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                                                                     Exhibit 3.4


                               i-STAT CORPORATION

                         CERTIFICATE OF DESIGNATIONS OF
                      SERIES C CONVERTIBLE PREFERRED STOCK

         i-STAT Corporation (the "Corporation"), a corporation organized and
existing under the General Corporation Law of the State of Delaware, does hereby
certify that, pursuant to authority conferred upon the Corporation's Board of
Directors (the "Board") by the Corporation's Restated Certificate of
Incorporation, as amended and including any Certificate of Designations filed
therewith (the "Certificate"), and pursuant to Section 151 of the General
Corporation Law of the State of Delaware, the Board at a meeting duly held on
August 1, 2001, adopted resolutions (i) authorizing a new series of the
Corporation's previously authorized preferred stock, $0.10 par value per share,
and (ii) providing for the designations, preferences and relative,
participating, optional or other rights, and the qualifications, limitations or
restrictions thereof, of 25,000 shares of Series C Convertible Preferred Stock
of the Corporation, as follows:

         RESOLVED, that the Corporation is authorized to issue 25,000 shares of
Series C Convertible Preferred Stock, $0.01 par value per share (the "Series C
Preferred Stock"), which shall have the following powers, designations,
preferences and other special rights:

                  Section 1. Designation, Amount and Par Value. The series of
preferred stock shall be designated as the Company's Series C Convertible
Preferred Stock (the "Preferred Stock") and the number of shares so designated
shall be 25,000 (which shall not be subject to increase without the consent of
the holders of the Preferred Stock (each, a "Holder" and collectively, the
"Holders")). Each share of Preferred Stock shall have a par value of $.10 per
share and a stated value equal to the greater of (i) $1,000 and (ii) an amount
equal to 60% of the aggregate purchase price paid by the original Holders
pursuant to the Purchase Agreement divided by the total number of shares of
Preferred Stock issued to the original Holders pursuant to the Purchase
Agreement (the "Stated Value"). Capitalized terms used and not defined elsewhere
in this certificate of designation shall have the respective meanings ascribed
to them in Section 5. Upon any liquidation, dissolution or winding-up of the
Company, no Holder shall be entitled to any liquidation preference in connection
with its ownership of the shares of Preferred Stock.

                  Section 2. Voting Rights. Except as otherwise provided herein
and as otherwise required by law, the Preferred Stock shall have no voting
rights. However, so long as any shares of Preferred Stock are outstanding, the
Company shall not, without the affirmative vote of the Holders the shares of the
Preferred Stock then outstanding, (a) alter or change adversely the powers,
preferences or rights given to the Preferred Stock or alter or amend this
Certificate of Designations, (b) amend its certificate or articles of
incorporation or other charter documents so as to affect adversely any rights of
the Holders, (c) increase the authorized number of shares of Preferred Stock, or
(d) enter into any agreement with respect to the foregoing.
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                  Section 3. Conversion.

                  (a)(i) Conversion at the option of Holder. Subject to the
limitations set forth in Section 3(a)(iii), each share of Preferred Stock shall
be convertible into shares of Common Stock at the Conversion Ratio, at the
option of the Holder, at any time and from time to time from and after the 125th
day following the Original Issue Date (such 125th day, the "Initial Conversion
Date"), provided, that the Holder shall be entitled, upon receipt of the
Company's written consent, to convert shares of Preferred Stock commencing the
63rd day following the Original Issue Date, even if prior to the Initial
Conversion Date. Holders shall effect conversions by providing the Company with
the form of conversion notice attached hereto as Exhibit A (a "Conversion
Notice"). Each Conversion Notice shall specify the number of shares of Preferred
Stock to be converted, the number of shares of Preferred Stock owned prior to
the conversion at issue, number of shares of Preferred Stock owned subsequent to
the conversion at issue and the date on which such conversion is to be effected,
which date may not be prior to the date the Holder delivers such Conversion
Notice by facsimile (the "Holder Conversion Date"). The number of shares of
Preferred Stock shown as owned by the Holder prior to and giving effect to a
conversion shall control absent manifest or mathematical error. If no Holder
Conversion Date is specified in a Conversion Notice, the Holder Conversion Date
shall be the date that such Conversion Notice is deemed delivered hereunder. To
effect conversions of Preferred Stock, a Holder shall not be required to
surrender the certificate(s) representing such shares of Preferred Stock to the
Company unless all of the shares of Preferred Stock represented thereby are so
converted.

