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                                                                    EXHIBIT 10.3

                             ANSYS DIAGNOSTICS, INC.
                            1997 STOCK INCENTIVE PLAN
                      (As amended through April 20, 1999)


                                   ARTICLE ONE

                               GENERAL PROVISIONS


       I.      PURPOSE OF THE PLAN

               This 1997 Stock Incentive Plan is intended to promote the
interests of Ansys Diagnostics, Inc., a California corporation, by providing
eligible persons in the Corporation's employ or service with the opportunity to
acquire a proprietary interest, or otherwise increase their proprietary
interest, in the Corporation as an incentive for them to continue in such employ
or service.

               Capitalized terms herein shall have the meanings assigned to such
terms in the attached Appendix.

      II.      STRUCTURE OF THE PLAN

        A. The Plan shall be divided into two (2) separate equity programs:

                           (i) the Option Grant Program under which eligible
        persons may, at the discretion of the Plan Administrator, be granted
        options to purchase shares of Common Stock, and

                          (ii) the Stock Issuance Program under which eligible
        persons may, at the discretion of the Plan Administrator, be issued
        shares of Common Stock directly, either through the immediate purchase
        of such shares or as a bonus for services rendered the Corporation (or
        any Parent or Subsidiary).

        B. The provisions of Articles One and Four shall apply to both equity
programs under the Plan and shall accordingly govern the interests of all
persons under the Plan.

     III.      ADMINISTRATION OF THE PLAN

        A. The Plan shall be administered by the Board. However, any or all
administrative functions otherwise exercisable by the Board may be delegated to
the Committee. Members of the Committee shall serve for such period of time as
the Board may determine and shall be subject to

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removal by the Board at any time. The Board may also at any time terminate the
functions of the Committee and reassume all powers and authority previously
delegated to the Committee.

        B. The Plan Administrator shall have full power and authority (subject
to the provisions of the Plan) to establish such rules and regulations as it may
deem appropriate for proper administration of the Plan and to make such
determinations under, and issue such interpretations of, the Plan and any
outstanding options or stock issuances thereunder as it may deem necessary or
advisable. Decisions of the Plan Administrator shall be final and binding on all
parties who have an interest in the Plan or any option or stock issuance
thereunder.

      IV.      ELIGIBILITY

        A. The persons eligible to participate in the Plan are as follows:

                         (i) Employees,

                         (ii) non-employee members of the Board or the
        non-employee members of the board of directors of any Parent or
        Subsidiary, and

                         (iii) consultants and other independent advisors who
        provide services to the Corporation (or any Parent or Subsidiary).

        B. The Plan Administrator shall have full authority to determine, (i)
with respect to the grants under the Option Grant Program, which eligible
persons are to receive the option grants, the time or times when those grants
are to be made, the number of shares to be covered by each such grant, the
status of the granted option as either an Incentive Option or a Non- Statutory
Option, the time or times when each option is to become exercisable, the vesting
schedule (if any) applicable to the option shares and the maximum term for which
the option is to remain outstanding, and (ii) with respect to stock issuances
under the Stock Issuance Program, which eligible persons are to receive such
stock issuances, the time or times when those issuances are to be made, the
number of shares to be issued to each Participant, the vesting schedule (if any)
applicable to the issued shares and the consideration to be paid by the
Participant for such shares.

        C. The Plan Administrator shall have the absolute discretion either to
grant options in accordance with the Option Grant Program or to effect stock
issuances in accordance with the Stock Issuance Program.

       V.      STOCK SUBJECT TO THE PLAN

        A. The stock issuable under the Plan shall be shares of authorized but
unissued or reacquired Common Stock. The maximum number of shares of Common
Stock which may be issued over the term of the Plan shall not exceed
1,088,800(1) shares. Such share reserve consists of (i) the 600,000 shares of
Common Stock initially reserved under the Plan plus (ii) an additional increase
of 488,800 shares authorized by the Board and the shareholders on March 31,
1999.

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(1)  All share numbers in the Plan reflect the 1.2-for-1 stock split effected
     on April 20, 1999.


                                       2.


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        B. Shares of Common Stock subject to outstanding options shall be
available for subsequent issuance under the Plan to the extent the options
expire or terminate for any reason prior to exercise in full. Unvested shares
issued under the Plan and subsequently repurchased by the Corporation, at the
option exercise price or direct issue price paid per share, pursuant to the
Corporation's repurchase rights under the Plan shall be added back to the number
of shares of Common Stock reserved for issuance under the Plan and shall
accordingly be available for reissuance through one or more subsequent option
grants or direct stock issuances under the Plan.

        C. Should any change be made to the Common Stock by reason of any stock
split, stock dividend, recapitalization, combination of shares, exchange of
shares or other change affecting the outstanding Common Stock as a class without
the Corporation's receipt of consideration, appropriate adjustments shall be
made to (i) the maximum number and/or class of securities issuable under the
Plan and (ii) the number and/or class of securities and the exercise price per
share in effect under each outstanding option in order to prevent the dilution
or enlargement of benefits thereunder. The adjustments determined by the Plan
Administrator shall be final, binding and conclusive. In no event shall any such
adjustments be made in connection with the conversion of one or more outstanding
shares of the Corporation's preferred stock into shares of Common Stock.


                                       3.


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                                   ARTICLE TWO

                              OPTION GRANT PROGRAM

       I.      OPTION TERMS

               Each option shall be evidenced by one or more documents in the
form approved by the Plan Administrator; provided, however, that each such
document shall comply with the terms specified below. Each document evidencing
an Incentive Option shall, in addition, be subject to the provisions of the Plan
applicable to such options.

        A.     EXERCISE PRICE.

               1. The exercise price per share shall be fixed by the Plan
Administrator in accordance with the following provisions:

                           (i) The exercise price per share shall not be less
        than one hundred percent (100%) of the Fair Market Value per share of
        Common Stock on the option grant date.

                          (ii) If the person to whom the option is granted is a
        10% Shareholder, then the exercise price per share shall not be less
        than one hundred ten percent (110%) of the Fair Market Value per share
        of Common Stock on the option grant date.

               2. The exercise price shall become immediately due upon exercise
of the option and shall, subject to the provisions of Section I of Article Four
and the documents evidencing the option, be payable in cash or check made
payable to the Corporation. Should the Common Stock be registered under Section
12 of the 1934 Act at the time the option is exercised, then the exercise price
may also be paid as follows:

                           (i) in shares of Common Stock held for the requisite
        period necessary to avoid a charge to the Corporation's earnings for
        financial reporting purposes and valued at Fair Market Value on the
        Exercise Date, or

                          (ii) to the extent the option is exercised for vested
        shares, through a special sale and remittance procedure pursuant to
        which the Optionee shall concurrently provide irrevocable instructions
        (A) to a Corporation-designated brokerage firm to effect the immediate
        sale of the purchased shares and remit to the Corporation, out of the
        sale proceeds available on the settlement date, sufficient funds to
        cover the aggregate exercise price payable for the purchased shares plus
        all



                                       4.
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        applicable Federal, state and local income and employment taxes
        required to be withheld by the Corporation by reason of such exercise
        and (B) to the Corporation to deliver the certificates for the purchased
        shares directly to such brokerage firm in order to complete the sale.

               Except to the extent such sale and remittance procedure is
utilized, payment of the exercise price for the purchased shares must be made on
the Exercise Date.

        B. EXERCISE AND TERM OF OPTIONS. Each option shall be exercisable at
such time or times, during such period and for such number of shares as shall be
determined by the Plan Administrator and set forth in the documents evidencing
the option grant. However, no option shall have a term in excess of ten (10)
years measured from the option grant date.

        C. EFFECT OF TERMINATION OF SERVICE.

                    1. The following provisions shall govern the exercise of any
options held by the Optionee at the time of cessation of Service or death:

                           (i) Should the Optionee cease to remain in Service
        for any reason other than death, Disability or Misconduct, then the
        Optionee shall have a period of three (3) months following the date of
        such cessation of Service during which to exercise each outstanding
        option held by such Optionee.

                          (ii) Should Optionee's Service terminate by reason of
        Disability, then the Optionee shall have a period of twelve (12) months
        following the date of such cessation of Service during which to exercise
        each outstanding option held by such Optionee.

                         (iii) If the Optionee dies while holding an outstanding
        option, then the personal representative of his or her estate or the
        person or persons to whom the option is transferred pursuant to the
        Optionee's will or the laws of inheritance shall have a twelve
        (12)-month period following the date of the Optionee's death to exercise
        such option.

                          (iv) Under no circumstances, however, shall any such
        option be exercisable after the specified expiration of the option term.

                           (v) During the applicable post-Service exercise
        period, the option may not be exercised in the aggregate for more than
        the number of vested shares for which the option is exercisable on the
        date of the Optionee's cessation of Service. Upon the expiration of the
        applicable exercise period or (if earlier) upon the expiration of the
        option term, the option shall terminate and cease to be outstanding



                                       5.
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        for any vested shares for which the option has not been exercised.
        However, the option shall, immediately upon the Optionee's cessation of
        Service, terminate and cease to be outstanding with respect to any and
        all option shares for which the option is not otherwise at the time
        exercisable or in which the Optionee is not otherwise at that time
        vested.

                          (vi) Should Optionee's Service be terminated for
        Misconduct, then all outstanding options held by the Optionee shall
        terminate immediately and cease to remain outstanding.

               2. The Plan Administrator shall have the discretion, exercisable
either at the time an option is granted or at any time while the option remains
outstanding, to:

                           (i) extend the period of time for which the option is
        to remain exercisable following Optionee's cessation of Service or death
        from the limited period otherwise in effect for that option to such
        greater period of time as the Plan Administrator shall deem appropriate,
        but in no event beyond the expiration of the option term, and/or

                          (ii) permit the option to be exercised, during the
        applicable post-Service exercise period, not only with respect to the
        number of vested shares of Common Stock for which such option is
        exercisable at the time of the Optionee's cessation of Service but also
        with respect to one or more additional installments in which the
        Optionee would have vested under the option had the Optionee continued
        in Service.

        D. SHAREHOLDER RIGHTS. The holder of an option shall have no shareholder
rights with respect to the shares subject to the option until such person shall
have exercised the option, paid the exercise price and become the recordholder
of the purchased shares.

        E. UNVESTED SHARES. The Plan Administrator shall have the discretion to
grant options which are exercisable for unvested shares of Common Stock. Should
the Optionee cease Service while holding such unvested shares, the Corporation
shall have the right to repurchase, at the exercise price paid per share, any or
all of those unvested shares. The terms upon which such repurchase right shall
be exercisable (including the period and procedure for exercise and the
appropriate vesting schedule for the purchased shares) shall be established by
the Plan Administrator and set forth in the document evidencing such repurchase
right. The Plan Administrator may not impose a vesting schedule upon any option
grant or the shares of Common Stock subject to that option which is more
restrictive than twenty percent (20%) per year vesting, with the initial vesting
to occur not later than one (1) year after the option grant date. However, such
limitation shall not be applicable to any option grants made to individuals who
are officers of the Corporation, non-employee Board members or independent
consultants.



                                       6.


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        F. FIRST REFUSAL RIGHTS. Until such time as the Common Stock is first
registered under Section 12 of the 1934 Act, the Corporation shall have the
right of first refusal with respect to any proposed disposition by the Optionee
(or any successor in interest) of any shares of Common Stock issued under the
Plan. Such right of first refusal shall be exercisable in accordance with the
terms established by the Plan Administrator and set forth in the document
evidencing such right.

        G. LIMITED TRANSFERABILITY OF OPTIONS. During the lifetime of the
Optionee, the option shall be exercisable only by the Optionee and shall not be
assignable or transferable other than by will or by the laws of descent and
distribution following the Optionee's death.

        H. WITHHOLDING. The Corporation's obligation to deliver shares of Common
Stock upon the exercise of any options granted under the Plan shall be subject
to the satisfaction of all applicable Federal, state and local income and
employment tax withholding requirements.

     II.       INCENTIVE OPTIONS

        The terms specified below shall be applicable to all Incentive Options.
Except as modified by the provisions of this Section II, all the provisions of
the Plan shall be applicable to Incentive Options. Options which are
specifically designated as Non-Statutory Options shall not be subject to the
terms of this Section II.

        A. ELIGIBILITY. Incentive Options may only be granted to Employees.

        B. EXERCISE PRICE. The exercise price per share shall not be less than
one hundred percent (100%) of the Fair Market Value per share of Common Stock on
the option grant date.

        C. DOLLAR LIMITATION. The aggregate Fair Market Value of the shares of
Common Stock (determined as of the respective date or dates of grant) for which
one or more options granted to any Employee under the Plan (or any other option
plan of the Corporation or any Parent or Subsidiary) may for the first time
become exercisable as Incentive Options during any one (1) calendar year shall
not exceed the sum of One Hundred Thousand Dollars ($100,000). To the extent the
Employee holds two (2) or more such options which become exercisable for the
first time in the same calendar year, the foregoing limitation on the
exercisability of such options as Incentive Options shall be applied on the
basis of the order in which such options are granted.

        D. 10% SHAREHOLDER. If any Employee to whom an Incentive Option is
granted is a 10% Shareholder, then the option term shall not exceed five (5)
years measured from the option grant date.


                                       7.


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     III.      CORPORATE TRANSACTION

        A. The shares subject to each option outstanding under the Plan at the
time of a Corporate Transaction shall automatically vest in full so that each
such option shall, immediately prior to the effective date of the Corporate
Transaction, become fully exercisable for all of the shares of Common Stock at
the time subject to that option and may be exercised for any or all of those
shares as fully-vested shares of Common Stock. However, the shares subject to an
outstanding option shall NOT vest on such an accelerated basis if and to the
extent: (i) such option is assumed by the successor corporation (or parent
thereof) in the Corporate Transaction and the Corporation's repurchase rights
with respect to the unvested option shares are concurrently assigned to such
successor corporation (or parent thereof) or (ii) such option is to be replaced
with a cash incentive program of the successor corporation which preserves the
spread existing on the unvested option shares at the time of the Corporate
Transaction and provides for subsequent payout in accordance with the same
vesting schedule applicable to those unvested option shares or (iii) the
acceleration of such option is subject to other limitations imposed by the Plan
Administrator at the time of the option grant.

        B. All outstanding repurchase rights shall also terminate automatically,
and the shares of Common Stock subject to those terminated rights shall
immediately vest in full, in the event of any Corporate Transaction, except to
the extent: (i) those repurchase rights are assigned to the successor
corporation (or parent thereof) in connection with such Corporate Transaction or
(ii) such accelerated vesting is precluded by other limitations imposed by the
Plan Administrator at the time the repurchase right is issued.

        C. Immediately following the consummation of the Corporate Transaction,
all outstanding options shall terminate and cease to be outstanding, except to
the extent assumed by the successor corporation (or parent thereof).

        D. Each option which is assumed in connection with a Corporate
Transaction shall be appropriately adjusted, immediately after such Corporate
Transaction, to apply to the number and class of securities which would have
been issuable to the Optionee in consummation of such Corporate Transaction, had
the option been exercised immediately prior to such Corporate Transaction.
Appropriate adjustments shall also be made to (i) the number and class of
securities available for issuance under the Plan following the consummation of
such Corporate Transaction and (ii) the exercise price payable per share under
each outstanding option, provided the aggregate exercise price payable for such
securities shall remain the same.

        E. The Plan Administrator shall have the discretion, exercisable either
at the time the option is granted or at any time while the option remains
outstanding, to provide for the automatic acceleration (in whole or in part) of
one or more outstanding options (and the immediate termination of the
Corporation's repurchase rights with respect to the shares subject to those
options) upon the



                                       8.
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occurrence of a Corporate Transaction, whether or not those options are to be
assumed in the Corporate Transaction.

        F. The Plan Administrator shall also have full power and authority,
exercisable either at the time the option is granted or at any time while the
option remains outstanding, to structure such option so that the shares subject
to that option will automatically vest on an accelerated basis should the
Optionee's Service terminate by reason of an Involuntary Termination within a
designated period (not to exceed eighteen (18) months) following the effective
date of any Corporate Transaction in which the option is assumed and the
repurchase rights applicable to those shares do not otherwise terminate. Any
option so accelerated shall remain exercisable for the fully-vested option
shares until the earlier of (i) the expiration of the option term or (ii) the
expiration of the one (1)-year period measured from the effective date of the
Involuntary Termination. In addition, the Plan Administrator may provide that
one or more of the Corporation's outstanding repurchase rights with respect to
shares held by the Optionee at the time of such Involuntary Termination shall
immediately terminate on an accelerated basis, and the shares subject to those
terminated rights shall accordingly vest at that time.

