the
benefit of or enforceable by any creditors of the Partnership.



            [The remainder of this page is intentionally left blank]

                                      -30-


<PAGE>



                  IN WITNESS  WHEREOF,  the parties have executed this Agreement
of Limited Partnership as of the day and year first above written.

                                            GENERAL PARTNER:

                                            PRIME KIDNEY STONE TREATMENT, INC.,
                                            a New Jersey corporation


                                    By:      /s/ Philip J. Gallina
                                             ------------------------------
                                             Philip J. Gallina, Vice President

ATTEST:
/s/ Louis Mestier
__________________                                            [CORPORATE SEAL]
Secretary

[CORPORATE SEAL]
                            INITIAL LIMITED PARTNER:

                                        /s/ Dan A. Myers
                                       ---------------------------------------
                                            Dan A. Myers, M.D.


STATE OF TEXAS                              )
                                            )
COUNTY OF TRAVIS                            )

                  On this  21st  day of  October,  1997,  before  me, the
undersigned Notary Public in and for the County of Travis in the State of Texas,
personally  came Michael  Madler,  who, being by me duly sworn,  said that he is
President of Prime Kidney Stone  Treatment,  Inc.,  the sole general  partner of
Great  Lakes  Lithotripsy  Limited  Partnership,  that the seal  affixed  to the
foregoing  instrument in writing is the corporate seal of the  corporation,  and
that said  writing  was  signed,  sworn to,  and sealed by him in behalf of said
corporation by its authority duly given.  And the said Michael  Madler,  further
certified  that the facts set forth in said  writing are true and  correct,  and
acknowledged said instrument to be the act and deed of said corporation.

                  WITNESS my hand and notarial seal.

                                    /s/ Lou Ann Barnes
                                    ------------------------------------------

                                    Notary Public
My commission expires:
May 26, 2001
- ---------------------------


                                      -31-


<PAGE>



STATE OF NORTH CAROLINA                     )
                                            )
COUNTY OF CUMBERLAND                        )


                  I, Lou Ann Barnes, a notary public, do hereby
certify that Dan A. Myers, M.D.  personally appeared before me this 21st day of
October, 1997 and acknowledged and swore to the due execution of the foregoing
Limited Partnership Agreement in his capacity as the initial limited partner.



                                    /s/ Lou Ann Barnes
                                    ------------------------------------------

                                    Notary Public

My commission expires:
May 26, 2001
- ---------------------------


                                      -32-


<PAGE>



                           COUNTERPART SIGNATURE PAGE


                  By signing this  Counterpart  Signature  Page, the undersigned
acknowledges  his or  her  acceptance  of  that  certain  Agreement  of  Limited
Partnership  of Great  Lakes  Lithotripsy  Limited  Partnership,  and his or her
intention to be legally bound thereby.

                  Dated this _________ day of ___________________, 1997.



                                    -------------------------------------------

                                    Signature



                                    -------------------------------------------

                                    Printed Name




STATE OF _______________                    )
                                            )
COUNTY OF _____________                     )


                  BEFORE ME, the undersigned  Notary Public in and for the State
and County set forth  above,  on the  _______ day of  __________________,  1997,
personally  appeared  ___________________,  and,  being by me first duly  sworn,
stated that (s)he  signed this  Counterpart  Signature  Page for the purpose set
forth above and that the statements contained therein are true.




                                    -------------------------------------------

                                    Signature of Notary Public



                                    -------------------------------------------

                                    Printed Name of Notary

My Commission Expires:

- ---------------------------

[SEAL]

                                      -33-


<PAGE>




                                   SCHEDULE A

                        Schedule of Partnership Interests

                   GREAT LAKES LITHOTRIPSY LIMITED PARTNERSHIP

             CONTRIBUTIONS OF CAPITAL TO THE PARTNERSHIP, GUARANTIES
                            AND PERCENTAGE INTERESTS

                                            Cash                      Percentage
General Partner                           Contribution  Guaranty(1)    Interest

Prime Kidney Stone Treatment, Inc.          $50,000      $211,200          20%
1301 Capital of Texas Highway
Suite C-300
Austin, Texas 78746

Limited Partners
Omar Atassi                                  10,000       42,240            4%
Mark Beard                                   10,000       42,240            4%
James Cauley                                 10,000       42,240            4%
Mark Chelsky                                 10,000       42,240            4%
Frank Chybowski                              10,000       42,240            4%
Daniel Degroot                                2,500       10,560            1%
Doug DeWire                                   5,000       21,120            2%
William Dougherty                             2,500       10,560            1%
Thomas Ferber                                10,000       42,240            4%
Dirk Fisher                                  10,000       42,240            4%
John Fuller                                  10,000       42,240            4%
John Herman                                  10,000       42,240            4%
Christopher Kearn                            10,000       42,240            4%
Timothy Kennedy                              10,000       42,240            4%
Scott Kolbeck                                10,000       42,240            4%
Myron Marlett                                10,000       42,240            4%
Neil Mittleberg                              10,000       42,240            4%
Bruce Neal                                    5,000       21,120            2%
William Roberts                               5,000       21,120            2%
Peter Slocum                                 10,000       42,240            4%
Arthur Sonneland                             10,000       42,240            4%
Richard Windsor                              10,000       42,240            4%
Robert Vlach                                 10,000       42,240            4%
                                             -----        ------          ---


         TOTAL:                            $250,000     $1,056,000        100%
                                            ======       =======        =====

(1)      Represents the principal portion of each Partner's guaranty obligation,
         as each  Partner's  obligation  under the  Guaranty  includes  not only
         principal,  but also (as provided in the  Guaranty)  accrued and unpaid
         interest,  late payment penalties and all costs incurred by the Bank in
         collecting any defaulted obligations.  The principal amount of the loan
         is up to $1,056,000. The General Partner will guarantee 20% of the Loan
         (up to a $211,200  principal  guaranty) as provided in the  Memorandum.
         The Limited  Partners  will  guarantee  1% of the loan (up to a $10,560
         principal  guaranty)  for  each  unit  purchased  as  provided  in  the
         Memorandum.

 

<PAGE>




                        AGREEMENT OF LIMITED PARTNERSHIP

                                       OF

                 TEXAS LITHOTRIPSY LIMITED PARTNERSHIP VI, L.P.

<PAGE>

                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                 TEXAS LITHOTRIPSY LIMITED PARTNERSHIP VI, L.P.

                                TABLE OF CONTENTS

         Article Heading                                                 Page

         1.       FORMATION.................................................1

         2.       NAME......................................................1

         3.       OFFICES...................................................1

         4.       PURPOSE...................................................2

         5.       TERM......................................................2

         6.       CERTAIN DEFINED TERMS.....................................2

         7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS..............6

         8.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE LIMITED
                  PARTNERS..................................................6

         9.       REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                  GENERAL PARTNER...........................................7

         10.      ADMISSION OF LIMITED PARTNERS.............................7

         11.      CAPITAL ACCOUNTS..........................................8

         12.      ALLOCATIONS...............................................9

         13.      DISTRIBUTIONS............................................10

         14.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS...............10

         15.      LIMITED LIABILITY........................................12

         16.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS..........12

         17.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON CERTAIN
                  EVENTS...................................................16




<PAGE>



         18.      SALE, ASSIGNMENT OR OTHER TRANSFER OF THE GENERAL
                  PARTNER'S INTEREST.......................................20

         19.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER.......21

         20.      MANAGEMENT AND OPERATION OF BUSINESS.....................21

         21.      RESERVES.................................................24

         22.      INDEMNIFICATION AND EXCULPATION OF THE GENERAL PARTNER
                   ........................................................24

         23.      DISSOLUTION OF THE PARTNERSHIP...........................25

         24.      DISTRIBUTION UPON DISSOLUTION............................26

         25.      BOOKS OF ACCOUNT, RECORDS AND REPORTS....................26

         26.      NOTICES..................................................27

         27.      AMENDMENTS...............................................28

         28.      LIMITATIONS ON AMENDMENTS................................28

         29.      MEETINGS, CONSENTS AND VOTING............................28

         30.      SUBMISSIONS TO THE LIMITED PARTNERS......................29

         31.      ADDITIONAL DOCUMENTS.....................................29

         32.      SURVIVAL OF RIGHTS.......................................29

         33.      INTERPRETATION AND GOVERNING LAW.........................29

         34.      SEVERABILITY.............................................29

         35.      AGREEMENT IN COUNTERPARTS................................29

         36.      THIRD PARTIES............................................30

         37.      POWER OF ATTORNEY........................................30

         38.      ARBITRATION..............................................30

         39.      CREDITORS................................................31

                  Schedule A...............  Schedule of Partnership Interests



<PAGE>



THE  LIMITED  PARTNERSHIP  INTERESTS  REPRESENTED  BY THIS  LIMITED  PARTNERSHIP
AGREEMENT HAVE NOT BEEN REGISTERED  WITH THE SECURITIES AND EXCHANGE  COMMISSION
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, UNDER THE TEXAS SECURITIES ACT, AS
AMENDED,  OR  UNDER  SIMILAR  LAWS OR ACTS OF  OTHER  STATES  IN  RELIANCE  UPON
EXEMPTIONS UNDER SUCH LAWS.


                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
                                TEXAS LITHOTRIPSY
                          LIMITED PARTNERSHIP VI, L.P.


                  THIS AGREEMENT OF LIMITED  PARTNERSHIP  (the  "Agreement")  is
made as of  May 23,  1997, by and among  LITHOTRIPTERS,  INC., a North
Carolina corporation (the "General Partner"), and the persons listed on Schedule
A attached hereto as the Limited Partners.

                  1.       FORMATION.

                  The  Partnership was formed pursuant to a filing in the Office
of the  Secretary of State of Texas on or about April 21, 1997 of a  Certificate
of Limited Partnership in accordance with the provisions of the Act.

                  2.       NAME.

                  2.1      The name of the Partnership is "Texas Lithotripsy 
Limited Partnership VI, L.P."

                  2.2 The  Partnership  business  shall be conducted  under such
names as the General  Partner may from time to time deem necessary or advisable,
provided that appropriate amendments to this Agreement and all necessary filings
under  applicable  assumed  or  fictitious  name  statutes  or the Act are first
obtained.

                  3.       OFFICES.

                  3.1 The principal  office of the Partnership  shall be at 2008
Litho Place,  Fayetteville,  North Carolina 28304, or at such other place as the
General  Partner  may,  from time to time,  designate  by notice to the  Limited
Partners (the "Records Office").

                  3.2 The Partnership  may have such  additional  offices as the
General Partner may, from time to time, deem necessary or advisable.


                                                      -1-


<PAGE>



                  4.       PURPOSE.

                  The purpose and business of the  Partnership  shall be: (i) to
acquire and hold an interest (the "Venture Interest") in Texas Lithotripsy Joint
Venture,  L.L.C., a limited liability company to be formed under the laws of the
State of Texas (the  "Venture")  and in all respects to act as a venturer in the
Venture, (ii) to operate a Lithostar(TM) extracorporeal, shock-wave lithotripter
for the  treatment of renal stones  primarily in the Austin and Round Rock areas
of Texas, or in such other location(s) as the General Partner may determine,  in
its sole discretion,  to be in the best interests of the  Partnership,  (iii) to
acquire and operate in the future any other urological  device or equipment that
as of the date of  acquisition  by the  Partnership  has received FDA  premarket
approval; (iv) to acquire an interest in any business entity, including, without
limitation,  a limited  partnership,  limited  liability company or corporation,
that  engages in any business  activity  described in this Article 4; and (v) to
engage in any and all activities  incidental or related to the  foregoing,  upon
and subject to the terms and conditions of this Agreement.

                  5.       TERM.

                  The  Partnership  shall  terminate on January 1, 2047,  unless
sooner terminated as herein provided.

                  6.       CERTAIN DEFINED TERMS.

                  Certain terms used in this Agreement  shall have the following
meanings:

                  Act.  The Act means the Texas Revised Limited Partnership Act,
as then in effect.

                  Affiliate.  An  Affiliate  is  (i)  any  person,  partnership,
corporation, association or other legal entity ("person") directly or indirectly
controlling, controlled by or under common control with another person; (ii) any
person owning or controlling 10% or more of the  outstanding  voting interest of
such other person;  (iii) any officer,  director or partner of such person;  and
(iv) if such other  person is an officer,  director  or partner,  any entity for
which such person acts in such capacity.

                  Agreement.  This Agreement of Limited Partnership, as the same
may be amended from time to time.

                  Calumet Coach.  The self-propelled mobile vehicle manufactured
by the Calumet Coach Company and which houses the Lithostar(TM).

                  Capital Account.  The Partnership capital account of a Partner
as computed pursuant to Article 11 of this Agreement.

                  Capital  Contributions.  All capital  contributions  made by a
Partner or his predecessor in interest which shall include,  without limitation,
contributions made pursuant to Article 7 of this Agreement.


                                                      -2-


<PAGE>



                  Capital Transaction.  Any transaction which, were it to 
generate proceeds, would produce Partnership Sales Proceeds or Partnership 
Refinancing Proceeds.

                  Code.  The Internal Revenue Code of 1986, as amended, or 
corresponding provisions of subsequent, superseding revenue laws.

                  Dilution  Offering.   As  provided  in  Section  7.4  of  this
Agreement,  the future offering of additional limited  partnership  interests in
the Partnership by the General Partner.  Any successful  Dilution  Offering will
proportionately  reduce the  Percentage  Interests of the then  current  Limited
Partners in the Partnership.

                  Domestic Proceeding.  Any divorce, annulment, separation or
similar domestic proceeding between a married couple.

                  Equipment.  The equipment used in the operation of the 
Lithostar(TM) Mobile System which includes the Calumet Coach, the Lithostar(TM),
 and miscellaneous medical equipment and supplies.

                  Expense-Sharing   Agreement.   The   agreement   between   the
Partnership  and Texas III whereby the  Partnership and Texas III will share the
maintenance,  repair and operating expenses associated with the operation of the
Lithostar(TM) Mobile System.

                  FDA.  The United States Food and Drug Administration.

                  General Partner.  The General Partner of the Partnership, 
Lithotripters, Inc., a North Carolina corporation.

                  Initial  Limited  Partner.  Dan A. Myers,  M.D., a resident of
North  Carolina  and an Affiliate of the General  Partner.  The Initial  Limited
Partner is to be the only limited partner of the Part nership until such time as
the new Limited  Partners  are  admitted to the  Partnership,  at which time the
Initial Limited Partner shall withdraw from the Partnership.

                  Limited Partners.  The Limited Partners are those investors in
the Units  admitted  to the  Partnership  and any person  admitted  as a Limited
Partner in accordance with the provisions of this Agreement.

                  Lithostar(TM).  The Lithostar(TM)  model extra corporeal shock
wave lithotripter manufactured by Siemens and to be acquired by the Venture from
Texas III pursuant to the terms of the Venture Agreement.

                  Lithostar(TM) Mobile System.  The Coach with the installed and
 operational Lithostar(TM).

                  Losses.  The net loss (including Net Losses from Capital 
Transactions) of the Partnership for each Year of the Partnership as determined
for federal income tax purposes.

                  Majority  in Interest  of the  Limited  Partners.  The Limited
Partners who hold more than 50% of the Limited Partner  Percentage  Interests in
the Partnership.

                                                      -3-


<PAGE>



                  Memorandum.  The Confidential Private Placement Memorandum of 
the Partnership dated May 22, 1997, as amended or as supplemented.

                  Net Gains from Capital Transactions. The gains realized by the
Partnership  as a result of or upon any sale,  exchange,  condemnation  or other
disposition of the capital assets of the Partnership (which assets shall include
Code Section 1231 assets) or as a result of or upon the damage or destruction of
such capital assets.

                  Net Losses from Capital  Transactions.  The losses realized by
the Partnership as a result of or upon any sale, exchange, condemnation or other
disposition of the capital assets of the  Partnership  (which shall include Code
Section 1231 assets) or as a result of or upon the damage or destruction of such
capital assets.

                  Partners.  The General Partner and the Limited Partners, 
collectively, where no distinction is required by the context in which the term 
is used herein.

                  Partnership.  Texas Lithotripsy Limited Partnership VI, L.P., 
a Texas limited partnership.

                  Partnership  Cash Flow. For the applicable  period the excess,
if any,  of (A) the sum of (i) all  gross  receipts  from  any  source  for such
period,  other than from  Partnership  loans,  Capital  Transactions and Capital
Contributions,  and (ii) any funds released by the  Partnership  from previously
established  reserves,  over  (B) the sum of (i) all cash  expenses  paid by the
Partnership  for such  period;  (ii) the amount of all  payments of principal on
loans to the Partnership;  (iii) capital  expenditures of the  Partnership;  and
(iv) such  reasonable  reserves as the General  Partner shall deem  necessary or
prudent to set aside for future repairs,  improvements or equipment  replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities and contingencies of the Partnership; provided, however, that
the  amounts  referred  to in (B)(i),  (ii) and (iii)  above shall be taken into
account  only to the extent not funded by Capital  Contributions,  loans or paid
out of previously  established reserves.  Such term shall also include all other
funds deemed  available for  distribution  and designated as  "Partnership  Cash
Flow" by the General Partner.

                  Partnership Interest.  The interest of a Partner in the 
Partnership as defined by the Act and this Agreement.

                  Partnership  Refinancing Proceeds.  The cash realized from the
refinancing of Partnership assets after retirement of any secured loans and less
(i) payment of all expenses  relating to the transaction and (ii)  establishment
of such  reasonable  reserves as the General  Partner  shall deem  necessary  or
prudent to set aside for future repairs,  improvements, or equipment replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities or contingencies of the Partnership.

                  Partnership  Sales Proceeds.  The cash realized from the sale,
exchange,  casualty  or other  disposition  of all or a portion  of  Partnership
assets after the retirement of all secured loans and less (i) the payment of all
expenses  related to the transaction and (ii)  establishment  of such reasonable
reserves as the General Partner shall deem necessary or prudent to set aside for
future repairs,  improvements, or equipment replacement or additions, or to meet
working  capital  requirements or foreseen or unforeseen  future  liabilities or
contingencies of the Partnership.

                                                      -4-


<PAGE>



                  Percentage  Interest.  The  interest  of each  Partner  in the
Partnership,  to be  determined  initially  in the case of a Limited  Partner by
reference  to his Unit  ownership  based upon the  Limited  Partners  holding an
aggregate 80%  Percentage  Interest in the  Partnership,  with each initial Unit
sold  representing an initial 0.5% interest.  The General Partner initially will
own a 20%  Percentage  Interest  in  the  Partnership.  A  Partner's  Percentage
Interest may be reduced by a future Dilution Offering.  The Partners' Percentage
Interests in the  Partnership as of the date hereof are as set forth in Schedule
A attached hereto. Any future adjustments in the Partners' Percentage Interests,
due to future Dilution Offerings or otherwise, will be reflected by revisions to
Schedule A.

                  Profit.  The net income of the Partnership (including Net 
Gains from Capital Transactions) for each Year of the Partnership as determined 
for federal income tax purposes.

                  Pro  Rata  Basis.   In   connection   with  an  allocation  or
distribution,  an allocation  or  distribution  in proportion to the  respective
Percentage Interests of the class of Partners to which reference is made.

                  Sales Agency  Agreement.  The sales agency  agreement  through
which  MedTech  Investments,  Inc.,  an Affiliate  of the General  Partner and a
broker-dealer company registered with the Securities and Exchange commission and
a member of the National Association of Securities Dealers, Inc. shall offer and
sell  the  limited  partnership  interest  of the  Partnership  pursuant  to the
Memorandum.

                  Sales Commission.  The $100 sales commission paid to MedTech 
Investments, Inc. for each Unit sold.

                  Service.  The Internal Revenue Service.

                  Texas III. Texas Lithotripsy  Limited  Partnership III L.P., a
Texas limited partnership organized and operated by its general partner, Pacific
Lithotripsy, a North Carolina general partnership.

                  Units.  The 160 equal limited partner interests in the 
Partnership offered pursuant to the Memorandum for a price per Unit of $2,275 in
cash.

                  Venture.  Texas Lithotripsy  Joint Venture,  L.L.C., a limited
liability  company  to be  formed  under  the laws of the  State of Texas by the
Partnership  and Texas III pursuant to the Venture  Agreement.  The Venture will
own the Lithostar(TM) Mobile System.

                  Venture Agreement.  The limited liability company  regulations
to be executed by the Partnership and Texas III pursuant to which they will form
and operate the Venture.

                  Venture Interest.  The interest of the Partnership in the 
Venture as defined by the Venture Agreement.

                  Year.  An annual accounting period ending on December 31 of 
each year during the term of the Partnership.


                                                      -5-


<PAGE>



                  7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS.

                  7.1  General  Partner  Contribution.  On or before the date of
this  Agreement,  the  General  Partner  will  contribute  to the capital of the
Partnership  cash in an amount  equal to 20% (up to  $91,000)  of the total cash
contributed to the  Partnership by the Partners in the offering made pursuant to
the Memorandum.

                  7.2 Limited Partner Contribution.  Each Limited Partner hereby
agrees to contribute and shall  contribute to the capital of the  Partnership on
the date of his admission to the  Partnership the cash amount set forth opposite
his name on Schedule A attached hereto.

                  7.3      No Interest.  Except as otherwise provided herein, no
interest shall be paid on any contribution to the capital of the Partnership.

                  7.4 Dilution  Offerings.  If the General Partner,  in its sole
discretion,  determines that it is in the best interest of the Partnership,  the
General Partner may, from time to time, issue, offer and sell additional limited
partnership  interests  in the  Partnership  (a  "Dilution  Offering")  to local
urologists who are not already Limited  Partners  ("Qualified  Investors").  The
primary  purpose  of any  Dilution  Offering  would be (i) to  raise  additional
capital for any  legitimate  Partnership  purpose as set forth in Article 4, and
(ii) to assure  the  highest  quality  of patient  care by  admitting  Qualified
Investors to the  Partnership  who would be dedicated and motivated as owners to
follow  the  Partnership's  treatment  protocol,  and  comply  with its  quality
assurance  and outcome  analysis  programs.  Any limited  partnership  interests
offered by the  Partnership  in a Dilution  Offering shall be sold in the manner
and  according to the terms  prescribed  in the sole  discretion  of the General
Partner;  provided,  however,  that any additional limited partnership interests
offered  in a  Dilution  Offering  will be sold for a price  no  lower  than the
highest  price for which  proportionate  limited  partnership  interests  in the
Partnership have been previously sold by the Partnership. Any sale of additional
limited partnership  interests will result in the proportionate  dilution of the
Partnership  Percentage Interests of the existing Partners.  Notwithstanding the
above,  in the event of a Dilution  Offering,  the  General  Partner  and/or its
Affiliates  may elect,  in their sole  discretion,  to prevent  dilution  of the
Percentage  Interests of the General  Partner  and/or its  Affiliates  by either
contributing a proportionate  amount of additional capital to the Partnership or
purchasing  additional limited  partnership  interests in any Dilution Offering.
Limited Partners will have no right to purchase  additional limited  partnership
interests in any Dilution Offering. Any investor acquiring a limited partnership
interest  in a Dilution  Offering  shall  agree to be bound by the terms of this
Agreement,  and shall be  automatically  admitted  as a Limited  Partner  of the
Partnership. Any adjustment in the Partners' Percentage Interests resulting from
a Dilution Offering shall be set forth on Schedule A attached hereto.

                  8.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE
                           LIMITED PARTNERS.

                  The  obligations of the Limited  Partners to make cash Capital
Contributions  hereunder are subject to the condition that the  representations,
warranties, agreements and covenants of the General Partner set forth in Article
9 of this Agreement are and shall be true and correct or have been and will have
been  complied  with  in  all  material   respects  on  the  date  such  Capital
Contributions are required to

                                                      -6-


<PAGE>



be made, except to the extent that any such representation or warranty expressly
pertains to an earlier date.

                  9.       REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                           GENERAL PARTNER.

                  9.1 The General Partner hereby  represents and warrants to the
Limited Partners that:

                  (a)  The  Partnership  is  a  limited  partnership  formed  in
         accordance  with  and  validly  existing  under  the Act and the  other
         applicable laws of the State of Texas;

                  (b) The interests in the  Partnership of the Limited  Partners
         will have been duly  authorized  or created and validly  issued and the
         Limited  Partners shall have no personal  liability to contribute money
         to the  Partnership  other than the amounts agreed to be contributed by
         them in the  manner  and on the  terms  set  forth  in this  Agreement,
         subject, however, to such limitations as may be imposed under the Act;

                  (c) No material  breach or default  adverse to the Partnership
         exists under the terms of any other  material  agreement  affecting the
         Partnership; and

                  (d) The General Partner is a North Carolina corporation formed
         and existing under the laws of the State of North Carolina.