                  (ii) Automatic Conversion. Subject to the provisions of this
paragraph and Section 4(b)(i), all of the shares of Preferred Stock issued to
the Holder on the Original Issue Date less any shares of Preferred Stock for
which Conversion Notices have previously been received or for which redemption
has been made or required hereunder shall be automatically converted on the
130th day following the Original Issue Date (such 130th day, the "Automatic
Conversion Date"), at the Conversion Ratio. If, on the Automatic Conversion
Date: (a)(1) the Underlying Shares Registration Statement is not then effective;
(b) there are not sufficient shares of Common Stock authorized and reserved for
issuance upon such conversion; (c) the Common Stock is not being listed or
quoted for trading on the Nasdaq or on a Subsequent Market or (d) an automatic
conversion pursuant to this Section shall violate the provisions of Section
3(a)(iii), then the Holder shall be entitled to delay the automatic conversion
pursuant to this Section, in whole or in part, until each applicable event or
violation is cured. Each of a Holder Conversion Date and the Automatic
Conversion Date is collectively referred to herein as a "Conversion Date."

                  (iii) Certain Conversion Restrictions.

                  (A) Notwithstanding anything to the contrary contained herein,
the number of shares of Common Stock that may be acquired by a Holder upon any
conversion of shares of Preferred Stock (or otherwise in respect hereof) shall,
until the 217th day following the Original Issue Date, be limited to the extent
necessary to insure that, following such conversion (or other issuance), the
total number of shares of Common Stock then beneficially owned by such Holder
and its affiliates and any other persons whose beneficial ownership of Common
Stock would be aggregated with such Holder's for purposes of Section 13(d) of
the Exchange Act, does not


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exceed 9.999% of the total number of issued and outstanding shares of Common
Stock (including for such purpose the shares of Common Stock issuable upon such
exercise). For such purposes, beneficial ownership shall be determined in
accordance with Section 13(d) of the Exchange Act and the rules and regulations
promulgated thereunder. Each delivery of a Conversion Notice hereunder will
constitute a representation by a Holder that it has evaluated the limitation set
forth in this paragraph and determined that issuance of the full number of
Underlying Shares requested in such Conversion Notice is permitted under this
paragraph. The Company will have no obligation to issue shares of Common Stock
in excess of the limitation referred to in this Section until such time, if any,
as such shares of Common Stock may be issued in compliance with such limitation.
By written notice to the Company, a Holder may waive the provisions of this
Section, but (i) any such waiver or increase will not be effective until the
61st day after such notice is delivered to the Company, and (ii) any such waiver
will apply only to such Holder and not to any other Holder.

                  (B) The Company may not issue in excess of 3,713,195 shares of
Common Stock (which equals 19.999% of the number of shares of Common Stock
outstanding on the Trading Day immediately preceding the Original Issue Date)
(subject to equitable adjustment for stock splits, recombinations and similar
events affecting the Common Stock) upon conversions of Preferred Stock at a
price per share that is less than the closing sales price of the Common Stock on
the Trading Day immediately preceding the Original Issue Date (such number of
shares, the "Issuable Maximum"). Each Holder shall be entitled to a portion of
the Issuable Maximum equal to the quotient obtained by dividing: (x) the number
of shares of Preferred Stock issued and sold to such Holder on the Original
Issue Date by (y) the total number of shares of Preferred Stock issued and sold
by the Company on the Original Issue Date. If any Holder shall no longer hold
shares of Preferred Stock, then such Holder's remaining portion of the Issuable
Maximum shall be allocated pro-rata among the remaining Holders.

