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                                                                    Exhibit 10.1

                           DIAMETRICS MEDICAL, INC.
                             AMENDED AND RESTATED
                            1990 STOCK OPTION PLAN
                           (as amended May 23, 2001)

1.   Purpose of Plan.
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     This Plan shall be known as the "DIAMETRICS MEDICAL, INC. 1990 STOCK OPTION
PLAN" and is hereinafter referred to as the "Plan." The purpose of the Plan is
to aid in maintaining and developing personnel capable of assuring the future
success of Diametrics Medical, Inc., a Minnesota corporation (the "Company"), to
offer such personnel additional incentives to put forth maximum efforts for the
success of the business, and to afford them an opportunity to acquire a
proprietary interest in the Company through stock options and other long-term
incentive awards as provided herein. Options granted under this Plan may be
either incentive stock options ("Incentive Stock Options") within the meaning of
Section 422 of the Internal Revenue Code of 1986 (the "Code"), or options which
do not qualify as Incentive Stock Options. Awards granted under this Plan shall
be SARs, restricted stock or performance awards as hereinafter described.

2.   Stock Subject to Plan.
--------------------------

     Subject to the provisions of Section 15 hereof, the stock to be subject to
options or other awards under the Plan shall be the Company's authorized but
unissued shares of Common Stock, par value $.01 per share. Such shares may be
either authorized but unissued shares, or issued shares which have been
reacquired by the Company. Subject to adjustment as provided in Section 15
hereof, the maximum number of shares on which options may be exercised or other
awards issued under this Plan shall be 4,450,000 shares. If an option or award
under the Plan expires, or for any reason is terminated or unexercised with
respect to any shares, such shares shall again be available for options or
awards thereafter granted during the term of the Plan.

3.   Administration of Plan.
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     (a)  The Plan shall be administered by a committee (the "Committee") of two
or more members of the Board of Directors of the Company, none of whom shall be
officers or employees of the Company and all of whom shall be "disinterested
persons" with respect to the Plan within the meaning of Rule 16b-3 under the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), or any
successor rule or regulation thereto. The members of any such committee shall be
appointed by and serve at the pleasure of the Board of Directors.

     (b)  The Committee shall have plenary authority in its discretion, but
subject to the express provisions of the Plan: (i) to determine the purchase
price of the Common Stock covered by each option or award, (ii) to determine the
employees to whom and the time or times at which such options and awards shall
be granted and the number of shares to be subject to each, (iii) to

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determine the form of payment to be made upon the exercise of an SAR or in
connection with performance awards, either cash, Common Stock of the Company or
a combination thereof, (iv) to determine the terms of exercise of each option
and award, (v) to accelerate the time at which all or any part of an option or
award may be exercised, (vi) to amend or modify the terms of any option or award
with the consent of the optionee, (vii) to interpret the Plan, (viii) to
prescribe, amend and rescind rules and regulations relating to the Plan, (ix) to
determine the terms and provisions of each option and award agreement under the
Plan (which agreements need not be identical), including the designation of
those options intended to be Incentive Stock Options, and (x) to make all other
determinations necessary or advisable for the administration of the Plan,
subject to the exclusive authority of the Board of Directors under Section 16
herein to amend or terminate the Plan.

     (c)  The Committee shall select one of its members as its Chairman and
shall hold its meetings at such times and places as it may determine. A majority
of its members shall constitute a quorum, provided that if the Committee is
comprised of no more than two members, all of its members must be present to
constitute a quorum. All determinations of the Committee shall be made by not
less than a majority of its members, provided that if the Committee is comprised
of no more than two members, such determinations may not be made by less than
all of its members. Any decision or determination reduced to writing and signed
by all of the members of the Committee shall be fully effective as if it had
been made by a majority vote at a meeting duly called and held. The grant of an
option or award shall be effective only if a written agreement shall have been
duly executed and delivered by and on behalf of the Company following such
grant. The Committee may appoint a Secretary and may make such rules and
regulations for the conduct of business as it shall deem advisable.