                  9.2  The  General  Partner  hereby  covenants  to the  Limited
Partners that:

                  (a)      It will at all times act in a fiduciary manner with 
         respect to the Partnership and the Limited Partners;

                  (b) Except as  provided  in  Article  18, it will serve as the
         General Partner of the Partnership  until the Partnership is terminated
         without reconstitution; and

                  (c) It will cause the  Partnership  to carry  adequate  public
         liability,  property  damage and other insurance as is customary in the
         business to be engaged in by the Partnership.

                  10.      ADMISSION OF LIMITED PARTNERS.

                  The  General  Partner may permit the offer and sale of limited
partnership  interests on the terms and conditions provided in the Memorandum or
future  Dilution  Offering and may admit  persons  subscribing  for interests as
Limited  Partners in the  Partnership  on the terms and  conditions set forth in
this Article 10.

                  (a) The General  Partner  shall have approved of the admission
         of said person in writing on such terms and  conditions  as the General
         Partner shall determine;


                                                      -7-


<PAGE>



                  (b)  Said  person  shall  have  executed  such   documents  or
         instruments  as the General  Partner may deem necessary or desirable to
         effect his admission as a Limited Partner;

                  (c) Said  person  shall have  accepted  and adopted all of the
         terms and provisions of this Agreement, as then amended;

                  (d)  Said  person  (if a  corporation)  shall  deliver  to the
         General  Partner  a  certified  copy of a  resolution  of its  Board of
         Directors  authorizing  it to become a Limited  Partner under the terms
         and conditions of this Agreement; and

                  (e) Said person,  upon request by the General  Partner,  shall
         pay such reasonable  expenses as may be incurred in connection with its
         admission as a Limited Partner.

                  11.      CAPITAL ACCOUNTS.

                  A capital  account shall be  established  for each Partner and
shall at all  times be  determined  and  maintained  as  provided  by the  Final
Treasury  Regulations  under  Section  704(b)  of the  Code,  as the same may be
amended.  A Partner  shall not be entitled  to withdraw  any part of his capital
account or to receive any distribution from the Partnership,  except as provided
in Articles 13 and 24.

                  (a)      Each Partners' capital account shall be increased by:

                           (i)      The amount of his Capital Contribution 
                  pursuant to Article 7; and

                           (ii)     The amount of Profits allocated to him 
                  pursuant to Article 12; and

                           (iii) The Partner's pro rata share (determined in the
                  same  manner as such  Partner's  share of  Profits  and Losses
                  allocated pursuant to Article 12 hereof) of any income or gain
                  exempt from tax.

                  (b) Each Partner's capital account shall be decreased by:

                           (i)      The amount of Losses allocated to him 
                  pursuant to Article 12; and

                           (ii) The amount of Partnership Cash Flow, Partnership
                  Sales   Proceeds   and   Partnership    Refinancing   Proceeds
                  distributed to him pursuant to Article 13; and

                           (iii)  The  Partner's  pro rata  share  of any  other
                  expenditures  of the  Partnership  which are not deductible in
                  computing  Partnership  Profits  or  Losses  and which are not
                  added to the tax basis of any

                                                      -8-


<PAGE>



                  Partnership   property,    including,    without   limitation,
                  expenditures  described in Section  705(a)(2)(B)  of the Code.
                  The  Partner's  pro rata share of such  expenditures  shall be
                  determined  in the  same  manner  as such  Partner's  share of
                  Profits and Losses allocated pursuant to Article 12.

                  12.      ALLOCATIONS

                  (a)  Profits  and  Losses.  The  Profits  and  Losses  of  the
         Partnership  shall be allocated  among the Partners in accordance  with
         their  respective  Percentage  Interests.  In  allocating  Profits  and
         Losses,  Net Gains and  Losses  from  Capital  Transactions  (a part of
         Profits and Losses), if any, shall be allocated first.

                  (b)  Qualified  Income  Offset.  If any  Partner  unexpectedly
         receives  any  adjustment,  allocation  or  distribution  described  in
         Treasury Regulations Section 1.704- 1(b)(2)(ii)(d)(4) through (6) which
         causes or increases a deficit balance in such Partner's Capital Account
         (adjusted  for  this  purpose  in  the  manner   provided  in  Treasury
         Regulations Section 1.704-1(b)(2)(ii)(d)),  items of Partnership income
         and gain shall be specially allocated to each such Partner in an amount
         and manner  sufficient  to  eliminate,  to the extent  required  by the
         Regulations,  the deficit Capital Account of such Partner as quickly as
         possible,   provided  that  an  allocation  pursuant  to  this  Article
         12(d)(iii)  shall be made if and only to the extent  that such  Partner
         would  have a deficit  Capital  Account  after  all  other  allocations
         provided for in this  Article  12(d) have been  tentatively  made as if
         this Article  12(d)(iii)  were not in the Agreement.  This provision is
         intended  to be a  "qualified  income  offset,"  as defined in Treasury
         Regulations  Section  1.704-  1(b)(2)(ii)(d),   such  Regulation  being
         specifically incorporated herein by reference.

                  (c) Sales Commission.  The Sales Commission shall be allocated
         to the  Units  which  are  not  held  by the  General  Partner  and its
         Affiliates  in  proportion to their  respective  capital  contributions
         represented  by such Units (i.e.,  $100 in Sales  Commissions  per each
         such Unit).  The purpose of Article  12(d)(iv) is to allocate the Sales
         Commission to those Partners who actually bore the burden of paying the
         Sales Commission.

                  (d)  Allocations  Between  Transferor and  Transferee.  In the
         event of the transfer (other than the pledges of the General  Partner's
         interest  permitted  by Article 18 or  Permitted  Pledges  described in
         Article  16.2(b))  of all or  any  part  of a  Partner's  interest  (in
         accordance with the provisions of this Agreement) in the Partnership at
         any time other  than at the end of a Year,  or the  admission  of a new
         Partner  (in  accordance  with  the  terms  of  this  Agreement),   the
         transferring  Partner  or new  Partner's  share  of  the  Partnership's
         income,  gain,  loss,  deductions  and  credits,  as computed  both for
         accounting  purposes  and for  Federal  income tax  purposes,  shall be
         allocated between the transferor Partner and the transferee Partner (or
         Partners),  or the new Partner and the other Partners,  as the case may
         be, in the same  ratio as the  number of days in such Year  before  and
         after the date of the transfer or admission; provided, however, that if
         there  has  been a sale  or  other  disposition  of the  assets  of the
         Partnership (or any part thereof) during such Year,

                                                      -9-


<PAGE>



         then the General  Partner may elect, in its sole  discretion,  to treat
         the periods  before and after the date of the  transfer or admission as
         separate  Years and allocate the  Partnership's  net income,  gain, net
         loss,  deductions and credits for each of such deemed  separate  Years.
         Notwithstanding the foregoing,  the Partnership's "allocable cash basis
         items," as that term is used in Section 706(d)(2)(B) of the Code, shall
         be  allocated  as  required  by Section  706(d)(2)  of the Code and the
         regulations thereunder.

                  (e) Tax  Withholding.  The Partnership  shall be authorized to
         pay, on behalf of any  Partner,  any amounts to any  federal,  state or
         local taxing  authority,  as may be necessary  for the  Partnership  to
         comply with tax withholding  provisions of the Code or the other income
         tax or  revenue  laws  of any  taxing  authority.  To  the  extent  the
         Partnership  pays any such  amounts  that it may be  required to pay on
         behalf  of  a  Partner,  such  amounts  shall  be  treated  as  a  cash
         Distribution  to such  Partner  and shall  reduce the amount  otherwise
         distributable to such Partner.

                  (f) For the  purposes of the  allocations  as provided in this
         Article 12, all  allocations  of income,  gains,  losses and deductions
         allocated from the Venture to the  Partnership  shall maintain the same
         character  at the  Partnership  level  as such  allocations  had at the
         Venture level.

                  13.      DISTRIBUTIONS.

                  (a)  Distribution of Partnership  Cash Flow.  Partnership Cash
         Flow shall be distributed to the Partners  within 60 days after the end
         of each Year, or earlier in the discretion of the General  Partner,  in
         proportion  to their  respective  Percentage  Interests  at the time of
         distribution.

                  (b)  Distribution  of  Partnership  Refinancing  Proceeds  and
         Partnership  Sales  Proceeds.   Partnership  Refinancing  Proceeds  and
         Partnership  Sales Proceeds shall be distributed to the Partners within
         60 days of the Capital  Transaction  giving rise to such  proceeds,  or
         earlier in the  discretion  of the General  Partner,  in  proportion to
         their respective Percentage Interests at the time of distribution.

                  (c)  Distribution  in  Liquidation.  Upon  liquidation  of the
         Partnership,  all of the  Partnership's  property  shall  be  sold  and
         Profits and Losses allocated accordingly. Proceeds from the liquidation
         of the Partnership shall be distributed in accordance with Article 24.

                  (d) For the purposes of the  distributions as provided in this
         Article  13,  all  distributions  allocated  from  the  Venture  to the
         Partnership  shall maintain the same character at the Partnership level
         as such distributions had at the Venture level.

                  14.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS.

                  14.1  Management.  The Limited Partners shall not take part in
the management of the business,  nor transact any business for the  Partnership,
nor shall they have power to sign for or to bind

                                                      -10-


<PAGE>



the Partnership. The Partnership may, however, contract with one or more Limited
Partners to act as the local  manager of the  Lithostar(TM)  Mobile  System.  No
Limited Partner may withdraw from the Partnership except as expressly  permitted
herein.

                  14.2  Operation of  Lithostar(R)  Mobile  System.  The Limited
Partners shall not operate or utilize the  Lithostar(TM)  Mobile System or other
Partnership  equipment except pursuant to (i) an Agreement with the Partnership;
or (ii) any other arrangement specifically approved by the General Partner.

                  14.3 Outside Activities.  The Limited Partners agree that they
owe a fiduciary  duty to the  Partnership  and, as a  consequence,  each Limited
Partner (that is not an Affiliate of the General  Partner) shall not directly or
indirectly  own,  lease or  sublease a Mobile  Lithotripsy  System  (or  similar
equipment used for lithotripsy of renal stones) or any other therapeutic  device
acquired by the Partnership  while they are Limited  Partners in the Partnership
(collectively,  the "Outside  Activities").  Prohibited  indirect ownership of a
competing  device  shall  include the  ownership  of any  interest in a business
venture  (through  stock  ownership,   partnership  interest  ownership,  or  as
otherwise  determined in the sole discretion of the General  Partner)  involving
the  ownership,  purchase,  use,  lease,  sublease  or  operation  of  a  Mobile
Lithotripsy  System (or similar  equipment used for lithotripsy of renal stones)
or other competing  device or equipment,  unless the General Partner  determines
that  such  activity  by the  Limited  Partner  is not  detrimental  to the best
interest of the Partnership.  In the event a Limited Partner elects to engage in
an Outside  Activity in violation of this Article  15.3,  he or she must provide
written  notice of such intent to the General  Partner prior to engaging in such
activity,  and such election shall be deemed an election by the Limited  Partner
to withdraw  from the  Partnership  (the "Notice of  Withdrawal").  If a Limited
Partner  engages in an Outside  Activity  without  first  notifying  the General
Partner of his or her election to do so, the Limited  Partner shall be deemed to
have given a Notice of Withdrawal on the date the General  Partner first becomes
aware of the  Limited  Partner's  Outside  Activity.  Upon  receiving  a Limited
Partner's Notice of Withdrawal or equivalent  thereof,  the  Partnership's  sole
remedy shall be the purchase rights provided in Article 17.3.

                  14.4  Disclosure  of  Confidential  Information.  Each Limited
Partner acknowledges and agrees that his or her participation in the Partnership
under this Agreement necessarily involves his or her understanding of and access
to certain trade secrets and other  confidential  information  pertaining to the
business of the  Partnership.  Accordingly,  each Limited Partner agrees that at
all  times  during  his or her  participation  in the  Partnership  as a Limited
Partner and thereafter, he or she will not, directly or indirectly,  without the
express written authority of the Partnership, unless required by law or directed
by a applicable  legal authority having  jurisdiction  over the Limited Partner,
disclose  or use for the  benefit of any  person,  corporation  or other  entity
(other than the Partnership),  or himself or herself, (i) any trade,  technical,
operational, management or other secrets, any patient or customer lists or other
confidential  or secret data, or any other  proprietary,  confidential or secret
information of the Partnership or (ii) any confidential  information  concerning
any of the financial  arrangements,  financial positions,  hospital or physician
contracts,  third  party  payor  arrangements,  quality  assurance  and  outcome
analysis programs,  competitive status,  customer or supplier matters,  internal
organizational  matters,  technical  abilities,  or other business affairs of or
relating to the Partnership.  The Limited  Partners  acknowledge that all of the
foregoing constitutes proprietary  information,  which is the exclusive property
of the Partnership. In the event of breach of this Article 14.4 as determined by
the General Partner, the Partnership shall be entitled

                                                      -11-


<PAGE>



to any remedy at law or equity with  respect to such breach,  including  without
limitation, an injunction or suit for damages.

                  15.      LIMITED LIABILITY.

                  No Limited Partner shall be required to make any  contribution
to the  capital of the  Partnership  except as set forth in Article 7, nor shall
any Limited  Partner in his capacity as such, be bound by, or personally  liable
for,  any expense,  liability or  obligation  of the  Partnership  except to the
extent of his or her (i) interest in the  Partnership;  and (ii)  obligation  to
return distributions made to him or her under certain  circumstances as required
by the Act.

                  16.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS.

                  16.1     Transferability.

                  (a) The  term  "transfer"  when  used in this  Agreement  with
         respect to a Partnership  Interest includes a sale,  assignment,  gift,
         pledge,  exchange,  or any other  disposition (but does not include the
         issuance of new Partnership Interests pursuant to a Dilution Offering);

                  (b) Except as otherwise  provided herein,  the General Partner
         shall not at any time  transfer or assign its interest or obligation as
         General Partner;

                  (c) The Partnership  Interest of any Limited Partner shall not
         be  transferred,  in whole or in part,  except in  accordance  with the
         conditions and limitations set forth in Articles 16.2 or 17;

                  (d) The  transferee of a Partnership  Interest by  assignment,
         operation of law or otherwise,  shall have only the rights,  powers and
         privileges  enumerated in Article 16.3 or otherwise provided by law and
         may not be admitted to the  Partnership as a Limited  Partner except as
         provided in Article 16.4 or as a General  Partner except as provided in
         Article 16.5;

                  (e) Notwithstanding any provision herein to the contrary,  the
         Partnership  Agreement  shall  in  no  way  restrict  the  issuance  or
         transfers of stock of the General Partner; and

                  (f) Notwithstanding any provision herein to the contrary,  the
         issuance of Partnership  Interests  pursuant to a Dilution Offering and
         the admission of new Limited Partners  pursuant to a Dilution  Offering
         shall be governed by the provisions of Section 7.4 of this Agreement.






                                                      -12-


<PAGE>



                  16.2     Restrictions on Transfers by Limited Partners.

                  (a) All or part of a Partnership  Interest may be  transferred
         by a  Limited  Partner  only  with the prior  written  approval  of the
         General  Partner,  which  approval may be granted or denied in the sole
         discretion of the General Partner.

                  (b) The General  Partner  shall not approve any  transfer of a
         Partnership  Interest,  except a pledge of any Partnership  Interest by
         the General Partner to any bank,  insurance  company or other financial
         institution to secure payment of indebtedness  (a "Permitted  Pledge"),
         or otherwise  unless the proposed  transferee  shall have furnished the
         General Partner with a sworn statement that:

                           (i) The proposed  transferee  proposes to acquire his
                  Partnership  Interest as a principal,  for  investment and not
                  with a view to resale or distribution;

                           (ii) The proposed  transferee meets such requirements
                  regarding sophistication,  income and net worth as required by
                  applicable state and Federal securities laws;

                           (iii) The proposed  transferee has met such net worth
                  and income  suitability  standards as have been established by
                  the General Partner;

                           (iv)  The   proposed   transferee   recognizes   that
                  investment in the Partnership  involves  certain risks and has
                  taken  full  cognizance  of and  understands  all of the  risk
                  factors related to the purchase of a Partnership Interest; and

                           (v)  The  proposed   transferee  has  met  all  other
                  requirements of the General Partner for the proposed transfer.

                  (c) Other than in the case of a Permitted  Pledge,  a transfer
         of a  Partnership  Interest  may be made  only  if,  prior  to the date
         thereof,  the Partnership  upon request receives an opinion of counsel,
         satisfactory in form and substance to the General Partner, that neither
         the offering nor the proposed transfer will require  registration under
         Federal or applicable state securities laws or regulations.

                  16.3     Rights of Transferee.

                  Unless  admitted to the Partnership in accordance with Article
16.4, the  transferee of a Partnership  Interest or a part thereof or any right,
title or interest therein shall not be entitled to any of the rights, powers, or
privileges of his  predecessor in interest,  except that he shall be entitled to
receive and be credited or debited with his  proportionate  share of Partnership
income, gains, Profits, Losses, deductions, credits or Distributions.


                                                      -13-


<PAGE>




                  16.4     Admission of Limited Partners.

                  Except as  otherwise  provided  in  Article  17,  the  General
Partner, or the transferee of all or part of the Partnership  Interest of either
a General Partner or a Limited Partner,  may be admitted to the Partnership as a
Limited Partner upon furnishing to the General Partner all of the following:

                  (a) The  written  approval of a Majority in Interest of all of
         the Limited  Partners  (except the assignor  Partner),  or the assignor
         Partner  alone,  which  approval  may be  granted or denied in the sole
         discretion of such Partners or Partner (as the case may be);

                  (b)  The  written  approval  of  the  General  Partner,  which
         approval may be granted or denied in the sole discretion of the General
         Partner;

                  (c) Acceptance, in a form satisfactory to the General Partner,
         of all the  terms  and  conditions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d)  A  properly  executed  power  of  attorney  substantially
         identical to that contained in Article 37;

                  (e) Such other  documents or instruments as may be required in
         order to effect his or her admission as a Limited Partner; and

                  (f) Payment of such reasonable  expenses as may be incurred in
         connection with his or her admission as a Limited Partner.

                  16.5     Admission of General Partners.

                  A Limited  Partner,  or the  transferee  of all or part of the
Partnership  Interest of the General Partner, may be admitted to the Partnership
as a  general  partner  upon  furnishing  to  the  General  Partner  all  of the
following:

                  (a) The  written  consent of both the  General  Partner  and a
         Majority  in Interest of the  Limited  Partners,  which  consent may be
         granted or denied in the sole discretion of the Partners;

                  (b) Such financial statements,  guarantees or other assurances
         as the General  Partner  may require  with regard to the ability of the
         proposed  general  partner to fulfill the  financial  obligations  of a
         general partner hereunder;

                  (c) Acceptance,  in form  satisfactory to the General Partner,
         of all the  terms  and  provisions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;


                                                      -14-


<PAGE>



                  (d) A certified copy of a resolution of its Board of Directors
         (if it is a  corporation)  authorizing  it to become a general  partner
         under the terms and conditions of this Agreement;

                  (e)      A power of attorney substantially identical to that 
         contained in Article 37;

                  (f) Such other  documents or instruments as may be required in
         order to effect its admission as a general partner; and

                  (g) Payment of such reasonable  expenses as may be incurred in
         connection with its admission as a general partner.

                  Notwithstanding  the above,  a transferee  that controls or is
controlled by the General Partner or one or more of its Affiliates that receives
all or part of the  Partnership  Interest of the General Partner may be admitted
to the  Partnership as a general  partner upon complying with all the provisions
of Article  16.5  except for  subparagraph  16.5(a).  As long as the  transferee
either  controls or is controlled  by the General  Partner or one or more of its
Affiliates,  no  Limited  Partner  consents  will  be  required  to  admit  such
transferee as a General Partner to the Partnership.

                  16.6     Amendment of Certificate of Limited Partnership and 
Qualification.

                  The  General  Partner  shall  take  all  steps  necessary  and
appropriate to prepare and record any  amendments to the  Certificate of Limited
Partnership, as may be necessary or appropriate from time to time to comply with
the requirements of the Act, including,  without limitation,  upon the admission
to the Partnership of any general partner  pursuant to the provisions of Article
16.5, and may for this purpose  exercise the power of attorney  delivered to the
General Partner pursuant to Article 16.5 or 37. In addition, the General Partner
shall take all steps necessary and appropriate to prepare and record any and all
documents  necessary to qualify the Partnership to do business in  jurisdictions
where the Partnership is doing business,  and may for this purpose  exercise the
power of attorney  delivered to the General  Partner  pursuant to Articles 16.4,
16.5 or 37.

                  16.7     Fundamental Changes.

                  In the  event  a plan  is  approved  by  the  General  Partner
providing for the merger or consolidation of the Partnership with another person
or entity, or the sale of all or substantially all of the Partnership Interests,
including  without  limitation the exchange of Partnership  Interests for equity
interests  in  another  person or entity or for cash or other  consideration  or
combination  thereof,  then and in such  event,  the Limited  Partners  shall be
obligated to take or refrain  from  taking,  as the case may be, such actions as
the  plan  may  provide,   including,   without   limitations,   executing  such
instruments,  and  providing  such  information  as the  General  Partner  shall
reasonably  request.  Any plan described in this Article 16.7 may also effect an
amendment to the  Partnership  Agreement  or the  adoption of a new  partnership
agreement in connection with the merger of the  Partnership  with another person
or entity as provided in Section 2.11 of the Act. The plan may also provide that
the General Partner and its Affiliates shall receive fees for services  rendered
in connection  with the  operation of the  Partnership  or any successor  entity
following  the  consummation  of the  transactions  described  in the plan,  and
neither the

                                                      -15-


<PAGE>



Partnership nor the Partners shall have any right by virtue of this Agreement in
the income  derived  therefrom.  Any  securities  or other  consideration  to be
distributed  to the Partners  pursuant to the plan shall be  distributed  in the
manner  set  forth in  Article  24(c)  as  though  the  Partnership  were  being
liquidated.  For this purpose only,  the fair market value of the  securities or
other  consideration  to be  received  pursuant  to the plan shall be treated as
"Profits"  and the capital  accounts of the  Partners  shall be increased in the
manner  provided  in Article  11(a)(ii).  No Partner  shall be  entitled  to any
appraisal  or similar  rights in  connection  with a plan  contemplated  by this
Article 16.7.

                  16.8     Withdrawal of Initial Limited Partner.

                  Upon the date the first  Limited  Partner is  admitted  to the
Partnership in accordance with Article 10 of this Agreement, the Initial Limited
Partner  shall  withdraw  from  the  Partnership,   and  thereupon  his  Capital
Contribution shall be returned and his Partnership Interest shall be reallocated
to the Limited Partners.

                  17.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON
                           CERTAIN EVENTS.

                  17.1     Death.

                  Upon the  death of a Limited  Partner,  the  deceased  Limited
Partner's  executor,  administrator,  or other legal or personal  representative
shall give  written  notice of that fact to the  General  Partner.  The  General
Partner shall have the option to purchase at the Closing (as defined  below) the
Partnership   Interest  of  the  deceased   Limited  Partner  (whose   executor,
administrator  or other  legal or  personal  representative  shall  then  become
obligated  to sell such  Partnership  Interest) at the price  determined  in the
manner  provided  in  Article  17.6  of  this  Agreement  and on the  terms  and
conditions provided in Article 17.7 of this Agreement. The General Partner shall
have a period of thirty (30) days  following  the date of notice of the death of
the Limited Partner (the "Option  Period") within which to notify in writing the
deceased Limited  Partner's  executor,  administrator or other legal or personal
representative,  whether the General Partner wishes to purchase all or a portion
of the  Partnership  Interest of the deceased  Limited  Partner.  If the General
Partner  does not elect to  purchase  the  entire  Partnership  Interest  of the
deceased  Limited  Partner before the expiration of the Option Period and in the
manner provided  herein,  the portion of the Partnership  Interest not purchased
shall be held by the deceased  Limited  Partner's  executor,  administrator,  or
other legal representative pursuant to the terms of this Agreement.  The General
Partner, in its sole discretion,  may elect to assign its rights to purchase the
Partnership  Interest of a deceased  Limited  Partner under this Section 17.1 to
the Partnership and, in such case, the Partnership shall have the same rights as
provided for the General Partner under this Section 17.1.