                  (b)(i) Not later than three Trading Days after each Conversion
Date, the Company will deliver to the Holder a certificate or certificates which
shall be free of restrictive legends and trading restrictions (other than those
required by Section 4.1(b) of the Purchase Agreement) representing the number of
shares of Common Stock being acquired upon the conversion of shares of Preferred
Stock. The Company shall, upon request of the Holder, if available, use its best
efforts to deliver any certificate or certificates required to be delivered by
the Company under this Section electronically through the Depository Trust
Corporation or another established clearing corporation performing similar
functions. If in the case of any Conversion Notice such certificate or
certificates are not delivered to or as directed by the applicable Holder by the
fourth Trading Day after the Conversion Date, the Holder shall be entitled to
elect by written notice to the Company at any time on or before its receipt of
such certificate or certificates thereafter, to rescind such conversion, in
which event the Company shall immediately return the certificates representing
the shares of Preferred Stock tendered for conversion.

                  (ii) In addition to any other rights available to the Holder,
if the Company fails to deliver to the Holder such certificate or certificates
pursuant to Section 3(b)(i), by the fourth Trading Day after the Conversion
Date, and if after such fourth Trading Day the Holder purchases (in an open
market transaction or otherwise) Common Stock to deliver in satisfaction of a
sale by such Holder of the Underlying Shares which the Holder was entitled to
receive upon such conversion (a "Buy-In"), then the Company shall (A) pay in
cash to the Holder the amount

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by which (x) the Holder's total purchase price (including brokerage commissions,
if any) for the Common Stock so purchased exceeds (y) the product of (1) the
aggregate number of shares of Common Stock that such Holder was entitled to
receive from the conversion at issue multiplied by (2) the market price of the
Common Stock at the time of the sale giving rise to such purchase obligation and
(B) at the option of the Holder, either return the shares of Preferred Stock for
which such conversion was not honored or deliver to such Holder the number of
shares of Common Stock that would have been issued had the Company timely
complied with its conversion and delivery obligations under Section 3(b)(i). For
example, if the Holder purchases Common Stock having a total purchase price of
$11,000 to cover a Buy-In with respect to an attempted conversion of shares of
Preferred Stock with respect to which the market price of the Underlying Shares
on the date of conversion totaled $10,000, under clause (A) of the immediately
preceding sentence the Company shall be required to pay the Holder $1,000. The
Holder shall provide the Company written notice indicating the amounts payable
to the Holder in respect of the Buy-In. Nothing herein shall limit a Holder's
right to pursue any other remedies available to it hereunder, at law or in
equity including, without limitation, a decree of specific performance and/or
injunctive relief with respect to the Company's failure to timely deliver
certificates representing shares of Common Stock upon conversion of the shares
of Preferred Stock as required pursuant to the terms hereof.

               (c)(i) The conversion price for each share of Preferred Stock
in effect on any Conversion Date (the "Conversion Price") shall equal $18.45
(subject to equitable adjustment for stock splits, recombinations and similar
events), provided, that on and after the 120th day following the Original Issue
Date (such 120th day, the "Reset Date"), the Conversion Price shall be reset to
88% of the average of the 20 VWAP's during the 20 Trading Days immediately
preceding the Reset Date (subject to equitable adjustment for stock splits,
recombinations and similar events).

                  (ii) If the Company, at any time while shares of Preferred
Stock are outstanding, shall distribute to all holders of Common Stock (and not
to Holders) evidences of its indebtedness or assets or rights or warrants to
subscribe for or purchase any security, then in each such case the Conversion
Price at which each share of Preferred Stock shall thereafter be convertible
shall be determined by multiplying the Conversion Price in effect immediately
prior to the record date fixed for determination of stockholders entitled to
receive such distribution by a fraction of which the denominator shall be the
Per Share Market Value determined as of the record date mentioned above, and of
which the numerator shall be such Per Share Market Value on such record date
less the then fair market value at such record date of the portion of such
assets or evidence of indebtedness so distributed applicable to one outstanding
share of Common Stock as determined by the Board of Directors in good faith. If
the Holder shall dispute the findings of the Company's Board of Directors, then
such fair market value shall be determined by the Company's independent
certified public accountants that regularly examine the financial statements of
the Company. In either case the adjustments shall be described in a statement
provided to the Holders of the portion of assets or evidences of indebtedness so
distributed or such subscription rights applicable to one share of Common Stock.
Such adjustment shall be made whenever any such distribution is made and shall
become effective immediately after the record date mentioned above.

