<PAGE>

                                                                    EXHIBIT 10.1


          THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUED UPON ITS
                  EXERCISE ARE SUBJECT TO THE RESTRICTIONS ON
                TRANSFER SET FORTH IN SECTION 4 OF THIS WARRANT
     -----------------------------------------------------------------------


Warrant No. WSDF-4                                      Number of Shares: 25,000
                                                         (subject to adjustment)
Date of Issuance: April 14, 1999


                      Nitinol Medical Technologies, Inc.
                      ----------------------------------


                         Common Stock Purchase Warrant
                         -----------------------------

                        (Void after February 14, 2001)


     Nitinol Medical Technologies, Inc., a Delaware corporation (the "Company"),
for value received, hereby certifies that Whitney Subordinated Debt Fund, L.P.,
or its registered assigns (the "Registered Holder"), is entitled, subject to the
terms set forth below, to purchase from the Company, at any time or from time to
time on or after the date of issuance and on or before February 14, 2001 at not
later than 5:00 p.m. (Boston, Massachusetts time), 25,000 shares of Common
Stock, $.001 par value per share, of the Company, at a purchase price of $3.41
per share.  The shares purchasable upon exercise of this Warrant, and the
purchase price per share, each as adjusted from time to time pursuant to the
provisions of this Warrant, are hereinafter referred to as the "Warrant Shares"
and the "Purchase Price," respectively.

     1.   Exercise.
          --------

          (a)  This Warrant may be exercised by the Registered Holder, in whole
or in part, by surrendering this Warrant, with the purchase form appended hereto
as Exhibit I duly executed by such Registered Holder or by such Registered
   ---------
Holder's duly authorized attorney, at the principal office of the Company, or at
such other office or agency as the Company may designate, accompanied by payment
in full, in lawful money of the United States, of the Purchase Price payable in
respect of the number of Warrant Shares purchased upon such exercise.

          (b)  The Registered Holder may, at its option, elect to pay some or
all of the Purchase Price payable upon an exercise of this Warrant by cancelling
a portion of this Warrant exercisable for such number of Warrant Shares as is
determined by dividing (i) the total Purchase Price payable in respect of the
number of Warrant Shares being purchased upon such exercise by (ii) the excess
of the Fair

                                      -1-
<PAGE>

Market Value per share of Common Stock as of the effective date of exercise, as
determined pursuant to subsection 1(c) below (the "Exercise Date") over the
Purchase Price per share. If the Registered Holder wishes to exercise this
Warrant pursuant to this method of payment with respect to the maximum number of
Warrant Shares purchasable pursuant to this method, then the number of Warrant
Shares so purchasable shall be equal to the total number of Warrant Shares,
minus the product obtained by multiplying (x) the total number of Warrant Shares
by (y) a fraction, the numerator of which shall be the Purchase Price per share
and the denominator of which shall be the Fair Market Value per share of Common
Stock as of the Exercise Date. The Fair Market Value per share of Common Stock
shall be determined as follows:

               (i)  If the Common Stock is listed on a national securities
exchange, the NASDAQ National Market System, the NASDAQ system, or another
nationally recognized exchange or trading system as of the Exercise Date, the
Fair Market Value per share of Common Stock shall be deemed to be the last
reported sale price per share of Common Stock thereon on the Exercise Date; or,
if no such price is reported on such date, such price on the next preceding
business day (provided that if no such price is reported on the next preceding
business day, the Fair Market Value per share of Common Stock shall be
determined pursuant to clause (ii)).

               (ii) If the Common Stock is not listed on a national securities
exchange, the NASDAQ National Market System, the NASDAQ system or another
nationally recognized exchange or trading system as of the Exercise Date, the
Fair Market Value per share of Common Stock shall be deemed to be the amount
most recently determined by the Board of Directors to represent the fair market
value per share of the Common Stock (including without limitation a
determination for purposes of granting Common Stock options or issuing Common
Stock under an employee benefit plan of the Company); and, upon request of the
Registered Holder, the Board of Directors (or a representative thereof) shall
promptly notify the Registered Holder of the Fair Market Value per share of
Common Stock. Notwithstanding the foregoing, if the Board of Directors has not
made such a determination within the three-month period prior to the Exercise
Date, then (A) the Fair Market Value per share of Common Stock shall be the
amount next determined by the Board of Directors to represent the fair market
value per share of the Common Stock (including without limitation a
determination for purposes of granting Common Stock options or issuing Common
Stock under an employee benefit plan of the Company), (B) the Board of Directors
shall make such a determination within 15 days of a request by the Registered
Holder that it do so, and (C) the exercise of this Warrant pursuant to this
subsection 1(b) shall be delayed until such determination is made.