        G. The portion of any Incentive Option accelerated in connection with a
Corporate Transaction shall remain exercisable as an Incentive Option only to
the extent the applicable One Hundred Thousand Dollar limitation is not
exceeded. To the extent such dollar limitation is exceeded, the accelerated
portion of such option shall be exercisable as a Non-Statutory Option under the
Federal tax laws.

        H. The grant of options under the Plan shall in no way affect the right
of the Corporation to adjust, reclassify, reorganize or otherwise change its
capital or business structure or to merge, consolidate, dissolve, liquidate or
sell or transfer all or any part of its business or assets.




                                       9.


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                                  ARTICLE THREE

                             STOCK ISSUANCE PROGRAM


       I.      STOCK ISSUANCE TERMS

               Shares of Common Stock may be issued under the Stock Issuance
Program through direct and immediate issuances without any intervening option
grants. Each such stock issuance shall be evidenced by a Stock Issuance
Agreement which complies with the terms specified below.

        A.     Purchase Price.

                   1. The purchase price per share shall be fixed by the Plan
Administrator but shall not be less than one hundred percent (100%) of the Fair
Market Value per share of Common Stock on the issue date. However, the purchase
price per share of Common Stock issued to a 10% Shareholder shall not be less
than one hundred and ten percent (110%) of such Fair Market Value.

                   2. Subject to the provisions of Section I of Article Four,
shares of Common Stock may be issued under the Stock Issuance Program for any of
the following items of consideration which the Plan Administrator may deem
appropriate in each individual instance:

                                (i) cash or check made payable to the
       Corporation, or

                                (ii) past services rendered to the Corporation
        (or any Parent or Subsidiary).

        B. Vesting Provisions.

                   1. Shares of Common Stock issued under the Stock Issuance
Program may, in the discretion of the Plan Administrator, be fully and
immediately vested upon issuance or may vest in one or more installments over
the Participant's period of Service or upon attainment of specified performance
objectives. However, the Plan Administrator may not impose a vesting schedule
upon any stock issuance effected under the Stock Issuance Program which is more
restrictive than twenty percent (20%) per year vesting, with initial vesting to
occur not later than one (1) year after the issuance date. Such limitation shall
not apply to any Common Stock issuances made to the officers of the Corporation,
non-employee Board members or independent consultants.

                                       10.


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                   2. Any new, substituted or additional securities or other
property (including money paid other than as a regular cash dividend) which the
Participant may have the right to receive with respect to the Participant's
unvested shares of Common Stock by reason of any stock dividend, stock split,
recapitalization, combination of shares, exchange of shares or other change
affecting the outstanding Common Stock as a class without the Corporation's
receipt of consideration shall be issued subject to (i) the same vesting
requirements applicable to the Participant's unvested shares of Common Stock and
(ii) such escrow arrangements as the Plan Administrator shall deem appropriate.

                   3. The Participant shall have full shareholder rights with
respect to any shares of Common Stock issued to the Participant under the Stock
Issuance Program, whether or not the Participant's interest in those shares is
vested. Accordingly, the Participant shall have the right to vote such shares
and to receive any regular cash dividends paid on such shares.

                   4. Should the Participant cease to remain in Service while
holding one or more unvested shares of Common Stock issued under the Stock
Issuance Program or should the performance objectives not be attained with
respect to one or more such unvested shares of Common Stock, then those shares
shall be immediately surrendered to the Corporation for cancellation, and the
Participant shall have no further shareholder rights with respect to those
shares. To the extent the surrendered shares were previously issued to the
Participant for consideration paid in cash or cash equivalent (including the
Participant's purchase-money indebtedness), the Corporation shall repay to the
Participant the cash consideration paid for the surrendered shares and shall
cancel the unpaid principal balance of any outstanding purchase- money note of
the Participant attributable to such surrendered shares.

                   5. The Plan Administrator may in its discretion waive the
surrender and cancellation of one or more unvested shares of Common Stock (or
other assets attributable thereto) which would otherwise occur upon the
non-completion of the vesting schedule applicable to such shares. Such waiver
shall result in the immediate vesting of the Participant's interest in the
shares of Common Stock as to which the waiver applies. Such waiver may be
effected at any time, whether before or after the Participant's cessation of
Service or the attainment or non- attainment of the applicable performance
objectives.

        C. First Refusal Rights. Until such time as the Common Stock is first
registered under Section 12 of the 1934 Act, the Corporation shall have the
right of first refusal with respect to any proposed disposition by the
Participant (or any successor in interest) of any shares of Common Stock issued
under the Stock Issuance Program. Such right of first refusal shall be
exercisable in accordance with the terms established by the Plan Administrator
and set forth in the document evidencing such right.


                                       11.


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      II.      CORPORATE TRANSACTION

        A. Upon the occurrence of a Corporate Transaction, all outstanding
repurchase rights under the Stock Issuance Program shall terminate
automatically, and the shares of Common Stock subject to those terminated rights
shall immediately vest in full, except to the extent: (i) those repurchase
rights are assigned to the successor corporation (or parent thereof) in
connection with such Corporate Transaction or (ii) such accelerated vesting is
precluded by other limitations imposed by the Plan Administrator at the time the
repurchase right is issued.

        B. The Plan Administrator shall have the discretionary authority,
exercisable either at the time the unvested shares are issued or any time while
the Corporation's repurchase rights with respect to those shares remain
outstanding, to provide that those rights shall automatically terminate on an
accelerated basis, and the shares of Common Stock subject to those terminated
rights shall immediately vest, in the event the Participant's Service should
subsequently terminate by reason of an Involuntary Termination within a
designated period (not to exceed eighteen (18) months) following the effective
date of any Corporate Transaction in which those repurchase rights are assigned
to the successor corporation (or parent thereof).

     III.      SHARE ESCROW/LEGENDS

               Unvested shares may, in the Plan Administrator's discretion, be
held in escrow by the Corporation until the Participant's interest in such
shares vests or may be issued directly to the Participant with restrictive
legends on the certificates evidencing those unvested shares.


                                       12.


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                                  ARTICLE FOUR

                                  MISCELLANEOUS


       I.      FINANCING

               The Plan Administrator may permit any Optionee or Participant to
pay the option exercise price or the purchase price for shares issued to such
person under the Plan by delivering a full-recourse, interest-bearing promissory
note payable in one or more installments and secured by the purchased shares. In
no event shall the maximum credit available to the Optionee or Participant
exceed the sum of (i) the aggregate option exercise price or purchase price
payable for the purchased shares (less the par value of those shares) plus (ii)
any Federal, state and local income and employment tax liability incurred by the
Optionee or the Participant in connection with the option exercise or share
purchase.

      II.      EFFECTIVE DATE AND TERM OF PLAN

        A. The Plan shall become effective when adopted by the Board, but no
option granted under the Plan may be exercised, and no shares shall be issued
under the Plan, until the Plan is approved by the Corporation's shareholders. If
such shareholder approval is not obtained within twelve (12) months after the
date of the Board's adoption of the Plan, then all options previously granted
under the Plan shall terminate and cease to be outstanding, and no further
options shall be granted and no shares shall be issued under the Plan. Subject
to such limitation, the Plan Administrator may grant options and issue shares
under the Plan at any time after the effective date of the Plan and before the
date fixed herein for termination of the Plan.

        B. The Plan shall terminate upon the earliest of (i) the expiration of
the ten (10)-year period measured from the date the Plan is adopted by the
Board, (ii) the date on which all shares available for issuance under the Plan
shall have been issued as vested shares or (iii) the termination of all
outstanding options in connection with a Corporate Transaction. All options and
unvested stock issuances outstanding at the time of a clause (i) termination
event shall continue to have full force and effect in accordance with the
provisions of the documents evidencing such options or issuances.

     III.      AMENDMENT OF THE PLAN

        A. The Board shall have complete and exclusive power and authority to
amend or modify the Plan in any or all respects. However, no such amendment or
modification shall adversely affect the rights and obligations with respect to
options or unvested stock issuances at the time outstanding under the Plan
unless the Optionee or the Participant consents to such amendment or



                                       13.
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modification. In addition, certain amendments may require shareholder approval
pursuant to applicable laws and regulations.

        B. Options may be granted under the Option Grant Program and shares may
be issued under the Stock Issuance Program which are in each instance in excess
of the number of shares of Common Stock then available for issuance under the
Plan, provided any excess shares actually issued under those programs shall be
held in escrow until there is obtained shareholder approval of an amendment
sufficiently increasing the number of shares of Common Stock available for
issuance under the Plan. If such shareholder approval is not obtained within
twelve (12) months after the date the first such excess issuances are made, then
(i) any unexercised options granted on the basis of such excess shares shall
terminate and cease to be outstanding and (ii) the Corporation shall promptly
refund to the Optionees and the Participants the exercise or purchase price paid
for any excess shares issued under the Plan and held in escrow, together with
interest (at the applicable Short Term Federal Rate) for the period the shares
were held in escrow, and such shares shall thereupon be automatically cancelled
and cease to be outstanding.

      IV.      USE OF PROCEEDS

               Any cash proceeds received by the Corporation from the sale of
shares of Common Stock under the Plan shall be used for general corporate
purposes.

       V.      WITHHOLDING

               The Corporation's obligation to deliver shares of Common Stock
upon the exercise of any options or upon the issuance or vesting of any shares
issued under the Plan shall be subject to the satisfaction of all applicable
Federal, state and local income and employment tax withholding requirements.

      VI.      REGULATORY APPROVALS

               The implementation of the Plan, the granting of any options under
the Plan and the issuance of any shares of Common Stock (i) upon the exercise of
any option or (ii) under the Stock Issuance Program shall be subject to the
Corporation's procurement of all approvals and permits required by regulatory
authorities having jurisdiction over the Plan, the options granted under it and
the shares of Common Stock issued pursuant to it.

     VII.      NO EMPLOYMENT OR SERVICE RIGHTS

               Nothing in the Plan shall confer upon the Optionee or the
Participant any right to continue in Service for any period of specific duration
or interfere with or otherwise restrict in any way the rights of the Corporation
(or any Parent or Subsidiary employing or retaining such person)



                                      14.
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or of the Optionee or the Participant, which rights are hereby expressly
reserved by each, to terminate such person's Service at any time for any reason,
with or without cause.

    VIII.      FINANCIAL REPORTS

               The Corporation shall deliver a balance sheet and an income
statement at least annually to each individual holding an outstanding option
under the Plan, unless such individual is a key Employee whose duties in
connection with the Corporation (or any Parent or Subsidiary) assure such
individual access to equivalent information.



                                       15.


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                                    APPENDIX


               The following definitions shall be in effect under the Plan:

        A. BOARD shall mean the Corporation's Board of Directors.

        B. CODE shall mean the Internal Revenue Code of 1986, as amended.

        C. COMMITTEE shall mean a committee of two (2) or more Board members
appointed by the Board to exercise one or more administrative functions under
the Plan.

        D. COMMON STOCK shall mean the Corporation's common stock.

        E. CORPORATE TRANSACTION shall mean either of the following
shareholder-approved transactions to which the Corporation is a party:

                    (a) a merger or consolidation in which securities possessing
        more than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

                    (b) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. CORPORATION shall mean Ansys Diagnostics, Inc., a California
corporation.

        G. DISABILITY shall mean the inability of the Optionee or the
Participant to engage in any substantial gainful activity by reason of any
medically determinable physical or mental impairment and shall be determined by
the Plan Administrator on the basis of such medical evidence as the Plan
Administrator deems warranted under the circumstances.

        H. EMPLOYEE shall mean an individual who is in the employ of the
Corporation (or any Parent or Subsidiary), subject to the control and direction
of the employer entity as to both the work to be performed and the manner and
method of performance.

        I. EXERCISE DATE shall mean the date on which the Corporation shall have
received written notice of the option exercise.


                                      A-1.


   17

        J. FAIR MARKET VALUE per share of Common Stock on any relevant date
shall be determined in accordance with the following provisions:

                    (a) If the Common Stock is at the time traded on the Nasdaq
        National Market, then the Fair Market Value shall be the closing selling
        price per share of Common Stock on the date in question, as such price
        is reported by the National Association of Securities Dealers on the
        Nasdaq National Market or any successor system. If there is no closing
        selling price for the Common Stock on the date in question, then the
        Fair Market Value shall be the closing selling price on the last
        preceding date for which such quotation exists.

                    (b) If the Common Stock is at the time listed on any Stock
        Exchange, then the Fair Market Value shall be the closing selling price
        per share of Common Stock on the date in question on the Stock Exchange
        determined by the Plan Administrator to be the primary market for the
        Common Stock, as such price is officially quoted in the composite tape
        of transactions on such exchange. If there is no closing selling price
        for the Common Stock on the date in question, then the Fair Market Value
        shall be the closing selling price on the last preceding date for which
        such quotation exists.

                    (c) If the Common Stock is at the time neither listed on any
        Stock Exchange nor traded on the Nasdaq National Market, then the Fair
        Market Value shall be determined by the Plan Administrator after taking
        into account such factors as the Plan Administrator shall deem
        appropriate.

        K. INCENTIVE OPTION shall mean an option which satisfies the
requirements of Code Section 422.

        L. INVOLUNTARY TERMINATION shall mean the termination of the Service of
any individual which occurs by reason of:

                    (a) such individual's involuntary dismissal or discharge by
        the Corporation for reasons other than Misconduct, or

                    (b) such individual's voluntary resignation following (A) a
        change in his or her position with the Corporation which materially
        reduces his or her duties and responsibilities or the level of
        management to which he or she reports, (B) a reduction in his or her
        level of compensation (including base salary, fringe benefits and target
        bonuses under any corporate performance-based bonus or incentive
        programs) by more than fifteen percent (15%) or (C) a relocation of such
        individual's place of employment by more than fifty (50) miles, provided
        and only if such change, reduction or relocation is effected without the
        individual's consent.

                                      A-2.


   18

        M. MISCONDUCT shall mean the commission of any act of fraud,
embezzlement or dishonesty by the Optionee or Participant, any unauthorized use
or disclosure by such person of confidential information or trade secrets of the
Corporation (or any Parent or Subsidiary), or any other intentional misconduct
by such person adversely affecting the business or affairs of the Corporation
(or any Parent or Subsidiary) in a material manner. The foregoing definition
shall not be deemed to be inclusive of all the acts or omissions which the
Corporation (or any Parent or Subsidiary) may consider as grounds for the
dismissal or discharge of any Optionee, Participant or other person in the
Service of the Corporation (or any Parent or Subsidiary).

        N. 1934 ACT shall mean the Securities Exchange Act of 1934, as amended.

        O. NON-STATUTORY OPTION shall mean an option not intended to satisfy the
requirements of Code Section 422.

        P. OPTION GRANT PROGRAM shall mean the option grant program in effect
under the Plan.

        Q. OPTIONEE shall mean any person to whom an option is granted under the
Plan.

        R. PARENT shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, 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.

        S. PARTICIPANT shall mean any person who is issued shares of Common
Stock under the Stock Issuance Program.

        T. PLAN shall mean the Corporation's 1997 Stock Incentive Plan, as set
forth in this document.

        U. PLAN ADMINISTRATOR shall mean either the Board or the Committee
acting in its capacity as administrator of the Plan.

        V. SERVICE shall mean the provision of services to the Corporation (or
any Parent or Subsidiary) by a person in the capacity of an Employee, a
non-employee member of the board of directors or a consultant or independent
advisor, except to the extent otherwise specifically provided in the documents
evidencing the option grant.

        W. STOCK EXCHANGE shall mean either the American Stock Exchange or the
New York Stock Exchange.


                                      A-3.


   19

        X. STOCK ISSUANCE AGREEMENT shall mean the agreement entered into by the
Corporation and the Participant at the time of issuance of shares of Common
Stock under the Stock Issuance Program.

        Y. STOCK ISSUANCE PROGRAM shall mean the stock issuance program in
effect under the Plan.

        Z. SUBSIDIARY shall mean any corporation (other than the Corporation) in
an unbroken chain of corporations beginning with the Corporation, provided each
corporation (other than the last corporation) in the unbroken chain owns, at the
time of the determination, 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.