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                  (iii) All calculations under this Section 3 shall be made to
the nearest cent or the nearest 1/100th of a share, as the case may be. The
number of shares of Common Stock outstanding at any given time shall not include
shares owned or held by or for the account of the Company, and the disposition
of any such shares shall be considered an issue or sale of Common Stock.

                  (iv) Whenever the Conversion Price is adjusted pursuant to the
terms hereof the Company shall promptly mail to each Holder, a notice setting
forth the Conversion Price after such adjustment and setting forth a brief
statement of the facts requiring such adjustment.

                  (v) In case of any reclassification of the Common Stock, or
any compulsory share exchange pursuant to which the Common Stock is converted
into other securities, cash or property, the Holders shall have the right
thereafter to convert such shares only into the shares of stock and other
securities, cash and property receivable upon or deemed to be held by holders of
Common Stock following such reclassification or share exchange, and the Holders
shall be entitled upon such event to receive such amount of securities, cash or
property as a holder of the number of shares of Common Stock of the Company into
which such shares of Preferred Stock could have been converted immediately prior
to such reclassification or share exchange would have been entitled. This
provision shall similarly apply to successive reclassifications or share
exchanges.

                  (vi) Subject to Section 4, in case of any merger or
consolidation of the Company with or into another Person, or sale by the Company
of more than one-half of the assets of the Company (on an as valued basis) in
one or a series of related transactions, a Holder shall have the right
thereafter to convert its shares of Preferred Stock into the shares of stock and
other securities, cash and property receivable upon or deemed to be held by
holders of Common Stock following such merger, consolidation or sale, and such
Holder shall be entitled upon such event or series of related events to receive
such amount of securities, cash and property as the shares of Common Stock into
which such shares of Preferred Stock could have been converted immediately prior
to such merger, consolidation or sales would have been entitled. The terms of
any such merger, sale or consolidation shall include such terms so as continue
to give the Holders the right to receive the securities, cash and property set
forth in this Section upon any conversion or redemption following such event.
This provision shall similarly apply to successive such events.

                  (vii) If (a) the Company shall declare a dividend (or any
other distribution) on the Common Stock, (b) the Company shall declare a special
nonrecurring cash dividend on or a redemption of the Common Stock, (c) the
Company shall authorize the granting to all holders of Common Stock, rights or
warrants to subscribe for or purchase any shares of capital stock of any class
or of any rights, (d) the approval of any stockholders of the Company shall be
required in connection with any reclassification of the Common Stock, any
consolidation or merger to which the Company is a party, any sale or transfer of
all or substantially all of the assets of the Company, or any compulsory share
of exchange whereby the Common Stock is converted into other securities, cash or
property, or (e) the Company shall authorize the voluntary or involuntary
dissolution, liquidation or winding up of the affairs of the Company; then the
Company shall notify the Holders at their last addresses as they shall appear

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upon the stock books of the Company, at least 20 calendar days prior to the
applicable record or effective date hereinafter specified, a notice stating (x)
the date on which a record is to be taken for the purpose of such dividend,
distribution, redemption, rights or warrants, or if a record is not to be taken,
the date as of which the holders of Common Stock of record to be entitled to
such dividend, distributions, redemption, rights or warrants are to be
determined or (y) the date on which such reclassification, consolidation,
merger, sale, transfer or share exchange is expected to become effective or
close, and the date as of which it is expected that holders of Common Stock of
record shall be entitled to exchange their Common Stock for securities, cash or
other property deliverable upon such reclassification, consolidation, merger,
sale, transfer or share exchange. Holders are entitled to convert shares of
Preferred Stock during the 20-day period commencing the date of such notice to
the effective date of the event triggering such notice.

                  (d) The Company covenants that it will at all times reserve
and keep available out of its authorized and unissued shares of Common Stock
solely for the purpose of issuance upon conversion of Preferred Stock, each as
herein provided, free from preemptive rights or any other actual contingent
purchase rights of persons other than the Holders, not less than such number of
shares of Common Stock as shall be issuable upon the conversion of all
outstanding shares of Preferred Stock. The Company covenants that all shares of
Common Stock that shall be so issuable shall, upon issue, be duly and validly
authorized and issued and fully paid and nonassessable.

