<PAGE>   1
                              CONSULTING AGREEMENT
                                     BETWEEN
                       I-STAT CORPORATION (THE "COMPANY")
                                       AND
                            IMANTS R. LAUKS ("LAUKS")
                             DATED SEPTEMBER 1, 1999




1.  POSITION:              Senior Consultant.

2.  CONSULTING
SERVICES:                  Lauks shall render exclusive consulting services to
                           the Company in connection with the manufacture and
                           marketing of medical diagnostic products, and in
                           connection with the completion of development of
                           coagulation products currently under development and
                           the redesign of the Company's existing products for
                           point-of-care blood analysis based on the Company's
                           core technology. The Consulting Agreement does not
                           extend to work on new products, whether or not based
                           on the Company's core technology and whether or not
                           for point-of-care blood analysis applications. It is
                           the expectation that Lauks shall make himself
                           available to the Company for consulting services for
                           up to 80 full working days during the first 12 months
                           of the Term (as defined below) and up to 44 full
                           working days during the last 6 months of the Term.
                           While the operating assumption will be that Lauks
                           will perform the consulting services on the basis of
                           two days per week, the parties acknowledge the need
                           for mutual flexibility in the work schedule.
                           Accordingly, the parties will cooperate in designing
                           a work schedule that gives due weight to the need for
                           reliability, dependability and continuity in the
                           performance of services as well as the need to
                           respond to operational emergencies, while at the same
                           time recognizing Lauks' desire to pursue other,
                           non-conflicting interests. Notwithstanding anything
                           contained in the Consulting Agreement to the
                           contrary, the Company shall be entitled to request
                           that no services be provided at any given time,
                           without affecting any of the Company's obligations to
                           Lauks.

3.  RESIGNATION:           Lauks hereby resigns from all of his positions at the
                           Company and i- STAT Canada, Ltd., including his
                           positions as Executive Vice President and Chief
                           Technology Officer of the Company, and as Vice
                           President of Research and Development of i-STAT
                           Canada, Ltd.




                                          -1-
<PAGE>   2
4.  TERM:                  Eighteen (18) months.

5.  COMPENSATION:          $412,500 payable over the term of the Consulting
                           Agreement in accordance with the Company's customary
                           payroll practices for its senior management
                           personnel.

6.  EXPENSES:              During the term of the Consulting Agreement, the
                           Company shall reimburse Lauks for his reasonable
                           out-of-pocket expenses incurred in the performance of
                           his duties under the Consulting Agreement, upon
                           receipt by the Company of reasonably satisfactory
                           documentation of such expenses.

7.  BENEFITS:              The Company shall continue to provide Lauks with
                           medical and dental benefits in accordance with
                           existing policy so long as Lauks is providing
                           consulting services to the Company in accordance with
                           the terms of the Consulting Agreement.

8.  STATUS OF CURRENT
STOCK OPTIONS:             Upon execution of the Consulting Agreement, of the
                           non-statutory options held by Lauks to purchase up to
                           306,440 shares of Common Stock, (i) options to
                           purchase up to 58,234 shares will be canceled; (ii)
                           options to purchase up to 25,400 shares (the
                           "Remaining Unvested Options") will continue to vest
                           and remain exercisable in accordance with the terms
                           of their respective agreements (except that vesting
                           and exercisability will be tied to Lauks' continued
                           service as a consultant rather than as an employee);
                           and (iii) options to purchase up to 222,806 shares
                           (which currently are fully vested) will remain
                           exercisable in accordance with the terms of their
                           respective agreements (except that exercisability
                           will be tied to Lauks' continued service as a
                           consultant rather than an employee). In accordance
                           with the terms of the Company's 1985 Stock Option
                           Plan, Lauks' outstanding incentive stock options to
                           purchase up to 30,705 shares of Common Stock shall
                           terminate three months after termination of Lauks'
                           employment with the Company. Lauks shall no longer be
                           required to comply with the reporting, limited
                           "window" sales periods and other obligations
                           applicable to the Company's executive officers and
                           directors under the Company's "Policy Regarding
                           Confidential Information and Insider Trading".
                           However, Lauks will acknowledge that in the
                           performance of his consulting services he may become
                           privy to information which may render him an
                           "insider" for purposes of both such Policy and the
                           trading proscriptions applicable under U.S.
                           securities laws.