     (d)  The Chief Executive Officer of the Company shall have the authority,
as granted by the Committee pursuant to clause (ix) of subsection (b) of this
Section 3, to grant, pursuant to the Plan, options or other awards to eligible
persons who are not considered by the Company as its officers or directors for
purposes of Section 16 of the Securities Exchange Act of 1934, as amended. The
Chief Executive Officer of the Company shall provide information as to any
grants made pursuant to this subsection to the Committee at their next meeting.

4.   Eligibility.
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     Incentive Stock Options may only be granted under this Plan to any full or
part-time employee (which term as used herein includes, but is not limited to,
officers and directors who are also employees) of the Company and of its present
and future subsidiary corporations within the meaning of Section 424(f) of the
Code (herein called "subsidiaries"). Full or part-time employees, consultants or
independent contractors to the Company or one of its subsidiaries shall be
eligible to receive options which do not qualify as Incentive Stock Options and
awards. In determining the persons to whom options and awards shall be granted
and the number of shares subject to each, the Committee may take into account
the nature of services rendered by the respective employees or consultant their
present and potential contributions to the success of the Company and such other
factors as the Committee in its discretion shall deem relevant. A person

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who has been granted an option or award under this Plan may be granted
additional options or awards under the Plan if the Committee shall so determine;
provided, however, that for Incentive Stock Options granted after December 31,
1986, to the extent the aggregate fair market value (determined at the time the
Incentive Stock Option is granted) of the Common Stock with respect to which all
Incentive Stock Options are exercisable for the first time by an employee during
any calendar year (under all plans described in subsection (d) of Section 422 of
the Code of his employer corporation and its parent and subsidiary corporations)
exceeds $100,000, such options shall be treated as options which do not qualify
as Incentive Stock Options. Nothing in the Plan or in any agreement thereunder
shall confer on any employee any right to continue in the employ of the Company
or any of its subsidiaries or affect, in any way, the right of the Company or
any of its subsidiaries to terminate his or her employment at any time.

5.   Price.
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     The option price for all Incentive Stock Options granted under the Plan
shall be determined by the Committee but shall not be less than 100% of the fair
market value of the Common Stock at the date of grant of such option. The option
price for options granted under the Plan which do not qualify as Incentive Stock
Options and, if applicable, the price for all awards shall also be determined by
the Committee. For purposes of the preceding sentence and for all other
valuation purposes under the Plan, the fair market value of shares of Common
Stock shall be (i) the closing price of the Common Stock as reported for
composite transactions if the Common Stock is then traded on a national
securities exchange, (ii) the last sale price if the Common Stock is then quoted
on the NASDAQ National Market System, or (iii) the average of the closing
representative bid and asked prices of the Common Stock as reported on NASDAQ on
the date as of which the fair market value is being determined. If on the date
of grant of any option or award hereunder the Common Stock is not traded on an
established securities market, the Committee shall make a good faith attempt to
satisfy the requirements of this Section 5 and in connection therewith shall
take such action as it deems necessary or advisable.

6.   Term.
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     Each option and award and all rights and obligations thereunder shall
expire on the date determined by the Committee and specified in the option or
award agreement. The Committee shall be under no duty to provide terms of like
duration for options or awards granted under the Plan, but the term of an
Incentive Stock Option may not extend more than ten (10) years from the date of
grant of such option and the term of options granted under the Plan which do not
qualify as Incentive Stock Options may not extend more than fifteen (15) years
from the date of granting of such option.

7.   Exercise of Option or Award.
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     (a)  The Committee shall have full and complete authority to determine
whether an option or award will be exercisable in full at any time or from time
to time during the term thereof, or to provide for the exercise thereof in such
installments, upon the occurrence of such

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events (such as termination of employment for any reason) and at such times
during the term of the option as the Committee may determine and specify in the
option or award agreement.

     (b)  The exercise of any option or award granted hereunder shall only be
effective at such time that the sale of Common Stock pursuant to such exercise
will not violate any state or federal securities or other laws. Only to the
extent required in order to comply with Rule 16b-3 under the Exchange Act, in
the case of an option or other award granted to a person considered by the
Company as one of its officers or directors for purposes of Section 16 of the
Exchange Act, the terms of the option or other award will require that such
shares are not disposed of by such officer or director for a period of at least
six months from the date of grant.