          (c)  Each exercise of this Warrant shall be deemed to have been
effected immediately prior to the close of business on the day on which this
Warrant

                                      -2-
<PAGE>

shall have been surrendered to the Company as provided in subsection 1(a) above.
At such time, the person or persons in whose name or names any certificates for
Warrant Shares shall be issuable upon such exercise as provided in subsection
1(d) below shall be deemed to have become the holder or holders of record of the
Warrant Shares represented by such certificates.

          (d)  As soon as practicable after the exercise of this Warrant in full
or in part, and in any event within 10 days thereafter, the Company, at its
expense, will cause to be issued in the name of, and delivered to, the
Registered Holder, or as such Holder (upon payment by such Holder of any
applicable transfer taxes) may direct:

               (i)  a certificate or certificates for the number of full Warrant
Shares to which such Registered Holder shall be entitled upon such exercise
plus, in lieu of any fractional share to which such Registered Holder would
otherwise be entitled, cash in an amount determined pursuant to Section 3
hereof; and

               (ii) in case such exercise is in part only, a new warrant or
warrants (dated the date hereof) of like tenor, calling in the aggregate on the
face or faces thereof for the number of Warrant Shares equal (without giving
effect to any adjustment therein) to the number of such shares called for on the
face of this Warrant minus the sum of (a) the number of such shares purchased by
the Registered Holder upon such exercise plus (b) the number of Warrant Shares
(if any) covered by the portion of this Warrant cancelled in payment of the
Purchase Price payable upon such exercise pursuant to subsection 1(b) above.

     2.   Adjustments.
          -----------

          (a)  General. The Purchase Price shall be subject to adjustment from
               -------
time to time pursuant to the terms of this Section 2.

          (b)  Diluting Issuances.
               ------------------

               (i)  Special Definitions.  For purposes of this subsection 2(b),
                    -------------------
the following definitions shall apply:

                    (A)  "Option" shall mean rights, options or warrants to
                          ------
subscribe for, purchase or otherwise acquire Common Stock or Convertible
Securities, excluding options described in clause (III) of subsection 2(b)(i)(D)
below.

                    (B)  "Original Issue Date" shall mean the date on which this
                          -------------------
Warrant was first issued.

                    (C)  "Convertible Securities" shall mean any evidences of
                          ----------------------
indebtedness, shares or other securities directly or indirectly convertible into
or exchangeable for Common Stock.

                                      -3-
<PAGE>

                     (D)  "Additional Shares of Common Stock" shall mean all
                           ---------------------------------
shares of Common Stock issued (or, pursuant to subsection 2(b)(iii) below,
deemed to be issued) by the Company after the Original Issue Date, other than
shares of Common Stock issued or issuable:

                     (I)   upon conversion of shares of Preferred Stock
                           outstanding on the Original Issue Date;

                     (II)  by reason of a dividend, stock split, split-up or
                           other distribution on shares of Common Stock that are
                           excluded from the definition of Additional Shares of
                           Common Stock by the foregoing clause (I) or this
                           clause (II); or

                     (III) to employees or directors of, or consultants to, the
                           Company pursuant to a plan adopted by the Board of
                           Directors of the Company.

               (ii)  No Adjustment of Purchase Price. No adjustments to the
                     -------------------------------
Purchase Price shall be made unless the consideration per share (determined
pursuant to subsection 2(b)(v)) for an Additional Share of Common Stock issued
or deemed to be issued by the Company is less than the Purchase Price in effect
on the date of, and immediately prior to, the issue of such Additional Shares.