9.  TAX EQUALIZATION
BENEFITS:                  So long as Lauks continues to provide consulting
                           services under the Consulting Agreement, and Lauks
                           resides in Canada, the Company shall reimburse Lauks
                           for any income taxes paid in Canada by Lauks in
                           respect of (i) any compensation paid to Lauks under
                           the Consulting Agreement, (ii) the exercise of stock
                           options during the term of the Consulting Agreement
                           and (iii) the sale of the shares of Common


                                       -2-
<PAGE>   3
                          Stock issued upon such exercise during the term of the
                          Consulting Agreement, but only (A) to the extent such
                          taxes exceed the taxes payable by Lauks under the
                          highest combined United States Federal marginal income
                          tax rate applicable to Lauks were Lauks a United
                          States and Pennsylvania resident during the period in
                          question; and (B) to the extent of $300,000 in the
                          aggregate over the term of the Consulting Agreement.
                          The parties hereby agree that Lauks owes the Company
                          $59,822.62 in respect of past tax equalization advance
                          payments made by the Company on behalf of Lauks
                          through December 31, 1998. Such amount shall be paid
                          upon execution of the Consulting Agreement. In
                          addition, Lauks shall execute the promissory note
                          attached as Exhibit A (the "Promissory Note") in the
                          principal amount of $82,660.25, as such amount may be
                          adjusted pursuant to the terms of the Promissory Note,
                          in respect of tax equalization advance payments made
                          by the Company on behalf of Lauks for calendar year
                          1999.

10.  TERMINATION
OF CONSULTING
AGREEMENT AND
PAYMENTS UPON
TERMINATION:              Either the Company or Lauks may terminate the
                          Consulting Agreement, as provided below upon thirty
                          (30) days written notice to the other, subject to the
                          continuing obligations set forth elsewhere in the
                          Consulting Agreement.

                          1.     Termination By Lauks

                          a. No Reason
                                 Payments:   None.

                          b. Breach by Company of its material obligations under
                             the Consulting Agreement, provided that the Company
                             shall be entitled to a reasonable opportunity to
                             cure (the term "reasonable" to be judged in
                             relation to the circumstances applicable at the
                             time, but in no event to exceed 10 days)

                                 Payments: Payments equal to the amount required
                                 to be paid over the balance of the Term,
                                 payable at Lauks' option in a lump sum or in
                                 accordance with the Company's customary payroll
                                 practices for its senior management personnel.
                                 The Company also shall be obligated to make tax
                                 equalization payments as described above as if
                                 the Consulting Agreement had not been
                                 terminated.

                                 Remaining Unvested Options Acceleration: All
                                 Remaining Unvested Options then held by Lauks
                                 shall become fully exercisable.



                                       -3-
<PAGE>   4
                                 In the event of a breach by the Company, in
                                 addition to and without prejudice to Lauks'
                                 right to terminate this Consulting Agreement,
                                 Lauks shall have the right to demand the
                                 payments referred to in 1(b) above without
                                 terminating the Consulting Agreement, and in
                                 such event Lauks' stock options shall continue
                                 to vest and remain exercisable for the
                                 remainder of the term of the Consulting
                                 Agreement.

                      2.  Termination By Company

                          a. For Cause, as defined as: (i) any felony conviction
                             or admission of felonious guilt, (ii) any breach or
                             nonobservance by Lauks of any material covenant in
                             the Consulting Agreement (including the Existing
                             Confidentiality Agreement, defined below), or (iii)
                             any willful or deliberate conduct by Lauks which is
                             materially injurious to the Company. In the case of
                             (ii), Lauks shall be entitled to a reasonable
                             opportunity to cure (the term "reasonable" to be
                             judged in relation to the circumstances applicable
                             at the time, but in no event to exceed 10 days).

                                 Payments: Accrued payments to that date.  No
                                 further compensation payable.