                  (e) Upon a conversion hereunder the Company shall not be
required to issue stock certificates representing fractions of shares of Common
Stock, but may if otherwise permitted, make a cash payment in respect of any
final fraction of a share based on the Per Share Market Value at such time. If
any fraction of an Underlying Share would, except for the provisions of this
Section, be issuable upon a conversion hereunder, the Company shall pay an
amount in cash equal to the Conversion Ratio multiplied by such fraction.

                  (f) The issuance of certificates for Common Stock on
conversion of Preferred Stock shall be made without charge to the Holders
thereof for any documentary stamp or similar taxes that may be payable in
respect of the issue or delivery of such certificate, provided that the Company
shall not be required to pay any tax that may be payable in respect of any
transfer involved in the issuance and delivery of any such certificate upon
conversion in a name other than that of the Holder of such shares of Preferred
Stock so converted.

                  (g) Any and all notices or other communications or deliveries
to be provided by the Holders of the Preferred Stock hereunder, including,
without limitation, any Conversion Notice, shall be in writing and delivered
personally, by facsimile or sent by a nationally recognized overnight courier
service, addressed to the attention of the Chief Financial Officer of the
Company addressed to104 Windsor Center Drive, East Windsor, NJ 08520, Facsimile
No.: (609) 243-9311, attention Chief Financial Officer, or to such other address
or facsimile number as shall be specified in writing by the Company for such
purpose. Any and all notices or other communications or deliveries to be
provided by the Company hereunder shall be in writing and delivered personally,
by facsimile or sent by a nationally recognized overnight courier service,
addressed to each Holder at the facsimile telephone number or address of such
Holder appearing on the books of the Company, or if no such facsimile telephone
number or address appears, at the principal place of business of the Holder. Any
notice or other communication or deliveries

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hereunder shall be deemed given and effective on the earliest of (i) the date of
transmission, if such notice or communication is delivered via facsimile at the
facsimile telephone number specified in this Section prior to 5:30 p.m. (New
York City time)(with confirmation of transmission), (ii) the date after the date
of transmission, if such notice or communication is delivered via facsimile at
the facsimile telephone number specified in this Section later than 5:30 p.m.
(New York City time) (with confirmation of transmission) on any date and earlier
than 11:59 p.m. (New York City time) on such date (with confirmation of
transmission), (iii) upon receipt, if sent by a nationally recognized overnight
courier service (next day service specified), or (iv) upon actual receipt by the
party to whom such notice is required to be given.

                  Section 4. Redemption. During the period between the Reset
Date and the 5th day following the Reset Date, if the Conversion Price
(subsequent to the reset pursuant to Section 3(c)(i)) shall be less than the
average of the 5 VWAP's during a period which includes the Original Issue Date
and the 4 Trading Days immediately following the Original Issue Date, provided,
that such number shall not be greater than $10.00 nor less than the greater of
(A) $9.00 and (B) the greater of (i) average of the Per Share Market Values for
the five Trading Days preceding the Original Issue Date and (ii) the Per Share
Market Value for the Trading Day immediately preceding the Original Issue Date.
(subject to equitable adjustment for stock splits, recombinations and similar
events, the "Target Price"), the Holder shall have a one-time right to require
the Company to redeem all or a portion of the shares of Preferred Stock then
held by such Holder and the Company shall have a one-time right to redeem all or
a portion of the shares of Preferred Stock then held by such Holder, in each
case, for a redemption price equal to the aggregate Stated Value for such shares
of Preferred Stock being redeemed (such price, the "Redemption Price"). In
addition, if the Underlying Shares Registration Statement is not declared
effective by the Commission on or before the Reset Date, the Holder may require
the Company to redeem all or a portion of the shares of Preferred Stock then
held by such Holder for the Redemption Price. The redemption obligations of the
Company pursuant to this Section shall be secured by those certain standby
letters of credit, dated as of the Original Issue Date, as amended, and such
additional standby letters of credit, as the case may be, which may be issued in
accordance with Section 2.3 of the Purchase Agreement (collectively, the "Letter
of Credit"), issued by PNC Bank, National Association ("PNC"). In connection
with any request for redemption of shares of Preferred Stock by a Holder, such
Holder shall simultaneously deliver to PNC a redemption notice to the Company
and a draw certificate in the form provided for in the Letter of Credit (the
"Draw Certificate"), with a copy of each such item to the Company. In connection
with any request for redemption of shares of Preferred Stock by the Company, the
Company shall deliver a redemption notice to the Holder and, unless the Holder
elects to convert such shares of Preferred Stock pursuant to the last sentence
of this Section, the Holder shall thereafter deliver to PNC a redemption notice
and the Draw Certificate. Assuming due compliance by the Holder with the
completion and delivery of the Draw Certificate pursuant to the terms of the
Letter of Credit, the Redemption Price shall be due and payable in cash by PNC
on the second (2nd) Trading Day following the date on which the redemption
notice and Draw Certificate is delivered by the Holder to PNC (such second (2nd)
Trading Day, the "Payment Date"). Assuming due compliance by the Holder with the
completion and delivery of the Draw Certificate pursuant to the terms of the
Letter of Credit, if PNC fails to pay the Redemption Price hereunder in full
pursuant to this Section on the Payment Date, then, the Holder may require the
Company to immediately pay the Redemption Price, provided, that the Holder may:
(i) require the Company to pay interest on all or any portion of the unpaid
Redemption Price at a rate of