               (iii) Issue of Securities Deemed Issue of Additional Shares of
                     --------------------------------------------------------
Common Stock. If the Company at any time or from time to time after the
------------
Original Issue Date shall issue any Options or Convertible Securities or shall
fix a record date for the determination of holders of any class of securities
entitled to receive any such Options or Convertible Securities, then the maximum
number of shares of Common Stock (as set forth in the instrument relating
thereto without regard to any provision contained therein for a subsequent
adjustment of such number) issuable upon the exercise of such Options or, in the
case of Convertible Securities and Options therefor, the conversion or exchange
of such Convertible Securities, shall be deemed to be Additional Shares of
Common Stock issued as of the time of such issue or, in case such a record date
shall have been fixed, as of the close of business on such record date, provided
that Additional Shares of Common Stock shall not be deemed to have been issued
unless the consideration per share (determined pursuant to subsection 2(b)(v)
hereof) of such Additional Shares of Common Stock would be less than the
Purchase Price in effect on the date of and immediately prior to such issue, or
such record date, as the case may be, and provided further that in any such case
in which Additional Shares of Common Stock are deemed to be issued:

                     (A)   No further adjustment in the Purchase Price shall be
made upon the subsequent issue of Convertible Securities or shares of Common
Stock

                                      -4-
<PAGE>

upon the exercise of such Options or conversion or exchange of such Convertible
Securities;

                     (B)   If such Options or Convertible Securities by their
terms provide, with the passage of time or otherwise, for any increase in the
consideration payable to the Company, upon the exercise, conversion or exchange
thereof, the Purchase Price computed upon the original issue thereof (or upon
the occurrence of a record date with respect thereto), and any subsequent
adjustments based thereon, shall, upon any such increase becoming effective, be
recomputed to reflect such increase insofar as it affects such Options or the
rights of conversion or exchange under such Convertible Securities;

                     (C)   Upon the expiration or termination of any unexercised
Option, the Purchase Price shall not be readjusted, but the Additional Shares of
Common Stock deemed issued as the result of the original issue of such Option
shall not be deemed issued for the purposes of any subsequent adjustment of the
Purchase Price;

                     (D)   In the event of any change in the number of shares of
Common Stock issuable upon the exercise, conversion or exchange of any Option or
Convertible Security, including, but not limited to, a change resulting from the
anti-dilution provisions thereof, the Purchase Price then in effect shall
forthwith be readjusted to such Purchase Price as would have obtained had the
adjustment which was made upon the issuance of such Option or Convertible
Security not exercised or converted prior to such change been made upon the
basis of such change; and

                     (E)   No readjustment pursuant to Clause (B) or (D) above
shall have the effect of increasing the Purchase Price to an amount which
exceeds the lower of (i) the Purchase Price on the original adjustment date, or
(ii) the Purchase Price that would have resulted from any issuances of
Additional Shares of Common Stock between the original adjustment date and such
readjustment date.

               (iv)  Adjustment of Purchase Price Upon Issuance of Additional
                     --------------------------------------------------------
Shares of Common Stock. In the event the Company shall at any time after the
----------------------
Original Issue Date issue Additional Shares of Common Stock (including
Additional Shares of Common Stock deemed to be issued pursuant to subsection
2(b)(iii), but excluding shares issued as a dividend or distribution or upon a
stock split or combination as provided in subsection 2(c)), without
consideration or for a consideration per share less than the Purchase Price in
effect on the date of and immediately prior to such issue, then and in such
event, such Purchase Price shall be reduced, concurrently with such issue, to a
price (calculated to the nearest cent) determined by multiplying such Purchase
Price by a fraction, (A) the numerator of which shall be (1) the number of
shares of Common Stock outstanding immediately prior to such issue plus (2) the
number of shares of Common Stock which the aggregate consideration received or
to be received by the Company for the total

                                      -5-
<PAGE>

number of Additional Shares of Common Stock so issued would purchase at such
Purchase Price; and (B) the denominator of which shall be the number of shares
of Common Stock outstanding immediately prior to such issue plus the number of
such Additional Shares of Common Stock so issued; provided that, (i) for the
                                                  -------- ----
purpose of this subsection 2(b)(iv), all shares of Common Stock issuable upon
exercise or conversion of Options or Convertible Securities outstanding
immediately prior to such issue shall be deemed to be outstanding (other than
shares excluded from the definition of "Additional Shares of Common Stock" by
virtue of clause (III) of subsection 2(b)(i)(D)), and (ii) the number of shares
of Common Stock deemed issuable upon conversion of such outstanding Options and
Convertible Securities shall not give effect to any adjustments to the
conversion price or conversion rate of such Options or Convertible Securities
resulting from the issuance of Additional Shares of Common Stock that is the
subject of this calculation.