        AA. 10% SHAREHOLDER shall mean the owner of stock (as determined under
Code Section 424(d)) possessing more than ten percent (10%) of the total
combined voting power of all classes of stock of the Corporation (or any Parent
or Subsidiary).


                                      A-4.




   20

                             ANSYS DIAGNOSTICS, INC.
                         NOTICE OF GRANT OF STOCK OPTION

               Notice is hereby given of the following option grant (the
"Option") to purchase shares of the Common Stock of Ansys Diagnostics, Inc. (the
"Corporation"):

               Optionee: _____________________________________________________
               Grant Date: ___________________________________________________
               Vesting Commencement Date: ____________________________________
               Exercise Price:  $____________ per share
               Number of Option Shares: ____________ shares of Common Stock
               Expiration Date: ______________________________________________
               Type of Option:              [ ] Incentive Stock Option
                                            [ ] Non-Statutory Stock Option
               Date Exercisable:  Immediately Exercisable

               Vesting Schedule: The Option Shares shall be initially unvested
               and subject to repurchase by the Corporation at the Exercise
               Price paid per share. Optionee shall acquire a vested interest
               in, and the Corporation's repurchase right shall accordingly
               lapse with respect to, (i) twenty five percent (25%) of the
               Option Shares upon Optionee's completion of one (1) year of
               Service measured from the Vesting Commencement Date and (ii) the
               balance of the Option Shares in a series of thirty-six (36)
               successive equal monthly installments upon Optionee's completion
               of each additional month of Service over the thirty-six
               (36)-month period measured from the first anniversary of the
               Vesting Commencement Date. In no event shall any additional
               Option Shares vest after Optionee's cessation of Service.

               Optionee understands and agrees that the Option is granted
subject to and in accordance with the terms of the Ansys Diagnostics, Inc. 1997
Stock Incentive Plan (the "Plan"). Optionee further agrees to be bound by the
terms of the Plan and the terms of the Option as set forth in the Stock Option
Agreement attached hereto as Exhibit A.

               Optionee understands that any Option Shares purchased under the
Option will be subject to the terms set forth in the Stock Purchase Agreement
attached hereto as Exhibit B.



   21
Optionee further acknowledges receipt of a copy of the Plan in the form attached
hereto as Exhibit C.

               REPURCHASE RIGHTS. OPTIONEE HEREBY AGREES THAT ALL OPTION SHARES
ACQUIRED UPON THE EXERCISE OF THE OPTION SHALL BE SUBJECT TO CERTAIN REPURCHASE
RIGHTS AND RIGHTS OF FIRST REFUSAL EXERCISABLE BY THE CORPORATION AND ITS
ASSIGNS. THE TERMS OF SUCH RIGHTS ARE SPECIFIED IN THE ATTACHED STOCK PURCHASE
AGREEMENT.

               No Employment or Service Contract. Nothing in this Notice or in
the attached Stock Option Agreement or Plan shall confer upon Optionee any right
to continue in Service for any period of specific duration or interfere with or
otherwise restrict in any way the rights of the Corporation (or any Parent or
Subsidiary employing or retaining Optionee) or of Optionee, which rights are
hereby expressly reserved by each, to terminate Optionee's Service at any time
for any reason, with or without cause.

               Definitions. All capitalized terms in this Notice shall have the
meaning assigned to them in this Notice or in the attached Stock Option
Agreement.

DATED:                     , 199
      --------------------      --

                                     ANSYS DIAGNOSTICS, INC.

                                     By:
                                         ---------------------------------------
                                     Title:
                                           -------------------------------------

                                     -------------------------------------------
                                                   OPTIONEE

                                     Address:
                                             -----------------------------------

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

ATTACHMENTS:
EXHIBIT A - STOCK OPTION AGREEMENT
EXHIBIT B - STOCK PURCHASE AGREEMENT
EXHIBIT C - 1997 STOCK INCENTIVE PLAN


                                       2.
   22

                                    EXHIBIT A

                             STOCK OPTION AGREEMENT




   23

                                    EXHIBIT B

                            STOCK PURCHASE AGREEMENT



   24

                                    EXHIBIT C

                            1997 STOCK INCENTIVE PLAN


   25

                             ANSYS DIAGNOSTICS, INC.
                             STOCK OPTION AGREEMENT



RECITALS

        A. The Board has adopted the Plan for the purpose of retaining the
services of selected Employees, non-employee members of the Board or the board
of directors of any Parent or Subsidiary and consultants and other independent
advisors in the service of the Corporation (or any Parent or Subsidiary).

        B. Optionee is to render valuable services to the Corporation (or a
Parent or Subsidiary), and this Agreement is executed pursuant to, and is
intended to carry out the purposes of, the Plan in connection with the
Corporation's grant of an option to Optionee.

        C. All capitalized terms in this Agreement shall have the meaning
assigned to them in the attached Appendix.

               NOW, THEREFORE, it is hereby agreed as follows:

               1. GRANT OF OPTION. The Corporation hereby grants to Optionee, as
of the Grant Date, an option to purchase up to the number of Option Shares
specified in the Grant Notice. The Option Shares shall be purchasable from time
to time during the option term specified in Paragraph 2 at the Exercise Price.

               2. OPTION TERM. This option shall have a term of ten (10) years
measured from the Grant Date and shall accordingly expire at the close of
business on the Expiration Date, unless sooner terminated in accordance with
Paragraph 5 or 6.

               3. LIMITED TRANSFERABILITY. During Optionee's lifetime, this
option shall be exercisable only by Optionee and shall not be assignable or
transferable other than by will or by the laws of descent and distribution
following Optionee's death.

               4. DATES OF EXERCISE. This option shall become exercisable for
the Option Shares in one or more installments as specified in the Grant Notice.
As the option becomes exercisable for such installments, those installments
shall accumulate, and the option shall remain exercisable for the accumulated
installments until the Expiration Date or sooner termination of the option term
under Paragraph 5 or 6.

               5. CESSATION OF SERVICE. The option term specified in Paragraph 2
shall terminate (and this option shall cease to be outstanding) prior to the
Expiration Date should any of the following provisions become applicable:



   26
                   (a) Should Optionee cease to remain in Service for any reason
(other than death, Disability or Misconduct) while this option is outstanding,
then Optionee shall have a period of three (3) months (commencing with the date
of such cessation of Service) during which to exercise this option, but in no
event shall this option be exercisable at any time after the Expiration Date.

                   (b) Should Optionee die while this option is outstanding,
then the personal representative of Optionee's estate or the person or persons
to whom the option is transferred pursuant to Optionee's will or in accordance
with the laws of inheritance shall have the right to exercise this option. Such
right shall lapse, and this option shall cease to be outstanding, upon the
earlier of (i) the expiration of the twelve (12)-month period measured from the
date of Optionee's death or (ii) the Expiration Date.

                   (c) Should Optionee cease Service by reason of Disability
while this option is outstanding, then Optionee shall have a period of twelve
(12) months (commencing with the date of such cessation of Service) during which
to exercise this option. In no event shall this option be exercisable at any
time after the Expiration Date.

               Note: Exercise of this option on a date later than three (3)
               months following cessation of Service due to Disability will
               result in loss of favorable Incentive Option treatment, unless
               such Disability constitutes Permanent Disability. In the event
               that Incentive Option treatment is not available, this option
               will be taxed as a Non-Statutory Option upon exercise.

                   (d) During the limited period of post-Service exercisability,
this option may not be exercised in the aggregate for more than the number of
Option Shares in which Optionee is, at the time of Optionee's cessation of
Service, vested pursuant to the Vesting Schedule specified in the Grant Notice
or the special vesting acceleration provisions of Paragraph 6. Upon the
]expiration of such limited exercise period or (if earlier) upon the Expiration
Date, this option shall terminate and cease to be outstanding for any vested
Option Shares for which the option has not been exercised. To the extent
Optionee is not vested in the Option Shares at the time of Optionee's cessation
of Service, this option shall immediately terminate and cease to be outstanding
with respect to those shares.

                   (e) Should Optionee's Service be terminated for Misconduct,
then this option shall terminate immediately and cease to remain outstanding.

            6. ACCELERATED VESTING.

                   (a) In the event of any Corporate Transaction, the Option
Shares at the time subject to this option but not otherwise vested shall
automatically vest in full so that this option shall, immediately prior to the
effective date of the Corporate Transaction, become exercisable for all of the
Option Shares as fully-vested shares and may be exercised for any or
all of those vested


                                       2.
   27

shares. However, the Option Shares shall NOT vest on such an accelerated basis
if and to the extent: (i) this option is assumed by the successor corporation
(or parent thereof) in the Corporate Transaction and the Corporation's
repurchase rights with respect to the unvested Option Shares are assigned to
such successor corporation (or parent thereof) or (ii) this option is to be
replaced with a cash incentive program of the successor corporation which
preserves the spread existing on the unvested Option Shares at the time of the
Corporate Transaction (the excess of the Fair Market Value of those Option
Shares over the Exercise Price payable for such shares) and provides for
subsequent payout in accordance with the same Vesting Schedule applicable to
those unvested Option Shares as set forth in the Grant Notice.

                      (b) Immediately following the Corporate Transaction, this
option shall terminate and cease to be outstanding, except to the extent assumed
by the successor corporation (or parent thereof) in connection with the
Corporate Transaction.

                      (c) If this option is assumed in connection with a
Corporate Transaction, then this option shall be appropriately adjusted,
immediately after such Corporate Transaction, to apply to the number and class
of securities which would have been issuable to Optionee in consummation of such
Corporate Transaction had the option been exercised immediately prior to such
Corporate Transaction, and appropriate adjustments shall also be made to the
Exercise Price, provided the aggregate Exercise Price shall remain the same.

                      (d) The Option Shares may also vest upon an accelerated
basis in accordance with the terms and conditions of any special addendum
attached to this Agreement.

                      (e) This Agreement shall not in any way affect the right
of the Corporation to adjust, reclassify, reorganize or otherwise change its
capital or business structure or to merge, consolidate, dissolve, liquidate or
sell or transfer all or any part of its business or assets.

               7. ADJUSTMENT IN OPTION SHARES. Should any change be made to the
Common Stock by reason of any stock split, stock dividend, recapitalization,
combination of shares, exchange of shares or other change affecting the
outstanding Common Stock as a class without the Corporation's receipt of
consideration, appropriate adjustments shall be made to (i) the total number
and/or class of securities subject to this option and (ii) the Exercise Price in
order to reflect such change and thereby preclude a dilution or enlargement of
benefits hereunder.

               8. SHAREHOLDER RIGHTS. The holder of this option shall not have
any shareholder rights with respect to the Option Shares until such person shall
have exercised the option, paid the Exercise Price and become the record holder
of the purchased shares.

                9. MANNER OF EXERCISING OPTION.

                      (a) In order to exercise this option with respect to all
or any part of the Option Shares for which this option is at the time
exercisable, Optionee (or any other person or persons exercising the option)
must take the following actions:

                                       3.
   28
                                (i) Execute and deliver to the Corporation a
        Purchase Agreement for the Option Shares for which the option is
        exercised.

                                 (ii) Pay the aggregate Exercise Price for the
        purchased shares in one or more of the following forms:

                                      (A) cash or check made payable to the
                Corporation; or

                                      (B) a promissory note payable to the
                Corporation, but only to the extent authorized by the Plan
                Administrator in accordance with Paragraph 14.

                      Should the Common Stock be registered under Section 12 of
                the 1934 Act at the time the option is exercised, then the
                Exercise Price may also be paid as follows:

                                      (C) in shares of Common Stock held by
                Optionee (or any other person or persons exercising the option)
                for the requisite period necessary to avoid a charge to the
                Corporation's earnings for financial reporting purposes and
                valued at Fair Market Value on the Exercise Date; or

                                      (D) to the extent the option is exercised
                for vested Option Shares, through a special sale and remittance
                procedure pursuant to which Optionee (or any other person or
                persons exercising the option) shall concurrently provide
                irrevocable instructions (a) to a Corporation-designated
                brokerage firm to effect the immediate sale of the purchased
                shares and remit to the Corporation, out of the sale proceeds
                available on the settlement date, sufficient funds to cover the
                aggregate Exercise Price payable for the purchased shares plus
                all applicable Federal, state and local income and employment
                taxes required to be withheld by the Corporation by reason of
                such exercise and (b) to the Corporation to deliver the
                certificates for the purchased shares directly to such brokerage
                firm in order to complete the sale.

                      Except to the extent the sale and remittance procedure is
               utilized in connection with the option exercise, payment of the
               Exercise Price must accompany the Purchase Agreement delivered to
               the Corporation in connection with the option exercise.

                                (iii) Furnish to the Corporation appropriate
        documentation that the person or persons exercising the option (if other
        than Optionee) have the right to exercise this option.



                                       4.
   29

                                 (iv) Execute and deliver to the Corporation
        such written representations as may be requested by the Corporation in
        order for it to comply with the applicable requirements of Federal and
        state securities laws.

                                  (v) Make appropriate arrangements with the
        Corporation (or Parent or Subsidiary employing or retaining Optionee)
        for the satisfaction of all Federal, state and local income and
        employment tax withholding requirements applicable to the option
        exercise.

                          (b) As soon as practical after the Exercise Date, the
Corporation shall issue to or on behalf of Optionee (or any other person or
persons exercising this option) a certificate for the purchased Option Shares,
with the appropriate legends affixed thereto.

                          (c) In no event may this option be exercised for any
fractional shares.

               10. REPURCHASE RIGHTS. ALL OPTION SHARES ACQUIRED UPON THE
EXERCISE OF THIS OPTION SHALL BE SUBJECT TO CERTAIN RIGHTS OF THE CORPORATION
AND ITS ASSIGNS TO REPURCHASE THOSE SHARES IN ACCORDANCE WITH THE TERMS
SPECIFIED IN THE PURCHASE AGREEMENT.

               11. COMPLIANCE WITH LAWS AND REGULATIONS.

                          (a) The exercise of this option and the issuance of
the Option Shares upon such exercise shall be subject to compliance by the
Corporation and Optionee with all applicable requirements of law relating
thereto and with all applicable regulations of any stock exchange (or the Nasdaq
National Market, if applicable) on which the Common Stock may be listed for
trading at the time of such exercise and issuance.

                          (b) The inability of the Corporation to obtain
approval from any regulatory body having authority deemed by the Corporation to
be necessary to the lawful issuance and sale of any Common Stock pursuant to
this option shall relieve the Corporation of any liability with respect to the
non-issuance or sale of the Common Stock as to which such approval shall not
have been obtained. The Corporation, however, shall use its best efforts to
obtain all such approvals.

               12. SUCCESSORS AND ASSIGNS. Except to the extent otherwise
provided in Paragraphs 3 and 6, the provisions of this Agreement shall inure to
the benefit of, and be binding upon, the Corporation and its successors and
assigns and Optionee, Optionee's assigns and the legal representatives, heirs
and legatees of Optionee's estate.

               13. NOTICES. Any notice required to be given or delivered to the
Corporation under the terms of this Agreement shall be in writing and addressed
to the Corporation at its principal corporate offices. Any notice required to be
given or delivered to Optionee shall be in writing and addressed to Optionee at
the address indicated below Optionee's signature line on the



                                       5.
   30

Grant Notice. All notices shall be deemed effective upon personal delivery or
upon deposit in the U.S. mail, postage prepaid and properly addressed to the
party to be notified.

               14. FINANCING. The Plan Administrator may, in its absolute
discretion and without any obligation to do so, permit Optionee to pay the
Exercise Price for the purchased Option Shares by delivering a full-recourse,
interest-bearing promissory note secured by those Option Shares. The payment
schedule in effect for any such promissory note shall be established by the Plan
Administrator in its sole discretion.

               15. CONSTRUCTION. This Agreement and the option evidenced hereby
are made and granted pursuant to the Plan and are in all respects limited by and
subject to the terms of the Plan. All decisions of the Plan Administrator with
respect to any question or issue arising under the Plan or this Agreement shall
be conclusive and binding on all persons having an interest in this option.

               16. GOVERNING LAW. The interpretation, performance and
enforcement of this Agreement shall be governed by the laws of the State of
California without resort to that State's conflict-of-laws rules.

