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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                  SCHEDULE 13D/A
                               (AMENDMENT NO. 2)

           INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO
                   RULE 13D-1(a) AND AMENDMENTS THERETO FILED
                           PURSUANT TO RULE 13D-2(a).

                            DIAMETRICS MEDICAL, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                     COMMON STOCK, PAR VALUE $0.01 PER SHARE
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   252532 10 6
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                                 WARREN T. OATES
                  PHILIPS ELECTRONICS NORTH AMERICA CORPORATION
                           1251 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10020
--------------------------------------------------------------------------------
            (Name, Address and Telephone Number of Person Authorized
                     to Receive Notices and Communications)

                        APRIL 10, 2003 AND AUGUST 4, 2003
--------------------------------------------------------------------------------
             (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(e), 13d-1(f) or 13d-1(g), check the following box
[_].

NOTE:  Schedules  filed in paper format shall include a signed original and five
copies of the  schedule,  including  all  exhibits.  See Rule 13d-7(b) 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
disclosures 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 (the "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).

         PERSONS WHO RESPOND TO THE COLLECTION OF INFORMATION CONTAINED
         IN THIS  FORM ARE NOT  REQUIRED  TO  RESPOND  UNLESS  THE FORM
         DISPLAYS A CURRENTLY VALID OMB CONTROL NUMBER.

SEC 1746 (03-00)



                                  SCHEDULE 13D/A

--------------------------------------------------------------------------------
CUSIP No. 252532 10 6                                       Page 2 of 7 Pages
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
1    NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

     KONINKLIJKE PHILIPS ELECTRONICS N.V.
--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                   (a) [_]
                                                                         (b) [X]
--------------------------------------------------------------------------------
3    SEC USE ONLY
--------------------------------------------------------------------------------
4    SOURCE OF FUNDS*

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) OR 2(e)                                          [_]
--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     THE NETHERLANDS
--------------------------------------------------------------------------------
                  7    SOLE VOTING POWER

                       1,357,143
 NUMBER OF        --------------------------------------------------------------
  SHARES          8    SHARED VOTING POWER
BENEFICIALLY
 OWNED BY              0
   EACH           --------------------------------------------------------------
 REPORTING        9    SOLE DISPOSITIVE POWER
  PERSON
   WITH                1,357,143
                  --------------------------------------------------------------
                  10   SHARED DISPOSITIVE POWER

                       0
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,357,143
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES*                                                         [_]
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     3.90%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     CO/HC
--------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!
          INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
       (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION




                                  SCHEDULE 13D/A

--------------------------------------------------------------------------------
CUSIP No. 252532 10 6                                       Page 3 of 7 Pages
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
1    NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

     PHILIPS HOLDING USA INC.
--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                   (a) [_]
                                                                         (b) [X]
--------------------------------------------------------------------------------
3    SEC USE ONLY
--------------------------------------------------------------------------------
4    SOURCE OF FUNDS*

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) OR 2(e)                                          [_]
--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     DELAWARE
--------------------------------------------------------------------------------
                  7    SOLE VOTING POWER

                       1,357,143
 NUMBER OF        --------------------------------------------------------------
  SHARES          8    SHARED VOTING POWER
BENEFICIALLY
 OWNED BY              0
   EACH           --------------------------------------------------------------
 REPORTING        9    SOLE DISPOSITIVE POWER
  PERSON
   WITH                1,357,143
                  --------------------------------------------------------------
                  10   SHARED DISPOSITIVE POWER

                       0
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,357,143
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES*                                                         [_]
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     3.90%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     CO/HC
--------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!
          INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
       (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION




                                  SCHEDULE 13D/A

--------------------------------------------------------------------------------
CUSIP No. 252532 10 6                                       Page 4 of 7 Pages
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
1    NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

     PHILIPS ELECTRONICS NORTH AMERICA CORPORATION
--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                   (a) [_]
                                                                         (b) [X]
--------------------------------------------------------------------------------
3    SEC USE ONLY
--------------------------------------------------------------------------------
4    SOURCE OF FUNDS*

     WC
--------------------------------------------------------------------------------
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) OR 2(e)                                          [_]
--------------------------------------------------------------------------------
6    CITIZENSHIP OR PLACE OF ORGANIZATION

     DELAWARE
--------------------------------------------------------------------------------
                  7    SOLE VOTING POWER

                       1,357,143
 NUMBER OF        --------------------------------------------------------------
  SHARES          8    SHARED VOTING POWER
BENEFICIALLY
 OWNED BY              0
   EACH           --------------------------------------------------------------
 REPORTING        9    SOLE DISPOSITIVE POWER
  PERSON
   WITH                1,357,143
                  --------------------------------------------------------------
                  10   SHARED DISPOSITIVE POWER