                  17.2     Bankruptcy, Insolvency or Assignment for Benefit of 
                           Creditors of a Limited Partner.

                   In the event  that an  involuntary  or  voluntary  proceeding
under the  Federal  Bankruptcy  Code,  as  amended,  is filed for or against any
Limited  Partner,  or if any Limited  Partner shall make an  assignment  for the
benefit of his creditors,  or if any Limited Partner has a receiver or custodian
appointed  for his assets,  or any Limited  Partner  generally  fails to pay his
debts when due, the insolvent Limited

                                                      -16-


<PAGE>



Partner shall give written  notice (the "Notice of  Insolvency")  to the General
Partner of the  commencement  of any such  proceeding or the  occurrence of such
event  within  five days of the  first  notice  to him of such  commencement  or
occurrence of such event.  The General Partner shall have the option to purchase
at the Closing  (as defined  below) the  Partnership  Interest of the  insolvent
Limited  Partner (which  insolvent  Limited  Partner or his trustee,  custodian,
receiver or other  personal or legal  representative,  as the case may be, shall
then become obligated to sell such Partnership Interest) at the price determined
in the manner  provided in Article 17.6 of this  Agreement  and on the terms and
conditions provided in Article 17.7 of this Agreement. The General Partner shall
have a period of thirty (30) days following the date of the Notice of Insolvency
(the "Option  Period")  within which to notify in writing the insolvent  Limited
Partner  or his  trustee,  custodian,  receiver,  or  other  legal  or  personal
representative,  whether the General Partner wishes to purchase all or a portion
of the Partnership  Interest of the insolvent  Limited  Partner.  If the General
Partner  does not elect to  purchase  the  entire  Partnership  Interest  of the
insolvent  Limited Partner before the expiration of the Option Period and in the
manner provided  herein,  the portion of the Partnership  Interest not purchased
shall be held by the  insolvent  Partner,  his trustee,  custodian,  receiver or
other legal or personal  representative pursuant to the terms of this Agreement.
The General Partner,  in its sole discretion,  may elect to assign its rights to
purchase the  Partnership  Interest of an insolvent  Limited  Partner under this
Section 17.2 to the Partnership  and, in such case, the  Partnership  shall have
the same rights as provided for the General Partner under this Section 17.2.

                  17.3     Breach of Article 14.3.

                  In the event the  General  Partner  (the  "Defaulting  Limited
Partner")  either receives a Notice of Withdrawal as provided in Article 14.3 or
receives notice of breach of Article 14.3, the General Partner may elect, in its
sole  discretion,  to treat such event as a default  under  this  Agreement  and
enforce the  provisions of this Article 17.3. If the General  Partner  elects to
enforce the  provisions  of this Article  17.3,  the General  Partner shall give
written  notice of such  election  (the "Notice of  Default") to the  Defaulting
Limited  Partner within 180 days of the date the General  Partner first received
the Notice of Default or notice of the  defaulting  event.  The General  Partner
shall  have the  option to  purchase  at the  Closing  (as  defined  below)  the
Partnership Interest of the Defaulting Limited Partner (which Defaulting Limited
Partner shall then become  obligated to sell such  Partnership  Interest) at the
price determined in the manner provided in Article 17.6 of this Agreement and on
the terms and conditions provided in Article 17.7 of this Agreement. The General
Partner shall have a period of thirty (30) days  following the date of the close
of the date of the Notice of Default (the "First Option Period") within which to
notify in writing the Defaulting  Limited  Partner,  whether the General Partner
wishes  to  purchase  all  or a  portion  of  the  Partnership  Interest  of the
Defaulting  Limited  Partner.  If the General Partner does not elect to purchase
the entire  Partnership  Interest of the Defaulting  Limited  Partner before the
expiration of the Option Period and in the manner provided  herein,  the portion
of the  Partnership  Interest  not  purchased  shall  be held by the  Defaulting
Limited Partner pursuant to the terms of this Agreement. The General Partner, in
its sole discretion,  may elect to assign its rights to purchase the Partnership
Interest  of a  Defaulting  Limited  Partner  under  this  Section  17.3  to the
Partnership  and, in such case,  the  Partnership  shall have the same rights as
provided for the General Partner under this Section 17.3.





                                                      -17-


<PAGE>



                  17.4     Domestic Proceeding.

                  In the  event  that a spouse of a  Limited  Partner  commences
against  a  Limited  Partner,  or a  Limited  Partner  is named  in, a  Domestic
Proceeding,  the Limited  Partner  shall give  written  notice  (the  "Notice of
Domestic  Proceeding")  to the General  Partner of the  commencement of any such
proceeding within five days of the first notice to him of such commencement. The
General  Partner  shall have the option to  purchase  at the Closing (as defined
below) the Partnership  Interest of the Limited Partner involved in the Domestic
Proceeding  (which  Limited  Partner  shall then become  obligated  to sell such
Partnership Interest), at the price determined in the manner provided in Article
17.6 of this Agreement and on the terms and conditions  provided in Article 17.7
of this  Agreement.  The General Partner shall have a period of thirty (30) days
following the date of the Notice of Domestic  Proceeding  (the "Option  Period")
within which to notify in writing the Limited  Partner  involved in the Domestic
Proceeding,  whether the General  Partner wishes to purchase all or a portion of
the Partnership  Interest of such Limited  Partner.  If the General Partner does
not elect to purchase the Partnership  Interest of the Limited Partner  involved
in the Domestic Proceeding before the expiration of the Option Period and in the
manner provided  herein,  the portion of the Partnership  Interest not purchased
shall be held by such Limited  Partner  pursuant to the terms of this Agreement.
The General Partner,  in its sole discretion,  may elect to assign its rights to
purchase  the  Partnership  Interest  of the  Limited  Partner  involved  in the
Domestic  Proceeding  under this  Section 17.4 to the  Partnership  and, in such
case,  the  Partnership  shall have the same rights as provided  for the General
Partner under this Section 17.4.

                  17.5     Divestiture Option.

                  If  state  or  federal  regulations  or laws  are  enacted  or
applied,  or if any other legal developments occur, which, in the opinion of the
General Partner adversely affect (or potentially adversely affect) the operation
of the Partnership (e.g., the enactment or application of prohibitory  physician
self-referral  legislation against the Partnership or its Partners), the General
Partner shall promptly either, in its discretion, (i) take the steps outlined in
this Article 17.5 to divest the Limited Partners of their Partnership Interests,
or (ii) dissolve the Partnership as provided in Article 23.1(d).  If the General
Partner  chooses  option  (i), it shall  deliver a written  notice to all of the
Limited  Partners  (the  "Notice of  Election")  and purchase  such  Partnership
Interests  for  its  own  account.  The  purchase  price  to be  paid  for  each
Partnership  Interest  shall be  determined in the manner as provided in Article
17.6 and shall be on the terms and  conditions as provided in Article 17.7.  The
transfer of the Partnership  Interests and the payment of the purchase price (as
provided  in  Article  17.6)  shall be made at such  time as  determined  by the
General  Partner to be in the best interests of the  Partnership and its Limited
Partners.  Each  Limited  Partner  hereby  makes,  constitutes  and appoints the
General  Partner,  with  full  power  of  substitution,   his  true  and  lawful
attorney-in-fact,  to take such actions and execute such documents on his behalf
to effect the transfer of his  Partnership  Interest as provided in this Article
17.5.

                  17.6     Purchase Price.

                  The purchase price to be paid for the Partnership  Interest of
any Limited Partner whose interest is being purchased pursuant to the provisions
of Articles 17.1,  17.2,  17.3,  17.4 or 17.5 (the "Retiring  Limited  Partner")
shall  be an  amount  equal  to the  Retiring  Limited  Partner's  share  of the
Partnership's  book value, if any, (prorated in the event that only a portion of
his Partnership Interest is being purchased) as reflected by the Capital Account
of the Retiring Limited Partner (unadjusted for any

                                                      -18-


<PAGE>



appreciation  in Partnership  assets and as reduced by  depreciation  deductions
claimed by the Partnership for tax purposes).  The determination of the Retiring
Limited Partner's Capital Account on the Valuation Date (as defined below) shall
be made by the Partnership's internal accountant (the "Partnership  Accountant")
upon a review  of the  Partnership  books  of  account,  and a  formal  audit is
expressly  waived.  The statement of the Partnership  Accountant with respect to
the Capital Account of the Retiring  Limited Partner on the Valuation Date shall
be binding and conclusive upon the  Partnership,  the purchaser and the Retiring
Limited Partner and his representative. The Valuation Date shall be the last day
of the month immediately preceding the month in which occurs: (i) the death of a
Limited  Partner,  in the  case of a  purchase  by  reason  of  death;  (ii) the
bankruptcy  or  insolvency  of a Limited  Partner,  in the case of a purchase by
reason of such bankruptcy or insolvency; (iii) the Notice of Default as provided
in  Article  17.3  in the  case  of a  purchase  by  reason  thereof;  (iv)  the
commencement  of the  Domestic  Proceeding,  in the case of a purchase by reason
thereof;  or (v) the Notice of Election as provided in Article 17.5, in the case
of a purchase by reason thereof.  Any Limited Partner whose Partnership Interest
is purchased  pursuant to the provisions of Article 17.1,  17.2,  17.3,  17.4 or
17.5 shall be  entitled  only to the  purchase  price which shall be paid at the
Closing in cash (or by certified  or cashier's  check) and shall not be entitled
to  any   Partnership   distributions   made  after  the  Valuation   Date.  Any
distributions  inadvertently  made  to a  Retiring  Limited  Partner  after  the
Valuation  Date may be applied in reduction of the purchase  price as determined
pursuant to this  Article  17.6.  The  transfer of a  Partnership  Interest of a
Retiring  Limited  Partner shall be deemed to occur as of the Valuation Date and
the Retiring  Limited  Partner shall have no voting or other rights as a Limited
Partner after such date.  The purchaser  shall be entitled to any  distributions
attributable to the transferred interest after the Valuation Date and shall have
the right to deduct the amount of any such  distributions  made to the  Retiring
Limited Partner from the purchase price.

                  17.7     Closing.

                  17.7.1  Closing  of  Purchase  and Sale.  The  Closing  of any
         purchase and sale of a Partnership  Interest  pursuant to Article 17.1,
         17.2,  17.3,  17.4 or 17.5 of this  Agreement  shall  take place at the
         principal office of the Partnership,  or such other place designated by
         the General Partner, on the date determined as follows (the "Closing"):

                  (a) In the case of a purchase and sale  occurring by reason of
         the death of a Limited  Partner as  provided  in  Article  17.1 of this
         Agreement,  the Closing  shall be held on the thirtieth day (or if such
         thirtieth  day is not a business  day, the next  business day following
         the thirtieth day) next following the last to occur of:

                           (i)      Qualification of the executor or personal 
                  administrator of the deceased Limited Partner's estate;

                           (ii) The date on which any necessary determination of
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (iii) The date that  coincides  with the close of the
                  Option Period.


                                                      -19-


<PAGE>



                  (b) In the case of a purchase and sale  occurring by reason of
         the  occurrence of one of the events  described in Article 17.2,  17.3,
         17.4 or  17.5  of this  Agreement,  the  Closing  shall  be held on the
         thirtieth day (or if such thirtieth day is not a business day, the next
         business day following the thirtieth  day) next  following the later to
         occur of:

                           (i)  The date on which any necessary determination of
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (ii) The date  that  coincides  with the close of the
                  Option Period.

         At the Closing,  although not  necessary  to effect the  transfer,  the
         Retiring Limited Partner shall  concurrently with tender and receipt of
         the applicable  purchase price,  deliver to the purchaser duly executed
         instruments of transfer and  assignment,  assigning good and marketable
         title to the  portion or  portions of the  Retiring  Limited  Partner's
         entire  Partnership  Interest thus  purchased,  free and clear from any
         liens  or  encumbrances  or  rights  of  others  therein.  The  parties
         acknowledge  that occurrence of any of the triggering  events described
         in Article 17.1,  17.2,  17.3, 17.4 or 17.5 and compliance with all the
         Articles  of this  Agreement,  except  the  execution  of the  transfer
         documents  by the  Retiring  Partner as provided  above in this Article
         17.7.1,  are sufficient to effect the complete transfer of the Retiring
         Limited  Partner's  interest and the Retiring  Limited Partner shall be
         deemed to  consent  to  admission  of the  transferee  as a  substitute
         Limited Partner.  Notwithstanding  the date of the Closing or whether a
         Closing is successfully held, the transfer of a Partnership Interest of
         a Retiring Limited Partner shall be deemed to occur as of the Valuation
         Date as defined in Article  17.6.  The  deemed  transfer  is  effective
         regardless of whether the Retiring  Limited Partner performs the duties
         set forth in this Article 17.7.1.

                  17.7.2  Terms and  Conditions  of  Purchase.  The  Partnership
         Interest of a Limited  Partner shall not be  transferred to any Partner
         unless the  requirements  of Articles 16.2 and 16.4 (b) through (f) are
         satisfied  with  respect to it. The  purchaser  shall be liable for all
         obligations  and  liabilities   connected  with  that  portion  of  the
         Partnership  Interest  transferred  to it  unless  otherwise  agreed in
         writing.

                  18.      SALE,  ASSIGNMENT  OR OTHER  TRANSFER  OF THE GENERAL
                           PARTNER'S INTEREST.

                  18.1  The   General   Partner   may  not   mortgage,   pledge,
hypothecate,  transfer,  sell, assign or otherwise dispose of all or any part of
its interest in the  Partnership,  whether  voluntarily,  by operation of law or
otherwise (the foregoing  actions being  hereafter  collectively  referred to as
"Transfers" or singularly as a "Transfer") except as permitted by this Article.

                  18.2 If the  General  Partner  makes a Transfer  (other than a
mortgage,  pledge or  hypothecation)  of its  general  partner  interest  in the
Partnership pursuant to this Article, it shall be liable for all obligations and
liabilities  incurred  by it as the  General  Partner of the  Partnership  on or
before the

                                                      -20-


<PAGE>



effective date of such Transfer,  but shall not be liable for any obligations or
liabilities of the Partnership arising after the effective date of the Transfer.

                  18.3     No Transfer by the General Partner shall be permitted
unless:

                  (a) Counsel for the Partnership shall have rendered an opinion
         that none of the actions  taken in  connection  with such Transfer will
         cause the Partnership to be classified  other than as a partnership for
         Federal income tax purpose or will cause the termination or dissolution
         of the Partnership under state law; and

                  (b) Such  documents  or  instruments,  in form  and  substance
         satisfactory to counsel for the  Partnership,  shall have been executed
         and  delivered  as may be  required  in the  opinion of counsel for the
         Partnership to effect fully any such Transfer.

                  Notwithstanding the foregoing provisions of this Article 18.3,
the General  Partner may pledge its  interest  in the  Partnership  to any bank,
insurance   company  or  other  financial   institution  to  secure  payment  of
indebtedness.

                  19.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER.

                  If the General Partner shall be finally adjudged by a court of
competent  jurisdiction to be liable to the Limited  Partners or the Partnership
for any act of gross negligence or willful  misconduct in the performance of its
duties under the terms of this Agreement, the General Partner may be removed and
another  substituted  with the  consent  of all of the  Limited  Partners.  Such
consent  shall be evidenced  by a  certificate  of removal  signed by all of the
Limited Partners. In the event of removal, the new general partner shall succeed
to all of the powers, privileges and obligations of the General Partner, and the
General  Partner's  interest in the  Partnership  shall become that of a Limited
Partner,  and the General Partner shall maintain its same Percentage Interest in
the Partnership  notwithstanding  anything contained in the Act to the contrary.
In addition,  in the event of removal,  the new general  partner  shall take all
steps  necessary  and  appropriate  to prepare  and record an  amendment  to the
Certificate of Limited Partnership to reflect the removal of the General Partner
and the admission of such new general partner.

                  20.      MANAGEMENT AND OPERATION OF BUSINESS.

                  20.1 All  decisions  with  respect  to the  management  of the
business and affairs of the Partnership shall be made by the General Partner.

                  20.2 The General  Partner shall be under no duty to devote all
of its time to the business of the Partnership,  but shall devote only such time
as it deems  necessary  to conduct the  Partnership  business and to operate and
manage the Partnership in an efficient manner.

                  20.3 The  General  Partner may charge to the  Partnership  all
ordinary and necessary costs and expenses, direct and indirect,  attributable to
the activities,  conduct and management of the business of the Partnership.  The
costs and expenses to be borne by the  Partnership  shall  include,  but are not
limited to, all  expenditures  incurred in acquiring and financing the Equipment
or other Partnership

                                                      -21-


<PAGE>



property,  legal and accounting fees and expenses,  salaries of employees of the
Partnership,   consulting  and  quality   assurance  fees  paid  to  independent
contractors, insurance premiums and interest.

                  20.4 In addition to, and not in limitation  of, any rights and
powers  covenanted by law or other  provisions of this agreement,  and except as
limited,  restricted or prohibited by the express  provisions of this Agreement,
the General Partner shall have and may exercise on behalf of the Partnership all
powers and rights necessary,  proper,  convenient or advisable to effectuate and
carry out the purposes, business and objectives of the Partnership.  Such powers
shall include, without limitation, the following:

                  (a) To acquire the Venture Interest and execute and deliver 
         the Venture Agreement and the Expense-Sharing Agreement;

                  (b) To acquire on behalf of the Partnership and/or the Venture
         (i) one or more  fixed-base  or mobile  lithotripsy  systems,  (ii) any
         other assets related to the provision of lithotripsy services, or (iii)
         any  other  assets  or  equipment  or an  interest  in  another  entity
         consistent  with the purposes of the Partnership as provided in Article
         4 (collectively,  the "Additional  Assets"),  at such times and at such
         price and upon such terms,  as the General  Partner  deems to be in the
         best interest of the Partnership;

                  (c) To purchase,  hold, manage,  lease, license and dispose of
         Partnership  assets  (including  the Venture  Interest),  including the
         purchase,  exchange,  trade or sale of the Partnership's assets at such
         price, or amount, for cash,  securities or other property and upon such
         terms,  as the General  Partner deems to be in the best interest of the
         Partnership;  provided, that should the Partnership assets be exchanged
         or traded for securities or other property (the "Replacement Property")
         the  General  Partner  shall have the same  powers  with  regard to the
         Replacement Property as it does towards the traded property;

                  (d) To  exercise  the  option of the  General  Partner  or the
         Partnership  to  purchase  a  Limited  Partner's  Partnership  Interest
         pursuant to Article 17;

                  (e) To determine the travel  itinerary and site  locations for
         the Lithostar(TM) Mobile System or other Partnership technology;

                  (f) To borrow  money for any  Partnership  or Venture  purpose
         (including the  acquisition of the Additional  Assets) and, if security
         is required therefor,  to subject to any security device any portion of
         the property for the Partnership,  to obtain  replacements of any other
         security device, to prepay, in whole or in part,  refinance,  increase,
         modify, consolidate or extend any encumbrance or other security device;

                  (g) To deposit,  withdraw,  invest, pay, retain (including the
         establishment  of reserves in order to acquire the  Additional  Assets)
         and distribute the  Partnership's  funds in any manner  consistent with
         the provisions of this Agreement;

                  (h)      To institute and defend actions at law or in equity;

                                                      -22-


<PAGE>



                  (i) To enter into and carry out contracts and  agreements  and
         any or all documents and  instruments  and to do any and all such other
         things as may be in furtherance of Partnership purposes or necessary or
         appropriate to the conduct of the Partnership activities;

                  (j)  To   execute,   acknowledge   and  deliver  any  and  all
         instruments  which may be deemed  necessary or convenient to effect the
         foregoing;

                  (k) To form a new  limited  partnership  made up of  qualified
         investors  to  treat  gallstone  patients  (if  the  FDA  approves  the
         Lithostar(TM)  for such  purpose),  and to  contract  on  behalf of the
         Partnership,  the  Venture  and/or  Texas  III  with  the  new  limited
         partnership  for  the  use  for a fee  of  the  Lithostar(TM)  for  the
         treatment of the new limited partnership's gallstone patients; and

                  (l) To engage or retain one or more persons to perform acts or
         provide  materials  as  may be  required  by  the  Partnership,  at the
         Partnership's  expense,  and to compensate  such person or persons at a
         rate to be set by the General  Partner,  provided that the compensation
         is at the then  prevailing  rate for the type of services and materials
         provided,  or both.  Any person,  whether a Partner,  an Affiliate of a
         Partner or otherwise, including without limitation the General Partner,
         may be employed or engaged by the  Partnership  to render  services and
         provide materials,  including, but not limited to, management services,
         professional   services,   accounting   services,   quality  assessment
         services, legal services,  marketing services,  maintenance services or
         provide materials; and if such person is a Partner or an Affiliate of a
         Partner,  he shall be entitled to, and shall be paid  compensation  for
         said services or materials,  anything in this Agreement to the contrary
         notwithstanding, provided that the compensation to be received for such
         services  or  materials  is  competitive  in price and terms  with then
         prevailing rate for the type of services and/or materials provided. The
         Partnership,  pursuant  to the terms of a  Management  Agreement,  will
         contract with the General Partner,  with respect to the supervision and
         coordination  of the  management and  administration  of the day-to-day
         operations of the  Lithostar(TM)  Mobile System for a monthly fee equal
         to the greater of 7.5% of Partnership Cash Flow per month or $6,400 per
         month. All costs incurred by the General  Partner,  excluding the costs
         of employing one or more local physicians to act as a Medical Director,
         shall be paid by the  Partnership  directly.  The  Partnership may also
         contract with qualified  physicians  desiring to use the  Lithostar(TM)
         Mobile System for the treatment of patients.  Owning an interest in the
         Partnership shall not be a condition to using the Lithostar(TM)  Mobile
         System. The General Partner and its Affiliates may engage in or possess
         an interest in other  business  ventures of any nature and  description
         independently  or with  others,  including,  but not  limited  to,  the
         operation of a mobile  lithotripsy  unit  similar to the  Lithostar(TM)
         Mobile System,  whether or not such business  ventures are in direct or
         indirect competition with the Partnership,  and neither the Partnership
         nor the  Partners  shall have any right by virtue of this  Agreement in
         and to said  independent  ventures or to the income or profits  derived
         therefrom.

                  20.5  In  addition  to  other  acts  expressly  prohibited  or
restricted  by this  Agreement  or by law,  the  General  Partner  shall have no
authority to act on behalf of the Partnership in:

                                                      -23-


<PAGE>



                  (a)      Doing any act in contravention of this Agreement or 
         the Partnership's Certificate of Limited Partnership;

                  (b) Doing any act which would make it  impossible  to carry on
         the ordinary business of the Partnership;

                  (c)   Confessing  a  judgment   against  the   Partnership  in
         connection with any threatened or pending legal action;

                  (d) Possessing or in any manner dealing with the Partnership's
         property  or   assigning   the  rights  of  the   Partnership   in  the
         Partnership's property for other than Partnership purposes;

                  (e)  Admitting  a person  as a  Limited  Partner  or a General
         Partner except as provided in this Agreement; or

                  (f)  Performing  any act (other  than an act  required by this
         Agreement  or any act  taken  in good  faith  reliance  upon  counsel's
         opinion)  which  would,  at the time  such act  occurred,  subject  any
         Limited Partner to liability as a general partner in any jurisdiction.

                  21.      RESERVES.

                  The  General  Partner  may cause the  Partnership  to create a
reserve account to be used exclusively for repairs and acquisition of Additional
Assets and for any other valid Partnership  purpose.  The General Partner shall,
in its sole discretion, determine the amount of payments to such reserve.

                  22.      INDEMNIFICATION AND EXCULPATION OF THE
                           GENERAL PARTNER.

                  22.1 The General  Partner is accountable to the Partnership as
a fiduciary and consequently  must exercise good faith and integrity in handling
Partnership  affairs.  The  General  Partner  and its  Affiliates  shall have no
liability to the  Partnership  which arises out of any action or inaction of the
General Partner or its Affiliates if the General  Partner or its Affiliates,  in
good faith,  determined  that such course of conduct was in the best interest of
the Partnership and such course of conduct did not constitute  gross  negligence
or willful  misconduct  of the General  Partner or its  Affiliates.  The General
Partner and its Affiliates  shall be indemnified by the Partnership  against any
losses, judgments,  liabilities,  expenses and amounts paid in settlement of any
claims sustained by them in connection with the  Partnership,  provided that the
same were not the result of gross  negligence or willful  misconduct on the part
of the General Partner or its Affiliates.