     (c)  An optionee or grantee electing to exercise an option or award shall
give written notice to the Company of such election and of the number of shares
subject to such exercise. The full purchase price of such shares shall be
tendered with such notice of exercise. Payment shall he made to the Company in
cash (including bank check, certified check, personal check, or money order),
or, at the discretion of the Committee and as specified by the Committee, (i) by
delivering certificates for the Company's Common Stock already owned by the
optionee or grantee having a fair market value as of the date of grant equal to
the full purchase price of the shares, or (ii) by delivering the optionee's or
grantee's promissory note, which shall provide for interest at a rate not less
than the minimum rate required to avoid the imputation of income, original issue
discount or a below-market-rate loan pursuant to Sections 483, 1274 or 7872 of
the Code or any successor provisions thereto, provided, however, that the
interest rate shall not be less than the market rate that would otherwise be
available to the optionee or grantee from a third-party lender on the date of
exercise of the option or award, as determined by the Committee, or (iii) a
combination of cash, the optionee's or grantee promissory note and such shares.
The fair market value of such tendered shares shall be determined as provided in
Section 5 herein. The optionee's or grantee's promissory note shall be a full
recourse liability of the optionee and may, at the discretion of the Committee,
be secured by a pledge of the shares being purchased. Until such person has been
issued the shares subject to such exercise, he or she shall possess no rights as
a shareholder with respect to such shares.

8.   Stock Appreciation Rights.
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     (a)  Grant. At the time of grant of an option or award under the Plan (or
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at any other time), the Committee, in its discretion, may grant a Stock
Appreciation Right ("SAR") evidenced by an agreement in such form as the
Committee shall from time to time approve. Any such SAR may be subject to
restrictions on the exercise thereof as may be set forth in the agreement
representing such SAR, which agreement shall comply with and be subject to the
following terms and conditions and any additional terms and conditions
established by the Committee that are consistent with the terms of the Plan.

     (b)  Exercise. An SAR shall be exercised by the delivery to the Company of
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a written notice which shall state that the holder thereof elects to exercise
his or her SAR as to the number of shares specified in the notice and which
shall further state what portion, if any, of the SAR

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exercise amount (hereinafter defined) the holder thereof requests be paid to in
cash and what portion, if any, is to be paid in Common Stock of the Company. The
Committee promptly shall cause to be paid to such holder the SAR exercise amount
either in cash, in Common Stock of the Company, or any combination of cash and
shares as the Committee may determine. Such determination may be either in
accordance with the request made by the holder of the SAR or in the sole and
absolute discretion of the Committee. The SAR exercise amount is the excess of
the fair market value of one share of the Company's Common Stock on the date of
exercise over the per share exercise price in respect of which the SAR was
granted, multiplied by the number of shares as to which the SAR is exercised.
For the purposes hereof, the fair market value of the Company's shares of Common
Stock shall be determined as provided in Section 5 herein.

9.   Restricted Stock Awards.
----------------------------

     Awards of Common Stock subject to forfeiture and transfer restrictions may
be granted by the Committee. Any restricted stock award shall be evidenced by an
agreement in such form as the Committee shall from time to time approve, which
agreement shall comply with and be subject to the following terms and conditions
and any additional terms and conditions established by the Committee that are
consistent with the terms of the Plan:

     (a)  Grant of Restricted Stock Awards. Each restricted stock award made
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under the Plan shall be for such number of shares of Common Stock as shall be
determined by the Committee and set forth in the agreement containing the terms
of such restricted stock award. Such agreement shall set forth a period of time
during which the grantee must remain in the continuous employment of the Company
in order for the forfeiture and transfer restrictions to lapse. If the Committee
so determines, the restrictions may lapse during such restricted period in
installments with respect to specified portions of the shares covered by the
restricted stock award. The agreement may also, in the discretion of the
Committee, set forth performance or other conditions that will subject the
Common Stock to forfeiture and transfer restrictions. The Committee may, at its
discretion, waive all or any part of the restrictions applicable to any or all
outstanding restricted stock awards.

