<PAGE>
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Schedule 13D
Under the Securities Exchange Act of 1934
(Amendment No. 3)*
DIAMETRICS MEDICAL, INC.
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(Name of Issuer)
Common Stock, $.01 par value
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(Title of Class of Securities)
252532 10 6
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(CUSIP Number)
Mindy C. Sircus, Esq., Neal, Gerber & Eisenberg, 2 North LaSalle Street,
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Chicago, Illinois 60602, (312) 269-8000
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(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)
January 9, 1998
-----------------------------------
(Date of Event which Requires
Filing of this Statement)
If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following box [_].
Note: Six copies of this Statement, including all exhibits, should be filed
with the Commission. See Rule 13d-1(a) for other parties to whom copies are to
be sent.
* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter disclosure
provided in a prior cover page.
The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
(Continued on following page(s))
Page 1 of 7 Pages
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13D
- ----------------------- ---------------------
CUSIP NO. PAGE 2 OF 7 PAGES
- ----------------------- ---------------------
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NAME OF REPORTING PERSON
1 S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
AMARFOUR, L.L.C.
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CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
2 (a) [_]
(b) [_]
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SEC USE ONLY
3
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SOURCE OF FUNDS*
4
00
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CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
TO ITEMS 2(d) or 2(e) [_]
5
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CITIZENSHIP OR PLACE OF ORGANIZATION
6
Delaware
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SOLE VOTING POWER
7
NUMBER OF 1,789,100 shares of Common Stock
SHARES -----------------------------------------------------------
SHARED VOTING POWER
BENEFICIALLY 8
0
OWNED BY
-----------------------------------------------------------
EACH SOLE DISPOSITIVE POWER
9
REPORTING 1,789,100 shares of Common Stock
PERSON -----------------------------------------------------------
SHARED DISPOSITIVE POWER
WITH 10
0
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AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
11
1,789,100 shares of Common Stock
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CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES*
12
See Item 5. [X]
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PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
13
Approximately 8.6%
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TYPE OF REPORTING PERSON*
14
00
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*SEE INSTRUCTIONS BEFORE FILLING OUT!
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ONLY THOSE ITEMS AMENDED
------------------------
ARE REPORTED HEREIN.
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Capitalized terms not otherwise defined herein are deemed to have the same
meanings as ascribed thereto in the initial Schedule 13 D.
Item 3. Source and Amount of Funds or Other Consideration.
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Page 3 of 7
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In addition to the purchases of Common Stock, Preferred Stock and Warrants
which Amarfour previously reported, from January 5, 1998 through January 9,
1998, Amarfour purchased an aggregate of 232,500 shares of Common Stock on the
open market in a series of four transactions. Amarfour borrowed the $1,431,407
aggregate purchase price for such shares of Common Stock from Diversified
Capital, L.P., an associated entity. This loan is payable on demand and bears
interest at prime.
Page 4 of 7
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Item 5. Interest in Securities of the Issuer.
------------------------------------
(a)-(b) For the purpose of Rule 13d-3 promulgated under the Exchange
Act, as of the date hereof, Amarfour beneficially owns, and has sole power to
vote and to dispose of, 1,789,100 shares of Common Stock, representing
approximately 8.6% of the outstanding Common Stock of the Issuer.
As previously reported by Amarfour, an affiliate of Amarfour owns
approximately a 5.57% limited partnership interest in Frazier Healthcare
Investments, L.P. On July 28, 1997, Frazier Healthcare Investments, L.P.
effected a distribution of shares of the Issuer's Common Stock to its partners.
As a result of such distribution, the afore-mentioned affiliate received 25,319
shares of Common Stock of the Issuer (or approximately .12% of the outstanding
Common Stock of the Issuer). Amarfour disclaims beneficial ownership of the
Issuer's securities, if any, owned by each of such affiliate, Frazier Healthcare
Investments, L.P., Frazier & Company, L.P. and Frazier Management, L.L.C. None
of such shares are included herein.
(c) As disclosed in Item 3 above, Amarfour purchased an aggregate of
232,500 shares of Common Stock on the open market in a series of four
transactions undertaken from January 5, 1998 through January 9, 1998 for an
aggregate purchase price of $1,431,407, as follows:
<TABLE>
<CAPTION>
Number of Price Per
Date Shares Share
---- --------- ---------
<S> <C> <C>
1/5/98 15,000 $6.0938
1/6/98 30,000 $6.1250
1/7/98 125,000 $6.1250
1/9/98 62,500 $6.2500
Total 232,500 $1,431,407
</TABLE>
During the past 60 days, neither Amarfour, nor, to the best knowledge of
Amarfour, any of the persons identified in Appendix A hereof, have effected any
other transactions in the Common Stock which have not been previously reported.
Page 5 of 7
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Item 7. Material to be Filed as Exhibits.
--------------------------------
None
Page 6 of 7
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SIGNATURES
After reasonable inquiry and to the best knowledge and belief of the
undersigned, the undersigned certifies that the information set forth in this
statement is true, complete and correct.
Date: January 21, 1998 AMARFOUR, L.L.C., a Delaware limited
liability company
By: AMARILLO RESIDUARY TRUST NO. 1, a member
By: /s/ Marshall E. Eisenberg
-------------------------------------------
Marshall E. Eisenberg, not individually,
but solely as Trustee of Amarillo Residuary
Trust No. 1
Page 7 of 7