                  22.2 The General Partner shall not be liable for the return of
the Capital Contributions of the Limited Partners, and upon dissolution, Limited
Partners shall look solely to the assets of the Partnership.


                                                      -24-


<PAGE>



                  23.      DISSOLUTION OF THE PARTNERSHIP.

                  23.1 The Partnership shall be dissolved and terminated and its
business wound up upon the occurrence of any one of the following events:

                  (a)      The expiration of its term on January 1, 2047;

                  (b) The  filing  by, on  behalf  of, or  against  the  General
         Partner of any  petition or  pleading,  voluntary  or  involuntary,  to
         declare the General  Partner  bankrupt under any bankruptcy law or act,
         or the  commencement  in any  court  of any  proceeding,  voluntary  or
         involuntary,  to declare the General Partner insolvent or unable to pay
         its debts, or the appointment by any court or supervisory  authority of
         a  receiver,  trustee or other  custodian  of the  property,  assets or
         business of the General  Partner or the  assignment by it of all or any
         part of its  property or assets for the benefit of  creditors,  if said
         action,  proceeding  or  appointment  is  not  dismissed,   vacated  or
         otherwise terminated within ninety (90) days of its commencement;

                  (c) The determination of the General Partner that the 
         Partnership should be dissolved;

                  (d) The  approval of a plan by the General  Partner  providing
         for the  merger,  consolidation  or sale of  Partnership  Interests  as
         described in Article 16.7;

                  (e) The  election  of the  General  Partner  to  dissolve  the
         Partnership  following the occurrence of an event  described in Article
         17.5;

                  (f)  The  sale,  exchange  or  other  disposition  of  all  or
         substantially  all of the property of the  Partnership  without  making
         provision for the replacement thereof; and

                  (g)   The   dissolution,   retirement,   resignation,   death,
         disability  or legal  incapacity  of a general  partner,  and any other
         event  resulting in the  dissolution or termination of the  Partnership
         under the laws of the State of Texas.

                  23.2  Notwithstanding  the  provisions  of Article  23.1,  the
Partnership   shall  not  be  dissolved  and  terminated  upon  the  retirement,
resignation,  bankruptcy,  assignment for the benefit of creditors, dissolution,
death,  disability or legal  incapacity of a general  partner,  and its business
shall continue  pursuant to the terms and conditions of this  Agreement,  if any
general partner or general partners remain  following such event;  provided that
such  remaining  general  partner or general  partners  are hereby  obligated to
continue the business of the  Partnership.  If no general  partner remains after
the  occurrence of such event,  the business of the  Partnership  shall continue
pursuant to the terms and conditions of this  Agreement,  if, within ninety (90)
days after the  occurrence of such event,  a Majority in Interest of the Limited
Partners agree in writing to continue the business of the  Partnership,  and, if
necessary,  to  the  appointment  of one  or  more  persons  or  entities  to be
substituted as the general  partner.  In the event the Limited Partners agree to
continue the  business of the  Partnership,  the new general  partner or general
partners shall succeed to all of the powers,  privileges and  obligations of the
General Partner,  and the General  Partner's  interest in the Partnership  shall
become a Limited Partner's interest

                                                      -25-


<PAGE>



hereunder.  Furthermore, in the event a remaining general partner or the Limited
Partners,  as the case may be, agree to continue the business of the Partnership
as provided herein, the remaining general partner or the newly appointed general
partner or general partners,  as the case may be, shall take all steps necessary
and appropriate to prepare and record an amendment to the Certificate of Limited
Partnership to reflect the  continuation  of the business of the Partnership and
the admission of a new general partner or general partners, if any.

                  24.      DISTRIBUTION UPON DISSOLUTION.

                  Upon the dissolution and termination of the  Partnership,  the
General Partner or, if there is none, a representative  of the Limited Partners,
shall  cause  the  cancellation  of the  Partnership's  Certificate  of  Limited
Partnership,  shall liquidate the assets of the Partnership, and shall apply and
distribute the proceeds of such liquidation in the following order of priority:

                  (a) First, to the payment of the debts and liabilities of the 
         Partnership, and the expenses of liquidation;

                  (b) Second,  to the creation of any reserves which the General
         Partner  (or the  representatives  of the  Limited  Partners)  may deem
         reasonably  necessary  for the payment of any  contingent or unforeseen
         liabilities or obligations of the Partnership or of the General Partner
         arising out of or in connection  with the business and operation of the
         Partnership; and

                  (c) Third,  the balance,  if any,  shall be distributed to the
         Partners in accordance  with the  Partners'  positive  Capital  Account
         balances  after such  capital  accounts  are  adjusted  as  provided by
         Article 12, and any other  adjustments  required by the Final  Treasury
         Regulations  under Section 704(b) of the Code. Any general partner with
         a negative  Capital Account  following the  distribution of liquidation
         proceeds or the  liquidation  of its interest  must  contribute  to the
         Partnership  an amount  equal to such  negative  Capital  Account on or
         before the end of the Partnership's  taxable year (or, if later, within
         ninety days after the date of liquidation).  Any capital so contributed
         shall  be (i)  distributed  to those  Partners  with  positive  Capital
         Accounts until such Capital  Accounts are reduced to zero,  and/or (ii)
         used to discharge recourse liabilities.

                  25.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.

                  25.1 Proper and complete records and books of account shall be
kept by the General  Partner in which shall be entered fully and  accurately all
transactions  and such other matters relating to the  Partnership's  business as
are usually  entered  into  records and books of account  maintained  by persons
engaged  in  businesses  of a like  character.  The  books  and  records  of the
Partnership  shall be prepared  according to the accounting method determined by
the General Partner.  The Partnership's  fiscal year shall be the calendar year.
The books and  records  shall at all times be  maintained  at the  Partnership's
Records Office and shall be open to the reasonable inspection and examination of
the Partners or their duly authorized representatives during reasonable business
hours.


                                                      -26-


<PAGE>



                  25.2 Within  ninety (90) days after the end of each Year,  the
General  Partner shall send to each person who was a Limited Partner at any time
during such year such tax information,  including,  without limitation,  Federal
tax Schedule K-1, as shall be reasonably  necessary for the  preparation by such
person of his Federal  income tax return.  The  General  Partner  will also make
available to the Limited Partners any other information required by the Act.

                  25.3 The General  Partner shall maintain at the  Partnership's
Records  Office  copies of the  Partnership's  original  Certificate  of Limited
Partnership   and  any  certificate  of  amendment,   restated   certificate  or
certificate of cancellation with respect thereto and such other documents as the
Act shall require.  The General Partner will furnish to any Limited Partner upon
request a copy of the Partnership's  original Certificate of Limited Partnership
and any  certificate  of amendment,  restated  certificate,  or  certificate  of
cancellation, if any.

                  25.4 The General Partner shall, in its sole  discretion,  make
for the  Partnership  any and all  elections  for  federal,  state and local tax
purposes including, without limitation, any election, if permitted by applicable
law, to adjust the basis of the Partnership's property pursuant to Code Sections
754,  734(b) and  743(b),  or  comparable  provisions  of state or local law, in
connection  with  transfers  of  interests in the  Partnership  and  Partnership
Distributions.

                  25.5 The  General  Partner is  designated  as the Tax  Matters
Partner  (as  defined  in  Section  6231 of the Code) and to act in any  similar
capacity  under  state or local law,  and is  authorized  (at the  Partnership's
expense):   (i)  to  represent  the   Partnership  and  Partners  before  taxing
authorities  or courts of competent  jurisdiction  in tax matters  affecting the
Partnership  or  Partners  in their  capacity  as  Partners;  (ii) to extend the
statute of limitations for assessment of tax deficiencies  against Partners with
respect to adjustments to the Partnership's federal, state or local tax returns;
(iii) to execute any agreements or other documents relating to or affecting such
tax matters, including agreements or other documents that bind the Partners with
respect to such tax matters or  otherwise  affect the rights of the  Partnership
and Partners; and (iv) to expend Partnership funds for professional services and
costs  associated  therewith.  The General partner is authorized and required to
notify the federal,  state or local tax  authorities of the appointment of a Tax
Matters  Partner  in  the  manner  provided  in  Treasury   Regulations  Section
301.6231(a)(7)-IT, as modified from time to time. In its capacity as Tax Matters
Partner,  the General  Partner shall oversee the  Partnership tax affairs in the
manner which, in its best judgment, are in the interests of the Partners.

                  26.      NOTICES.

                  All notices under this Agreement shall be in writing and shall
be deemed to have been given when delivered  personally,  or mailed by certified
or registered mail, postage prepaid,  return receipt  requested.  Notices to the
General  Partner  shall be  delivered  at, or mailed to, its  principal  office.
Notices to the  Partnership  shall be delivered  at, or mailed to, its principal
office with a copy to each of its business offices.  Notice to a Limited Partner
shall be  delivered  to such  Limited  Partner,  or mailed  to the last  address
furnished  by him for such  purposes to the General  Partner.  Limited  Partners
shall give  notice of a change of address to the  General  Partner in the manner
provided in this Article.


                                                      -27-


<PAGE>



                  27.      AMENDMENTS.

                  Subject to the  provisions  of Article 28, this  Agreement  is
subject to  amendment  only by  written  consent of the  General  Partner  and a
Majority in Interest of the Limited Partners;  provided, however, the consent of
the Limited Partners shall not be required if such amendments are ministerial in
nature and do not contravene the provisions of Article 28.

                  28.      LIMITATIONS ON AMENDMENTS.

                  Notwithstanding  the provisions of Article 27, no amendment to
this Agreement shall:

                  (a)  Enlarge  the   obligations  of  any  Partner  under  this
         Agreement  or convert the  interest in the  Partnership  of any Limited
         Partner  into the  interest of a general  partner or modify the limited
         liability of any Limited Partner, without the consent of such Partner;

                  (b) Amend the  provisions  of Article 12, 13, 15 or 24 without
         the  approval of the General  Partner and a Majority in Interest of the
         Limited Partners;  provided,  however,  that the General Partner may at
         any time  amend  such  Articles  without  the  consent  of the  Limited
         Partners in order to permit the Partnership allocations to be sustained
         for Federal  income tax  purposes,  but only if such  amendments do not
         materially  affect  adversely the rights and obligations of the Limited
         Partners, in which case such amendments may only be made as provided in
         this Article 28(b); or

                  (c) Amend this Article 28 without the consent of all Partners.

                  29.      MEETINGS, CONSENTS AND VOTING.

                  29.1 A meeting of the  Partnership to consider any matter with
respect to which the  Partners  may vote as set forth in this  Agreement  may be
called  by the  General  Partner  or by  Limited  Partners  who hold  more  than
twenty-five  percent (25%) of the aggregate interests in the Partnership held by
all the Limited Partners.  Upon receipt of a notice requesting a meeting by such
Partner or Partners and stating the purpose of the meeting,  the General Partner
shall, within ten (10) days thereafter, give notice to the Partners of a meeting
of the  Partnership  to be held at a time and place  convenient  to the  Limited
Partners  on a date not  earlier  than  fifteen  (15) days after  receipt by the
General  Partner of the notice  requesting a meeting.  The notice of the meeting
shall set forth the time, date, location and purpose of the meeting.

                  29.2 Any consent of a Partner  required by this  Agreement may
be given as follows:

                  (a) By a written  consent given by the consenting  Partner and
         received by the General  Partner at or prior to the doing of the act or
         thing for which the consent is solicited, or


                                                      -28-


<PAGE>



                  (b) By the affirmative  vote by the consenting  Partner to the
         doing of the act or thing for which the  consent  is  solicited  at any
         meeting  called  pursuant to this Article to consider the doing of such
         act or thing.

                  29.3 When exercising voting rights expressly granted under the
Articles of this  Agreement,  each Partner shall have that number of votes as is
equal to the  Percentage  Interest  of such  Partner  at the  time of the  vote,
multiplied by 100.

                  30.      SUBMISSIONS TO THE LIMITED PARTNERS.

                  The General Partner shall give the Limited  Partners notice of
any proposal or other matter  required by any provision of this  Agreement or by
law to be submitted for consideration and approval of the Limited Partners. Such
notice shall include any  information  required by the relevant  provision or by
law.

                  31.      ADDITIONAL DOCUMENTS.

                  Each  party  hereto  agrees to  execute  and  acknowledge  all
documents and writings which the General Partner may deem necessary or expedient
in the creation of this Partnership and the achievement of its purpose.

                  32.      SURVIVAL OF RIGHTS.

                  Except as herein  otherwise  provided  to the  contrary,  this
Agreement  shall be binding upon and inure to the benefit of the parties hereto,
their successor and assigns.

                  33.      INTERPRETATION AND GOVERNING LAW.

                  When the  context  in which  words are used in this  Agreement
indicates  that such is the intent,  words in the singular  number shall include
the plural and vise versa; in addition,  the masculine  gender shall include the
feminine and neuter  counterparts.  The Article headings or titles and the table
of  contents  shall not define,  limit,  extend or  interpret  the scope of this
Agreement  or any  particular  Article.  This  Agreement  shall be governed  and
construed  in  accordance  with the laws of the  State of Texas  without  giving
effect to the conflicts of laws provisions thereof.

                  34.      SEVERABILITY.

                  If any provision,  sentence,  phrase or word of this Agreement
or the application  thereof to any person or circumstance shall be held invalid,
the remainder of this Agreement, or the application of such provision, sentence,
phrase, or word to persons or circumstances,  other than those as to which it is
held invalid, shall not be affected thereby.

                  35.      AGREEMENT IN COUNTERPARTS.

                  This Agreement may be executed in several  counterparts,  each
of which shall be deemed an original,  but all of which shall constitute one and
the same instrument. In addition, this Agreement

                                                      -29-


<PAGE>



may contain more than one  counterpart  of the signature page and this Agreement
may be executed by the affixing of the signatures of each of the Partners to one
of such  counterpart  signature pages; all of such signature pages shall be read
as though  one,  and they  shall have the same force and effect as though all of
the signers had signed a single signature page.

                  36.      THIRD PARTIES.

                  The agreements, covenants and representations contained herein
are for the benefit of the parties  hereto  inter se and are not for the benefit
of any  third  parties  including,  without  limitation,  any  creditors  of the
Partnership.

                  37.      POWER OF ATTORNEY.

                  Each Limited  Partner hereby makes,  constitutes  and appoints
Dr.  Joseph  Jenkins  and Dr.  Dan A.  Myers,  severally,  with  full  power  of
substitution,  his true and lawful  attorneys-in-fact,  for him and in his name,
place and stead and for his use and  benefit to sign and  acknowledge,  file and
record,  any  amendments  hereto among the  Partners for the further  purpose of
executing and filing on behalf of each Limited Partner, any and all certificates
of  limited   partnership  or  other  documents   necessary  to  constitute  the
Partnership or to effect the continuation of the  Partnership,  the admission or
withdrawal of a general partner or a limited partner,  the  qualification of the
Partnership in a foreign jurisdiction (or amendment to such qualification),  the
admission of substitute  Limited  Partners or the  dissolution or termination of
the   Partnership,   provided   such   continuation,    admission,   withdrawal,
qualification,  or dissolution  and termination are in accordance with the terms
of this Agreement.

                  The foregoing power of attorney is a special power of attorney
coupled with an interest,  is  irrevocable  and shall survive the death or legal
incapacity  of each  Limited  Partner.  It may be  exercised  by any one of said
attorneys by listing all of the Limited  Partners  executing any instrument over
the  signature  of the  attorney-in-fact  acting  for all of them.  The power of
attorney shall survive the delivery of an assignment by a Limited Partner of the
whole or any portion of his Unit.  In those cases in which the  assignee  of, or
the  successor  to, a Limited  Partner  owning a Unit has been  approved  by the
Partners for admission to the Partnership as a substitute  Limited Partner,  the
power of attorney  shall  survive for the sole  purpose of enabling  the General
Partner to execute, acknowledge and file any instrument necessary to effect such
substitution.

                  This power of attorney shall not be affected by the subsequent
incapacity or mental incompetence of any Limited Partner.

                  38.      ARBITRATION.

                  Any  dispute  arising  out  of  or  in  connection  with  this
Agreement or the breach thereof shall be decided by arbitration in Austin, Texas
in  accordance  with  the then  effective  commercial  arbitration  rules of the
American  Arbitration  Association,  and judgment  thereof may be entered in any
court having jurisdiction thereof.

                                                      -30-


<PAGE>




                  39.      CREDITORS.

                  None of the  provisions  of this  Agreement  shall  be for the
benefit of or enforceable by any creditors of the Partnership.



            [The remainder of this page is intentionally left blank]

                                                      -31-


<PAGE>



                  IN WITNESS  WHEREOF,  the parties have executed this Agreement
of Limited Partnership as of the day and year first above written.

                               GENERAL PARTNER:

                               LITHOTRIPTERS, INC., a North Carolina corporation

                               By:      /s/ Joseph Jenkins
                                        -------------------------------
                                        Joseph Jenkins, M.D., President

ATTEST:
/s/ Philip J. Gallina
_________________________                                      [CORPORATE SEAL]
Secretary

[CORPORATE SEAL]
                            INITIAL LIMITED PARTNER:

                                        /s/ Dan Myers
                                       ---------------------------------------
                                            Dan A. Myers, M.D.


STATE OF NORTH CAROLINA                     )
                                            )
COUNTY OF CUMBERLAND                        )

                  On this  18th  day of  August,  1997,  before  me, the
undersigned  Notary  Public in and for the County of  Cumberland in the State of
North  Carolina,  personally  came Joseph  Jenkins,  M.D., who, being by me duly
sworn,  said that he is  President  of  Lithotripters,  Inc.,  the sole  general
partner of Texas Lithotripsy Limited Partnership VI, L.P., that the seal affixed
to the foregoing instrument in writing is the corporate seal of the corporation,
and that said writing was signed,  sworn to, and sealed by him in behalf of said
corporation  by its authority  duly given.  And the said Joseph  Jenkins,  M.D.,
further certified that the facts set forth in said writing are true and correct,
and acknowledged said instrument to be the act and deed of said corporation.

                  WITNESS my hand and notarial seal.

                                    /s/ Ricarda Kelly
                                    -------------------------------------------

                                    Notary Public
My commission expires:
Jan. 8, 2002

- ---------------------------



                                                      -32-


<PAGE>



STATE OF NORTH CAROLINA                     )
                                            )
COUNTY OF CUMBERLAND                        )


                  I, Ricarda Kelly , a notary public, do hereby
certify that Dan A. Myers, M.D.  personally appeared before me this 18th day of
August, 1997 and acknowledged and swore to the due execution of the foregoing
Limited Partnership Agreement in his capacity as the initial limited partner.



                                    /s/ Ricarda Kelly
                                    -------------------------------------------

                                    Notary Public

My commission expires:
January 8, 2002
- ---------------------------


                                                      -33-


<PAGE>



                           COUNTERPART SIGNATURE PAGE


                  By signing this  Counterpart  Signature  Page, the undersigned
acknowledges  his or  her  acceptance  of  that  certain  Agreement  of  Limited
Partnership of Texas  Lithotripsy  Limited  Partnership VI, L.P., and his or her
intention to be legally bound thereby.

                  Dated this 18th day of August, 1997.


                                    /s/ Dan A. Myers
                                    ------------------------------------------

                                    Signature


                                    Dan A. Myers
                                    ------------------------------------------

                                    Printed Name




STATE OF NORTH CAROLINA                    )
                                            
COUNTY OF CUMBERLAND                     )


                  BEFORE ME, the undersigned  Notary Public in and for the State
and County set forth  above,  on the  18TH day of  August,  1997,
personally  appeared  Dan A. Myers,  and,  being by me first duly  sworn,
stated that (s)he  signed this  Counterpart  Signature  Page for the purpose set
forth above and that the statements contained therein are true.



                                     /s/ Ricarda Kelly
                                    -------------------------------------------

                                    Signature of Notary Public


                                    Ricarda Kelly
                                    -------------------------------------------

                                    Printed Name of Notary

My Commission Expires:
Jan. 8, 2002
- ---------------------------

[SEAL]

                                                      -34-


<PAGE>



                                   SCHEDULE A

                        Schedule of Partnership Interests

                 TEXAS LITHOTRIPSY LIMITED PARTNERSHIP VI, L.P.

      CONTRIBUTIONS OF CAPITAL TO THE PARTNERSHIP AND PERCENTAGE INTERESTS

                                                        Cash         Percentage
                   General Partner                  Contribution      Interest

              Lithotripters, Inc.                      $ 90,275          20%
              2008 Litho Place
              Fayetteville, NC  28304

              Limited Partners                         
              ----------------
               Paul Brower                                9,100           2
               George Decherd                             2,275            .50
               David Friedberg                           18,200           4
               John Jaderlund                             9,100           2
               Lithotripters, Inc                        63,075          14.50
               Jeffrey Miller                            13,650           3
               Shaun Maloney                             13,650           3
               Jan Ogletree                               9,100           2
               David Phillips                             9,100           2
               Larry Phillips                             9,100           2
               Steven Pickett                            13,650           3
               Texas III                                182,000          40
               John Williamson                            9,100           2


              TOTAL:                                  $ 451,375         100 %
                                                        =======        ======




<PAGE>

                        AGREEMENT OF LIMITED PARTNERSHIP

                                       OF

               NORTH CAROLINA PROSTATHERAPY LIMITED PARTNERSHIP I

<PAGE>

                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                                       OF
               NORTH CAROLINA PROSTATHERAPY LIMITED PARTNERSHIP I

                                TABLE OF CONTENTS

         Article Heading                                                 Page

         1.       FORMATION..................................................1

         2.       NAME.......................................................1

         3.       OFFICES....................................................1

         4.       PURPOSE....................................................1

         5.       TERM.......................................................2

         6.       CERTAIN DEFINED TERMS......................................2

         7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS...............6

         8.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE LIMITED
                  PARTNERS...................................................6

         9.       REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                  GENERAL PARTNER............................................7

         10.      ADMISSION OF LIMITED PARTNERS..............................7

         11.      CAPITAL ACCOUNTS...........................................8

         12.      ALLOCATIONS................................................9

         13.      DISTRIBUTIONS.............................................10

         14.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS................10

         15.      LIMITED LIABILITY.........................................12

         16.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS...........12

         17.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON CERTAIN
                  EVENTS....................................................16



<PAGE>




         18.      SALE, ASSIGNMENT OR OTHER TRANSFER OF THE GENERAL
                  PARTNER'S INTEREST........................................22

         19.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER........22

         20.      MANAGEMENT AND OPERATION OF BUSINESS......................23

         21.      RESERVES..................................................25

         22.      INDEMNIFICATION AND EXCULPATION OF THE GENERAL PARTNER....26

         23.      DISSOLUTION OF THE PARTNERSHIP............................26

         24.      DISTRIBUTION UPON DISSOLUTION.............................27

         25.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.....................28

         26.      NOTICES...................................................29

         27.      AMENDMENTS................................................29

         28.      LIMITATIONS ON AMENDMENTS.................................29

         29.      MEETINGS, CONSENTS AND VOTING.............................30

         30.      SUBMISSIONS TO THE LIMITED PARTNERS.......................30

         31.      ADDITIONAL DOCUMENTS......................................30

         32.      SURVIVAL OF RIGHTS........................................30

         33.      INTERPRETATION AND GOVERNING LAW..........................31

         34.      SEVERABILITY..............................................31

         35.      AGREEMENT IN COUNTERPARTS.................................31

         36.      THIRD PARTIES.............................................31

         37.      POWER OF ATTORNEY.........................................31

         38.      ARBITRATION...............................................32

         39.      CREDITORS.................................................32

                  Schedule A...............  Schedule of Partnership Interests



<PAGE>



THE  LIMITED  PARTNERSHIP  INTERESTS  REPRESENTED  BY THIS  LIMITED  PARTNERSHIP
AGREEMENT HAVE NOT BEEN REGISTERED  WITH THE SECURITIES AND EXCHANGE  COMMISSION
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, QUALIFIED UNDER THE NORTH CAROLINA
SECURITIES ACT OR THE LAWS OF NORTH CAROLINA,  OR REGISTERED  UNDER SIMILAR LAWS
OR ACTS OF OTHER STATES IN RELIANCE UPON EXEMPTIONS UNDER SUCH LAWS.