     (b)  Delivery of Common Stock and Restrictions. At the time of a restricted
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stock award, a certificate representing the number of shares of Common Stock
awarded thereunder shall be registered in the name of the grantee. Such
certificate shall be held by the Company or any custodian appointed by the
Company for the account of the grantee subject to the terms and conditions of
the Plan, and shall bear such a legend setting forth the restrictions imposed
thereon as the Committee, in its discretion, may determine. The grantee shall
have all rights of a shareholder with respect to the Common Stock, including the
right to receive dividends and the right to vote such shares, subject to the
following restrictions: (i) the grantee shall not be entitled to delivery of the
stock certificate until the expiration of the restricted period and the
fulfillment of any other restrictive conditions set forth in the restricted
stock agreement with respect to such Common Stock; (ii) none of the shares of
Common Stock may be sold, assigned, transferred, pledged, hypothecated or
otherwise encumbered or disposed of during such restricted period or until after
the fulfillment of any such other restrictive conditions; and (iii) except as
otherwise

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determined by the Committee, all of the Common Stock shall be forfeited and all
rights of the grantee to such Common Stock shall terminate, without further
obligation on the part of the Company, unless the grantee remains in the
continuous employment of the Company for the entire restricted period in
relation to which such shares of Common Stock were granted and unless any other
restrictive conditions relating to the restricted stock award are met. Any
Common Stock, any other securities of the Company and any other property (except
for cash dividends) distributed with respect to the Common Stock subject to
restricted stock awards shall be subject to the same restrictions, terms and
conditions as such restricted Common Stock.

     (c)  Termination of Restrictions. At the end of the restricted period and
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provided that any other restrictive conditions of the restricted stock award are
met, or at such earlier time as otherwise determined by the Committee, all
restrictions set forth in the agreement relating to the restricted stock award
or in the Plan shall lapse as to the restricted Common Stock subject thereto,
and a stock certificate for the appropriate number of shares of Common Stock,
free of the restrictions and the restricted stock legend, shall be delivered to
the grantee or his beneficiary or estate, as the case may be.

10.  Performance Awards.
-----------------------

     The Committee is further authorized to grant performance awards
("Performance Award"). Subject to the terms of this Plan and any applicable
award agreement, Performance Awards granted under the Plan (i) may be
denominated or payable in cash, Common Stock (including, without limitation,
restricted stock), other securities, other awards, or other property and (ii)
shall confer on the holder thereof rights valued as determined by the Committee,
in its discretion, and payable to, or exercisable by, the holder of the
Performance Awards, in whole or in part, upon the achievement of such
performance goals during such performance periods as the Committee, in its
discretion, shall establish. Subject to the terms of this Plan and any
applicable award agreement, the performance goals to be achieved during any
performance period, the length of any performance period, the amount of any
Performance Awards granted, and the amount of any payment or transfer to be made
by the grantee and by the Company under any Performance Awards shall be
determined by the Committee.

11.  Income Tax Withholding and Tax Bonuses.
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     (a)  In order to comply with all applicable federal or state income tax
laws or regulations, the Company may take such action as it deems appropriate to
ensure that applicable federal or state payroll, withholding, income or other
taxes, which are the sole and absolute responsibility of an optionee or grantee
under the Plan, are withheld or collected from such optionee or grantee at the
required tax withholding rate. In order to assist an optionee or grantee in
paying all federal and state taxes to be withheld or collected upon exercise of
an option or award which does not qualify as an Incentive Stock Option
hereunder, the Committee, in its absolute discretion and subject to such
additional terms and conditions as it may adopt, shall permit the optionee or
grantee to satisfy such tax obligation by (i) electing to have the Company
withhold a portion of the shares otherwise to be delivered upon exercise of such
option or award

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with a fair market value, determined in accordance with Section 5 herein, equal
to the required tax withholding or (ii) delivering to the Company Common Stock
other than the shares issuable upon exercise of such option or award with a fair
market value, determined in accordance with Section 5, equal to the required tax
withholding. The "required" tax withholding is the employer's minimum statutory
withholding based on minimum statutory withholding rates for federal and state
tax purposes, including employee payroll taxes, that are applicable to an
optionee's or grantee's taxable income generated upon exercise of an option or
award. Withholdings in excess of the required tax withholding are not allowed.