               17. SHAREHOLDER APPROVAL. If the Option Shares covered by this
Agreement exceed, as of the Grant Date, the number of shares of Common Stock
which may be issued under the Plan as last approved by the shareholders, then
this option shall be void with respect to such excess shares, unless shareholder
approval of an amendment sufficiently increasing the number of shares of Common
Stock issuable under the Plan is obtained in accordance with the provisions of
the Plan.

               18. ADDITIONAL TERMS APPLICABLE TO AN INCENTIVE OPTION. In the
event this option is designated an Incentive Option in the Grant Notice, the
following terms and conditions shall also apply to the grant:

                        (a) This option shall cease to qualify for favorable tax
treatment as an Incentive Option if (and to the extent) this option is exercised
for one or more Option Shares: (i) more than three (3) months after the date
Optionee ceases to be an Employee for any reason other than death or Permanent
Disability or (ii) more than twelve (12) months after the date Optionee ceases
to be an Employee by reason of Permanent Disability.

                        (b) This option shall not become exercisable in the
calendar year in which granted if (and to the extent) the aggregate Fair Market
Value (determined at the Grant Date) of the Common Stock for which this option
would otherwise first become exercisable in such calendar year would, when added
to the aggregate value (determined as of the respective date or dates of grant)
of the Common Stock and any other securities for which one or more other
Incentive Options granted to Optionee prior to the Grant Date (whether under the
Plan or any other option plan of the Corporation or any Parent or Subsidiary)
first become exercisable during the same calendar year, exceed One Hundred
Thousand Dollars ($100,000) in the aggregate. To the extent the exercisability


                                       6.
   31
of this option is deferred by reason of the foregoing limitation, the deferred
portion shall become exercisable in the first calendar year or years thereafter
in which the One Hundred Thousand Dollar ($100,000) limitation of this Paragraph
18(b) would not be contravened, but such deferral shall in all events end
immediately prior to the effective date of a Corporate Transaction in which this
option is not to be assumed, whereupon the option shall become immediately
exercisable as a Non-Statutory Option for the deferred portion of the Option
Shares.

                      (c) Should Optionee hold, in addition to this option, one
or more other options to purchase Common Stock which become exercisable for the
first time in the same calendar year as this option, then the foregoing
limitations on the exercisability of such options as Incentive Options shall be
applied on the basis of the order in which such options are granted.




                                       7.
   32
                                    APPENDIX


               The following definitions shall be in effect under the Agreement:

        A. AGREEMENT shall mean this Stock Option Agreement.

        B. BOARD shall mean the Corporation's Board of Directors.

        C. CODE shall mean the Internal Revenue Code of 1986, as amended.

        D. COMMON STOCK shall mean the Corporation's common stock.

        E. CORPORATE TRANSACTION shall mean either of the following
shareholder-approved transactions to which the Corporation is a party:

                    (i) a merger or consolidation in which securities possessing
        more than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

                   (ii) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. CORPORATION shall mean Ansys Diagnostics, Inc., a California
corporation.

        G. DISABILITY shall mean the inability of Optionee to engage in any
substantial gainful activity by reason of any medically determinable physical or
mental impairment and shall be determined by the Plan Administrator on the basis
of such medical evidence as the Plan Administrator deems warranted under the
circumstances. Disability shall be deemed to constitute PERMANENT DISABILITY in
the event that such Disability is expected to result in death or has lasted or
can be expected to last for a continuous period of twelve (12) months or more.

        H. EMPLOYEE shall mean an individual who is in the employ of the
Corporation (or any Parent or Subsidiary), subject to the control and direction
of the employer entity as to both the work to be performed and the manner and
method of performance.

        I. EXERCISE DATE shall mean the date on which the option shall have been
exercised in accordance with Paragraph 9 of the Agreement.

        J. EXERCISE PRICE shall mean the exercise price payable per Option Share
as specified in the Grant Notice.



                                      A-1.

   33
        K. EXPIRATION DATE shall mean the date on which the option expires as
specified in the Grant Notice.

        L. FAIR MARKET VALUE per share of Common Stock on any relevant date
shall be determined in accordance with the following provisions:

                    (i) If the Common Stock is at the time traded on the Nasdaq
        National Market, then the Fair Market Value shall be the closing selling
        price per share of Common Stock on the date in question, as the price is
        reported by the National Association of Securities Dealers on the Nasdaq
        National Market. If there is no closing selling price for the Common
        Stock on the date in question, then the Fair Market Value shall be the
        closing selling price on the last preceding date for which such
        quotation exists.

                   (ii) If the Common Stock is at the time listed on any Stock
        Exchange, then the Fair Market Value shall be the closing selling price
        per share of Common Stock on the date in question on the Stock Exchange
        determined by the Plan Administrator to be the primary market for the
        Common Stock, as such price is officially quoted in the composite tape
        of transactions on such exchange. If there is no closing selling price
        for the Common Stock on the date in question, then the Fair Market Value
        shall be the closing selling price on the last preceding date for which
        such quotation exists.

                  (iii) If the Common Stock is at the time neither listed on any
        Stock Exchange nor traded on the Nasdaq National Market, then the Fair
        Market Value shall be determined by the Plan Administrator after taking
        into account such factors as the Plan Administrator shall deem
        appropriate.

        M. GRANT DATE shall mean the date of grant of the option as specified in
the Grant Notice.

        N. GRANT NOTICE shall mean the Notice of Grant of Stock Option
accompanying the Agreement, pursuant to which Optionee has been informed of the
basic terms of the option evidenced hereby.

        O. INCENTIVE OPTION shall mean an option which satisfies the
requirements of Code Section 422.

        P. MISCONDUCT shall mean the commission of any act of fraud,
embezzlement or dishonesty by Optionee, any unauthorized use or disclosure by
Optionee of confidential information or trade secrets of the Corporation (or any
Parent or Subsidiary), or any other intentional misconduct by Optionee adversely
affecting the business or affairs of the Corporation (or any Parent or
Subsidiary) in a material manner. The foregoing definition shall not be deemed
to be inclusive of all the acts or omissions which the Corporation (or any
Parent or Subsidiary)
may consider as



                                      A-2.
   34

grounds for the dismissal or discharge of Optionee or any other individual in
the Service of the Corporation (or any Parent or Subsidiary).

        Q. 1934 ACT shall mean the Securities Exchange Act of 1934, as amended.

        R. NON-STATUTORY OPTION shall mean an option not intended to satisfy the
requirements of Code Section 422.

        S. OPTION SHARES shall mean the number of shares of Common Stock subject
to the option.

        T. OPTIONEE shall mean the person to whom the option is granted as
specified in the Grant Notice.

        U. PARENT shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, 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.

        V. PLAN shall mean the Corporation's 1997 Stock Incentive Plan.

        W. PLAN ADMINISTRATOR shall mean either the Board or a committee of the
Board acting in its capacity as administrator of the Plan.

        X. PURCHASE AGREEMENT shall mean the stock purchase agreement in
substantially the form of Exhibit B to the Grant Notice.

        Y. SERVICE shall mean the Optionee's performance of services for the
Corporation (or any Parent or Subsidiary) in the capacity of an Employee, a
non-employee member of the board of directors or an independent consultant.

        Z. STOCK EXCHANGE shall mean the American Stock Exchange or the New York
Stock Exchange.

        AA. SUBSIDIARY shall mean any corporation (other than the Corporation)
in an unbroken chain of corporations beginning with the Corporation, provided
each corporation (other than the last corporation) in the unbroken chain owns,
at the time of the determination, 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.

        AB. VESTING SCHEDULE shall mean the vesting schedule specified in the
Grant Notice pursuant to which the Optionee is to vest in the Option Shares in a
series of installments over his or her period of Service.

                                      A-3.



   35

                                    ADDENDUM
                                       TO
                             STOCK OPTION AGREEMENT


               The following provisions are hereby incorporated into, and are
hereby made a part of, that certain Stock Option Agreement dated (the "Option
Agreement") by and between Ansys Diagnostics, Inc. (the "Corporation") and
         ("Optionee") evidencing the stock option (the "Option") granted on such
date to Optionee under the terms of the Corporation's 1997 Stock Incentive Plan,
and such provisions shall be effective immediately. All capitalized terms in
this Addendum, to the extent not otherwise defined herein, shall have the
meanings assigned to them in the Option Agreement.

                        INVOLUNTARY TERMINATION FOLLOWING
                              CORPORATE TRANSACTION

               1. To the extent the Option is, in connection with a Corporate
Transaction, to be assumed in accordance with Paragraph 6 of the Option
Agreement, the Option Shares shall not vest on an accelerated basis upon the
occurrence of that Corporate Transaction, and Optionee shall accordingly
continue, over his or her period of Service following the Corporate Transaction,
to vest in those Option Shares in one or more installments in accordance with
the provisions of the Option Agreement. However, upon an Involuntary Termination
of Optionee's Service within eighteen (18) months following such Corporate
Transaction, all the Option Shares at the time subject to the Option shall
automatically vest in full on an accelerated basis so that the Option shall
immediately become exercisable for all the Option Shares as fully-vested shares
and may be exercised for any or all of those Option Shares as vested shares. The
Option shall remain so exercisable until the earlier of (i) the Expiration Date
or (ii) the expiration of the one (1)-year period measured from the date of the
Involuntary Termination.

               2. For purposes of this Addendum, an INVOLUNTARY TERMINATION
shall mean the termination of Optionee's Service by reason of:

                        (i) Optionee's involuntary dismissal or discharge by the
                Corporation for reasons other than for Misconduct, or

                        (ii) Optionee's voluntary resignation following (A) a
                change in Optionee's position with the Corporation (or Parent or
                Subsidiary employing Optionee) which materially reduces
                Optionee's duties and responsibilities or the level of
                management to which he or she reports, (B) a reduction in
                Optionee's level of compensation (including base salary, fringe
                benefits and target bonuses under any corporate-performance
                based incentive programs) by more than fifteen percent (15%) or
                (C) a relocation of Optionee's place of employment by more than
                fifty (50) miles, provided and only if such change, reduction or
                relocation is effected by the Corporation without Optionee's
                consent.


   36



               3. The provisions of Paragraph 1 of this Addendum shall govern
the period for which the Option is to remain exercisable following the
Involuntary Termination of Optionee's Service within eighteen (18) months after
the Corporate Transaction and shall supersede any provisions to the contrary in
Paragraph 5 of the Option Agreement. The provisions of this Addendum shall also
supersede any provisions to the contrary in Paragraph 18 of the Option Agreement
concerning the deferred exercisability of the Option.

               IN WITNESS WHEREOF, Ansys Diagnostics, Inc. has caused this
Addendum to be executed by its duly-authorized officer as of the Effective Date
specified below.


                                                   ANSYS DIAGNOSTICS, INC.

                                                   BY:
                                                      --------------------------
                                                   TITLE:
                                                           ---------------------


EFFECTIVE DATE:                   , 199
                -----------------


                                       2.


   37
                             ANSYS DIAGNOSTICS, INC.

                            STOCK PURCHASE AGREEMENT


               AGREEMENT made this ________ day of _____________________ 199___,
by and between Ansys Diagnostics, Inc., a California corporation, and
____________________, Optionee under the Corporation's 1997 Stock Incentive
Plan.

               All capitalized terms in this Agreement shall have the meaning
assigned to them in this Agreement or in the attached Appendix.

        A. EXERCISE OF OPTION

               1. EXERCISE. Optionee hereby purchases ______ shares of Common
Stock (the "Purchased Shares") pursuant to that certain option (the "Option")
granted Optionee on ____________________, 199__ (the "Grant Date") to purchase
up to _______________ shares of Common Stock (the "Option Shares") under the
Plan at the exercise price of $___________ per share (the "Exercise Price").

               2. PAYMENT. Concurrently with the delivery of this Agreement to
the Corporation, Optionee shall pay the Exercise Price for the Purchased Shares
in accordance with the provisions of the Option Agreement and shall deliver
whatever additional documents may be required by the Option Agreement as a
condition for exercise, together with a duly-executed blank Assignment Separate
from Certificate (in the form attached hereto as Exhibit I) with respect to the
Purchased Shares.

               3. SHAREHOLDER RIGHTS. Until such time as the Corporation
exercises the Repurchase Right or the First Refusal Right, Optionee (or any
successor in interest) shall have all the rights of a shareholder (including
voting, dividend and liquidation rights) with respect to the Purchased Shares,
subject, however, to the transfer restrictions of Articles B and C.

        B. SECURITIES LAW COMPLIANCE

               1. RESTRICTED SECURITIES. The Purchased Shares have not been
registered under the 1933 Act and are being issued to Optionee in reliance upon
the exemption from such registration provided by SEC Rule 701 for stock
issuances under compensatory benefit plans such as the Plan. Optionee hereby
confirms that Optionee has been informed that the Purchased Shares are
restricted securities under the 1933 Act and may not be resold or transferred
unless the Purchased Shares are first registered under the Federal securities
laws or unless an exemption from such registration is available. Accordingly,
Optionee hereby acknowledges that Optionee is prepared to hold the


   38

Purchased Shares for an indefinite period and that Optionee is aware that SEC
Rule 144 issued under the 1933 Act which exempts certain resales of unrestricted
securities is not presently available to exempt the resale of the Purchased
Shares from the registration requirements of the 1933 Act.

               2. RESTRICTIONS ON DISPOSITION OF PURCHASED SHARES. Optionee
shall make no disposition of the Purchased Shares (other than a Permitted
Transfer) unless and until there is compliance with all of the following
requirements:

                           (i) Optionee shall have provided the Corporation with
        a written summary of the terms and conditions of the proposed
        disposition.

                          (ii) Optionee shall have complied with all
        requirements of this Agreement applicable to the disposition of the
        Purchased Shares.

                         (iii) Optionee shall have provided the Corporation with
        written assurances, in form and substance satisfactory to the
        Corporation, that (a) the proposed disposition does not require
        registration of the Purchased Shares under the 1933 Act or (b) all
        appropriate action necessary for compliance with the registration
        requirements of the 1933 Act or any exemption from registration
        available under the 1933 Act (including Rule 144) has been taken.

               The Corporation shall not be required (i) to transfer on its
books any Purchased Shares which have been sold or transferred in violation of
the provisions of this Agreement or (ii) to treat as the owner of the Purchased
Shares, or otherwise to accord voting, dividend or liquidation rights to, any
transferee to whom the Purchased Shares have been transferred in contravention
of this Agreement.

               3. RESTRICTIVE LEGENDS. The stock certificates for the Purchased
Shares shall be endorsed with one or more of the following restrictive legends:

                      "THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
        REGISTERED UNDER THE SECURITIES ACT OF 1933. THE SHARES MAY NOT BE SOLD
        OR OFFERED FOR SALE IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION
        STATEMENT FOR THE SHARES UNDER SUCH ACT, (B) A "NO ACTION" LETTER OF THE
        SECURITIES AND EXCHANGE COMMISSION WITH RESPECT TO SUCH SALE OR OFFER OR
        (C) SATISFACTORY ASSURANCES TO THE CORPORATION THAT REGISTRATION UNDER
        SUCH ACT IS NOT REQUIRED WITH RESPECT TO SUCH SALE OR OFFER."

                                       2.
   39

                      "THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO
        CERTAIN REPURCHASE RIGHTS AND RIGHTS OF FIRST REFUSAL GRANTED TO THE
        CORPORATION AND ACCORDINGLY MAY NOT BE SOLD, ASSIGNED, TRANSFERRED,
        ENCUMBERED, OR IN ANY MANNER DISPOSED OF EXCEPT IN CONFORMITY WITH THE
        TERMS OF A WRITTEN AGREEMENT DATED _______________, 199___ BETWEEN THE
        CORPORATION AND THE REGISTERED HOLDER OF THE SHARES (OR THE PREDECESSOR
        IN INTEREST TO THE SHARES). A COPY OF SUCH AGREEMENT IS MAINTAINED AT
        THE CORPORATION'S PRINCIPAL CORPORATE OFFICES."

        C. TRANSFER RESTRICTIONS

               1. RESTRICTION ON TRANSFER. Except for any Permitted Transfer,
Optionee shall not transfer, assign, encumber or otherwise dispose of any of the
Purchased Shares which are subject to the Repurchase Right. In addition,
Purchased Shares which are released from the Repurchase Right shall not be
transferred, assigned, encumbered or otherwise disposed of in contravention of
the First Refusal Right or the Market Stand-Off.