                                    AGREEMENT
                             OF LIMITED PARTNERSHIP
                         OF NORTH CAROLINA PROSTATHERAPY
                              LIMITED PARTNERSHIP I


                  THIS AGREEMENT OF LIMITED  PARTNERSHIP  (the  "Agreement")  is
made  as of  August 14,  1997,  by and  among  PROSTATHERAPIES,  INC.,  a
Delaware corporation (the "General Partner"), and the parties listed on Schedule
A attached hereto as the Limited Partners.

                  1.       FORMATION.

                  The  Partnership was formed pursuant to a filing in the Office
of the Secretary of State of North  Carolina on June 6, 1997, a  Certificate  of
Limited Partnership in accordance with the provisions of the Act.

                  2.       NAME.

                  2.1      The name of the Partnership is "North Carolina 
Prostatherapy Limited Partnership I."

                  2.2 The  Partnership  business  shall be conducted  under such
names as the General  Partner may from time to time deem necessary or advisable,
provided that appropriate amendments to this Agreement and all necessary filings
under  applicable  assumed  or  fictitious  name  statutes  or the Act are first
obtained.

                  3.       OFFICES.

                  3.1 The principal  office of the Partnership  shall be at 2008
Litho Place,  Fayetteville,  North Carolina 28304, or at such other place as the
General  Partner  may,  from time to time,  designate  by notice to the  Limited
Partners (the "Records Office").

                  3.2 The Partnership  may have such  additional  offices as the
General Partner may, from time to time, deem necessary or advisable.


                                                      -1-


<PAGE>



                  4.       PURPOSE.

                  The purpose and business of the  Partnership  shall be: (i) to
operate one or more Prostatron(R)  microwave thermotherapy devices (or any other
BPH treatment equipment) for the transurethral  treatment of the symptoms of BPH
in various  locations in eastern North Carolina or in such other  location(s) as
the General  Partner may determine,  in its sole  discretion,  to be in the best
interests  of the  Partnership,  (ii) to acquire  and  operate in the future any
other  urological  device  or  equipment  that as of the date of this  Agreement
either has not been invented or has not received FDA premarket approval, as long
as such device has such approval at the time it is acquired by the  Partnership;
(iii)  to  acquire  an  interest  in any  business  entity,  including,  without
limitation,  a limited  partnership,  limited  liability company or corporation,
that engages in any business  activity  described in this Article 4; and (iv) to
engage in any and all activities  incidental or related to the  foregoing,  upon
and subject to the terms and conditions of this Agreement.

                  5.       TERM.

                  The  Partnership  shall  terminate  on June 30,  2047,  unless
sooner terminated as herein provided.

                  6.       CERTAIN DEFINED TERMS.

                  Certain terms used in this Agreement  shall have the following
meanings:

                  Act.  The Act means the North Carolina Revised Uniform Limited
Partnership Act, as then in effect.

                  Affiliate.  An  Affiliate  is  (i)  any  person,  partnership,
corporation, association or other legal entity ("person") directly or indirectly
controlling, controlled by or under common control with another person; (ii) any
person owning or controlling 10% or more of the  outstanding  voting interest of
such other person;  (iii) any officer,  director or partner of such person;  and
(iv) if such other  person is an officer,  director  or partner,  any entity for
which such person acts in such capacity.

                  Agreement.  This Agreement of Limited Partnership, as the same
may be amended from time to time.

                  BPH.  Benign Prostatic Hyperplasia, common enlargement of the
prostate.

                  Capital Account.  The Partnership capital account of a Partner
as computed pursuant to Article 11 of this Agreement.

                  Capital  Contributions.  All capital  contributions  made by a
Partner or his predecessor in interest which shall include,  without limitation,
contributions made pursuant to Article 7 of this Agreement.


                                                      -2-


<PAGE>



                  Capital Transaction.  Any transaction which, were it to 
generate proceeds, would produce Partnership Sales Proceeds or Partnership 
Refinancing Proceeds.

                  Carolina Lithotripsy.  Carolina Lithotripsy, a North Carolina
limited partnership.  Carolina Lithotripsy initially is the holder of a Majority
in Interest of the Limited Partner interests in the Partnership.

                  Class A Units. The 200 equal limited partnership  interests in
the  Partnership  offered  pursuant  to the  Summary  for a  price  per  Unit of
$2,487.50 in cash.

                  Class B. Units.  The 120 equal limited partnership interests 
in the Partnership offered pursuant to the Summary for a price per Unit of
$2,600 in cash.

                  Code.  The Internal Revenue Code of 1986, as amended, or 
corresponding provisions of subsequent, superseding revenue laws.

                  Dilution  Offering.   As  provided  in  Section  7.4  of  this
Agreement,  the future offering of additional limited  partnership  interests in
the Partnership by the General Partner.  Except as otherwise provided in Section
7.4, any successful Dilution Offering will proportionately reduce the Percentage
Interests of the then current Partners in the Partnership.

                  Domestic Proceeding.  Any divorce, annulment, separation or
similar domestic proceeding between a married couple.

                  Equipment.  The  initial  equipment  to  be  acquired  by  the
Partnership for the operation of the  Prostatron(R)  Mobile System.  The initial
equipment to be used in the  operation of the  Prostatron(R)  Mobile System will
include the Trailer,  a tractor truck, the  Prostatron(R),  an ultrasound system
and miscellaneous medical equipment and supplies.

                  FDA.  The United States Food and Drug Administration.

                  General Partner.  The General Partner of the Partnership, 
Prostatherapies, Inc., a Delaware corporation and wholly owned subsidiary of 
Prime.

                  Initial  Limited  Partner.  Dan A. Myers,  M.D., a resident of
North Carolina. The Initial Limited Partner is to be the only limited partner of
the Partnership  until such time as the new Limited Partners are admitted to the
Partnership,  at which time the Initial  Limited Partner shall withdraw from the
Partnership.

                  Limited Partners.  The Limited Partners are those investors in
the Units  admitted  to the  Partnership  and any person  admitted  as a Limited
Partner in accordance with the provisions of this Agreement.

                  Losses.  The net loss (including Net Losses from Capital 
Transactions) of the Partnership for each Year of the Partnership as determined
for federal income tax purposes.

                                                      -3-


<PAGE>



                  Majority  in Interest  of the  Limited  Partners.  The Limited
Partners who hold more than 50% of the Limited Partner  Percentage  Interests in
the Partnership.

                  Net Gains from Capital Transactions. The gains realized by the
Partnership  as a result of or upon any sale,  exchange,  condemnation  or other
disposition of the capital assets of the Partnership (which assets shall include
Code Section 1231 assets) or as a result of or upon the damage or destruction of
such capital assets.

                  Net Losses from Capital  Transactions.  The losses realized by
the Partnership as a result of or upon any sale, exchange, condemnation or other
disposition of the capital assets of the  Partnership  (which shall include Code
Section 1231 assets) or as a result of or upon the damage or destruction of such
capital assets.

                  Partners.  The General Partner and the Limited Partners, 
collectively, where no distinction is required by the context in which the 
term is used herein.

                  Partnership.  North Carolina Prostatherapy Limited 
Partnership I, a North Carolina limited partnership.

                  Partnership  Cash Flow. For the applicable  period the excess,
if any,  of (A) the sum of (i) all  gross  receipts  from  any  source  for such
period,  other than from  Partnership  loans,  Capital  Transactions and Capital
Contributions,  and (ii) any funds released by the  Partnership  from previously
established  reserves,  over  (B) the sum of (i) all cash  expenses  paid by the
Partnership  for such  period;  (ii) the amount of all  payments of principal on
loans to the Partnership;  (iii) capital  expenditures of the  Partnership;  and
(iv) such  reasonable  reserves as the General  Partner shall deem  necessary or
prudent to set aside for future repairs,  improvements or equipment  replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities and contingencies of the Partnership; provided, however, that
the  amounts  referred  to in (B)(i),  (ii) and (iii)  above shall be taken into
account  only to the extent not funded by Capital  Contributions,  loans or paid
out of previously  established reserves.  Such term shall also include all other
funds deemed  available for  distribution  and designated as  "Partnership  Cash
Flow" by the General Partner.

                  Partnership Interest.  The interest of a Partner in the
Partnership as defined by the Act and this Agreement.

                  Partnership  Refinancing Proceeds.  The cash realized from the
refinancing of Partnership assets after retirement of any secured loans and less
(i) payment of all expenses  relating to the transaction and (ii)  establishment
of such  reasonable  reserves as the General  Partner  shall deem  necessary  or
prudent to set aside for future repairs,  improvements, or equipment replacement
or additions,  or to meet working capital requirements or foreseen or unforeseen
future liabilities or contingencies of the Partnership.

                  Partnership  Sales Proceeds.  The cash realized from the sale,
exchange,  casualty  or other  disposition  of all or a portion  of  Partnership
assets after the retirement of all secured loans and less (i) the payment of all
expenses related to the transaction and (ii) establishment of such reasonable

                                                      -4-


<PAGE>



reserves as the General Partner shall deem necessary or prudent to set aside for
future repairs,  improvements, or equipment replacement or additions, or to meet
working  capital  requirements or foreseen or unforeseen  future  liabilities or
contingencies of the Partnership.

                  Percentage  Interest.  The  interest  of each  Partner  in the
Partnership,  to be  determined  initially  in the case of a Limited  Partner by
reference to his or her Unit ownership based upon the Limited  Partners  holding
an aggregate 80% Percentage Interest in the Partnership,  with each initial Unit
sold representing an initial 0.25% interest.  The General Partner initially will
own a 20%  Percentage  Interest  in  the  Partnership.  A  Partner's  Percentage
Interest may be reduced by a future Dilution Offering.  The Partners' Percentage
Interests in the  Partnership as of the date hereof are as set forth in Schedule
A attached hereto. Any future adjustments in the Partners' Percentage Interests,
due to future Dilution Offerings or otherwise, will be reflected by revisions to
Schedule A.

                  Prime.   Prime Medical Services, Inc., a Delaware corporation.
Prime owns all the capital stock of the General Partner and Lithotripters, 
Inc., the management agent.

                  Profit.  The net income of the Partnership (including Net 
Gains from Capital Transactions) for each Year of the Partnership as determined
for federal income tax purposes.

                  Pro  Rata  Basis.   In   connection   with  an  allocation  or
distribution,  an allocation  or  distribution  in proportion to the  respective
Percentage Interests of the class of Partners to which reference is made.

                  Prostatron(R).   The  Prostatron(R)   microwave  thermotherapy
device manufactured by EDAP Technomed,  Inc., a Delaware corporation,  and to be
utilized by the Partnership for the treatment of the symptoms of BPH.

                  Prostatron(R) Mobile System.  The Trailer and tractor truck 
with the installed and operational Prostatron(R) and ultrasound system.

                  Related Parties.  Carolina Lithotripsy, the General Partner
and their Affiliates and designees.

                  Sales Agency  Agreement.  The sales agency  agreement  through
which  MedTech  Investments,  Inc.,  an Affiliate  of the General  Partner and a
broker-dealer company registered with the Securities and Exchange commission and
a member of the National Association of Securities Dealers, Inc. shall offer and
sell  the  limited  partnership  interest  of the  Partnership  pursuant  to the
Summary.

                  Sales Commission.  The $112.50 sales commission paid to 
MedTech Investments, Inc. for each Class B Unit sold to parties other than 
Related Parties.

                  Service.  The Internal Revenue Service.

                  Summary.  The Confidential Summary of the Offering of the 
Partnership dated June 18, 1997, including all Appendices thereto, and as 
amended or as supplemented.

                                                      -5-


<PAGE>



                  Trailer.  The new mobile trailer manufactured and upfitted by 
AK Associates, Inc. to house the Prostatron(R).

                  Units.   The  200   Class  A  and  the  120   Class  B  Units,
collectively,  where no distinction is required by the context in which the term
is used herein.

                  Year.  An annual accounting period ending on December 31 of 
each year during the term of the Partnership.

                  7.       CAPITAL CONTRIBUTIONS AND DILUTION OFFERINGS.

                  7.1  General  Partner  Contribution.  On or before the date of
this  Agreement,  the  General  Partner  will  contribute  to the capital of the
Partnership  cash in an amount  equal to 20% (up to  $202,375) of the total cash
contributed to the  Partnership by the Partners in the offering made pursuant to
the Summary.

                  7.2 Limited Partner Contribution.  Each Limited Partner hereby
agrees to contribute and shall  contribute to the capital of the  Partnership on
the date of his admission to the  Partnership the cash amount set forth opposite
his name on Schedule A attached hereto.

                  7.3      No Interest.  Except as otherwise provided herein, no
 interest shall be paid on any contribution to the capital of the Partnership.

                  7.4 Dilution Offerings. As provided in Article 20.5(a), if the
General  Partner and a Majority in  Interest of the Limited  Partners  determine
that it is in the best  interest of the  Partnership,  the General  Partner may,
from  time to  time,  issue,  offer  and  sell  additional  limited  partnership
interests in the Partnership (a "Dilution Offering") to local urologists who are
not already Limited Partners ("Qualified Investors"). The primary purpose of any
Dilution  Offering would be (i) to raise  additional  capital for any legitimate
Partnership  purpose as set forth in  Article 4, and (ii) to assure the  highest
quality of patient care by admitting  Qualified Investors to the Partnership who
would be dedicated and motivated as owners to follow the Partnership's treatment
protocol,  and comply with its quality assurance and outcome analysis  programs.
Any  limited  partnership  interests  offered by the  Partnership  in a Dilution
Offering  shall be sold in the manner and  according to the terms  prescribed in
the  sole  discretion  of the  General  Partner;  provided,  however,  that  any
additional limited partnership  interests offered in a Dilution Offering will be
sold for a price no lower than the highest price for which proportionate limited
partnership  interests  in the  Partnership  have  been  previously  sold by the
Partnership. Any sale of additional limited partnership interests will result in
the  proportionate  dilution  of the  Partnership  Percentage  Interests  of the
existing  Partners.  Notwithstanding  the  above,  in the  event  of a  Dilution
Offering,  the General  Partner,  Carolina  Lithotripsy  and Related Parties may
elect,  in their  sole  discretion,  to  prevent  dilution  of their  respective
Percentage Interests by either contributing a proportionate amount of additional
capital  to  the  Partnership  or  purchasing   additional  limited  partnership
interests in any Dilution  Offering.  Any other  Limited  Partners  will have no
right to purchase  additional  limited  partnership  interests  in any  Dilution
Offering.  Any investor acquiring a limited  partnership  interest in a Dilution
Offering  shall agree to be bound by the terms of this  Agreement,  and shall be
automatically  admitted as a Limited Partner of the Partnership  notwithstanding
any other provisions in

                                                      -6-


<PAGE>



this  Agreement to the contrary.  Any  adjustment  in the  Partners'  Percentage
Interests  resulting  from a Dilution  Offering shall be set forth on Schedule A
attached hereto.

                  8.       CONDITIONS TO THE CAPITAL CONTRIBUTIONS OF THE
                           LIMITED PARTNERS.

                  The  obligations of the Limited  Partners to make cash Capital
Contributions  hereunder are subject to the condition that the  representations,
warranties, agreements and covenants of the General Partner set forth in Article
9 of this Agreement are and shall be true and correct or have been and will have
been  complied  with  in  all  material   respects  on  the  date  such  Capital
Contributions  are  required  to be made,  except  to the  extent  that any such
representation or warranty expressly pertains to an earlier date.

                  9.       REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE
                           GENERAL PARTNER.

                  9.1 The General Partner hereby  represents and warrants to the
Limited Partners that:

                  (a)  The  Partnership  is  a  limited  partnership  formed  in
         accordance  with  and  validly  existing  under  the Act and the  other
         applicable laws of the State of North Carolina;

                  (b) The interests in the  Partnership of the Limited  Partners
         will have been duly  authorized  or created and validly  issued and the
         Limited  Partners shall have no personal  liability to contribute money
         to the  Partnership  other than the amounts agreed to be contributed by
         them in the  manner  and on the  terms  set  forth  in this  Agreement,
         subject, however, to such limitations as may be imposed under the Act;

                  (c) No material  breach or default  adverse to the Partnership
         exists under the terms of any other  material  agreement  affecting the
         Partnership; and

                  (d) The General Partner is a Delaware  corporation  formed and
         existing under the laws of the State of Delaware.

                  9.2  The  General  Partner  hereby  covenants  to the  Limited
Partners that:

                  (a)      It will at all times act in a fiduciary manner with 
respect to the Partnership and the Limited Partners;

                  (b) Except as provided in Articles 18 and 19, it will serve as
         the  General  Partner  of the  Partnership  until  the  Partnership  is
         terminated without reconstitution; and

                  (c) It will cause the  Partnership  to carry  adequate  public
         liability,  property  damage and other insurance as is customary in the
         business to be engaged in by the Partnership.

                                                      -7-


<PAGE>



                  10.      ADMISSION OF LIMITED PARTNERS.

                  The  General  Partner may permit the offer and sale of limited
partnership  interests  on the terms and  conditions  provided in the Summary or
future  Dilution  Offerings and may admit persons  subscribing  for interests as
Limited  Partners in the  Partnership  on the terms and  conditions set forth in
this Article 10.

                  (a) The General  Partner  shall have approved of the admission
         of said person in writing on such terms and  conditions  as the General
         Partner shall determine;

                  (b)  Said  person  shall  have  executed  such   documents  or
         instruments  as the General  Partner may deem necessary or desirable to
         effect his admission as a Limited Partner;

                  (c) Said  person  shall have  accepted  and adopted all of the
         terms and provisions of this Agreement, as then amended;

                  (d)  Said  person  (if a  corporation)  shall  deliver  to the
         General  Partner  a  certified  copy of a  resolution  of its  Board of
         Directors  authorizing  it to become a Limited  Partner under the terms
         and conditions of this Agreement; and

                  (e) Said person,  upon request by the General  Partner,  shall
         pay such reasonable  expenses as may be incurred in connection with its
         admission as a Limited Partner.

                  11.      CAPITAL ACCOUNTS.

                  A capital  account shall be  established  for each Partner and
shall at all  times be  determined  and  maintained  as  provided  by the  Final
Treasury  Regulations  under  Section  704(b)  of the  Code,  as the same may be
amended.  A Partner  shall not be entitled  to withdraw  any part of his capital
account or to receive any distribution from the Partnership,  except as provided
in Articles 13 and 24.

                  (a)      Each Partners' capital account shall be increased by:

                           (i)      The amount of his Capital Contribution 
                  pursuant to Article 7; and

                           (ii)     The amount of Profits allocated to him 
                  pursuant to Article 12; and

                           (iii) The Partner's pro rata share (determined in the
                  same  manner as such  Partner's  share of  Profits  and Losses
                  allocated pursuant to Article 12 hereof) of any income or gain
                  exempt from tax.

                  (b) Each Partner's capital account shall be decreased by:

                                                      -8-


<PAGE>



                           (i)      The amount of Losses allocated to him 
                  pursuant to Article 12; and

                           (ii) The amount of Partnership Cash Flow, Partnership
                  Sales   Proceeds   and   Partnership    Refinancing   Proceeds
                  distributed to him pursuant to Article 13; and

                           (iii)  The  Partner's  pro rata  share  of any  other
                  expenditures  of the  Partnership  which are not deductible in
                  computing  Partnership  Profits  or  Losses  and which are not
                  added to the tax basis of any Partnership property, including,
                  without   limitation,   expenditures   described   in  Section
                  705(a)(2)(B) of the Code. The Partner's pro rata share of such
                  expenditures  shall be  determined  in the same manner as such
                  Partner's  share of Profits and Losses  allocated  pursuant to
                  Article 12.

                  12.      ALLOCATIONS

                  (a)  Profits  and  Losses.  The  Profits  and  Losses  of  the
         Partnership  shall be allocated  among the Partners in accordance  with
         their  respective  Percentage  Interests.  In  allocating  Profits  and
         Losses,  Net Gains and  Losses  from  Capital  Transactions  (a part of
         Profits and Losses), if any, shall be allocated first.

                  (b)  Qualified  Income  Offset.  If any  Partner  unexpectedly
         receives  any  adjustment,  allocation  or  distribution  described  in
         Treasury Regulations Section 1.704- 1(b)(2)(ii)(d)(4) through (6) which
         causes or increases a deficit balance in such Partner's Capital Account
         (adjusted  for  this  purpose  in  the  manner   provided  in  Treasury
         Regulations Section 1.704-1(b)(2)(ii)(d)),  items of Partnership income
         and gain shall be specially allocated to each such Partner in an amount
         and manner  sufficient  to  eliminate,  to the extent  required  by the
         Regulations,  the deficit Capital Account of such Partner as quickly as
         possible,   provided  that  an  allocation  pursuant  to  this  Article
         12(d)(iii)  shall be made if and only to the extent  that such  Partner
         would  have a deficit  Capital  Account  after  all  other  allocations
         provided for in this  Article  12(d) have been  tentatively  made as if
         this Article  12(d)(iii)  were not in the Agreement.  This provision is
         intended  to be a  "qualified  income  offset,"  as defined in Treasury
         Regulations  Section  1.704-  1(b)(2)(ii)(d),   such  Regulation  being
         specifically incorporated herein by reference.

                  (c) Sales Commission.  The Sales Commission shall be allocated
         to the  Limited  Partners  holding  Class B Units  to the  extent  such
         Limited Partners paid the Sales Commission,  and in proportion to their
         respective  capital  contributions  represented  by such  Units  (i.e.,
         $112,50 in Sales  Commissions  per each Class B Unit).  The  purpose of
         this  Article  12(c)  is to  allocate  the  Sales  Commission  to those
         Partners who actually bore the burden of paying the Sales Commission.


                                                      -9-


<PAGE>



                  (d)  Allocations  Between  Transferor and  Transferee.  In the
         event of the transfer (other than the pledges of the General  Partner's
         interest  permitted  by Article 18 or  Permitted  Pledges  described in
         Article  16.2(b))  of all or  any  part  of a  Partner's  interest  (in
         accordance with the provisions of this Agreement) in the Partnership at
         any time other  than at the end of a Year,  or the  admission  of a new
         Partner  (in  accordance  with  the  terms  of  this  Agreement),   the
         transferring  Partner  or new  Partner's  share  of  the  Partnership's
         income,  gain,  loss,  deductions  and  credits,  as computed  both for
         accounting  purposes  and for  Federal  income tax  purposes,  shall be
         allocated between the transferor Partner and the transferee Partner (or
         Partners),  or the new Partner and the other Partners,  as the case may
         be, in the same  ratio as the  number of days in such Year  before  and
         after the date of the transfer or admission; provided, however, that if
         there  has  been a sale  or  other  disposition  of the  assets  of the
         Partnership  (or any part thereof)  during such Year,  then the General
         Partner may elect, in its sole discretion,  to treat the periods before
         and after the date of the transfer or  admission as separate  Years and
         allocate the Partnership's net income,  gain, net loss,  deductions and
         credits for each of such deemed  separate  Years.  Notwithstanding  the
         foregoing, the Partnership's "allocable cash basis items," as that term
         is used in Section  706(d)(2)(B)  of the Code,  shall be  allocated  as
         required  by  Section   706(d)(2)  of  the  Code  and  the  regulations
         thereunder.

                  (e) Tax  Withholding.  The Partnership  shall be authorized to
         pay, on behalf of any  Partner,  any amounts to any  federal,  state or
         local taxing  authority,  as may be necessary  for the  Partnership  to
         comply with tax withholding  provisions of the Code or the other income
         tax or  revenue  laws  of any  taxing  authority.  To  the  extent  the
         Partnership  pays any such  amounts  that it may be  required to pay on
         behalf  of  a  Partner,  such  amounts  shall  be  treated  as  a  cash
         Distribution  to such  Partner  and shall  reduce the amount  otherwise
         distributable to such Partner.

                  13.      DISTRIBUTIONS.

                  (a)  Distribution of Partnership  Cash Flow.  Partnership Cash
         Flow shall be distributed to the Partners  within 60 days after the end
         of each Year, or earlier in the discretion of the General  Partner,  in
         proportion  to their  respective  Percentage  Interests  at the time of
         distribution.

                  (b)  Distribution  of  Partnership  Refinancing  Proceeds  and
         Partnership  Sales  Proceeds.   Partnership  Refinancing  Proceeds  and
         Partnership  Sales Proceeds shall be distributed to the Partners within
         60 days of the Capital  Transaction  giving rise to such  proceeds,  or
         earlier in the  discretion  of the General  Partner,  in  proportion to
         their respective Percentage Interests at the time of distribution.

                  (c)  Distribution  in  Liquidation.  Upon  liquidation  of the
         Partnership,  all of the  Partnership's  property  shall  be  sold  and
         Profits and Losses allocated accordingly. Proceeds from the liquidation
         of the Partnership shall be distributed in accordance with Article 24.