                       0
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,357,143
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES*                                                         [_]
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     3.90%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     CO/HC
--------------------------------------------------------------------------------

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!
          INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
       (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION




         This Amendment No. 2 ("Amendment No. 2") to the statement on Schedule
13D, as amended (the "Schedule 13D"), previously filed by Koninklijke Philips
Electronics N.V. ("KPENV"), Philips Holding USA Inc. ("PHUSA") and Philips
Electronics North America Corporation ("PENAC" and, collectively with KPENV and
PHUSA, the "Reporting Persons") with respect to the shares of Common Stock,
$0.01 par value per share (the "Shares"), of Diametrics Medical, Inc., a
Minnesota corporation ("Diametrics"), hereby amends and supplements the Schedule
13D to revise the exhibit index, exhibit 2 (the Amendment to Manufacturing and
Distribution Agreement, dated April 10, 2003, between Diametrics and Philips
Medical Systems North America Company ("Philips Medical Systems"), a division of
PENAC) and exhibit 3 (the Portal Manufacturing Agreement, dated April 10, 2003,
between Diametrics and Philips Medical Systems) to the Schedule 13D to indicate
that certain portions of the exhibits have been omitted based upon a request for
confidential treatment and that unredacted copies of the exhibits have been
filed with the Securities and Exchange Commission (the "Commission"). In
addition, this Amendment No. 2 updates Item 5(a) of the Schedule 13D to make
current the percentage ownership interests held by each of the Reporting Persons
and Item 5(e) to indicate that as of August 4, 2003 each of the Reporting
Persons ceased to be the beneficial owner of more than five percent of the
Shares. Except as amended and supplemented hereby, the Schedule 13D previously
filed with respect to the Shares remains in full force and effect. Defined terms
used herein and not defined shall have the meaning ascribed to them in the
Schedule 13D.

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER.

         (a) The percentage interest held by each Reporting Person presented
below is based on the number of Shares reported in Diametrics' Revised
Preliminary Proxy Statement on Schedule 14A, filed on July 29, 2004, to be
outstanding as of July 20, 2004 (the "Outstanding Shares").

         PENAC is the direct beneficial owner of 1,357,143 Shares, which figure
represents approximately 3.90% of the Outstanding Shares.

         PHUSA may be deemed to beneficially own 1,357,143 Shares, which figure
represents approximately 3.90% of the Outstanding Shares.

         KPENV may be deemed to beneficially own 1,357,143 Shares, which figure
represents approximately 3.90% of the Outstanding Shares.

         None of the Reporting Persons or, to the best knowledge and belief of
the Reporting Persons, any of the persons listed on Schedules I, II or III
hereto beneficially owns any Shares other than as set forth herein.

         (b) As of the August 4, 2003, the expiration date of the warrant held
by PENAC to purchase from Diametrics 456,381 Shares, each of the Reporting
Persons ceased to be the beneficial owner of more than five percent of the
Shares.


                               Page 5 of 7 Pages




ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS.

Exhibit No.         Exhibit Description
-----------         -------------------

     1.             Joint Filing Agreement, dated as of March 21, 2003, among
                    the Reporting Persons (incorporated herein by reference to
                    Exhibit 1 of the Schedule 13D filed by the Reporting Persons
                    on March 21, 2003).

     2.             Amendment to Manufacturing and Distribution Agreement, dated
                    April 10, 2003, between Diametrics and Philips Medical
                    Systems.*

     3.             Portal Manufacturing Agreement, dated April 10, 2003,
                    between Diametrics and Philips Medical Systems.*

--------------------

*    Certain portions of this exhibit have been omitted based upon a request for
     confidential treatment filed with the Commission. An unredacted copy of
     this exhibit has been filed with the Commission.



                               Page 6 of 7 Pages





                                    SIGNATURE

         After reasonable inquiry and to the best of our knowledge and belief,
we certify that the information set forth in this statement is true, complete
and correct.


Date: August 3, 2004                       KONINKLIJKE PHILIPS ELECTRONICS N.V.


                                           By: /s/ Eric Coutinho
                                              ----------------------------------
                                              Name:  Eric Coutinho
                                              Title: Authorized Signatory



                                           PHILIPS HOLDING USA INC.


                                           By: /s/ Sies W. Plokker
                                              ----------------------------------
                                              Name:  Sies W. Plokker
                                              Title: Senior Vice President


                                           PHILIPS ELECTRONICS NORTH AMERICA
                                           CORPORATION


                                           By: /s/ Sies W. Plokker
                                              ----------------------------------
                                              Name:  Sies W. Plokker
                                              Title: Senior Vice President




                               Page 7 of 7 Pages