               2. TRANSFEREE OBLIGATIONS. Each person (other than the
Corporation) to whom the Purchased Shares are transferred by means of a
Permitted Transfer must, as a condition precedent to the validity of such
transfer, acknowledge in writing to the Corporation that such person is bound by
the provisions of this Agreement and that the transferred shares are subject to
(i) the Repurchase Right, (ii) the First Refusal Right and (iii) the Market
Stand-Off, to the same extent such shares would be so subject if retained by
Optionee.

               3. MARKET STAND-OFF.

                      (a) In connection with any underwritten public offering
by the Corporation of its equity securities pursuant to an effective
registration statement filed under the 1933 Act, including the Corporation's
initial public offering, Owner shall not sell, make any short sale of, loan,
hypothecate, pledge, grant any option for the purchase of, or otherwise dispose
or transfer for value or otherwise agree to engage in any of the foregoing
transactions with respect to, any Purchased Shares without the prior written
consent of the Corporation or its underwriters. Such restriction (the "Market
Stand-Off") shall be in effect for such period of time from and after the
effective date of the final prospectus for the offering as may be requested by
the Corporation or such underwriters. In no event, however, shall such period
exceed one hundred eighty (180) days and the Market Stand-Off shall in all
events terminate two (2) years after the effective date of the Corporation's
initial public offering.

                      (b) Owner shall be subject to the Market Stand-Off
provided and only if the officers and directors of the Corporation are also
subject to similar restrictions.


                                       3.
   40

                      (c) Any new, substituted or additional securities which
are by reason of any Recapitalization or Reorganization distributed with respect
to the Purchased Shares shall be immediately subject to the Market Stand-Off, to
the same extent the Purchased Shares are at such time covered by such
provisions.

                      (d) In order to enforce the Market Stand-Off, the
Corporation may impose stop-transfer instructions with respect to the Purchased
Shares until the end of the applicable stand-off period.

        D. REPURCHASE RIGHT

               1. GRANT. The Corporation is hereby granted the right (the
"Repurchase Right"), exercisable at any time during the sixty (60)-day period
following the date Optionee ceases for any reason to remain in Service or (if
later) during the sixty (60)-day period following the execution date of this
Agreement, to repurchase at the Exercise Price any or all of the Purchased
Shares in which Optionee is not, at the time of his or her cessation of Service,
vested in accordance with the Vesting Schedule applicable to those shares or the
special vesting acceleration provisions of Paragraph D.6 of this Agreement (such
shares to be hereinafter referred to as the "Unvested Shares").

               2. EXERCISE OF THE REPURCHASE RIGHT. The Repurchase Right shall
be exercisable by written notice delivered to each Owner of the Unvested Shares
prior to the expiration of the sixty (60)-day exercise period. The notice shall
indicate the number of Unvested Shares to be repurchased and the date on which
the repurchase is to be effected, such date to be not more than thirty (30) days
after the date of such notice. The certificates representing the Unvested Shares
to be repurchased shall be delivered to the Corporation on or before the close
of business on the date specified for the repurchase. Concurrently with the
receipt of such stock certificates, the Corporation shall pay to Owner, in cash
or cash equivalents (including the cancellation of any purchase-money
indebtedness), an amount equal to the Exercise Price previously paid for the
Unvested Shares which are to be repurchased from Owner.

               3. TERMINATION OF THE REPURCHASE RIGHT. The Repurchase Right
shall terminate with respect to any Unvested Shares for which it is not timely
exercised under Paragraph D.2. In addition, the Repurchase Right shall terminate
and cease to be exercisable with respect to any and all Purchased Shares in
which Optionee vests in accordance with the Vesting Schedule. All Purchased
Shares as to which the Repurchase Right lapses shall, however, remain subject to
(i) the First Refusal Right and (ii) the Market Stand-Off.

               4. AGGREGATE VESTING LIMITATION. If the Option is exercised in
more than one increment so that Optionee is a party to one or more other Stock
Purchase Agreements (the "Prior Purchase Agreements") which are executed prior
to the date of this Agreement, then the total number of Purchased Shares as to
which Optionee shall be deemed to have a fully-vested interest under this
Agreement and all Prior Purchase Agreements shall not exceed in the aggregate
the number of


                                       4.
   41

Purchased Shares in which Optionee would otherwise at the time be
vested, in accordance with the Vesting Schedule, had all the Purchased Shares
(including those acquired under the Prior Purchase Agreements) been acquired
exclusively under this Agreement.

               5. RECAPITALIZATION. Any new, substituted or additional
securities or other property (including cash paid other than as a regular cash
dividend) which is by reason of any Recapitalization distributed with respect to
the Purchased Shares shall be immediately subject to the Repurchase Right and
any escrow requirements hereunder, but only to the extent the Purchased Shares
are at the time covered by such right or escrow requirements. Appropriate
adjustments to reflect such distribution shall be made to the number and/or
class of Purchased Shares subject to this Agreement and to the price per share
to be paid upon the exercise of the Repurchase Right in order to reflect the
effect of any such Recapitalization upon the Corporation's capital structure;
provided, however, that the aggregate purchase price shall remain the same.

               6. CORPORATE TRANSACTION.

                      (a) The Repurchase Right shall automatically terminate
in its entirety, and all the Purchased Shares shall vest in full, immediately
prior to the consummation of any Corporate Transaction, except to the extent the
Repurchase Right is to be assigned to the successor entity in such Corporate
Transaction.

                      (b) To the extent the Repurchase Right remains in effect
following a Corporate Transaction, such right shall apply to any new securities
or other property (including any cash payments) received in exchange for the
Purchased Shares in consummation of the Corporate Transaction, but only to the
extent the Purchased Shares are at the time covered by such right. Appropriate
adjustments shall be made to the price per share payable upon exercise of the
Repurchase Right to reflect the effect of the Corporate Transaction upon the
Corporation's capital structure; provided, however, that the aggregate purchase
price shall remain the same. The new securities or other property (including any
cash payments) issued or distributed with respect to the Purchased Shares in
consummation of the Corporate Transaction shall be immediately deposited in
escrow with the Corporation (or the successor entity) and shall not be released
from escrow until Optionee vests in such securities or other property in
accordance with the same Vesting Schedule in effect for the Purchased Shares.

                      (c) The Repurchase Right may also terminate on an
accelerated basis, and the Purchased Shares shall immediately vest in full, in
accordance with the terms and conditions of any special addendum attached to
this Agreement.

        E. RIGHT OF FIRST REFUSAL

               1. GRANT. The Corporation is hereby granted the right of first
refusal (the "First Refusal Right"), exercisable in connection with any proposed
transfer of the Purchased Shares in


                                       5.
   42

which Optionee has vested in accordance with the provisions of Article D. For
purposes of this Article E, the term "transfer" shall include any sale,
assignment, pledge, encumbrance or other disposition of the Purchased Shares
intended to be made by Owner, but shall not include any Permitted Transfer.

               2. NOTICE OF INTENDED DISPOSITION. In the event any Owner of
Purchased Shares in which Optionee has vested desires to accept a bona fide
third-party offer for the transfer of any or all of such shares (the Purchased
Shares subject to such offer to be hereinafter referred to as the "Target
Shares"), Owner shall promptly (i) deliver to the Corporation written notice
(the "Disposition Notice") of the terms of the offer, including the purchase
price and the identity of the third-party offeror, and (ii) provide satisfactory
proof that the disposition of the Target Shares to such third-party offeror
would not be in contravention of the provisions set forth in Articles B and C.

               3. EXERCISE OF THE FIRST REFUSAL RIGHT. The Corporation shall,
for a period of twenty-five (25) days following receipt of the Disposition
Notice, have the right to repurchase any or all of the Target Shares subject to
the Disposition Notice upon the same terms as those specified therein or upon
such other terms (not materially different from those specified in the
Disposition Notice) to which Owner consents. Such right shall be exercisable by
delivery of written notice (the "Exercise Notice") to Owner prior to the
expiration of the twenty-five (25)-day exercise period. If such right is
exercised with respect to all the Target Shares, then the Corporation shall
effect the repurchase of such shares, including payment of the purchase price,
not more than five (5) business days after delivery of the Exercise Notice; and
at such time the certificates representing the Target Shares shall be delivered
to the Corporation.

               Should the purchase price specified in the Disposition Notice be
payable in property other than cash or evidences of indebtedness, the
Corporation shall have the right to pay the purchase price in the form of cash
equal in amount to the value of such property. If Owner and the Corporation
cannot agree on such cash value within ten (10) days after the Corporation's
receipt of the Disposition Notice, the valuation shall be made by an appraiser
of recognized standing selected by Owner and the Corporation or, if they cannot
agree on an appraiser within twenty (20) days after the Corporation's receipt of
the Disposition Notice, each shall select an appraiser of recognized standing
and the two (2) appraisers shall designate a third appraiser of recognized
standing, whose appraisal shall be determinative of such value. The cost of such
appraisal shall be shared equally by Owner and the Corporation. The closing
shall then be held on the later of (i) the fifth (5th) business day following
delivery of the Exercise Notice or (ii) the fifth (5th) business day after such
valuation shall have been made.

               4. NON-EXERCISE OF THE FIRST REFUSAL RIGHT. In the event the
Exercise Notice is not given to Owner prior to the expiration of the twenty-five
(25)-day exercise period, Owner shall have a period of thirty (30) days
thereafter in which to sell or otherwise dispose of the Target Shares to the
third-party offeror identified in the Disposition Notice upon terms (including
the purchase


                                       6.
   43

price) no more favorable to such third-party offeror than those specified in the
Disposition Notice; provided, however, that any such sale or disposition must
not be effected in contravention of the provisions of Articles B and C. The
third-party offeror shall acquire the Target Shares free and clear of the First
Refusal Right, but the acquired shares shall remain subject to the provisions of
Article B and Paragraph C.3. In the event Owner does not effect such sale or
disposition of the Target Shares within the specified thirty (30)-day period,
the First Refusal Right shall continue to be applicable to any subsequent
disposition of the Target Shares by Owner until such right lapses.

               5. PARTIAL EXERCISE OF THE FIRST REFUSAL RIGHT. In the event the
Corporation makes a timely exercise of the First Refusal Right with respect to a
portion, but not all, of the Target Shares specified in the Disposition Notice,
Owner shall have the option, exercisable by written notice to the Corporation
delivered within five (5) business days after Owner's receipt of the Exercise
Notice, to effect the sale of the Target Shares pursuant to either of the
following alternatives:

                      (i) sale or other disposition of all the Target Shares to
        the third-party offeror identified in the Disposition Notice, but in
        full compliance with the requirements of Paragraph E.4, as if the
        Corporation did not exercise the First Refusal Right; or

                      (ii) sale to the Corporation of the portion of the Target
        Shares which the Corporation has elected to purchase, such sale to be
        effected in substantial conformity with the provisions of Paragraph E.3.
        The First Refusal Right shall continue to be applicable to any
        subsequent disposition of the remaining Target Shares until such right
        lapses.

               Owner's failure to deliver timely notification to the Corporation
shall be deemed to be an election by Owner to sell the Target Shares pursuant to
alternative (i) above.

               6. RECAPITALIZATION/REORGANIZATION.

                      (a) Any new, substituted or additional securities or other
property which is by reason of any Recapitalization distributed with respect to
the Purchased Shares shall be immediately subject to the First Refusal Right,
but only to the extent the Purchased Shares are at the time covered by such
right.

                      (b) In the event of a Reorganization, the First Refusal
Right shall remain in full force and effect and shall apply to the new capital
stock or other property received in exchange for the Purchased Shares in
consummation of the Reorganization, but only to the extent the Purchased Shares
are at the time covered by such right.

               7. LAPSE. The First Refusal Right shall lapse upon the earliest
to occur of (i) the first date on which shares of the Common Stock are held of
record by more than five hundred



                                       7.
   44

(500) persons, (ii) a determination is made by the Board that a public market
exists for the outstanding shares of Common Stock or (iii) a firm commitment
underwritten public offering, pursuant to an effective registration statement
under the 1933 Act, covering the offer and sale of the Common Stock in the
aggregate amount of at least ten million dollars ($10,000,000). However, the
Market Stand-Off shall continue to remain in full force and effect following the
lapse of the First Refusal Right.

        F. SPECIAL TAX ELECTION

               The acquisition of the Purchased Shares may result in adverse tax
consequences which may be avoided or mitigated by filing an election under Code
Section 83(b). Such election must be filed within thirty (30) days after the
date of this Agreement. A description of the tax consequences applicable to the
acquisition of the Purchased Shares and the form for making the Code Section
83(b) election are set forth in Exhibit II. OPTIONEE SHOULD CONSULT WITH HIS OR
HER TAX ADVISOR TO DETERMINE THE TAX CONSEQUENCES OF ACQUIRING THE PURCHASED
SHARES AND THE ADVANTAGES AND DISADVANTAGES OF FILING THE CODE SECTION 83(b)
ELECTION. OPTIONEE ACKNOWLEDGES THAT IT IS OPTIONEE'S SOLE RESPONSIBILITY, AND
NOT THE CORPORATION'S, TO FILE A TIMELY ELECTION UNDER CODE SECTION 83(b), EVEN
IF OPTIONEE REQUESTS THE CORPORATION OR ITS REPRESENTATIVES TO MAKE THIS FILING
ON HIS OR HER BEHALF.

        G. GENERAL PROVISIONS

               1. ASSIGNMENT. The Corporation may assign the Repurchase Right
and/or the First Refusal Right to any person or entity selected by the Board,
including (without limitation) one or more shareholders of the Corporation.

               2. NO EMPLOYMENT OR SERVICE CONTRACT. Nothing in this Agreement
or in the Plan shall confer upon Optionee any right to continue in Service for
any period of specific duration or interfere with or otherwise restrict in any
way the rights of the Corporation (or any Parent or Subsidiary employing or
retaining Optionee) or of Optionee, which rights are hereby expressly reserved
by each, to terminate Optionee's Service at any time for any reason, with or
without cause.

               3. NOTICES. Any notice required to be given under this Agreement
shall be in writing and shall be deemed effective upon personal delivery or upon
deposit in the U.S. mail, registered or certified, postage prepaid and properly
addressed to the party entitled to such notice at the address indicated below
such party's signature line on this Agreement or at such other address as such
party may designate by ten (10) days advance written notice under this paragraph
to all other parties to this Agreement.

                                       8.
   45

               4. NO WAIVER. The failure of the Corporation in any instance to
exercise the Repurchase Right or the First Refusal Right shall not constitute a
waiver of any other repurchase rights and/or rights of first refusal that may
subsequently arise under the provisions of this Agreement or any other agreement
between the Corporation and Optionee. No waiver of any breach or condition of
this Agreement shall be deemed to be a waiver of any other or subsequent breach
or condition, whether of like or different nature.

               5. CANCELLATION OF SHARES. If the Corporation shall make
available, at the time and place and in the amount and form provided in this
Agreement, the consideration for the Purchased Shares to be repurchased in
accordance with the provisions of this Agreement, then from and after such time,
the person from whom such shares are to be repurchased shall no longer have any
rights as a holder of such shares (other than the right to receive payment of
such consideration in accordance with this Agreement). Such shares shall be
deemed purchased in accordance with the applicable provisions hereof, and the
Corporation shall be deemed the owner and holder of such shares, whether or not
the certificates therefor have been delivered as required by this Agreement.

        H. MISCELLANEOUS PROVISIONS

               1. OPTIONEE UNDERTAKING. Optionee hereby agrees to take whatever
additional action and execute whatever additional documents the Corporation may
deem necessary or advisable in order to carry out or effect one or more of the
obligations or restrictions imposed on either Optionee or the Purchased Shares
pursuant to the provisions of this Agreement.

               2. AGREEMENT IS ENTIRE CONTRACT. This Agreement constitutes the
entire contract between the parties hereto with regard to the subject matter
hereof. This Agreement is made pursuant to the provisions of the Plan and shall
in all respects be construed in conformity with the terms of the Plan.

               3. GOVERNING LAW. This Agreement shall be governed by, and
construed in accordance with, the laws of the State of California without resort
to that State's conflict-of-laws rules.

               4. COUNTERPARTS. This Agreement may be executed in counterparts,
each of which shall be deemed to be an original, but all of which together shall
constitute one and the same instrument.