                                                      -10-


<PAGE>



                  14.      RIGHTS AND OBLIGATIONS OF LIMITED PARTNERS.

                  14.1  Management.  The Limited Partners shall not take part in
the management of the business,  nor transact any business for the  Partnership,
nor  shall  they  have  power  to  sign  for or to  bind  the  Partnership.  The
Partnership may,  however,  contract with one or more Limited Partners to act as
the local Medical Director and Quality Assessment Director for the Prostatron(R)
Mobile System.  No Limited Partner may withdraw from the  Partnership  except as
expressly permitted herein.

                  14.2 Operation of  Prostatron(R)  Mobile  System.  The Limited
Partners shall not operate or utilize the  Prostatron(R)  Mobile System or other
Partnership  equipment except pursuant to (i) an Agreement with the Partnership;
or (ii) any other arrangement specifically approved by the General Partner.

                  14.3 Outside Activities.  The Limited Partners agree that they
owe fiduciary  duties to the  Partnership  and, as a  consequence,  each Limited
Partner (that is not the General Partner or an Affiliate of the General Partner)
agrees that he or she shall not engage in "Outside  Activities"  while he or she
is a Limited Partner in the Partnership.  The phrase "Outside  Activities" means
directly or indirectly  owning,  leasing or subleasing a  Prostatron(R)  (or any
similar  equipment  or competing  devices  used for  treating  BPH) or any other
therapeutic equipment acquired by the Partnership. Prohibited indirect ownership
shall include the ownership of any interest in a business venture (through stock
ownership,  partnership  interest ownership,  or as otherwise determined in good
faith by the General Partner) involving the ownership, purchase, lease, sublease
or operation of a Prostatron(R)  (or similar equipment or competing devices used
for treating BPH), or other  competing  device or equipment,  unless the General
Partner determines that such activity by the Limited Partners is not detrimental
to the best interests of the Partnership .

                  Upon  the  termination  or  transfer  of a  Limited  Partner's
interest in the  Partnership  for any reason,  including a transfer  pursuant to
Article 17.3 hereof, the withdrawing  Limited Partner shall not, for a period of
two (2)  years  following  the date of the  withdrawal,  engage  in any  Outside
Activities in any "Market Area" in which the Partnership is transacting business
or within the prior  twelve  months has  transacted  business  (the  "Restricted
Facilities").  For the purposes of this  Article  14.3,  the term "Market  Area"
shall mean (i) the area within a ten mile radius of any Restricted Facility, but
if such area is determined by a court of competent jurisdiction to be too broad,
then it shall  mean (ii) the area  within a five mile  radius of any  Restricted
Facility, but if such area is determined by a court of competent jurisdiction to
be too broad then it shall mean (iii) the area  within a two mile  radius of any
Restricted Facility.

                  In the event a Limited Partner wishes and intends to engage in
an Outside  Activity in a Market Area, he or she must provide  written notice of
such intent to the General  Partner  prior to engaging in the Outside  Activity.
The  written  notice  shall be deemed an  election  by the  Limited  Partner  to
withdraw from the Partnership (the "Notice of  Withdrawal"),  and shall give the
General Partner the purchase rights as provided  Article 17.3 hereof.  After the
Notice of  Withdrawal,  the  former  Limited  Partner  may  engage in an Outside
Activity in the Market Area only after waiting the period of two years specified
in this  Article  14.3.  In the  event of  breach  of the  waiting  period,  the
Partnership shall be

                                                      -11-


<PAGE>



entitled to any remedy at law or equity with respect to such  breach,  including
without limitation an injunction or suit for damages.

                  If a Limited  Partner during his or her  participation  in the
Partnership  engages in an  Outside  Activity  in a Market  Area  without  first
notifying  the General  Partner in violation of this Article  14.3,  the Limited
Partner  shall be deemed to have  given a Notice of  Withdrawal  on the date the
General Partner first becomes aware of the Limited Partner's Outside Activity in
the Market Area.  Upon  receiving a Limited  Partner's  Notice of  Withdrawal or
equivalent  thereof,  the Partnership may invoke the purchase rights provided in
Article  17.3  and  shall be  entitled  to any  other  remedy  at law or  equity
including without limitation an injunction or suit for damages.

                  14.4  Disclosure  of  Confidential  Information.  Each Limited
Partner acknowledges and agrees that his or her participation in the Partnership
under this Agreement necessarily involves his or her understanding of and access
to certain trade secrets and other  confidential  information  pertaining to the
business of the Partnership.  Accordingly,  each Limited Partner (other than the
General Partner and its Affiliates that may also hold Limited Partner interests)
agrees that at all times during his or her participation in the Partnership as a
Limited  Partner and  thereafter,  he or she will not,  directly or  indirectly,
without the express written authority of the Partnership, unless required by law
or directed by a applicable legal authority having jurisdiction over the Limited
Partner,  disclose or use for the benefit of any  person,  corporation  or other
entity  (other  than the  Partnership),  or himself or  herself,  (i) any trade,
technical,  operational,  management or other  secrets,  any patient or customer
lists  or  other   confidential  or  secret  data,  or  any  other  proprietary,
confidential or secret  information of the Partnership or (ii) any  confidential
information concerning any of the financial  arrangements,  financial positions,
hospital  or  physician  contracts,  third  party  payor  arrangements,  quality
assurance  and  outcome  analysis  programs,  competitive  status,  customer  or
supplier matters, internal organizational matters, technical abilities, or other
business affairs of or relating to the Partnership.  The Limited Partners (other
than the General  Partner and its Affiliates  that may also hold Limited Partner
interests)  acknowledge  that  all  of  the  foregoing  constitutes  proprietary
information, which is the exclusive property of the Partnership. In the event of
breach  of  this  Article  14.4  as  determined  by  the  General  Partner,  the
Partnership  shall be entitled  to any remedy at law or equity  with  respect to
such breach, including without limitation, an injunction or suit for damages.

                  15.      LIMITED LIABILITY.

                  No Limited Partner shall be required to make any  contribution
to the  capital of the  Partnership  except as set forth in Article 7, nor shall
any Limited  Partner in his capacity as such, be bound by, or personally  liable
for,  any expense,  liability or  obligation  of the  Partnership  except to the
extent of his or her (i) interest in the  Partnership;  and (ii)  obligation  to
return distributions made to him or her under certain  circumstances as required
by the Act.


                                                      -12-


<PAGE>



                  16.      TRANSFER OF INTERESTS AND ADMISSION OF PARTNERS.

                  16.1     Transferability.

                  (a) The  term  "transfer"  when  used in this  Agreement  with
         respect to a Partnership  Interest includes a sale,  assignment,  gift,
         pledge,  exchange,  or any other  disposition (but does not include the
         issuance of new Partnership Interests pursuant to a Dilution Offering);

                  (b) Except as otherwise  provided herein,  the General Partner
         shall not at any time  transfer or assign its interest or obligation as
         General Partner;

                  (c) The Partnership  Interest of any Limited Partner shall not
         be  transferred,  in whole or in part,  except in  accordance  with the
         conditions and limitations set forth in Articles 16.2 or 17;

                  (d) The  transferee of a Partnership  Interest by  assignment,
         operation of law or otherwise,  shall have only the rights,  powers and
         privileges  enumerated in Article 16.3 or otherwise provided by law and
         may not be admitted to the  Partnership as a Limited  Partner except as
         provided in  Articles  7.4 and 16.4 or as a General  Partner  except as
         provided in Article 16.5;

                  (e) Notwithstanding any provision herein to the contrary,  the
         Partnership  Agreement  shall  in  no  way  restrict  the  issuance  or
         transfers of stock of the General Partner; and

                  (f) Notwithstanding any provision herein to the contrary,  the
         issuance of Partnership  Interests  pursuant to a Dilution Offering and
         the admission of new Limited Partners  pursuant to a Dilution  Offering
         shall be governed by the provisions of Section 7.4 of this Agreement.

                  16.2     Restrictions on Transfers by Limited Partners.

                  (a) All or part of a Partnership  Interest may be  transferred
         by a  Limited  Partner  only  with the prior  written  approval  of the
         General  Partner,  which  approval may be granted or denied in its sole
         discretion

                  (b) The General  Partner  shall not approve any  transfer of a
         Partnership  Interest,  except a pledge of any Partnership  Interest by
         the General Partner to any bank,  insurance  company or other financial
         institution to secure payment of indebtedness  (a "Permitted  Pledge"),
         or otherwise  unless the proposed  transferee  shall have furnished the
         General Partner with a sworn statement that:


                                                      -13-


<PAGE>



                           (i) The proposed  transferee  proposes to acquire his
                  Partnership  Interest as a principal,  for  investment and not
                  with a view to resale or distribution;

                           (ii) The proposed  transferee meets such requirements
                  regarding sophistication,  income and net worth as required by
                  applicable state and Federal securities laws;

                           (iii) The proposed  transferee has met such net worth
                  and income  suitability  standards as have been established by
                  the General Partner;

                           (iv)  The   proposed   transferee   recognizes   that
                  investment in the Partnership  involves  certain risks and has
                  taken  full  cognizance  of and  understands  all of the  risk
                  factors related to the purchase of a Partnership Interest; and

                           (v)  The  proposed   transferee  has  met  all  other
                  requirements of the General Partner for the proposed transfer.

                  (c) Other than in the case of a Permitted  Pledge,  a transfer
         of a  Partnership  Interest  may be made  only  if,  prior  to the date
         thereof,  the Partnership  upon request receives an opinion of counsel,
         satisfactory in form and substance to the General Partner, that neither
         the offering nor the proposed transfer will require  registration under
         Federal or applicable state securities laws or regulations.

                  16.3     Rights of Transferee.

                  Unless  admitted to the Partnership in accordance with Article
16.4, the  transferee of a Partnership  Interest or a part thereof or any right,
title or interest therein shall not be entitled to any of the rights, powers, or
privileges of his  predecessor in interest,  except that he shall be entitled to
receive and be credited or debited with his  proportionate  share of Partnership
income, gains, Profits, Losses, deductions, credits or Distributions.

                  16.4     Admission of Limited Partners.

                  Except as  otherwise  provided  in  Articles  7.4 and 17,  the
General Partner, or the transferee of all or part of the Partnership Interest of
either  a  General  Partner  or a  Limited  Partner,  may  be  admitted  to  the
Partnership as a Limited  Partner upon  furnishing to the General Partner all of
the following:

                  (a) The  written  approval of a Majority in Interest of all of
         the Limited  Partners  (except the assignor  Partner),  or the assignor
         Partner  alone,  which  approval  may be  granted or denied in the sole
         discretion of such Partners or Partner (as the case may be);

                                                      -14-


<PAGE>



                  (b)  The  written  approval  of  the  General  Partner,  which
         approval may be granted or denied in the sole discretion of the General
         Partner;

                  (c) Acceptance, in a form satisfactory to the General Partner,
         of all the  terms  and  conditions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d)  A  properly  executed  power  of  attorney  substantially
         identical to that contained in Article 37;

                  (e) Such other  documents or instruments as may be required in
         order to effect his or her admission as a Limited Partner; and

                  (f) Payment of such reasonable  expenses as may be incurred in
         connection with his or her admission as a Limited Partner.

                  16.5     Admission of General Partners.

                  A Limited  Partner,  or the  transferee  of all or part of the
Partnership  Interest of the General Partner, may be admitted to the Partnership
as a  general  partner  upon  furnishing  to  the  General  Partner  all  of the
following:

                  (a) The  written  consent of both the  General  Partner  and a
         Majority  in Interest of the  Limited  Partners,  which  consent may be
         granted or denied in the sole discretion of the Partners;

                  (b) Such financial statements,  guarantees or other assurances
         as the General  Partner  may require  with regard to the ability of the
         proposed  general  partner to fulfill the  financial  obligations  of a
         general partner hereunder;

                  (c) Acceptance,  in form  satisfactory to the General Partner,
         of all the  terms  and  provisions  of  this  Agreement  and any  other
         documents  required in connection with the operation of the Partnership
         pursuant to the terms of this Agreement;

                  (d) A certified copy of a resolution of its Board of Directors
         (if it is a  corporation)  authorizing  it to become a general  partner
         under the terms and conditions of this Agreement;

                  (e)      A power of attorney substantially identical to that 
         contained in Article 37;

                  (f) Such other  documents or instruments as may be required in
         order to effect its admission as a general partner; and


                                                      -15-


<PAGE>



                  (g) Payment of such reasonable  expenses as may be incurred in
         connection with its admission as a general partner.

                  Notwithstanding  the above,  a transferee  that controls or is
controlled by the General Partner or one or more of its Affiliates that receives
all or part of the  Partnership  Interest of the General Partner may be admitted
to the  Partnership as a general  partner upon complying with all the provisions
of Article  16.5  except for  subparagraph  16.5(a).  As long as the  transferee
either  controls or is controlled  by the General  Partner or one or more of its
Affiliates,  no  Limited  Partner  consents  will  be  required  to  admit  such
transferee as a General Partner to the Partnership.

                  16.6     Amendment of Certificate of Limited Partnership and
Qualification.

                  The  General  Partner  shall  take  all  steps  necessary  and
appropriate to prepare and record any  amendments to the  Certificate of Limited
Partnership, as may be necessary or appropriate from time to time to comply with
the requirements of the Act, including,  without limitation,  upon the admission
to the Partnership of any general partner  pursuant to the provisions of Article
16.5, and may for this purpose  exercise the power of attorney  delivered to the
General Partner pursuant to Article 16.5 or 37. In addition, the General Partner
shall take all steps necessary and appropriate to prepare and record any and all
documents  necessary to qualify the Partnership to do business in  jurisdictions
where the Partnership is doing business,  and may for this purpose  exercise the
power of attorney  delivered to the General  Partner  pursuant to Articles 16.4,
16.5 or 37.

                  16.7     Fundamental Changes.

                  As provided in Article  20.5(b),  if the General Partner and a
Majority in Interest of the Limited  Partners  approve a plan  providing for the
merger or consolidation of the Partnership with another person or entity, or the
sale of all or substantially all of the Partnership Interests, including without
limitation the exchange of Partnership Interests for equity interests in another
person or entity or for cash or other consideration or combination thereof, then
and in such event,  the Limited  Partners  shall be obligated to take or refrain
from  taking,  as the  case  may be,  such  actions  as the  plan  may  provide,
including,  without limitations,  executing such instruments, and providing such
information as the General Partner shall reasonably request.  Any plan described
in this Article 16.7 may also effect an amendment to the  Partnership  Agreement
or the adoption of a new partnership  agreement in connection with the merger of
the  Partnership  with another person or entity.  The plan may also provide that
the General Partner and its Affiliates shall receive fees for services  rendered
in connection  with the  operation of the  Partnership  or any successor  entity
following  the  consummation  of the  transactions  described  in the plan,  and
neither the  Partnership nor the Partners shall have any right by virtue of this
Agreement in the income derived therefrom. Any securities or other consideration
to be distributed  to the Partners  pursuant to the plan shall be distributed in
the  manner  set forth in Article  24(c) as though  the  Partnership  were being
liquidated.  For this purpose only,  the fair market value of the  securities or
other  consideration  to be  received  pursuant  to the plan shall be treated as
"Profits"  and the capital  accounts of the  Partners  shall be increased in the
manner  provided  in Article  11(a)(ii).  No Partner  shall be  entitled  to any
appraisal  or similar  rights in  connection  with a plan  contemplated  by this
Article 16.7.


                                                      -16-


<PAGE>



                  16.8     Withdrawal of Initial Limited Partner.

                  Upon the date the first  Limited  Partner is  admitted  to the
Partnership in accordance with Article 10 of this Agreement, the Initial Limited
Partner  shall  withdraw  from  the  Partnership,   and  thereupon  his  Capital
Contribution shall be returned and his Partnership Interest shall be reallocated
to the Limited Partners.

                  17.      OPTIONAL PURCHASE OF LIMITED PARTNERSHIP INTERESTS ON
                           CERTAIN EVENTS.

                  17.1     Death.

                  Upon the  death of a Limited  Partner,  the  deceased  Limited
Partner's  executor,  administrator,  or other legal or personal  representative
shall give  written  notice of that fact to the  General  Partner.  The  General
Partner shall have the option to purchase at the Closing (as defined  below) the
Partnership   Interest  of  the  deceased   Limited  Partner  (whose   executor,
administrator  or other  legal or  personal  representative  shall  then  become
obligated  to sell such  Partnership  Interest) at the price  determined  in the
manner  provided  in  Article  17.8  of  this  Agreement  and on the  terms  and
conditions provided in Article 17.9 of this Agreement. The General Partner shall
have a period of thirty (30) days following the date it first received notice of
the death of the Limited Partner (the "Option Period") within which to notify in
writing the deceased Limited Partner's executor, administrator or other legal or
personal representative, whether the General Partner wishes to purchase all or a
portion of the  Partnership  Interest of the deceased  Limited  Partner.  If the
General  Partner does not elect to purchase the entire  Partnership  Interest of
the deceased  Limited  Partner before the expiration of the Option Period and in
the  manner  provided  herein,  the  portion  of the  Partnership  Interest  not
purchased   shall  be  held  by  the  deceased   Limited   Partner's   executor,
administrator,  or other  legal  representative  pursuant  to the  terms of this
Agreement. The General Partner, in its sole discretion,  may elect to assign its
rights to purchase the Partnership  Interest of a deceased Limited Partner under
this Section 17.1 to the Partnership  and, in such case, the  Partnership  shall
have the same rights as  provided  for the General  Partner  under this  Section
17.1.

                  17.2     Bankruptcy, Insolvency or Assignment for Benefit of 
                           Creditors of a Limited Partner.

                   In the event  that an  involuntary  or  voluntary  proceeding
under the  Federal  Bankruptcy  Code,  as  amended,  is filed for or against any
Limited  Partner,  or if any Limited  Partner shall make an  assignment  for the
benefit of his creditors,  or if any Limited Partner has a receiver or custodian
appointed  for his assets,  or any Limited  Partner  generally  fails to pay his
debts when due, the insolvent  Limited  Partner  shall give written  notice (the
"Notice of Insolvency")  to the General Partner of the  commencement of any such
proceeding or the  occurrence of such event within five days of the first notice
to him of such  commencement  or occurrence of such event.  The General  Partner
shall  have the  option to  purchase  at the  Closing  (as  defined  below)  the
Partnership  Interest of the insolvent  Limited Partner (which insolvent Limited
Partner  or  his  trustee,  custodian,  receiver  or  other  personal  or  legal
representative,  as the case may be,  shall then become  obligated  to sell such
Partnership  Interest) at the price determined in the manner provided in Article
17.8 of this Agreement and on the terms and

                                                      -17-


<PAGE>



conditions provided in Article 17.9 of this Agreement. The General Partner shall
have a period of thirty  (30) days  following  the date of either  the Notice of
Insolvency,  or if such formal notice is not given, the date the General Partner
first  becomes  aware of the  financial  condition  of the  Limited  Partner  as
outlined in this Article 17.2 (the "Option  Period"),  within which to notify in
writing the insolvent Limited Partner or his trustee,  custodian,  receiver,  or
other legal or personal  representative,  whether the General  Partner wishes to
purchase all or a portion of the Partnership  Interest of the insolvent  Limited
Partner.  If  the  General  Partner  does  not  elect  to  purchase  the  entire
Partnership  Interest of the insolvent  Limited Partner before the expiration of
the  Option  Period  and in the  manner  provided  herein,  the  portion  of the
Partnership  Interest not purchased shall be held by the insolvent Partner,  his
trustee, custodian,  receiver or other legal or personal representative pursuant
to the terms of this Agreement. The General Partner, in its sole discretion, may
elect to assign its rights to purchase the Partnership  Interest of an insolvent
Limited  Partner under this Section 17.2 to the  Partnership  and, in such case,
the  Partnership  shall have the same rights as provided for the General Partner
under this Section 17.2.

                  17.3     Breach of Article 14.3.

                  In the event the General  Partner either  receives a Notice of
Withdrawal  as provided in Article 14.3 or receives  notice of breach of Article
14.3 by a Limited  Partner  (the  "Defaulting  Limited  Partner"),  the  General
Partner  may  elect,  in its sole  discretion,  to treat such event as a default
under this  Agreement  and enforce the  provisions  of this Article 17.3. If the
General  Partner  elects to enforce the  provisions  of this Article  17.3,  the
General  Partner  shall give  written  notice of such  election  (the "Notice of
Default")  to the  Defaulting  Limited  Partner  within 180 days of the date the
General Partner first received notice of the defaulting  event.  Upon giving the
Notice of Default,  the General Partner shall have the option to purchase at the
Closing (as defined below) the  Partnership  Interest of the Defaulting  Limited
Partner (which  Defaulting  Limited Partner shall then become  obligated to sell
such  Partnership  Interest) at the price  determined in the manner  provided in
Article  17.8 of this  Agreement  and on the terms and  conditions  provided  in
Article  17.9 of this  Agreement.  The  General  Partner  shall have a period of
thirty (30) days  following the date of the Notice of Default (the "First Option
Period")  within  which to notify in writing  the  Defaulting  Limited  Partner,
whether  the  General  Partner  wishes  to  purchase  all  or a  portion  of the
Partnership  Interest of the Defaulting Limited Partner.  If the General Partner
does not elect to purchase  the entire  Partnership  Interest of the  Defaulting
Limited  Partner  before the  expiration  of the Option Period and in the manner
provided herein, the portion of the Partnership  Interest not purchased shall be
held by the Defaulting  Limited Partner pursuant to the terms of this Agreement.
The General Partner,  in its sole discretion,  may elect to assign its rights to
purchase the  Partnership  Interest of a Defaulting  Limited  Partner under this
Section 17.3 to the Partnership  and, in such case, the  Partnership  shall have
the same rights as provided for the General Partner under this Section 17.3.

                  17.4     Domestic Proceeding.

                  In the  event  that a spouse of a  Limited  Partner  commences
against  a  Limited  Partner,  or a  Limited  Partner  is named  in, a  Domestic
Proceeding,  the Limited  Partner  shall give  written  notice  (the  "Notice of
Domestic  Proceeding")  to the General  Partner of the  commencement of any such
proceeding within five days of the first notice to him of such commencement. The
General  Partner  shall have the option to  purchase  at the Closing (as defined
below) the Partnership Interest of the Limited

                                                      -18-


<PAGE>



Partner  involved in the Domestic  Proceeding  (which Limited Partner shall then
become obligated to sell such Partnership Interest),  at the price determined in
the manner  provided  in  Article  17.8 of this  Agreement  and on the terms and
conditions provided in Article 17.9 of this Agreement. The General Partner shall
have a period of thirty  (30) days  following  the date of either  the Notice of
Domestic  Proceeding or if such formal notice is not given, the date the General
Partner is first aware of the domestic  circumstances  of the Limited Partner as
provided in this Article 17.4 (the "Option  Period"),  within which to notify in
writing the Limited  Partner  involved in the Domestic  Proceeding,  whether the
General Partner wishes to purchase all or a portion of the Partnership  Interest
of such Limited  Partner.  If the General Partner does not elect to purchase the
Partnership  Interest of the Limited Partner involved in the Domestic Proceeding
before the  expiration of the Option Period and in the manner  provided  herein,
the portion of the  Partnership  Interest  not  purchased  shall be held by such
Limited Partner pursuant to the terms of this Agreement. The General Partner, in
its sole discretion,  may elect to assign its rights to purchase the Partnership
Interest of the Limited Partner  involved in the Domestic  Proceeding under this
Section 17.4 to the Partnership  and, in such case, the  Partnership  shall have
the same rights as provided for the General Partner under this Section 17.4.

                  17.5     Divestiture Option.

                  If  state  or  federal  regulations  or laws  are  enacted  or
applied,  or if any other legal developments occur, which, in the opinion of the
General Partner adversely affect (or potentially adversely affect) the operation
of the Partnership (e.g., the enactment or application of prohibitory  physician
self-referral  legislation against the Partnership or its Partners), the General
Partner shall promptly either, in its discretion, (i) take the steps outlined in
this Article 17.5 to divest the Limited Partners of their Partnership Interests,
or (ii) dissolve the Partnership as provided in Article 23.1(e).  If the General
Partner  chooses  option  (i), it shall  deliver a written  notice to all of the
Limited  Partners  (the  "Notice of  Election")  and purchase  such  Partnership
Interests  for  its  own  account.  The  purchase  price  to be  paid  for  each
Partnership  Interest  shall be  determined in the manner as provided in Article
17.8 and shall be on the terms and  conditions as provided in Article 17.9.  The
transfer of the Partnership  Interests and the payment of the purchase price (as
provided  in  Article  17.8)  shall be made at such  time as  determined  by the
General  Partner to be in the best interests of the  Partnership and its Limited
Partners.  Each  Limited  Partner  hereby  makes,  constitutes  and appoints the
General  Partner,  with  full  power  of  substitution,   his  true  and  lawful
attorney-in-fact,  to take such actions and execute such documents on his behalf
to effect the transfer of his  Partnership  Interest as provided in this Article
17.5.