                                 Stock Options: Lauks shall have no right to
                                 exercise any stock options to purchase Common
                                 Stock if he breaches any non-competition
                                 covenant contained in the Existing
                                 Confidentiality Agreement.

11.  CONTINUATION OF
EMPLOYEE
CONFIDENTIALITY,
NON-SOLICITATION AND
NON-COMPETITION
COVENANTS:            The existing agreement between Lauks and the Company
                      regarding confidentiality, non-solicitation and
                      non-competition (the "Existing Confidentiality Agreement")
                      shall remain in place as if Lauks remained employed by the
                      Company, except that the covenants regarding
                      non-competition shall run for 18 months after the
                      execution of the Consulting Agreement.

12. RELEASE:          Lauks shall release the Company and each of its officers,
                      directors, shareholders, employees and representatives
                      from and against any and all known and unknown claims
                      Lauks may have against the Company or any such officer,
                      director, shareholder, employee or representative.
                      Accordingly, as a term and condition of this Consulting
                      Agreement, Lauks shall execute and not revoke the release
                      attached as Exhibit B



                                       -4-
<PAGE>   5
                           hereto. Excluded from this release is any claim that
                           may arise under the Consulting Agreement, the
                           Promissory Note or the Director Indemnification
                           Agreement between the Company and Lauks. The Company
                           hereby represents that it has no present knowledge of
                           any claims it may have against Lauks.

13.  APPLICABLE LAW/
ARBITRATION OF
DISPUTES:                  The Consulting Agreement shall be governed by the
                           laws of the State of New Jersey. All controversies
                           and claims arising under the Consulting Agreement
                           that cannot be settled by the parties shall be
                           settled by arbitration in Toronto, Ontario or
                           Princeton, New Jersey (at the option of Lauks) in
                           accordance with the rules of the American Arbitration
                           Association and there shall be no action taken in any
                           other court or in any other jurisdiction. This
                           arbitration provision shall not affect the Company's
                           rights under the Existing Confidentiality Agreement
                           to seek specific enforcement of the provisions
                           thereof as provided therein.

14.  RENEWAL
OF TERM:                   The Term of the Consulting Agreement may be extended
                           upon the written agreement of each of Lauks and the
                           Company.

15.  LEGAL FEES:           The Company shall reimburse Lauks for up to U.S.
                           $10,000 for legal fees incurred in connection with
                           the preparation of the Consulting Agreement.

16.  ASSIGNABILITY:        Lauks acknowledges that the services to be rendered
                           to the Company are unique and personal. Accordingly,
                           Lauks may not assign his rights or delegate his
                           duties or obligations under the Consulting Agreement.
                           The Company's rights and obligations under the
                           Consulting Agreement shall inure to the benefit of
                           the Company's successors and assigns.

17.  AMENDMENT AND
WAIVER:                    No provision in the Consulting Agreement may be
                           amended unless such amendment is agreed to in writing
                           and signed by the party against whom enforcement is
                           sought . The waiver of any breach of any duty, term
                           or condition of the Consulting Agreement shall not be
                           deemed to constitute a waiver of any preceding or
                           succeeding breach of the same or any other duty, term
                           or condition of the Consulting Agreement.

18.  SEVERABILITY:         If any provision of the Consulting Agreement shall be
                           determined to be invalid or unenforceable for any
                           reason, in whole or in part, in any jurisdiction, the
                           provision shall be enforceable to the fullest extent
                           permitted by law in such jurisdiction and shall
                           continue to be enforceable in accordance with its
                           terms in any other jurisdiction and the validity,
                           legality and enforceability of the remaining
                           provisions contained in the Consulting Agreement
                           shall not be affected.



                                       -5-
<PAGE>   6
19.  WITHHOLDING:     All amounts required to be paid by the Company herein
                      shall be subject to reduction in order to comply with
                      applicable U.S. Federal, state and local tax withholding
                      requirements.


                                       i-STAT CORPORATION


                                       By:  /s/ William P. Moffitt
                                            ----------------------
                                               Name: William P. Moffitt
                                               Title: President and CEO



                                       /s/ Imants R. Lauks
                                       -------------------
                                       Imants R. Lauks



                                          -6-