               5. SUCCESSORS AND ASSIGNS. The provisions of this Agreement shall
inure to the benefit of, and be binding upon, the Corporation and its successors
and assigns and upon Optionee, Optionee's permitted assigns and the legal
representatives, heirs and legatees of Optionee's estate, whether or not any
such person shall have become a party to this Agreement and have agreed in
writing to join herein and be bound by the terms hereof.

                                       9.
   46

               IN WITNESS WHEREOF, the parties have executed this Agreement on
the day and year first indicated above.

                             ANSYS DIAGNOSTICS, INC.


                              By:
                                 -----------------------------------------------
                              Title:
                                     -------------------------------------------
                              Address:
                                       -----------------------------------------

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


                              --------------------------------------------------
                              OPTIONEE

                              Address:
                                       -----------------------------------------

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



                                       10.

   47



                             SPOUSAL ACKNOWLEDGMENT


               The undersigned spouse of Optionee has read and hereby approves
the foregoing Stock Purchase Agreement. In consideration of the Corporation's
granting Optionee the right to acquire the Purchased Shares in accordance with
the terms of such Agreement, the undersigned hereby agrees to be irrevocably
bound by all the terms of such Agreement, including (without limitation) the
right of the Corporation (or its assigns) to purchase any Purchased Shares in
which Optionee is not vested at time of his or her cessation of Service.


                                -----------------------------------------------
                                OPTIONEE'S SPOUSE

                                Address:
                                        ----------------------------------------

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


                                       11.

   48
                                    EXHIBIT I
                      ASSIGNMENT SEPARATE FROM CERTIFICATE

               FOR VALUE RECEIVED ___________ hereby sell(s), assign(s) and
transfer(s) unto Ansys Diagnostics, Inc. (the "Corporation"),
_________________(_____) shares of the Common Stock of the Corporation standing
in his or her name on the books of the Corporation represented by Certificate
No. _____ herewith and do(es) hereby irrevocably constitute and appoint
__________________________Attorney to transfer the said stock on the books of
the Corporation with full power of substitution in the premises.


Dated:_________


                                    Signature _________________________












INSTRUCTION: Please do not fill in any blanks other than the signature line.
Please sign exactly as you would like your name to appear on the issued stock
certificate. The purpose of this assignment is to enable the Corporation to
exercise the Repurchase Right without requiring additional signatures on the
part of Optionee.


   49
                                   EXHIBIT II

                       FEDERAL INCOME TAX CONSEQUENCES AND
                           SECTION 83(b) TAX ELECTION

        I. FEDERAL INCOME TAX CONSEQUENCES AND SECTION 83(b) ELECTION FOR
EXERCISE OF NON-STATUTORY OPTION. If the Purchased Shares are acquired pursuant
to the exercise of a Non-Statutory Option, as specified in the Grant Notice,
then under Code Section 83, the excess of the Fair Market Value of the Purchased
Shares on the date any forfeiture restrictions applicable to such shares lapse
over the Exercise Price paid for such shares will be reportable as ordinary
income on the lapse date. For this purpose, the term "forfeiture restrictions"
includes the right of the Corporation to repurchase the Purchased Shares
pursuant to the Repurchase Right. However, Optionee may elect under Code Section
83(b) to be taxed at the time the Purchased Shares are acquired, rather than
when and as such Purchased Shares cease to be subject to such forfeiture
restrictions. Such election must be filed with the Internal Revenue Service
within thirty (30) days after the date of the Agreement. Even if the Fair Market
Value of the Purchased Shares on the date of the Agreement equals the Exercise
Price paid (and thus no tax is payable), the election must be made to avoid
adverse tax consequences in the future. The form for making this election is
attached as part of this exhibit. FAILURE TO MAKE THIS FILING WITHIN THE
APPLICABLE THIRTY (30)-DAY PERIOD WILL RESULT IN THE RECOGNITION OF ORDINARY
INCOME BY OPTIONEE AS THE FORFEITURE RESTRICTIONS LAPSE.

        II. FEDERAL INCOME TAX CONSEQUENCES AND CONDITIONAL SECTION 83(b)
ELECTION FOR EXERCISE OF INCENTIVE OPTION. If the Purchased Shares are acquired
pursuant to the exercise of an Incentive Option, as specified in the Grant
Notice, then the following tax principles shall be applicable to the Purchased
Shares:

                      (i) For regular tax purposes, no taxable income will be
        recognized at the time the Option is exercised.

                      (ii) The excess of (a) the Fair Market Value of the
        Purchased Shares on the date the Option is exercised or (if later) on
        the date any forfeiture restrictions applicable to the Purchased Shares
        lapse over (b) the Exercise Price paid for the Purchased Shares will be
        includible in Optionee's taxable income for alternative minimum tax
        purposes.

                      (iii) If Optionee makes a disqualifying disposition of the
        Purchased Shares, then Optionee will recognize ordinary income in the
        year of such disposition equal in amount to the excess of (a) the Fair
        Market Value of the Purchased Shares on the date the Option is exercised
        or (if later) on the date any forfeiture restrictions applicable to the
        Purchased Shares lapse over (b) the Exercise Price paid for the




                                     II-1.

   50

        Purchased Shares. Any additional gain recognized upon the disqualifying
        disposition will be either short-term or long-term capital
        gain depending upon the period for which the Purchased Shares are held
        prior to the disposition.

                      (iv) For purposes of the foregoing, the term "forfeiture
        restrictions" will include the right of the Corporation to repurchase
        the Purchased Shares pursuant to the Repurchase Right. The term
        "disqualifying disposition" means any sale or other disposition(1) of
        the Purchased Shares within two (2) years after the Grant Date or within
        one (1) year after the exercise date of the Option.

                      (v) In the absence of final Treasury Regulations relating
        to Incentive Options, it is not certain whether Optionee may, in
        connection with the exercise of the Option for any Purchased Shares at
        the time subject to forfeiture restrictions, file a protective election
        under Code Section 83(b) which would limit (a) Optionee's alternative
        minimum taxable income upon exercise and (b) Optionee's ordinary income
        upon a disqualifying disposition to the excess of the Fair Market Value
        of the Purchased Shares on the date the Option is exercised over the
        Exercise Price paid for the Purchased Shares. Accordingly, such election
        if properly filed will only be allowed to the extent the final Treasury
        Regulations permit such a protective election. Page 2 of the attached
        form for making the election should be filed with any election made in
        connection with the exercise of an Incentive Option.

        --------
        (1) Generally, a disposition of shares purchased under an Incentive
        Option includes any transfer of legal title, including a transfer by
        sale, exchange or gift, but does not include a transfer to the
        Optionee's spouse, a transfer into joint ownership with right of
        survivorship if Optionee remains one of the joint owners, a pledge, a
        transfer by bequest or inheritance or certain tax free exchanges
        permitted under the Code.




                                     II-2.

   51



                             SECTION 83(b) ELECTION

               This statement is being made under Section 83(b) of the Internal
Revenue Code, pursuant to Treas. Reg. Section 1.83-2.

(1)     The taxpayer who performed the services is:

        Name:
        Address:
        Taxpayer Ident. No.:

(2)     The property with respect to which the election is being made is _______
        shares of the common stock of Ansys Diagnostics, Inc.

(3)     The property was issued on ____________ , 199__.

(4)     The taxable year in which the election is being made is the calendar
        year 199__.

(5)     The property is subject to a repurchase right pursuant to which the
        issuer has the right to acquire the property at the original purchase
        price if for any reason taxpayer's service with the issuer terminates.
        The issuer's repurchase right lapses in a series of annual and monthly
        installments over a four (4)-year period ending on ___________________,
        200__.

(6)     The fair market value at the time of transfer (determined without regard
        to any restriction other than a restriction which by its terms will
        never lapse) is $ per share.

(7)     The amount paid for such property is $ ____________ per share.

(8)     A copy of this statement was furnished to Ansys Diagnostics, Inc. for
        whom taxpayer rendered the services underlying the transfer of property.

(9)     This statement is executed on ________________________ , 199__.




- ------------------------------              ------------------------------------
Spouse (if any)                             Taxpayer


This election must be filed with the Internal Revenue Service Center with which
taxpayer files his or her Federal income tax returns and must be made within
thirty (30) days after the execution date of the Stock Purchase Agreement. This
filing should be made by registered or certified mail, return receipt requested.
Optionee must retain two (2) copies of the completed form for filing with his or
her Federal and state tax returns for the current tax year and an additional
copy for his or her records.



   52
               The property described in the above Section 83(b) election is
comprised of shares of common stock acquired pursuant to the exercise of an
incentive stock option under Section 422 of the Internal Revenue Code (the
"Code"). Accordingly, it is the intent of the Taxpayer to utilize this election
to achieve the following tax results:

               1. The purpose of this election is to have the alternative
minimum taxable income attributable to the purchased shares measured by the
amount by which the fair market value of such shares at the time of their
transfer to the Taxpayer exceeds the purchase price paid for the shares. In the
absence of this election, such alternative minimum taxable income would be
measured by the spread between the fair market value of the purchased shares and
the purchase price which exists on the various lapse dates in effect for the
forfeiture restrictions applicable to such shares. The election is to be
effective to the full extent permitted under the Code.

               2. Section 421(a)(1) of the Code expressly excludes from income
any excess of the fair market value of the purchased shares over the amount paid
for such shares. Accordingly, this election is also intended to be effective in
the event there is a "disqualifying disposition" of the shares, within the
meaning of Section 421(b) of the Code, which would otherwise render the
provisions of Section 83(a) of the Code applicable at that time. Consequently,
the Taxpayer hereby elects to have the amount of disqualifying disposition
income measured by the excess of the fair market value of the purchased shares
on the date of transfer to the Taxpayer over the amount paid for such shares.
Since Section 421(a) presently applies to the shares which are the subject of
this Section 83(b) election, no taxable income is actually recognized for
regular tax purposes at this time, and no income taxes are payable, by the
Taxpayer as a result of this election. The election shall be effective to the
full extent permitted under the Code.


THIS PAGE 2 IS TO BE ATTACHED TO ANY SECTION 83(b) ELECTION FILED IN
CONNECTION WITH THE EXERCISE OF AN INCENTIVE STOCK OPTION UNDER
THE FEDERAL TAX LAWS.



                                       2.

   53



                                           APPENDIX


               The following definitions shall be in effect under the Agreement:

        A. AGREEMENT shall mean this Stock Purchase Agreement.

        B. BOARD shall mean the Corporation's Board of Directors.

        C. CODE shall mean the Internal Revenue Code of 1986, as amended.

        D. COMMON STOCK shall mean the Corporation's common stock.

        E. CORPORATE TRANSACTION shall mean either of the following
shareholder-approved transactions:

                    (i) a merger or consolidation in which securities possessing
        more than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

                   (ii) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. CORPORATION shall mean Ansys Diagnostics, Inc., a California
corporation.

        G. DISPOSITION NOTICE shall have the meaning assigned to such term in
Paragraph E.2.

        H. EXERCISE NOTICE shall have the meaning assigned to such term in
Paragraph E.3.

        I. EXERCISE PRICE shall have the meaning assigned to such term in
Paragraph A.1.

        J. FAIR MARKET VALUE of a share of Common Stock on any relevant date,
prior to the initial public offering of the Common Stock, shall be determined by
the Plan Administrator after taking into account such factors as it shall deem
appropriate.

        K. FIRST REFUSAL RIGHT shall mean the right granted to the Corporation
in accordance with Article E.

        L. GRANT DATE shall have the meaning assigned to such term in Paragraph
A.1.


                                       A-1

   54



        M. GRANT NOTICE shall mean the Notice of Grant of Stock Option pursuant
to which Optionee has been informed of the basic terms of the Option.

        N. INCENTIVE OPTION shall mean an option which satisfies the
requirements of Code Section 422.

        O. MARKET STAND-OFF shall mean the market stand-off restriction
specified in Paragraph C.3.

        P. 1933 ACT shall mean the Securities Act of 1933, as amended.

        Q. 1934 ACT shall mean the Securities Exchange Act of 1934, as amended.

        R. NON-STATUTORY OPTION shall mean an option not intended to satisfy the
requirements of Code Section 422.

        S. OPTION shall have the meaning assigned to such term in Paragraph A.1.

        T. OPTION AGREEMENT shall mean all agreements and other documents
evidencing the Option.

        U. OPTIONEE shall mean the person to whom the Option is granted under
the Plan.

        V. OWNER shall mean Optionee and all subsequent holders of the Purchased
Shares who derive their chain of ownership through a Permitted Transfer from
Optionee.

        W. PARENT shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, 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.

        X. PERMITTED TRANSFER shall mean (i) a gratuitous transfer of the
Purchased Shares, provided and only if Optionee obtains the Corporation's prior
written consent to such transfer, (ii) a transfer of title to the Purchased
Shares effected pursuant to Optionee's will or the laws of intestate succession
following Optionee's death or (iii) a transfer to the Corporation in pledge as
security for any purchase-money indebtedness incurred by Optionee in connection
with the acquisition of the Purchased Shares.

        Y. PLAN shall mean the Corporation's 1997 Stock Incentive Plan.

                                       A-2
   55

        Z. PLAN ADMINISTRATOR shall mean either the Board or a committee of the
Board acting in its capacity as administrator of the Plan.

        AA. PRIOR PURCHASE AGREEMENT shall have the meaning assigned to such
term in Paragraph D.4.

        AB. PURCHASED SHARES shall have the meaning assigned to such term in
Paragraph A.1.

        AC. RECAPITALIZATION shall mean any stock split, stock dividend,
recapitalization, combination of shares, exchange of shares or other change
affecting the Corporation's outstanding Common Stock as a class without the
Corporation's receipt of consideration.

        AD. REORGANIZATION shall mean any of the following transactions:

                (i) a merger or consolidation in which the Corporation is not
        the surviving entity,

                (ii) a sale, transfer or other disposition of all or
        substantially all of the Corporation's assets,

                (iii) a reverse merger in which the Corporation is the surviving
        entity but in which the Corporation's outstanding voting securities are
        transferred in whole or in part to a person or persons different from
        the persons holding those securities immediately prior to the merger, or

                (iv) any transaction effected primarily to change the state in
        which the Corporation is incorporated or to create a holding company
        structure.

        AE. REPURCHASE RIGHT shall mean the right granted to the Corporation in
accordance with Article D.

        AF. SEC shall mean the Securities and Exchange Commission.

        AG. SERVICE shall mean the Optionee's performance of services for the
Corporation (or any Parent or Subsidiary) in the capacity of an employee,
subject to the control and direction of the employer entity as to both the work
to be performed and the manner and method of performance, a non-employee member
of the board of directors or an independent consultant.

        AH. SUBSIDIARY shall mean any corporation (other than the Corporation)
in an unbroken chain of corporations beginning with the Corporation, provided
each corporation (other than the last corporation) in the unbroken chain owns,
at the time of the determination, stock possessing

                                      A-3
   56

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.

        AI. TARGET SHARES shall have the meaning assigned to such term in
Paragraph E.2.

        AJ. VESTING SCHEDULE shall mean the vesting schedule specified in the
Grant Notice pursuant to which the Optionee is to vest in the Option Shares in a
series of installments over his or her period of Service.

        AK. UNVESTED SHARES shall have the meaning assigned to such term in
Paragraph D.1.


                                       A-4
   57

                                    ADDENDUM
                                       TO
                            STOCK PURCHASE AGREEMENT


               The following provisions are hereby incorporated into, and are
hereby made a part of, that certain Stock Purchase Agreement dated ____________
(the "Purchase Agreement") by and between Ansys Diagnostics, Inc. (the
"Corporation") and _______________________ ("Optionee") evidencing the shares of
Common Stock purchased on such date by Optionee pursuant to the option granted
to him or her under the Corporation's 1997 Stock Incentive Plan, and such
provisions shall be effective immediately. All capitalized terms in this
Addendum, to the extent not otherwise defined herein, shall have the meanings
assigned to such terms in the Purchase Agreement.

                        INVOLUNTARY TERMINATION FOLLOWING
                              CORPORATE TRANSACTION

               1. To the extent the Repurchase Right is assigned to the
successor corporation (or parent thereof) in connection with a Corporate
Transaction, no accelerated vesting of the Purchased Shares shall occur upon
such Corporate Transaction, and the Repurchase Right shall continue to remain in
full force and effect in accordance with the provisions of the Purchase
Agreement. Optionee shall, over his or her period of Service following the
Corporate Transaction, continue to vest in the Purchased Shares in one or more
installments in accordance with the provisions of the Purchase Agreement.
However, upon an Involuntary Termination of Optionee's Service within eighteen
(18) months following the Corporate Transaction, the Repurchase Right shall
terminate automatically, and all the Purchased Shares shall immediately vest in
full at that time.