                  17.6     Dissolution of Carolina Lithotripsy.

                  Upon the  voluntary  or  involuntary  dissolution  of Carolina
Lithotripsy,  Carolina  Lithotripsy's  general  partner or, if there is none,  a
representative  of its limited  partners  shall give written  notice of the fact
(the "Notice of Dissolution") to the General Partner.  The General Partner shall
have the option to purchase at the  Closing (as defined  below) the  Partnership
Interest of Carolina  Lithotripsy (whose general partner or other representative
shall then become  obligated  to sell such  Partnership  Interest)  at the price
determined in the manner  provided in Article 17.8 of this  Agreement and on the
terms and  conditions  provided in Article 17.9 of this  Agreement.  The General
Partner shall have a period of thirty (30) days following the date of either the
Notice of  Dissolution  of Carolina  Lithotripsy or if such formal notice is not
given, the date the General Partner is first aware of the dissolution (the

                                                      -19-


<PAGE>



"Option  Period"),  within  which to notify in  writing  Carolina  Lithotripsy's
general partner or other  representative,  whether the General Partner wishes to
purchase all or a portion of the Partnership  Interest of Carolina  Lithotripsy.
If the  General  Partner  does not  elect to  purchase  the  entire  Partnership
Interest of Carolina  Lithotripsy before the expiration of the Option Period and
in the manner  provided  herein,  the portion of the  Partnership  Interest  not
purchased  shall be held by the  successors in interest to Carolina  Lithotripsy
upon dissolution  pursuant to the terms of this Agreement.  The General Partner,
in its  sole  discretion,  may  elect to  assign  its  rights  to  purchase  the
Partnership  Interest of Carolina  Lithotripsy  under this  Section  17.6 to the
Partnership  and, in such case,  the  Partnership  shall have the same rights as
provided for the General Partner under this Section 17.6.

                  17.7     Regulatory Action Regarding Carolina Lithotripsy.

                  In the event Carolina  Lithotripsy is conclusively  determined
by a court of  competent  jurisdiction  or state or  federal  authority  to have
violated any law or  regulation,  and such action is  determined  by the General
Partner to effect the Partnership's participation under the Medicare or Medicaid
programs,   or  otherwise  adversely  effects  the  material  interests  of  the
Partnership,  the General Partner may elect to treat such action as a defaulting
event by Carolina  Lithotripsy (the "Defaulting  Event"). If the General Partner
elects to enforce the provisions of this Article 17.7, the General Partner shall
give  written  notice  of such  election  (the  "Default  Notice")  to  Carolina
Lithotripsy  within ninety days of the date the General  Partner first  received
notice of the  Defaulting  Event.  Upon giving the Default  Notice,  the General
Partner shall have the option to purchase at the Closing (as defined  below) the
Partnership   Interest  of  Carolina   Lithotripsy   (in  which  event  Carolina
Lithotripsy's general partner or other representative, as the case may be, shall
then become obligated to sell such Partnership Interest) at the price determined
in the manner  provided in Article 17.8 of this  Agreement  and on the terms and
conditions provided in Article 17.9 of this Agreement. The General Partner shall
have a period of thirty (30) days  following the date of the Default Notice (the
"Option Period") within which to notify Carolina  Lithotripsy in writing whether
the  General  Partner  wishes to  purchase  all or a portion of the  Partnership
Interest  of Carolina  Lithotripsy.  If the  General  Partner  does not elect to
purchase  the entire  Partnership  Interest of Carolina  Lithotripsy  before the
expiration of the Option Period and in the manner provided  herein,  the portion
of the Partnership  Interest not purchased shall be held by Carolina Lithotripsy
pursuant  to the  terms of this  Agreement.  The  General  Partner,  in its sole
discretion,  may elect to assign its rights to purchase the Partnership Interest
of Carolina  Lithotripsy under this Section 17.7 to the Partnership and, in such
case,  the  Partnership  shall have the same rights as provided  for the General
Partner under Section 17.7.

                  17.8     Purchase Price.

                  The purchase price to be paid for the Partnership  Interest of
any Limited Partner whose interest is being purchased pursuant to the provisions
of Articles 17.1, 17.2,  17.3,  17.4, 17.5, 17.6 or 17.7 (the "Retiring  Limited
Partner")  shall be an amount equal to the Retiring  Limited  Partner's share of
the Partnership's book value, if any, (prorated in the event that only a portion
of his  Partnership  Interest is being  purchased)  as  reflected by the Capital
Account of the Retiring  Limited  Partner  (unadjusted  for any  appreciation in
Partnership  assets  and as reduced by  depreciation  deductions  claimed by the
Partnership  for  tax  purposes).  The  determination  of the  Retiring  Limited
Partner's Capital Account on the Valuation Date (as defined below) shall be made
by the Partnership's internal accountant (the "Partnership

                                                      -20-


<PAGE>



Accountant")  upon a review of the  Partnership  books of account,  and a formal
audit is expressly  waived.  The statement of the  Partnership  Accountant  with
respect to the Capital Account of the Retiring  Limited Partner on the Valuation
Date shall be binding and conclusive upon the Partnership, the purchaser and the
Retiring Limited Partner and his representative. The Valuation Date shall be the
last day of the month immediately  preceding the month in which occurs:  (i) the
death of a Limited Partner,  in the case of a purchase by reason of death;  (ii)
the bankruptcy or insolvency of a Limited Partner,  in the case of a purchase by
reason of such  bankruptcy  or  insolvency;  (iii) the Notice of  Withdrawal  or
breach of Article  14.3 as provided in Article 17.3 in the case of a purchase by
reason thereof; (iv) the commencement of the Domestic Proceeding, in the case of
a purchase by reason thereof;  (v) the Notice of Election as provided in Article
17.5;  (vi) the date of  dissolution  as provided in Article  17.6; or (vii) the
Default  Notice as provided in Article 17.7, in the case of a purchase by reason
thereof. Any Limited Partner whose Partnership Interest is purchased pursuant to
the provisions of Article 17.1,  17.2,  17.3,  17.4, 17.5, 17.6 or 17.7 shall be
entitled  only to the purchase  price which shall be paid at the Closing in cash
(or  by  certified  or  cashier's  check)  and  shall  not  be  entitled  to any
Partnership  distributions  made after the  Valuation  Date.  The  transfer of a
Partnership  Interest of a Retiring  Limited Partner shall be deemed to occur as
of the Valuation Date and the Retiring  Limited  Partner shall have no voting or
other  rights as a Limited  Partner  after such  date.  The  purchaser  shall be
entitled to any distributions attributable to the transferred interest after the
Valuation  Date and  shall  have the  right to  deduct  the  amount  of any such
distributions made to the Retiring Limited Partner after the Valuation Date from
the purchase price.

                  17.9     Closing.

                  17.9.1  Closing  of  Purchase  and Sale.  The  Closing  of any
         purchase and sale of a Partnership  Interest  pursuant to Article 17.1,
         17.2, 17.3, 17.4, 17.5, 17.6 or 17.7 of this Agreement shall take place
         at the  principal  office  of the  Partnership,  or  such  other  place
         designated by the General  Partner,  on the date  determined as follows
         (the "Closing"):

                  (a) In the case of a purchase and sale  occurring by reason of
         the death of a Limited  Partner as  provided  in  Article  17.1 of this
         Agreement,  the Closing  shall be held on the thirtieth day (or if such
         thirtieth  day is not a business  day, the next  business day following
         the thirtieth day) next following the last to occur of:

                           (i)      Qualification of the executor or personal 
                  administrator of the deceased Limited Partner's estate;

                           (ii) The date on which any necessary determination of
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (iii) The date that  coincides  with the close of the
                  Option Period.

                  (b) In the case of a purchase and sale  occurring by reason of
         the  occurrence of one of the events  described in Article 17.2,  17.3,
         17.4, 17.5, 17.6 or 17.7 of this

                                                      -21-


<PAGE>



         Agreement,  the Closing  shall be held on the thirtieth day (or if such
         thirtieth  day is not a business  day, the next  business day following
         the thirtieth day) next following the later to occur of:

                           (i) The date on which any necessary determination of 
                  the purchase price of the Partnership Interest to be purchased
                  has been made; or

                           (ii) The date  that  coincides  with the close of the
                  Option Period.

         At the Closing,  although not  necessary  to effect the  transfer,  the
         Retiring Limited Partner shall  concurrently with tender and receipt of
         the applicable  purchase price,  deliver to the purchaser duly executed
         instruments of transfer and  assignment,  assigning good and marketable
         title to the  portion or  portions of the  Retiring  Limited  Partner's
         entire  Partnership  Interest thus  purchased,  free and clear from any
         liens  or  encumbrances  or  rights  of  others  therein.  The  parties
         acknowledge  that occurrence of any of the triggering  events described
         in Article 17.1,  17.2,  17.3,  17.4, 17.5, 17.6 or 17.7 and compliance
         with all the Articles of this  Agreement,  except the  execution of the
         transfer  documents by the Retiring  Partner as provided  above in this
         Article 17.9.1,  are sufficient to effect the complete  transfer of the
         Retiring  Limited  Partner's  interest and the Retiring Limited Partner
         shall  be  deemed  to  consent  to  admission  of the  transferee  as a
         substitute Limited Partner.  Notwithstanding the date of the Closing or
         whether a Closing is  successfully  held, the transfer of a Partnership
         Interest of a Retiring  Limited  Partner shall be deemed to occur as of
         the Valuation Date as defined in Article 17.8.  The deemed  transfer is
         effective  regardless of whether the Retiring  Limited Partner performs
         the duties set forth in this Article 17.9.1.

                  17.9.2  Terms and  Conditions  of  Purchase.  The  Partnership
         Interest of a Limited  Partner shall not be  transferred to any Partner
         unless the  requirements  of Articles 16.2 and 16.4 (b) through (f) are
         satisfied  with  respect to it. The  purchaser  shall be liable for all
         obligations  and  liabilities   connected  with  that  portion  of  the
         Partnership  Interest  transferred  to it  unless  otherwise  agreed in
         writing.


                                                      -22-


<PAGE>



                  18.      SALE,  ASSIGNMENT  OR OTHER  TRANSFER  OF THE GENERAL
                           PARTNER'S INTEREST.

                  18.1  The   General   Partner   may  not   mortgage,   pledge,
hypothecate,  transfer,  sell, assign or otherwise dispose of all or any part of
its interest in the  Partnership,  whether  voluntarily,  by operation of law or
otherwise (the foregoing  actions being  hereafter  collectively  referred to as
"Transfers" or singularly as a "Transfer") except as permitted by this Article.

                  18.2 If the  General  Partner  makes a Transfer  (other than a
mortgage,  pledge or  hypothecation)  of its  general  partner  interest  in the
Partnership pursuant to this Article, it shall be liable for all obligations and
liabilities  incurred  by it as the  General  Partner of the  Partnership  on or
before  the  effective  date of such  Transfer,  but shall not be liable for any
obligations or liabilities of the  Partnership  arising after the effective date
of the Transfer.

                  18.3     No Transfer by the General Partner shall be permitted
unless:

                  (a) Counsel for the Partnership shall have rendered an opinion
         that none of the actions  taken in  connection  with such Transfer will
         cause the Partnership to be classified  other than as a partnership for
         Federal income tax purpose or will cause the termination or dissolution
         of the Partnership under state law; and

                  (b) Such  documents  or  instruments,  in form  and  substance
         satisfactory to counsel for the  Partnership,  shall have been executed
         and  delivered  as may be  required  in the  opinion of counsel for the
         Partnership to effect fully any such Transfer.

                  Notwithstanding the foregoing provisions of this Article 18.3,
the General  Partner may pledge its  interest  in the  Partnership  to any bank,
insurance   company  or  other  financial   institution  to  secure  payment  of
indebtedness.

                  19.      TERMINATION OF THE SERVICES OF THE GENERAL PARTNER.

                  The General  Partner  shall be removed and another  designated
and  substituted  upon (i) the election and consent of a Majority in Interest of
the Limited  Partners  upon the  General  Partner  being  adjudged by a court of
competent  jurisdiction to be liable to the Limited  Partners or the Partnership
for any act of gross negligence or willful  misconduct in the performance of its
duties  under the terms of this  Agreement,  or (ii) the election and consent of
the Limited Partners representing 80% of the aggregate limited partner interests
in the Partnership.  Such consent shall be evidenced by a certificate of removal
signed  by  the  Limited  Partners  constituting  the  requisite  percentage  of
partnership  interests necessary for removal under either proviso (i) or (ii) of
the preceding sentence.  In the event of removal,  the new general partner shall
succeed to all of the powers, privileges and obligations of the General Partner,
and the General  Partner's  interest in the  Partnership  shall become that of a
Limited  Partner,  and the General  Partner shall  maintain its same  Percentage
Interest in the Partnership notwithstanding anything contained in the Act to the
contrary.  In addition,  in the event of removal,  the new general partner shall
take all steps  necessary and  appropriate to prepare and record an amendment to
the  Certificate  of Limited  Partnership  to reflect the removal of the General
Partner and the admission of such new general partner.


                                                      -23-


<PAGE>



                  20.      MANAGEMENT AND OPERATION OF BUSINESS.

                  20.1 All  decisions  with  respect  to the  management  of the
business and affairs of the Partnership shall be made by the General Partner.

                  20.2 The General  Partner shall be under no duty to devote all
of its time to the business of the Partnership,  but shall devote only such time
as it deems  necessary  to conduct the  Partnership  business and to operate and
manage the Partnership in an efficient manner.

                  20.3 The  General  Partner may charge to the  Partnership  all
ordinary and necessary costs and expenses, direct and indirect,  attributable to
the activities,  conduct and management of the business of the Partnership.  The
costs and expenses to be borne by the  Partnership  shall  include,  but are not
limited to, all  expenditures  incurred in acquiring and financing the Equipment
or other Partnership property, legal and accounting fees and expenses,  salaries
of employees of the Partnership,  consulting and quality  assurance fees paid to
independent contractors, insurance premiums and interest.

                  20.4 In addition to, and not in limitation  of, any rights and
powers  covenanted by law or other  provisions of this agreement,  and except as
limited,  restricted or prohibited by the express  provisions of this Agreement,
the General Partner shall have and may exercise on behalf of the Partnership all
powers and rights necessary,  proper,  convenient or advisable to effectuate and
carry out the purposes, business and objectives of the Partnership.  Such powers
shall include, without limitation, the following:

                  (a)      To acquire the initial Prostatron(R) Mobile System;

                  (b) To  exercise  the  option of the  General  Partner  or the
         Partnership  to  purchase  a  Limited  Partner's  Partnership  Interest
         pursuant to Article 17;

                  (c) To determine the travel  itinerary and site  locations for
         the Prostatron(R) Mobile System or other Partnership technology;

                  (d) To borrow money for any Partnership purpose (including the
         acquisition  of the  Additional  Assets)  and,  if security is required
         therefor, to subject to any security device any portion of the property
         for the  Partnership,  to obtain  replacements  of any  other  security
         device, to prepay, in whole or in part,  refinance,  increase,  modify,
         consolidate or extend any encumbrance or other security device;

                  (e) To deposit,  withdraw,  invest, pay, retain (including the
         establishment  of reserves in order to acquire the  Additional  Assets)
         and distribute the  Partnership's  funds in any manner  consistent with
         the provisions of this Agreement;

                  (f)      To institute and defend actions at law or in equity;

                  (g) To enter into and carry out contracts and  agreements  and
         any or all documents and  instruments  and to do any and all such other
         things as may be in

                                                      -24-


<PAGE>



         furtherance of Partnership purposes or necessary or appropriate to the 
         conduct of the Partnership activities;

                  (h)  To   execute,   acknowledge   and  deliver  any  and  all
         instruments  which may be deemed  necessary or convenient to effect the
         foregoing; and

                  (i) To engage or retain one or more persons to perform acts or
         provide  materials  as  may be  required  by  the  Partnership,  at the
         Partnership's  expense,  and to compensate  such person or persons at a
         rate to be set by the General  Partner,  provided that the compensation
         is at the then  prevailing  rate for the type of services and materials
         provided,  or both.  Any person,  whether a Partner,  an Affiliate of a
         Partner or otherwise, including without limitation the General Partner,
         may be employed or engaged by the  Partnership  to render  services and
         provide materials,  including, but not limited to, management services,
         professional   services,   accounting   services,   quality  assessment
         services, legal services,  marketing services,  maintenance services or
         provide materials; and if such person is a Partner or an Affiliate of a
         Partner,  he shall be entitled to, and shall be paid  compensation  for
         said services or materials,  anything in this Agreement to the contrary
         notwithstanding, provided that the compensation to be received for such
         services  or  materials  is  competitive  in price and terms  with then
         prevailing rate for the type of services and/or materials provided. The
         Partnership,  pursuant  to the terms of a  Management  Agreement,  will
         contract with Lithotripters,  Inc., a North Carolina corporation and an
         Affiliate of the General  Partner,  with respect to the supervision and
         coordination  of the  management and  administration  of the day-to-day
         operations of the  Prostatron(R)  Mobile System for a monthly fee equal
         to the greater of 7.5% of Partnership Cash Flow per month or $8,000 per
         month.  All costs  incurred by  Lithotripters,  Inc. in performing  its
         duties as management  agent shall be paid by the Partnership  directly.
         The Partnership may also contract with qualified physicians desiring to
         use the  Prostatron(R)  Mobile  System for the  treatment  of patients.
         Owning an interest in the Partnership shall not be a condition to using
         the Prostatron(R) Mobile System. The General Partner and its Affiliates
         may engage in or possess an interest in other business  ventures of any
         nature and description independently or with others, including, but not
         limited to, the  operation  of a mobile  benign  prostatic  hyperplasia
         treatment unit similar to the Prostatron(R)  Mobile System,  whether or
         not such business  ventures are in direct or indirect  competition with
         the  Partnership,  and neither the  Partnership  nor the Partners shall
         have any right by virtue of this  Agreement in and to said  independent
         ventures or to the income or profits derived therefrom.

                  20.5 Notwithstanding the provisions of Article 20.4 above, the
General  Partner shall have the authority to take the following  actions only if
it first  receives  the prior  written  consent of a Majority in Interest of the
Limited Partners:

                  (a) Offer and sell additional limited partnership interests in
         the Partnership pursuant to a Dilution Offering as described in Article
         7.4 hereof;

                  (b) Institute and carry out any plan providing for the merger,
         consolidation  or sale of  Partnership  Interests or any other  actions
         outlined in Article 16.7 hereof;

                                                      -25-


<PAGE>



                  (c)      Voluntarily dissolve the Partnership as provided in
Article 23 hereof;

                  (d) Acquire (i) additional  Prostatron(R) Mobile Systems, (ii)
         any  other  assets  related  to  the  provision  of  benign   prostatic
         hyperplasia  treatment services, or (iii) any other assets or equipment
         or an interest in another  entity  consistent  with the purposes of the
         Partnership  as provided in Article 4  (collectively,  the  "Additional
         Assets") other than in the ordinary course of business; or

                  (e)  Purchase,  hold,  manage,  lease,  license and dispose of
         Partnership assets (including the Prostatron(R)  Mobile System),  other
         than in the ordinary course of business.

                  20.6 Notwithstanding the provisions of Articles 20.4 and 20.5,
and in  addition  to other  acts  expressly  prohibited  or  restricted  by this
Agreement  or by law,  the General  Partner  shall have no  authority  to act on
behalf of the Partnership in:

                  (a) Doing any act in contravention of this Agreement or the 
         Partnership's Certificate of Limited Partnership;

                  (b) Doing any act which would make it  impossible  to carry on
         the ordinary business of the Partnership;

                  (c)   Confessing  a  judgment   against  the   Partnership  in
         connection with any threatened or pending legal action;

                  (d) Possessing or in any manner dealing with the Partnership's
         property  or   assigning   the  rights  of  the   Partnership   in  the
         Partnership's property for other than Partnership purposes;

                  (e)  Admitting  a person  as a  Limited  Partner  or a General
         Partner except as provided in this Agreement; or

                  (f)  Performing  any act (other  than an act  required by this
         Agreement  or any act  taken  in good  faith  reliance  upon  counsel's
         opinion)  which  would,  at the time  such act  occurred,  subject  any
         Limited Partner to liability as a general partner in any jurisdiction.

                  21.      RESERVES.

                  Subject  to the  consent  requirements  of Article  20.5,  the
General Partner may cause the Partnership to create a reserve account to be used
exclusively for repairs and  acquisition of Additional  Assets and for any other
valid Partnership  purpose.  The Partners,  in accordance with the provisions of
Article 20.5(d), shall determine the amount of payments to such reserve.


                                                      -26-


<PAGE>



                  22.    INDEMNIFICATION AND EXCULPATION OF THE GENERAL PARTNER.

                  22.1 The General  Partner is accountable to the Partnership as
a fiduciary and consequently  must exercise good faith and integrity in handling
Partnership  affairs.  This is a rapidly developing and changing area of the law
and Limited  Partners who have  questions  concerning  the duties of the General
Partner  should  consult  with  their  counsel.  The  General  Partner  and  its
Affiliates  shall have no liability to the  Partnership  which arises out of any
action or  inaction  of the  General  Partner or its  Affiliates  if the General
Partner or its Affiliates, in good faith, determined that such course of conduct
was in the best interest of the  Partnership  and such course of conduct did not
constitute gross negligence or willful  misconduct of the General Partner or its
Affiliates.  The General Partner and its Affiliates  shall be indemnified by the
Partnership  against any losses,  judgments,  liabilities,  expenses and amounts
paid in  settlement  of any  claims  sustained  by them in  connection  with the
Partnership,  provided that the same were not the result of gross  negligence or
willful misconduct on the part of the General Partner or its Affiliates.

                  22.2 The General Partner shall not be liable for the return of
the Capital Contributions of the Limited Partners, and upon dissolution, Limited
Partners shall look solely to the assets of the Partnership.

                  23.      DISSOLUTION OF THE PARTNERSHIP.

                  23.1 The Partnership shall be dissolved and terminated and its
business wound up upon the occurrence of any one of the following events:

                  (a)      The expiration of its term on June 30, 2047;

                  (b) The  filing  by, on  behalf  of, or  against  the  General
         Partner of any  petition or  pleading,  voluntary  or  involuntary,  to
         declare the General  Partner  bankrupt under any bankruptcy law or act,
         or the  commencement  in any  court  of any  proceeding,  voluntary  or
         involuntary,  to declare the General Partner insolvent or unable to pay
         its debts, or the appointment by any court or supervisory  authority of
         a  receiver,  trustee or other  custodian  of the  property,  assets or
         business of the General  Partner or the  assignment by it of all or any
         part of its  property or assets for the benefit of  creditors,  if said
         action,  proceeding  or  appointment  is  not  dismissed,   vacated  or
         otherwise terminated within ninety (90) days of its commencement;

                  (c) The  determination  of the  Partners  in  accordance  with
         Article 20.5(c) that the Partnership should be dissolved;

                  (d) The approval of a plan by the Partners, in accordance with
         Article  20.5(b),  providing for the merger,  consolidation  or sale of
         Partnership Interests or other action as described in Article 16.7.

                  (e) The  election  of the  General  Partner  to  dissolve  the
         Partnership  following the occurrence of an event  described in Article
         17.5;


                                                      -27-


<PAGE>



                  (f)  The  sale,  exchange  or  other  disposition  of  all  or
         substantially  all of the property of the  Partnership  without  making
         provision for the replacement thereof; and

                  (g)   The   dissolution,   retirement,   resignation,   death,
         disability  or legal  incapacity  of a general  partner,  and any other
         event  resulting in the  dissolution or termination of the  Partnership
         under the laws of the State of North Carolina.