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18% per annum (or the lesser amount permitted by applicable law), accruing daily
from the Payment Date until the Redemption Price, plus all such interest
thereon, is paid in full or (ii) deem such redemption null and void with respect
to all or any portion of the shares of Preferred Stock for which the Redemption
Price has not been paid in full and convert such shares of Preferred Stock
pursuant to Section 3(a)(ii) hereof. Unless the Holder deems such redemption
null and void, the Holder shall be deemed a creditor and not subject to any
conversion provisions hereof. Notwithstanding anything herein to the contrary,
if the Company elects to redeem shares of Preferred Stock pursuant to the terms
hereof, then the Holder shall be entitled to convert all or a portion of the
shares of Preferred Stock subject to the Company's redemption notice by delivery
of a notice to the Company no later than one (1) Trading Day following the
Holder's receipt of the Company's redemption notice, provided, that the
Conversion Price for any such conversion shall equal the Target Price.

                  Section 5. Definitions. For the purposes hereof, the following
terms shall have the following meanings:

                  "Commission" means the Securities and Exchange Commission.

                  "Common Stock" means the Company's common stock, par value
$0.15 per share, and stock of any other class into which such shares may
hereafter have been reclassified or changed.

                  "Conversion Ratio" means, at any time, a fraction, the
numerator of which is Stated Value and the denominator of which is the
Conversion Price at such time.

                  "Exchange Act" means the Securities Exchange Act of 1934, as
amended.

                  "Nasdaq" means the Nasdaq National Market

                  "Original Issue Date" shall mean the Closing Date (as defined
in the Purchase Agreement).

                  "Per Share Market Value" means, for any date, the price
determined by the first of the following clauses that applies: (a) if the Common
Stock is then listed or quoted on the Nasdaq or a Subsequent Market, the closing
bid price per share of the Common Stock for such date (or the nearest preceding
date) on the Nasdaq or such Subsequent Market on which the Common Stock is then
listed or quoted; (b) if prices for the Common Stock are then quoted on the OTC
Bulletin Board, the closing bid price per share of the Common Stock for such
date (or the nearest preceding date) so quoted; (c) if prices for the Common
Stock are then reported in the "Pink Sheets" published by the National Quotation
Bureau Incorporated (or a similar organization or agency succeeding to its
functions of reporting prices), the most recent bid price per share of the
Common Stock so reported; or (d) in all other cases, the fair market value of a
share of Common Stock as determined by an independent appraiser selected in good
faith by a majority-in-interest of the Holders.

                  "Person" means a corporation, an association, a partnership,
an organization, a business, an individual, a government or political
subdivision thereof or a governmental agency.