               2. For purposes of this Addendum, the following definitions shall
be in effect:

                      An INVOLUNTARY TERMINATION shall mean the termination of
Optionee's Service by reason of:

                        (i) Optionee's involuntary dismissal or discharge by the
            Corporation for reasons other than for Misconduct, or

                        (ii) Optionee's voluntary resignation following (A) a
            change in his or her position with the Corporation (or Parent or
            Subsidiary employing Participant) which materially reduces his or
            her duties and responsibilities or the level of management to which
            he or she reports, (B) a reduction in Optionee's level of
            compensation (including base salary, fringe benefits and target
            bonuses under any corporate-performance based incentive programs) by
            more than fifteen percent (15%) or (C) a relocation of Optionee's
            place of employment by more than fifty (50) miles, provided and only
            if such change, reduction or relocation is effected by the
            Corporation without Optionee's consent.

   58
               MISCONDUCT shall mean the termination of Optionee's Service by
reason of Optionee's commission of any act of fraud, embezzlement or dishonesty,
any unauthorized use or disclosure by Optionee of confidential information or
trade secrets of the Corporation (or any Parent or Subsidiary), or any other
intentional misconduct by Optionee adversely affecting the business or affairs
of the Corporation (or any Parent or Subsidiary) in a material manner. The
foregoing definition shall not be deemed to be inclusive of all the acts or
omissions which the Corporation (or any Parent or Subsidiary) may consider as
grounds for the dismissal or discharge of Optionee or any other individual in
the Service of the Corporation (or any Parent or Subsidiary).

               IN WITNESS WHEREOF, Ansys Diagnostics, Inc. has caused this
Addendum to be executed by its duly-authorized officer as of the Effective Date
specified below.


                                                   ANSYS DIAGNOSTICS, INC.

                                                   By:
                                                      --------------------------
                                                   Title:
                                                        ------------------------


EFFECTIVE DATE:                   , 199
                ------------------     --



                                       2.
   59

                             ANSYS DIAGNOSTICS, INC.
                            STOCK ISSUANCE AGREEMENT


               AGREEMENT made as of this _____ day of ______________ 199__,
by and between Ansys Diagnostics, Inc., a California corporation, and _______
________________________________ , Participant in the Corporation's 1997 Stock
Incentive Plan.

               All capitalized terms in this Agreement shall have the meaning
assigned to them in this Agreement or in the attached Appendix.

        A. PURCHASE OF SHARES

               1. PURCHASE. Participant hereby purchases ______shares of Common
Stock (the "Purchased Shares") pursuant to the provisions of the Stock Issuance
Program at the purchase price of $______ per share (the "Purchase Price").

               2. PAYMENT. Concurrently with the delivery of this Agreement to
the Corporation, Participant shall pay the Purchase Price for the Purchased
Shares in cash or cash equivalent and shall deliver a duly-executed blank
Assignment Separate from Certificate (in the form attached hereto as Exhibit I)
with respect to the Purchased Shares.

               3. SHAREHOLDER RIGHTS. Until such time as the Corporation
exercises the Repurchase Right or the First Refusal Right, Participant (or any
successor in interest) shall have all shareholder rights (including voting,
dividend and liquidation rights) with respect to the Purchased Shares, subject,
however, to the transfer restrictions of Articles B and C.

        B. SECURITIES LAW COMPLIANCE

               1. RESTRICTED SECURITIES. The Purchased Shares have not been
registered under the 1933 Act and are being issued to Participant in reliance
upon the exemption from such registration provided by SEC Rule 701 for stock
issuances under compensatory benefit plans such as the Plan. Participant hereby
confirms that Participant has been informed that the Purchased Shares are
restricted securities under the 1933 Act and may not be resold or transferred
unless the Purchased Shares are first registered under the Federal securities
laws or unless an exemption from such registration is available. Accordingly,
Participant hereby acknowledges that Participant is prepared to hold the
Purchased Shares for an indefinite period and that Participant is aware that SEC
Rule 144 issued under the 1933 Act which exempts certain resales of unrestricted
securities is not presently available to exempt the resale of the Purchased
Shares from the registration requirements of the 1933 Act.




   60
               2. DISPOSITION OF PURCHASED SHARES. Participant shall make no
disposition of the Purchased Shares (other than a Permitted Transfer) unless and
until there is compliance with all of the following requirements:

                    (i) Participant shall have provided the Corporation with a
        written summary of the terms and conditions of the proposed disposition.

                   (ii) Participant shall have complied with all requirements of
        this Agreement applicable to the disposition of the Purchased Shares.

                  (iii) Participant shall have provided the Corporation with
        written assurances, in form and substance satisfactory to the
        Corporation, that (a) the proposed disposition does not require
        registration of the Purchased Shares under the 1933 Act or (b) all
        appropriate action necessary for compliance with the registration
        requirements of the 1933 Act or any exemption from registration
        available under the 1933 Act (including Rule 144) has been taken.

               The Corporation shall not be required (i) to transfer on its
books any Purchased Shares which have been sold or transferred in violation of
the provisions of this Agreement or (ii) to treat as the owner of the Purchased
Shares, or otherwise to accord voting, dividend or liquidation rights to, any
transferee to whom the Purchased Shares have been transferred in contravention
of this Agreement.

               3. RESTRICTIVE LEGENDS. The stock certificates for the Purchased
Shares shall be endorsed with one or more of the following restrictive legends:

                      "THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. THE SHARES MAY NOT BE SOLD OR
OFFERED FOR SALE IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR
THE SHARES UNDER SUCH ACT, (B) A "NO ACTION" LETTER OF THE SECURITIES AND
EXCHANGE COMMISSION WITH RESPECT TO SUCH SALE OR OFFER OR (C) SATISFACTORY
ASSURANCES TO THE CORPORATION THAT REGISTRATION UNDER SUCH ACT IS NOT REQUIRED
WITH RESPECT TO SUCH SALE OR OFFER."

                      "THE SHARES REPRESENTED BY THIS CERTIFICATE ARE
SUBJECT TO CERTAIN REPURCHASE RIGHTS AND RIGHTS OF FIRST REFUSAL GRANTED TO THE
CORPORATION AND ACCORDINGLY MAY NOT BE SOLD, ASSIGNED, TRANSFERRED, ENCUMBERED,
OR IN ANY MANNER DISPOSED OF EXCEPT IN CONFORMITY WITH THE TERMS OF A WRITTEN
AGREEMENT DATED _________ , 199__ BETWEEN THE CORPORATION AND THE REGISTERED
HOLDER OF THE SHARES (OR THE PREDECESSOR IN INTEREST TO THE SHARES). A COPY OF
SUCH AGREEMENT IS MAINTAINED AT THE CORPORATION'S PRINCIPAL CORPORATE OFFICES."


   61




        C. TRANSFER RESTRICTIONS

               1. RESTRICTION ON TRANSFER. Except for any Permitted Transfer,
Participant shall not transfer, assign, encumber or otherwise dispose of any of
the Purchased Shares which are subject to the Repurchase Right. In addition,
Purchased Shares which are released from the Repurchase Right shall not be
transferred, assigned, encumbered or otherwise disposed of in contravention of
the First Refusal Right or the Market Stand-Off.

               2. TRANSFEREE OBLIGATIONS. Each person (other than the
Corporation) to whom the Purchased Shares are transferred by means of a
Permitted Transfer must, as a condition precedent to the validity of such
transfer, acknowledge in writing to the Corporation that such person is bound by
the provisions of this Agreement and that the transferred shares are subject to
(i) the Repurchase Right, (ii) the First Refusal Right and (iii) the Market
Stand-Off, to the same extent such shares would be so subject if retained by
Participant.

               3. MARKET STAND-OFF.

                        (a) In connection with any underwritten public offering
by the Corporation of its equity securities pursuant to an effective
registration statement filed under the 1933 Act, including the Corporation's
initial public offering, Owner shall not sell, make any short sale of, loan,
hypothecate, pledge, grant any option for the purchase of, or otherwise dispose
or transfer for value or otherwise agree to engage in any of the foregoing
transactions with respect to, any Purchased Shares without the prior written
consent of the Corporation or its underwriters. Such restriction (the "Market
Stand-Off") shall be in effect for such period of time from and after the
effective date of the final prospectus for the offering as may be requested by
the Corporation or such underwriters. In no event, however, shall such period
exceed one hundred eighty (180) days and the Market Stand-Off shall in all
events terminate two (2) years after the effective date of the Corporation's
initial public offering.

                        (b) Owner shall be subject to the Market Stand-Off
provided and only if the officers and directors of the Corporation are also
subject to similar restrictions.

                        (c) Any new, substituted or additional securities which
are by reason of any Recapitalization or Reorganization distributed with respect
to the Purchased Shares shall be immediately subject to the Market Stand-Off, to
the same extent the Purchased Shares are at such time covered by such
provisions.

                        (d) In order to enforce the Market Stand-Off, the
Corporation may impose stop-transfer instructions with respect to the Purchased
Shares until the end of the applicable stand-off period.

        D. REPURCHASE RIGHT

               1. GRANT. The Corporation is hereby granted the right (the
"Repurchase Right"), exercisable at any time during the sixty (60)-day period
following the date Participant ceases for any


   62
reason to remain in Service, to repurchase at the Purchase Price any or all of
the Purchased Shares in which Participant is not, at the time of his or her
cessation of Service, vested in accordance with the provisions of the Vesting
Schedule set forth in Paragraph D.3 or the special accelerated vesting
provisions of Paragraph D.5 (such shares to be hereinafter referred to as the
"Unvested Shares").

               2. EXERCISE OF THE REPURCHASE RIGHT. The Repurchase Right shall
be exercisable by written notice delivered to each Owner of the Unvested Shares
prior to the expiration of the sixty (60)-day exercise period. The notice shall
indicate the number of Unvested Shares to be repurchased and the date on which
the repurchase is to be effected, such date to be not more than thirty (30) days
after the date of such notice. The certificates representing the Unvested Shares
to be repurchased shall be delivered to the Corporation on or before the close
of business on the date specified for the repurchase. Concurrently with the
receipt of such stock certificates, the Corporation shall pay to Owner, in cash
or cash equivalents (including the cancellation of any purchase-money
indebtedness), an amount equal to the Purchase Price previously paid for the
Unvested Shares which are to be repurchased from Owner.

               3. TERMINATION OF THE REPURCHASE RIGHT. The Repurchase Right
shall terminate with respect to any Unvested Shares for which it is not timely
exercised under Paragraph D.2. In addition, the Repurchase Right shall terminate
and cease to be exercisable with respect to any and all Purchased Shares in
which Participant vests in accordance with the following Vesting Schedule:

                      Participant shall vest in twenty-five percent (25%) of the
        Purchased Shares, and the Repurchase Right shall concurrently lapse with
        respect to those Purchased Shares, upon Participant's completion of one
        (1) year of Service measured from _____________, 199__.

                      Participant shall vest in the remaining seventy-five
        percent (75%) of the Purchased Shares, and the Repurchase Right shall
        concurrently lapse with respect to those Purchased Shares, in a series
        of thirty-six (36) successive equal monthly installments upon
        Participant's completion of each additional month of Service over the
        thirty-six (36)-month period measured from the date on which the first
        twenty-five percent (25%) of the Purchased Shares vests hereunder.

               All Purchased Shares as to which the Repurchase Right lapses
shall, however, remain subject to (i) the First Refusal Right and (ii) the
Market Stand-Off.

               4. RECAPITALIZATION. Any new, substituted or additional
securities or other property (including cash paid other than as a regular cash
dividend) which is by reason of any Recapitalization distributed with respect to
the Purchased Shares shall be immediately subject to the Repurchase Right and
any escrow requirements hereunder, but only to the extent the Purchased Shares
are at the time covered by such right or escrow requirements. Appropriate
adjustments to reflect such distribution shall be made to the number and/or
class of Purchased Shares subject to this Agreement and to the price per share
to be paid upon the exercise of the Repurchase Right in order


   63

to reflect the effect of any such Recapitalization upon the Corporation's
capital structure; provided, however, that the aggregate purchase price shall
remain the same.

               5. CORPORATE TRANSACTION.

                      (a) The Repurchase Right shall automatically terminate
in its entirety, and all the Purchased Shares shall vest in full, immediately
prior to the consummation of any Corporate Transaction, except to the extent the
Repurchase Right is to be assigned to the successor entity in such Corporate
Transaction.

                      (b) To the extent the Repurchase Right remains in effect
following a Corporate Transaction, such right shall apply to any new securities
or other property (including any cash payments) received in exchange for the
Purchased Shares in consummation of the Corporate Transaction, but only to the
extent the Purchased Shares are at the time covered by such right. Appropriate
adjustments shall be made to the price per share payable upon exercise of the
Repurchase Right to reflect the effect of the Corporate Transaction upon the
Corporation's capital structure; provided, however, that the aggregate purchase
price shall remain the same. The new securities or other property (including any
cash payments) issued or distributed with respect to the Purchased Shares in
consummation of the Corporate Transaction shall be immediately deposited in
escrow with the Corporation (or the successor entity) and shall not be released
from escrow until Participant vests in such securities or other property in
accordance with the same Vesting Schedule in effect for the Purchased Shares.

                      (c) The Repurchase Right may also terminate on an
accelerated basis, and the Purchased Shares shall immediately vest in full, in
accordance with the terms and conditions of any special addendum attached to
this Agreement.

        E. RIGHT OF FIRST REFUSAL

               1. GRANT. The Corporation is hereby granted the right of first
refusal (the "First Refusal Right"), exercisable in connection with any proposed
transfer of the Purchased Shares in which Participant has vested in accordance
with the provisions of Article D. For purposes of this Article E, the term
"transfer" shall include any sale, assignment, pledge, encumbrance or other
disposition of the Purchased Shares intended to be made by Owner, but shall not
include any Permitted Transfer.

               2. NOTICE OF INTENDED DISPOSITION. In the event any Owner of
Purchased Shares in which Participant has vested desires to accept a bona fide
third-party offer for the transfer of any or all of such shares (the Purchased
Shares subject to such offer to be hereinafter referred to as the "Target
Shares"), Owner shall promptly (i) deliver to the Corporation written notice
(the "Disposition Notice") of the terms of the offer, including the purchase
price and the identity of the third-party offeror, and (ii) provide satisfactory
proof that the disposition of the Target Shares to such third-party offeror
would not be in contravention of the provisions set forth in Articles B and C.



   64

               3. EXERCISE OF THE FIRST REFUSAL RIGHT. The Corporation shall,
for a period of twenty-five (25) days following receipt of the Disposition
Notice, have the right to repurchase any or all of the Target Shares subject to
the Disposition Notice upon the same terms as those specified therein or upon
such other terms (not materially different from those specified in the
Disposition Notice) to which Owner consents. Such right shall be exercisable by
delivery of written notice (the "Exercise Notice") to Owner prior to the
expiration of the twenty-five (25)-day exercise period. If such right is
exercised with respect to all the Target Shares, then the Corporation shall
effect the repurchase of such shares, including payment of the purchase price,
not more than five (5) business days after delivery of the Exercise Notice; and
at such time the certificates representing the Target Shares shall be delivered
to the Corporation.

               Should the purchase price specified in the Disposition Notice be
payable in property other than cash or evidences of indebtedness, the
Corporation shall have the right to pay the purchase price in the form of cash
equal in amount to the value of such property. If Owner and the Corporation
cannot agree on such cash value within ten (10) days after the Corporation's
receipt of the Disposition Notice, the valuation shall be made by an appraiser
of recognized standing selected by Owner and the Corporation or, if they cannot
agree on an appraiser within twenty (20) days after the Corporation's receipt of
the Disposition Notice, each shall select an appraiser of recognized standing
and the two (2) appraisers shall designate a third appraiser of recognized
standing, whose appraisal shall be determinative of such value. The cost of such
appraisal shall be shared equally by Owner and the Corporation. The closing
shall then be held on the later of (i) the fifth (5th) business day following
delivery of the Exercise Notice or (ii) the fifth (5th) business day after such
valuation shall have been made.