                  23.2  Notwithstanding  the  provisions  of Article  23.1,  the
Partnership   shall  not  be  dissolved  and  terminated  upon  the  retirement,
resignation,  bankruptcy,  assignment for the benefit of creditors, dissolution,
death,  disability or legal  incapacity of a general  partner,  and its business
shall continue  pursuant to the terms and conditions of this  Agreement,  if any
general partner or general partners remain  following such event;  provided that
such  remaining  general  partner or general  partners  are hereby  obligated to
continue the business of the  Partnership.  If no general  partner remains after
the  occurrence of such event,  the business of the  Partnership  shall continue
pursuant to the terms and conditions of this  Agreement,  if, within ninety (90)
days after the  occurrence of such event,  a Majority in Interest of the Limited
Partners agree in writing to continue the business of the  Partnership,  and, if
necessary,  to  the  appointment  of one  or  more  persons  or  entities  to be
substituted as the general  partner.  In the event the Limited Partners agree to
continue the  business of the  Partnership,  the new general  partner or general
partners shall succeed to all of the powers,  privileges and  obligations of the
General Partner,  and the General  Partner's  interest in the Partnership  shall
become a  Limited  Partner's  interest  hereunder.  Furthermore,  in the event a
remaining general partner or the Limited Partners,  as the case may be, agree to
continue the  business of the  Partnership  as provided  herein,  the  remaining
general partner or the newly appointed general partner or general  partners,  as
the case may be, shall take all steps  necessary and  appropriate to prepare and
record an amendment to the  Certificate  of Limited  Partnership  to reflect the
continuation  of the  business of the  Partnership  and the  admission  of a new
general partner or general partners, if any.

                  24.      DISTRIBUTION UPON DISSOLUTION.

                  Upon the dissolution and termination of the  Partnership,  the
General Partner or, if there is none, a representative  of the Limited Partners,
shall  cause  the  cancellation  of the  Partnership's  Certificate  of  Limited
Partnership,  shall liquidate the assets of the Partnership, and shall apply and
distribute the proceeds of such liquidation in the following order of priority:

                  (a)  First, to the payment of the debts and liabilities of the
         Partnership, and the expenses of liquidation;

                  (b) Second,  to the creation of any reserves which the General
         Partner  (or the  representatives  of the  Limited  Partners)  may deem
         reasonably  necessary  for the payment of any  contingent or unforeseen
         liabilities or obligations of the Partnership or of the General Partner
         arising out of or in connection  with the business and operation of the
         Partnership; and

                  (c) Third,  the balance,  if any,  shall be distributed to the
         Partners in accordance  with the  Partners'  positive  Capital  Account
         balances  after such  capital  accounts  are  adjusted  as  provided by
         Article 13, and any other adjustments required by

                                                      -28-


<PAGE>



         the Final  Treasury  Regulations  under Section 704(b) of the Code. Any
         general  partner  with  a  negative   Capital  Account   following  the
         distribution of liquidation proceeds or the liquidation of its interest
         must  contribute  to the  Partnership  an amount equal to such negative
         Capital Account on or before the end of the Partnership's  taxable year
         (or, if later,  within ninety days after the date of liquidation).  Any
         capital so contributed  shall be (i) distributed to those Partners with
         positive  Capital  Accounts until such Capital  Accounts are reduced to
         zero, and/or (ii) used to discharge recourse liabilities.

                  25.      BOOKS OF ACCOUNT, RECORDS AND REPORTS.

                  25.1 Proper and complete records and books of account shall be
kept by the General  Partner in which shall be entered fully and  accurately all
transactions  and such other matters relating to the  Partnership's  business as
are usually  entered  into  records and books of account  maintained  by persons
engaged  in  businesses  of a like  character.  The  books  and  records  of the
Partnership  shall be prepared  according to the accounting method determined by
the General Partner.  The Partnership's  fiscal year shall be the calendar year.
The books and  records  shall at all times be  maintained  at the  Partnership's
Records Office and shall be open to the reasonable inspection and examination of
the Partners or their duly authorized representatives during reasonable business
hours.

                  25.2 Within  ninety (90) days after the end of each Year,  the
General  Partner shall send to each person who was a Limited Partner at any time
during such year such tax information,  including,  without limitation,  Federal
tax Schedule K-1, as shall be reasonably  necessary for the  preparation by such
person of his Federal  income tax return.  The  General  Partner  will also make
available to the Limited Partners any other information required by the Act.

                  25.3 The General  Partner shall maintain at the  Partnership's
Records  Office  copies of the  Partnership's  original  Certificate  of Limited
Partnership   and  any  certificate  of  amendment,   restated   certificate  or
certificate of cancellation with respect thereto and such other documents as the
Act shall require.  The General Partner will furnish to any Limited Partner upon
request a copy of the Partnership's  original Certificate of Limited Partnership
and any  certificate  of amendment,  restated  certificate,  or  certificate  of
cancellation, if any.

                  25.4 The General Partner shall, in its sole  discretion,  make
for the  Partnership  any and all  elections  for  federal,  state and local tax
purposes including, without limitation, any election, if permitted by applicable
law, to adjust the basis of the Partnership's property pursuant to Code Sections
754,  734(b) and  743(b),  or  comparable  provisions  of state or local law, in
connection  with  transfers  of  interests in the  Partnership  and  Partnership
Distributions.

                  25.5 The  General  Partner is  designated  as the Tax  Matters
Partner  (as  defined  in  Section  6231 of the Code) and to act in any  similar
capacity  under  state or local law,  and is  authorized  (at the  Partnership's
expense):   (i)  to  represent  the   Partnership  and  Partners  before  taxing
authorities  or courts of competent  jurisdiction  in tax matters  affecting the
Partnership  or  Partners  in their  capacity  as  Partners;  (ii) to extend the
statute of limitations for assessment of tax deficiencies  against Partners with
respect to adjustments to the Partnership's federal, state or local tax returns;
(iii) to execute any agreements or other documents relating to or affecting such
tax matters, including agreements or other documents that bind the Partners with
respect to such tax matters or otherwise affect the rights of the

                                                      -29-


<PAGE>



Partnership and Partners;  and (iv) to expend Partnership funds for professional
services and costs associated  therewith.  The General partner is authorized and
required  to  notify  the  federal,  state  or  local  tax  authorities  of  the
appointment  of a Tax  Matters  Partner  in  the  manner  provided  in  Treasury
Regulations  Section  301.6231(a)(7)-IT,  as modified  from time to time. In its
capacity  as  Tax  Matters  Partner,  the  General  Partner  shall  oversee  the
Partnership  tax affairs in the manner which,  in its best judgment,  are in the
interests of the Partners.

                  26.      NOTICES.

                  All notices under this Agreement shall be in writing and shall
be deemed to have been given when delivered  personally,  or mailed by certified
or registered mail, postage prepaid,  return receipt  requested.  Notices to the
General  Partner  shall be  delivered  at, or mailed to, its  principal  office.
Notices to the  Partnership  shall be delivered  at, or mailed to, its principal
office with a copy to each of its business offices.  Notice to a Limited Partner
shall be  delivered  to such  Limited  Partner,  or mailed  to the last  address
furnished  by him for such  purposes to the General  Partner.  Limited  Partners
shall give  notice of a change of address to the  General  Partner in the manner
provided in this Article.

                  27.      AMENDMENTS.

                  Subject to the  provisions  of Article 28, this  Agreement  is
subject to  amendment  only by  written  consent of the  General  Partner  and a
Majority in Interest of the Limited Partners;  provided, however, the consent of
the Limited Partners shall not be required if such amendments are ministerial in
nature and do not contravene the provisions of Article 28.

                  28.      LIMITATIONS ON AMENDMENTS.

                  Notwithstanding  the provisions of Article 27, no amendment to
this Agreement shall:

                  (a)  Enlarge  the   obligations  of  any  Partner  under  this
         Agreement  or convert the  interest in the  Partnership  of any Limited
         Partner  into the  interest of a general  partner or modify the limited
         liability of any Limited Partner, without the consent of such Partner;

                  (b) Amend the  provisions  of Article 11, 12, 13 or 24 without
         the  approval of the General  Partner and a Majority in Interest of the
         Limited Partners;  provided,  however,  that the General Partner may at
         any time  amend  such  Articles  without  the  consent  of the  Limited
         Partners in order to permit the Partnership allocations to be sustained
         for Federal  income tax  purposes,  but only if such  amendments do not
         materially  affect  adversely the rights and obligations of the Limited
         Partners, in which case such amendments may only be made as provided in
         this Article 28(b); or

                  (c) Amend this Article 28 without the consent of all Partners.





                                                      -30-


<PAGE>



                  29.      MEETINGS, CONSENTS AND VOTING.

                  29.1 A meeting of the  Partnership to consider any matter with
respect to which the  Partners  may vote as set forth in this  Agreement  may be
called  by the  General  Partner  or by  Limited  Partners  who hold  more  than
twenty-five  percent (25%) of the aggregate interests in the Partnership held by
all the Limited Partners.  Upon receipt of a notice requesting a meeting by such
Partner or Partners and stating the purpose of the meeting,  the General Partner
shall, within ten (10) days thereafter, give notice to the Partners of a meeting
of the  Partnership  to be held at a time and place  convenient  to the  Limited
Partners  on a date not  earlier  than  fifteen  (15) days after  receipt by the
General  Partner of the notice  requesting a meeting.  The notice of the meeting
shall set forth the time, date, location and purpose of the meeting.

                  29.2 Any consent of a Partner  required by this  Agreement may
be given as follows:

                  (a) By a written  consent given by the consenting  Partner and
         received by the General  Partner at or prior to the doing of the act or
         thing for which the consent is solicited, or

                  (b) By the affirmative  vote by the consenting  Partner to the
         doing of the act or thing for which the  consent  is  solicited  at any
         meeting  called  pursuant to this Article to consider the doing of such
         act or thing.

                  29.3 When exercising voting rights expressly granted under the
Articles of this  Agreement,  each Partner shall have that number of votes as is
equal to the  Percentage  Interest  of such  Partner  at the  time of the  vote,
multiplied by 100.

                  30.      SUBMISSIONS TO THE LIMITED PARTNERS.

                  The General Partner shall give the Limited  Partners notice of
any proposal or other matter  required by any provision of this  Agreement or by
law to be submitted for consideration and approval of the Limited Partners. Such
notice shall include any  information  required by the relevant  provision or by
law.

                  31.      ADDITIONAL DOCUMENTS.

                  Each  party  hereto  agrees to  execute  and  acknowledge  all
documents and writings which the General Partner may deem necessary or expedient
in the creation of this Partnership and the achievement of its purpose.

                  32.      SURVIVAL OF RIGHTS.

                  Except as herein  otherwise  provided  to the  contrary,  this
Agreement  shall be binding upon and inure to the benefit of the parties hereto,
their successor and assigns.


                                                      -31-


<PAGE>



                  33.      INTERPRETATION AND GOVERNING LAW.

                  When the  context  in which  words are used in this  Agreement
indicates  that such is the intent,  words in the singular  number shall include
the plural and vise versa; in addition,  the masculine  gender shall include the
feminine and neuter  counterparts.  The Article headings or titles and the table
of  contents  shall not define,  limit,  extend or  interpret  the scope of this
Agreement  or any  particular  Article.  This  Agreement  shall be governed  and
construed in  accordance  with the laws of the State of North  Carolina  without
giving effect to the conflicts of laws provisions thereof.

                  34.      SEVERABILITY.

                  If any provision,  sentence,  phrase or word of this Agreement
or the application  thereof to any person or circumstance shall be held invalid,
the remainder of this Agreement, or the application of such provision, sentence,
phrase, or word to persons or circumstances,  other than those as to which it is
held invalid, shall not be affected thereby.

                  35.      AGREEMENT IN COUNTERPARTS.

                  This Agreement may be executed in several  counterparts,  each
of which shall be deemed an original,  but all of which shall constitute one and
the same  instrument.  In  addition,  this  Agreement  may contain more than one
counterpart  of the  signature  page and this  Agreement  may be executed by the
affixing of the  signatures  of each of the Partners to one of such  counterpart
signature  pages;  all of such signature  pages shall be read as though one, and
they  shall have the same  force and  effect as though  all of the  signers  had
signed a single signature page.

                  36.      THIRD PARTIES.

                  The agreements, covenants and representations contained herein
are for the benefit of the parties  hereto  inter se and are not for the benefit
of any  third  parties  including,  without  limitation,  any  creditors  of the
Partnership.

                  37.      POWER OF ATTORNEY.

                  Each Limited  Partner hereby makes,  constitutes  and appoints
Dr.  Joseph  Jenkins  and Dr.  Dan A.  Myers,  severally,  with  full  power  of
substitution,  his true and lawful  attorneys-in-fact,  for him and in his name,
place and stead and for his use and  benefit to sign and  acknowledge,  file and
record,  any  amendments  hereto among the  Partners for the further  purpose of
executing and filing on behalf of each Limited Partner, any and all certificates
of  limited   partnership  or  other  documents   necessary  to  constitute  the
Partnership or to effect the continuation of the  Partnership,  the admission or
withdrawal of a general partner or a limited partner,  the  qualification of the
Partnership in a foreign jurisdiction (or amendment to such qualification),  the
admission of substitute  Limited  Partners or the  dissolution or termination of
the   Partnership,   provided   such   continuation,    admission,   withdrawal,
qualification,  or dissolution  and termination are in accordance with the terms
of this Agreement.

                  The foregoing power of attorney is a special power of attorney
coupled with an interest,  is  irrevocable  and shall survive the death or legal
incapacity of each Limited Partner. It may be exercised

                                                      -32-


<PAGE>



by any one of said  attorneys by listing all of the Limited  Partners  executing
any  instrument  over the  signature of the  attorney-in-fact  acting for all of
them.  The power of attorney  shall  survive the delivery of an  assignment by a
Limited Partner of the whole or any portion of his Unit. In those cases in which
the assignee of, or the successor to, a Limited  Partner  owning a Unit has been
approved by the  Partners  for  admission  to the  Partnership  as a  substitute
Limited  Partner,  the power of attorney  shall  survive for the sole purpose of
enabling the General  Partner to execute,  acknowledge  and file any  instrument
necessary to effect such substitution.

                  This power of attorney shall not be affected by the subsequent
incapacity or mental incompetence of any Limited Partner.

                  38.      ARBITRATION.

                  Any  dispute  arising  out  of  or  in  connection  with  this
Agreement  or the breach  thereof  shall be decided by  arbitration  in Raleigh,
North  Carolina in accordance  with the then  effective  commercial  arbitration
rules of the  American  Arbitration  Association,  and  judgment  thereof may be
entered in any court having jurisdiction thereof.

                  39.      CREDITORS.

                  None of the  provisions  of this  Agreement  shall  be for the
benefit of or enforceable by any creditors of the Partnership.



                                                      -33-


<PAGE>



                  IN WITNESS  WHEREOF,  the parties have executed this Agreement
of Limited Partnership as of the day and year first above written.

                                   GENERAL PARTNER:

                                   PROSTATHERAPIES, INC., a Delaware corporation


                                    By:      /s/ Dan A. Myers
                                             --------------------
                                             Dan A. Myers, M.D., President

ATTEST:

Philip J. Gallina
- -------------------                                     [CORPORATE SEAL]
Secretary


                            INITIAL LIMITED PARTNER:

                                    /s/ Dan A. Myers
                                    ---------------------------------------
                                    Dan A. Myers, M.D.


STATE OF NORTH CAROLINA                     )
                                            )
COUNTY OF CUMBERLAND                        )

                  On this  14th  day of  August,  1997,  before  me, the
undersigned  Notary  Public in and for the County of  Cumberland in the State of
North Carolina, personally came Dan A. Myers, M.D., who, being by me duly sworn,
said that he is President of Prostatherapies,  Inc., the sole general partner of
North Carolina Prostatherapy Limited Partnership I, that the seal affixed to the
foregoing  instrument in writing is the corporate seal of the  corporation,  and
that said  writing  was  signed,  sworn to,  and sealed by him in behalf of said
corporation  by its  authority  duly  given.  And the said Dan A.  Myers,  M.D.,
further certified that the facts set forth in said writing are true and correct,
and acknowledged said instrument to be the act and deed of said corporation.

                  WITNESS my hand and notarial seal.

                                    /s/ Ricarda Kelly
                                    ------------------------------------------

                                    Notary Public
My commission expires:
January 8, 2002
- ---------------------------



                                                      -34-


<PAGE>



STATE OF NORTH CAROLINA                     )
                                            )
COUNTY OF CUMBERLAND                        )


                  I, Ricarda Kelly, a notary public, do hereby
certify that Dan A. Myers, M.D.  personally appeared before me this 14th day of
August, 1997 and acknowledged and swore to the due execution of the foregoing
Limited Partnership Agreement in his capacity as the initial limited partner.



                                    /s/ Ricarda Kelly
                                    -------------------------------------------

                                    Notary Public

My commission expires:
January 8, 2002
- ---------------------------


                                                      -35-


<PAGE>



                           COUNTERPART SIGNATURE PAGE


                  By signing this  Counterpart  Signature  Page, the undersigned
acknowledges  his or  her  acceptance  of  that  certain  Agreement  of  Limited
Partnership of North Carolina  Prostatherapy  Limited  Partnership I, and his or
her intention to be legally bound thereby.

                  Dated this _________ day of ___________________, 1997.



                                    -------------------------------------------

                                    Signature



                                    -------------------------------------------

                                    Printed Name




STATE OF _______________                    )
                                            )
COUNTY OF _____________                     )


                  BEFORE ME, the undersigned  Notary Public in and for the State
and County set forth  above,  on the  _______ day of  __________________,  1997,
personally  appeared  ___________________,  and,  being by me first duly  sworn,
stated that (s)he  signed this  Counterpart  Signature  Page for the purpose set
forth above and that the statements contained therein are true.




                                    -------------------------------------------

                                    Signature of Notary Public



                                    -------------------------------------------

                                    Printed Name of Notary

My Commission Expires:

- ---------------------------

[SEAL]

                                                      -36-


<PAGE>



 

                                   SCHEDULE A

                        Schedule of Partnership Interests

               NORTH CAROLINA PROSTATHERAPY LIMITED PARTNERSHIP I

      CONTRIBUTIONS OF CAPITAL TO THE PARTNERSHIP AND PERCENTAGE INTERESTS

                                                Cash               Percentage
                   General Partner           Contribution            Interest

              Prostatherapies, Inc.         $200,856.25                20%
              2008 Litho Place
              Fayetteville, NC  28304

              Limited Partners

              Preston Bradshaw                 2,600.00                   .250
              Carolina Lithotripsy           564,662.50                 56.750
              Michael Crawford                 2,600.00                   .250
              G. Mark Doyle                    7,800.00                   .750
              Richard Gavigan                  5,200.00                   .500
              Benjamin Hines                   5,200.00                   .500
              Edward Janosko                   5,200.00                   .500
              Clifford Johnson                  6500.00                   .625
              John Kaspar                      2,600.00                   .250
              Art Klose                       10,400.00                  1.000
              John Lasater                    10,400.00                  1.000
              C. Rodney Lenahan               10,400.00                  1.000
              Robert Lippitt                  10,400.00                  1.000
              Michael Lobos                    5,200.00                   .500
              John Lovett                     10,400.00                  1.000
              Louis Marchetti                 10,400.00                  1.000
              George Mozingo                   5,200.00                   .500
              Gregory Murphy                   5,200.00                   .500
              Richard Mynatt                  13,000.00                  1.250
              Robert Nichols                   5,200.00                   .500
              Prostatherapies, Inc.           67,162.50                  6.750
              James Rounder                    2,600.00                   .250
              John Seddon                      5,200.00                   .500
              Kasturi Shanker                  3,900.00                   .375
              Bernard Stanfield                2,600.00                   .250
              Thomas Stewart                  10,400.00                  1.000
              William Turner                   5,200.00                   .500
              David Varney                     5,200.00                   .500
              Edward Whitesides                2,600.00                   .250

              TOTAL:                     $ 1,004,281.25                100 %
                                         ==============                ======




<PAGE>







                                                    
                                                                    EXHIBIT 21.1
                  SUBSIDIARIES OF PRIME MEDICAL SERVICES, INC.
                              AS OF MARCH 20, 1998

    EXHIBIT 21.1
    Name of Subsidiary                           State of Incorporation
    -------------------                          --------------------
    Prime Medical Operating, Inc.                Delaware

    Prime Management, Inc.                       Nevada

    Prime Cardiac Rehabilitation Services, Inc.  Delaware

    Prime Diagnostic Services, Inc.              Delaware

    Prime Lithotripsy Services, Inc.             New York

    Prime Kidney Stone Treatment, Inc.           New Jersey

    Prime Diagnostic Corp. of Florida            Delaware

    Prime Lithotripter Operations, Inc.          New York

    Prime Practice Management, Inc.              New York

    Texas Litho, Inc.                            Delaware

    R.R. Litho, Inc.                             Delaware

    Ohio Litho, Inc.                             Delaware

    Alabama Renal Stone Institute, Inc.          Alabama

    Sun Medical Technologies, Inc.               California

    Sun Acquisition, Inc.                        California

    Lithotripters, Inc.                          North Carolina

    FastStart, Inc.                              North Carolina

    National Lithotripters Association, Inc.     North Carolina

    Prostatherapies, Inc                         Delaware

    MedTech Investments, Inc.                    North Carolina

    Executive Medical Enterprises, Inc.          Delaware






                          INDEPENDENT AUDITORS' CONSENT
              ----------------------------------------------------


     We consent to  incorporation  by reference in the  registration  statements
(No.  33- 70478) on Form S-8 and (No.  333-12893)  on Form S-3 of Prime  Medical
Services,  Inc. of our report dated  February 27, 1998,  except Note N, to which
the date is March 27, 1998, relating to the consolidated balance sheets of Prime
Medical  Services,  Inc. and  subsidiaries as of December 31, 1997 and 1996, and
the related consolidated  statements of income,  stockholders'  equity, and cash
flows for each of the years in the  three-year  period ended  December 31, 1997,
which  report  appears  in the  Annual  Report  on Form  10-K of  Prime  Medical
Services, Inc. for the year ended December 31, 1997.


/s/ KPMG Peat Marwick, LLP
- --------------------------
Austin, Texas
March 30, 1998

<TABLE> <S> <C>


<ARTICLE>                     5
<LEGEND>
This schedule contains summary financial information extracted from the
December 31, 1997 Form 10-K and is qualified in its entirety by reference to 
such financial statements.
</LEGEND>
<MULTIPLIER>                                   1,000
       
<S>                            <C>               <C>
<PERIOD-TYPE>                   12-mos           12-mos
<FISCAL-YEAR-END>               DEC-31-1997      DEC-31-1996
<PERIOD-START>                  JAN-01-1997      JAN-01-1996
<PERIOD-END>                    DEC-31-1997      DEC-31-1996
<CASH>                          23,770             20,096 
<SECURITIES>                         0                  0
<RECEIVABLES>                   19,387             16,346
<ALLOWANCES>                       811                335
<INVENTORY>                          0                  0
<CURRENT-ASSETS>                47,542             40,073   
<PP&E>                          27,225             22,452
<DEPRECIATION>                   7,518              7,122
<TOTAL-ASSETS>                 225,826            197,753
<CURRENT-LIABILITIES>           37,383             31,555
<BONDS>                              0                  0
                0                  0
                          0                  0
<COMMON>                           193                191
<OTHER-SE>                      91,871             76,236
<TOTAL-LIABILITY-AND-EQUITY>   225,826            197,753
<SALES>                              0                  0
<TOTAL-REVENUES>                95,979             72,404
<CGS>                                0                  0
<TOTAL-COSTS>                   33,285             24,799
<OTHER-EXPENSES>                 9,911              7,455
<LOSS-PROVISION>                     0                  0
<INTEREST-EXPENSE>               7,477              5,977
<INCOME-PRETAX>                 20,651             10,957
<INCOME-TAX>                     5,795              1,996
<INCOME-CONTINUING>             14,856              8,961
<DISCONTINUED>                       0                  0
<EXTRAORDINARY>                      0                  0
<CHANGES>                            0                  0
<NET-INCOME>                    14,856              8,961
<EPS-PRIMARY>                     0.77               0.51  
<EPS-DILUTED>                     0.76               0.49
        
<FN>
NOTE: Due to the change in computing EPS per FASB No. 128, the tags per the 
FDS schedule will correspond to FASB No. 128 as follows: 
     FDS tag                  FASB No. 128
     EPS - Primary            EPS - Basic
     EPS - Diluted            EPS - Diluted
In addition, the EPS amounts for the year ended December 31, 1996 presented 
above have been restated to reflect the changes promulgated by FASB No. 128.
No other amounts for 1996 presented above have been restated.
</FN>

</TABLE>


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