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                  "Purchase Agreement" means the Securities Purchase Agreement,
dated as of August 2, 2001, to which the Company and the original Holders are
parties, as amended, modified or supplemented from time to time in accordance
with its terms.

                  "Registration Rights Agreement" means the Registration Rights
Agreement, dated as of August 2, 2001, to which the Company and the original
Holders are parties, as amended, modified or supplemented from time to time in
accordance with its terms.

                  "Securities Act" means the Securities Act of 1933, as amended.

                  "Subsequent Market" means either the New York Stock Exchange,
American Stock Exchange or Nasdaq SmallCap Market.

                  "Trading Day" means (a) a day on which the shares of Common
Stock are traded on the Nasdaq or on such Subsequent Market on which the shares
of Common Stock are then listed or quoted, or (b) if the shares of Common Stock
are not listed on the Nasdaq or a Subsequent Market, a day on which the shares
of Common Stock are traded in the over-the-counter market, as reported by the
OTC Bulletin Board, or (c) if the shares of Common Stock are not quoted on the
OTC Bulletin Board, a day on which the shares of Common Stock are quoted in the
over-the-counter market as reported by the National Quotation Bureau
Incorporated (or any similar organization or agency succeeding its functions of
reporting prices); provided, that in the event that the shares of Common Stock
are not listed or quoted as set forth in (a), (b) and (c) hereof, then Trading
Day shall mean any day except Saturday, Sunday and any day which shall be a
legal holiday or a day on which banking institutions in the State of New York
are authorized or required by law or other government action to close.

                  "Transaction Documents" shall have the meaning set forth in
the Purchase Agreement.

                  "Underlying Shares" means, collectively, the shares of Common
Stock into which the shares of Preferred Stock are convertible in accordance
with the terms hereof.

                  "Underlying Shares Registration Statement" means a
registration statement that meets the requirements of the Registration Rights
Agreement and registers the resale of all Registrable Securities (as defined in
the Registration Rights Agreement) by the Holder, who shall be named as a
"selling stockholder" thereunder.

                  "VWAP" means the daily volume weighted average price (as
reported by Bloomberg Financial L.P. using the "VAP" function for the date in
question (it being understood that the average of the VWAP's for a certain
number of Trading Days shall be obtained by using the "HP" function)) of the
Common Stock on the date in question, or if there is no such price on such date,
then the daily volume weighted average price on the date nearest preceding such
date.


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                                    EXHIBIT A

                              NOTICE OF CONVERSION

(To be Executed by the Registered Holder
in order to convert shares of Preferred Stock)

The undersigned hereby elects to convert the number of shares of Series C
Convertible Preferred Stock indicated below, into shares of common stock, par
value $0.15 per share (the "Common Stock"), of i-STAT Corporation, a Delaware
corporation (the "Company"), according to the conditions hereof, as of the date
written below. If shares are to be issued in the name of a person other than
undersigned, the undersigned will pay all transfer taxes payable with respect
thereto and is delivering herewith such certificates and opinions as reasonably
requested by the Company in accordance therewith. No fee will be charged to the
Holder for any conversion, except for such transfer taxes, if any.



                                         
Conversion calculations:
                                            Date to Effect Conversion


                                            Number of shares of Preferred Stock to be Converted


                                            Stated Value of shares of Preferred Stock to be Converted


                                            Number of shares of Preferred Stock remaining after Conversion

                                            Number of shares of Common Stock to be Issued

                                            Applicable Conversion Price
                                            Signature

                                            Name
                                            Address


[ ] By the delivery of this Notice of Conversion the undersigned represents and
warrants to the Company that its ownership of the Common Stock does not exceed
the amounts determined in accordance with Section 13(d) of the Exchange Act,
specified under Section 3(a)(iii)(A) of the certificate of designation governing
the rights and privileges of the Preferred Stock.


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         IN WITNESS WHEREOF, the Corporation has caused this Certificate of
Designation to be duly executed as of the 1st day of August, 2001.


                             i-STAT Corporation

                             By: /s/ Roger J. Mason
                                ------------------------------------------------
                                Name: Roger J. Mason
                                Title: Vice President
                                Chief Financial Officer