     (b)  The Committee shall have the authority, at the time of grant of an
option under the Plan or at any time thereafter, to approve tax bonuses to
designated optionees or grantees to be paid upon their exercise of options or
awards granted hereunder. The amount of any such payments shall be determined by
the Committee. The Committee shall have full authority in its absolute
discretion to determine the amount of any such tax bonus and the terms and
conditions affecting the vesting and payment thereafter.

12.  Additional Restrictions.
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     The Committee shall have full and complete authority to determine whether
all or any part of the Common Stock of the Company acquired upon exercise of any
of the options or awards granted under the Plan shall be subject to restrictions
on the transferability thereof or any other restrictions affecting in any manner
the optionee's or grantee's rights with respect thereto, but any such
restriction shall be contained in the agreement relating to such options or
awards.

13.  Ten Percent Shareholder Rule.
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     Notwithstanding any other provision in the Plan, if at the time an option
is otherwise to be granted pursuant to the Plan the optionee owns directly or
indirectly (within the meaning of Section 424(d) of the Code) Common Stock of
the Company possessing more than ten percent (10%) of the total combined voting
power of all classes of stock of the Company or its parent or subsidiary
corporations, if any (within the meaning of Section 422(b)(6) of the Code), then
any Incentive Stock Option to be granted to such optionee pursuant to the Plan
shall satisfy the requirements of Section 422(c)(5) of the Code, and the option
price shall be not less than 110% of the fair market value of the Common Stock
of the Company determined as described herein, and such option by its terms
shall not be exercisable after the expiration of five (5) years from the date
such option is granted.

14.  Non-Transferability.
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     No option may be sold, pledged, assigned, hypothecated, transferred, or
disposed of in any manner other than (i) by will or by the laws of descent or
distribution, or (ii) in the case of options that are not Incentive Stock
Options, to members of the optionee's immediate family or to one or more trusts
for the benefit of the optionee or members of his or her immediate family,

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and the option may be exercised, during the lifetime of the Optionee, only by
the optionee or a permitted transferee.

15.  Dilution or Other Adjustments.
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     If there shall be any change in the Common Stock through merger,
consolidation, reorganization, recapitalization, dividend in the form of stock
(of whatever amount), stock split or other change in the corporate structure,
appropriate adjustments in the Plan and outstanding options and awards shall be
made by the Committee. In the event of any such changes, adjustments shall
include, where appropriate, changes in the aggregate number of shares subject to
the Plan, the number of shares and the price per share subject to outstanding
options and awards and the amount payable upon exercise of outstanding awards,
in order to prevent dilution or enlargement of option or award rights.

16.  Amendment or Discontinuance of Plan.
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     The Board of Directors may amend or discontinue the Plan at any time.
Subject to the provisions of Section 15 no amendment of the Plan, however, shall
without shareholder approval: (i) increase the maximum number of shares under
the Plan as provided in Section 2 herein, (ii) decrease the minimum price
provided in Section 5 herein, (iii) extend the maximum term under Section 6, or
(iv) modify the eligibility requirements for participation in the Plan. The
Board of Directors shall not alter or impair any option or award theretofore
granted under the Plan without the consent of the holder of the option.

17.  Time of Granting.
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     Nothing contained in the Plan or in any resolution adopted or to be adopted
by the Board of Directors or by the shareholders of the Company, and no action
taken by the Committee or the Board of Directors (other than the execution and
delivery of an option or award agreement), shall constitute the granting of an
option or award hereunder.

18.  Effective Date and Termination of Plan.
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     (a)  The Plan was approved by the Board of Directors on June 29, 1990 and
shall be approved by the shareholders of the Company within twelve (12) months
thereof.

     (b)  Unless the Plan shall have been discontinued as provided in Section 16
hereof, the Plan shall terminate June 29, 2005. No option or award may be
granted after such termination, but termination of the Plan shall not, without
the consent of the optionee or grantee, alter or impair any rights or
obligations under any option or award theretofore granted.

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