               4. NON-EXERCISE OF THE FIRST REFUSAL RIGHT. In the event the
Exercise Notice is not given to Owner prior to the expiration of the twenty-five
(25)-day exercise period, Owner shall have a period of thirty (30) days
thereafter in which to sell or otherwise dispose of the Target Shares to the
third-party offeror identified in the Disposition Notice upon terms (including
the purchase price) no more favorable to such third-party offeror than those
specified in the Disposition Notice; provided, however, that any such sale or
disposition must not be effected in contravention of the provisions of Articles
B and C. The third-party offeror shall acquire the Target Shares free and clear
of the First Refusal Right, but the acquired shares shall remain subject to the
provisions of Article B and Paragraph C.3. In the event Owner does not effect
such sale or disposition of the Target Shares within the specified thirty
(30)-day period, the First Refusal Right shall continue to be applicable to any
subsequent disposition of the Target Shares by Owner until such right lapses.

               5. PARTIAL EXERCISE OF THE FIRST REFUSAL RIGHT. In the event the
Corporation makes a timely exercise of the First Refusal Right with respect to a
portion, but not all, of the Target Shares specified in the Disposition Notice,
Owner shall have the option, exercisable by written notice to the Corporation
delivered within five (5) business days after Owner's receipt of the Exercise
Notice, to effect the sale of the Target Shares pursuant to either of the
following alternatives:

                           (i) sale or other disposition of all the Target
        Shares to the third-party offeror identified in the Disposition Notice,
        but in full compliance with



   65

        the requirements of Paragraph E.4, as if the Corporation did not
        exercise the First Refusal Right; or

                          (ii) sale to the Corporation of the portion of the
        Target Shares which the Corporation has elected to purchase, such sale
        to be effected in substantial conformity with the provisions of
        Paragraph E.3. The First Refusal Right shall continue to be applicable
        to any subsequent disposition of the remaining Target Shares until such
        right lapses.

               Owner's failure to deliver timely notification to the Corporation
shall be deemed to be an election by Owner to sell the Target Shares pursuant to
alternative (i) above.

               6. RECAPITALIZATION/REORGANIZATION.

                      (a) Any new, substituted or additional securities or other
property which is by reason of any Recapitalization distributed with respect to
the Purchased Shares shall be immediately subject to the First Refusal Right,
but only to the extent the Purchased Shares are at the time covered by such
right.

                      (b) In the event of a Reorganization, the First Refusal
Right shall remain in full force and effect and shall apply to the new capital
stock or other property received in exchange for the Purchased Shares in
consummation of the Reorganization, but only to the extent the Purchased Shares
are at the time covered by such right.

               7. LAPSE. The First Refusal Right shall lapse upon the earliest
to occur of (i) the first date on which shares of the Common Stock are held of
record by more than five hundred (500) persons, (ii) a determination is made by
the Board that a public market exists for the outstanding shares of Common Stock
or (iii) a firm commitment underwritten public offering, pursuant to an
effective registration statement under the 1933 Act, covering the offer and sale
of the Common Stock in the aggregate amount of at least ten million dollars
($10,000,000). However, the Market Stand-Off shall continue to remain in full
force and effect following the lapse of the First Refusal Right.

        F. SPECIAL TAX ELECTION

               1. SECTION 83(b) ELECTION . Under Code Section 83, the excess of
the Fair Market Value of the Purchased Shares on the date any forfeiture
restrictions applicable to such shares lapse over the Purchase Price paid for
such shares will be reportable as ordinary income on the lapse date. For this
purpose, the term "forfeiture restrictions" includes the right of the
Corporation to repurchase the Purchased Shares pursuant to the Repurchase Right.
Participant may elect under Code Section 83(b) to be taxed at the time the
Purchased Shares are acquired, rather than when and as such Purchased Shares
cease to be subject to such forfeiture restrictions. Such election must be filed
with the Internal Revenue Service within thirty (30) days after the date of this
Agreement. Even if the Fair Market Value of the Purchased Shares on the date of
this Agreement equals the Purchase Price paid (and thus no tax is payable), the
election must be made to avoid


   66

adverse tax consequences in the future. THE FORM FOR MAKING THIS ELECTION IS
ATTACHED AS EXHIBIT II HERETO. PARTICIPANT UNDERSTANDS THAT FAILURE TO MAKE THIS
FILING WITHIN THE APPLICABLE THIRTY (30)-DAY PERIOD WILL RESULT IN THE
RECOGNITION OF ORDINARY INCOME AS THE FORFEITURE RESTRICTIONS LAPSE.

               2. FILING RESPONSIBILITY. PARTICIPANT ACKNOWLEDGES THAT IT IS
PARTICIPANT'S SOLE RESPONSIBILITY, AND NOT THE CORPORATION'S, TO FILE A TIMELY
ELECTION UNDER CODE SECTION 83(B), EVEN IF PARTICIPANT REQUESTS THE CORPORATION
OR ITS REPRESENTATIVES TO MAKE THIS FILING ON HIS OR HER BEHALF.

        G. GENERAL PROVISIONS

               1. ASSIGNMENT. The Corporation may assign the Repurchase Right
and/or the First Refusal Right to any person or entity selected by the Board,
including (without limitation) one or more shareholders of the Corporation.

               2. NO EMPLOYMENT OR SERVICE CONTRACT. Nothing in this Agreement
or in the Plan shall confer upon Participant any right to continue in Service
for any period of specific duration or interfere with or otherwise restrict in
any way the rights of the Corporation (or any Parent or Subsidiary employing or
retaining Participant) or of Participant, which rights are hereby expressly
reserved by each, to terminate Participant's Service at any time for any reason,
with or without cause.

               3. NOTICES. Any notice required to be given under this Agreement
shall be in writing and shall be deemed effective upon personal delivery or upon
deposit in the U.S. mail, registered or certified, postage prepaid and properly
addressed to the party entitled to such notice at the address indicated below
such party's signature line on this Agreement or at such other address as such
party may designate by ten (10) days advance written notice under this paragraph
to all other parties to this Agreement.

               4. NO WAIVER. The failure of the Corporation in any instance to
exercise the Repurchase Right or the First Refusal Right shall not constitute a
waiver of any other repurchase rights and/or rights of first refusal that may
subsequently arise under the provisions of this Agreement or any other agreement
between the Corporation and Participant. No waiver of any breach or condition of
this Agreement shall be deemed to be a waiver of any other or subsequent breach
or condition, whether of like or different nature.

               5. CANCELLATION OF SHARES. If the Corporation shall make
available, at the time and place and in the amount and form provided in this
Agreement, the consideration for the Purchased Shares to be repurchased in
accordance with the provisions of this Agreement, then from and after such time,
the person from whom such shares are to be repurchased shall no longer have any
rights as a holder of such shares (other than the right to receive payment of
such consideration in accordance with this Agreement). Such shares shall be
deemed purchased in accordance with the


   67

applicable provisions hereof, and the Corporation shall be deemed the owner and
holder of such shares, whether or not the certificates therefor have been
delivered as required by this Agreement.

        H. MISCELLANEOUS PROVISIONS

               1. GOVERNING LAW. This Agreement shall be governed by, and
construed in accordance with, the laws of the State of California without resort
to that State's conflict-of-laws rules.

               2. PARTICIPANT UNDERTAKING. Participant hereby agrees to take
whatever additional action and execute whatever additional documents the
Corporation may deem necessary or advisable in order to carry out or effect one
or more of the obligations or restrictions imposed on either Participant or the
Purchased Shares pursuant to the provisions of this Agreement.

               3. AGREEMENT IS ENTIRE CONTRACT. This Agreement constitutes the
entire contract between the parties hereto with regard to the subject matter
hereof. This Agreement is made pursuant to the provisions of the Plan and shall
in all respects be construed in conformity with the terms of the Plan.

               4. COUNTERPARTS. This Agreement may be executed in counterparts,
each of which shall be deemed to be an original, but all of which together shall
constitute one and the same instrument.

               5. SUCCESSORS AND ASSIGNS. The provisions of this Agreement shall
inure to the benefit of, and be binding upon, the Corporation and its successors
and assigns and upon Participant, Participant's assigns and the legal
representatives, heirs and legatees of Participant's estate, whether or not any
such person shall have become a party to this Agreement and have agreed in
writing to join herein and be bound by the terms hereof.

               IN WITNESS WHEREOF, the parties have executed this Agreement on
the day and year first indicated above.

                                            ANSYS DIAGNOSTICS, INC.



                                            By:
                                              ---------------------------------
                                            Title:
                                                  -----------------------------
                                            Address:
                                                    ---------------------------

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


                                            -----------------------------------
                                            PARTICIPANT

                                            Address:
                                                    ---------------------------

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



   68




                             SPOUSAL ACKNOWLEDGMENT

               The undersigned spouse of Participant has read and hereby
approves the foregoing Stock Issuance Agreement. In consideration of the
Corporation's granting Participant the right to acquire the Purchased Shares in
accordance with the terms of such Agreement, the undersigned hereby agrees to be
irrevocably bound by all the terms of such Agreement, including (without
limitation) the right of the Corporation (or its assigns) to purchase any
Purchased Shares in which Participant is not vested at the time of his or her
cessation of Service.




                                           -------------------------------------
                                           PARTICIPANT'S SPOUSE

                                           Address:
                                                    ---------------------------

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




   69

                                    EXHIBIT I
                      ASSIGNMENT SEPARATE FROM CERTIFICATE

              FOR VALUE RECEIVED ________________ hereby sell(s),

assign(s) and transfer(s) unto Ansys Diagnostics, Inc. (the "Corporation"),
__________________(______) shares of the Common Stock of the Corporation
standing in his or her name on the books of the Corporation represented by
Certificate No.      herewith and do(es) hereby irrevocably constitute and
appoint            Attorney to transfer the said stock on the books of the
Corporation with full power of substitution in the premises.

Dated:______________


                                    Signature _________________________





INSTRUCTION: Please do not fill in any blanks other than the signature line.
Please sign exactly as you would like your name to appear on the issued stock
certificate. The purpose of this assignment is to enable the Corporation to
exercise the Repurchase Right without requiring additional signatures on the
part of Participant.



   70

                                   EXHIBIT II

                           SECTION 83(b) TAX ELECTION


   71
                                  SECTION 83(b) TAX ELECTION

This statement is being made under Section 83(b) of the Internal Revenue Code,
pursuant to Treas. Reg. Section 1.83-2.

(1)     The taxpayer who performed the services is:

        Name:
        Address:
        Taxpayer Ident. No.:

(2)     The property with respect to which the election is being made is
        _____ shares of the common stock of Ansys Diagnostics, Inc.

(3)     The property was issued on _____________________, 199__.


(4)     The taxable year in which the election is being made is the calendar
        year 1997.

(5)     The property is subject to a repurchase right pursuant to which the
        issuer has the right to acquire the property at the original purchase
        price if for any reason taxpayer's service with the issuer terminates.
        The issuer's repurchase right lapses in a series of annual and monthly
        installments over a four (4)-year period ending on ______, 200__.

(6)     The fair market value at the time of transfer (determined without regard
        to any restriction other than a restriction which by its terms will
        never lapse) is $ per share.

(7)     The amount paid for such property is $ ________ per share.

(8)     A copy of this statement was furnished to Ansys Diagnostics, Inc. for
        whom taxpayer rendered the services underlying the transfer of property.

(9)     This statement is executed on _____________________, 199____.



___________________________                 ____________________________________
Spouse (if any)                             Taxpayer

This election must be filed with the Internal Revenue Service Center with which
taxpayer files his or her Federal income tax returns and must be made within
thirty (30) days after the execution date of the Stock Issuance Agreement. This
filing should be made by registered or certified mail, return receipt requested.
Participant must retain two (2) copies of the completed form for filing with his
or her Federal and state tax returns for the current tax year and an additional
copy for his or her records.


   72

                                   EXHIBIT III

                            1997 STOCK INCENTIVE PLAN



   73
                                    APPENDIX


             The following definitions shall be in effect under the Agreement:

        A. AGREEMENT shall mean this Stock Issuance Agreement.

        B. BOARD shall mean the Corporation's Board of Directors.

        C. CODE shall mean the Internal Revenue Code of 1986, as amended.

        D. COMMON STOCK shall mean the Corporation's common stock.

        E. CORPORATE TRANSACTION shall mean either of the following
shareholder-approved transactions:

                    (i) a merger or consolidation in which securities possessing
        more than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

                   (ii) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. CORPORATION shall mean Ansys Diagnostics, Inc., a California
corporation.

        G. DISPOSITION NOTICE shall have the meaning assigned to such term in
Paragraph E.2.

        H. EXERCISE NOTICE shall have the meaning assigned to such term in
Paragraph E.3.

        I. FAIR MARKET VALUE of a share of Common Stock on any relevant date,
prior to the initial public offering of the Common Stock, shall be determined by
the Plan Administrator after taking into account such factors as it shall deem
appropriate.

        J. FIRST REFUSAL RIGHT shall mean the right granted to the Corporation
in accordance with Article E.

        K. MARKET STAND-OFF shall mean the market stand-off restriction
specified in Paragraph C.3.

        L. 1933 ACT shall mean the Securities Act of 1933, as amended.




                                      A-1.
   74
        M. OWNER shall mean Participant and all subsequent holders of the
Purchased Shares who derive their chain of ownership through a Permitted
Transfer from Participant.

        N. PARENT shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, 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.

        O. PARTICIPANT shall mean the person to whom shares are issued under the
Stock Issuance Program.

        P. PERMITTED TRANSFER shall mean (i) a gratuitous transfer of the
Purchased Shares, provided and only if Participant obtains the Corporation's
prior written consent to such transfer, (ii) a transfer of title to the
Purchased Shares effected pursuant to Participant's will or the laws of
intestate succession following Participant's death or (iii) a transfer to the
Corporation in pledge as security for any purchase-money indebtedness incurred
by Participant in connection with the acquisition of the Purchased Shares.

        Q. PLAN shall mean the Corporation's 1997 Stock Incentive Plan attached
hereto as Exhibit III.

        R. PLAN ADMINISTRATOR shall mean either the Board or a committee of the
Board acting in its capacity as administrator of the Plan.

        S. PURCHASE PRICE shall have the meaning assigned to such term in
Paragraph A.1.

        T. PURCHASED SHARES shall have the meaning assigned to such term in
Paragraph A.1.

        U. RECAPITALIZATION shall mean any stock split, stock dividend,
recapitalization, combination of shares, exchange of shares or other change
affecting the Corporation's outstanding Common Stock as a class without the
Corporation's receipt of consideration.

        V. REORGANIZATION shall mean any of the following transactions:

                    (i) a merger or consolidation in which the Corporation is
        not the surviving entity,

                   (ii) a sale, transfer or other disposition of all or
        substantially all of the Corporation's assets,


                                      A-2.

   75


                  (iii) a reverse merger in which the Corporation is the
        surviving entity but in which the Corporation's outstanding voting
        securities are transferred in whole or in part to a person or persons
        different from the persons holding those securities immediately prior to
        the merger, or

                   (iv) any transaction effected primarily to change the state
        in which the Corporation is incorporated or to create a holding company
        structure.

        W. REPURCHASE RIGHT shall mean the right granted to the Corporation in
accordance with Article D.

        X. SEC shall mean the Securities and Exchange Commission.

        Y. SERVICE shall mean the Participant's performance of services for the
Corporation (or any Parent or Subsidiary) in the capacity of an employee,
subject to the control and direction of the employer entity as to both the work
to be performed and the manner and method of performance, a non-employee member
of the board of directors or an independent consultant.

        Z. STOCK ISSUANCE PROGRAM shall mean the Stock Issuance Program under
the Plan.

        AA. SUBSIDIARY shall mean any corporation (other than the Corporation)
in an unbroken chain of corporations beginning with the Corporation, provided
each corporation (other than the last corporation) in the unbroken chain owns,
at the time of the determination, 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.

        AB. TARGET SHARES shall have the meaning assigned to such term in
Paragraph E.2.

        AC. VESTING SCHEDULE shall mean the vesting schedule specified in
Paragraph D.3 pursuant to which Participant is to vest in the Purchased Shares
in a series of installments over the Participant's period of Service.

        AD. UNVESTED SHARES shall have the meaning assigned to such term in
Paragraph D.1.


                                      A-3.