          Notwithstanding the foregoing, the applicable Purchase Price shall not
be so reduced at such time if the amount of such reduction would be an amount
less than $.05, but any such amount shall be carried forward and reduction with
respect thereto made at the time of and together with any subsequent reduction
which, together with such amount and any other amount or amounts so carried
forward, shall aggregate $.05 or more.

               (v)  Determination of Consideration. For purposes of this
                    ------------------------------
subsection 2(b), the consideration received by the Company for the issue of any
Additional Shares of Common Stock shall be computed as follows:

                    (A)  Cash and Property:  Such consideration shall:
                         -----------------

                         (I)   insofar as it consists of cash, be computed at
the aggregate of cash received by the Company, excluding amounts paid or payable
for accrued interest or accrued dividends;

                         (II)  insofar as it consists of property other than
cash, be computed at the fair market value thereof at the time of such issue, as
determined in good faith by the Board of Directors; and

                         (III) in the event Additional Shares of Common Stock
are issued together with other shares or securities or other assets of the
Company for consideration which covers both, be the proportion of such
consideration so received, computed as provided in clauses (I) and (II) above,
as determined in good faith by the Board of Directors.

                    (B)  Options and Convertible Securities. The consideration
                         ----------------------------------
per share received by the Company for Additional Shares of Common Stock deemed
to have been issued pursuant to subsection 2(b)(iii), relating to Options and
Convertible Securities, shall be determined by dividing

                                      -6-
<PAGE>

                         (x)  the total amount, if any, received or receivable
by the Company as consideration for the issue of such Options or Convertible
Securities, plus the minimum aggregate amount of additional consideration (as
set forth in the instruments relating thereto, without regard to any provision
contained therein for a subsequent adjustment of such consideration) payable to
the Company upon the exercise of such Options or the conversion or exchange of
such Convertible Securities, or in the case of Options for Convertible
Securities, the exercise of such Options for Convertible Securities and the
conversion or exchange of such Convertible Securities, by

                         (y)  the maximum number of shares of Common Stock (as
set forth in the instruments relating thereto, without regard to any provision
contained therein for a subsequent adjustment of such number) issuable upon the
exercise of such Options or the conversion or exchange of such Convertible
Securities.

               (vi) Multiple Closing Dates.  In the event the Company shall
                    ----------------------
issue on more than one date Additional Shares of Common Stock which are
comprised of shares of the same series or class of Preferred Stock, and such
issuance dates occur within a period of no more than 120 days, then the Purchase
Price shall be adjusted only once on account of such issuances, with such
adjustment to occur upon the final such issuance and to give effect to all such
issuances as if they occurred on the date of the final such issuance.

          (c)  Recapitalizations. If outstanding shares of the Company's Common
               -----------------
Stock shall be subdivided into a greater number of shares or a dividend in
Common Stock shall be paid in respect of Common Stock, the Purchase Price in
effect immediately prior to such subdivision or at the record date of such
dividend shall simultaneously with the effectiveness of such subdivision or
immediately after the record date of such dividend be proportionately reduced.
If outstanding shares of Common Stock shall be combined into a smaller number of
shares, the Purchase Price in effect immediately prior to such combination
shall, simultaneously with the effectiveness of such combination, be
proportionately increased.

          (d)  Mergers, etc. If there shall occur any capital reorganization or
               ------------
reclassification of the Company's Common Stock (other than a change in par value
or a subdivision or combination as provided for in subsection 2(c) above), or
any consolidation or merger of the Company with or into another corporation, or
a transfer of all or substantially all of the assets of the Company, then, as
part of any such reorganization, reclassification, consolidation, merger or
sale, as the case may be, lawful provision shall be made so that the Registered
Holder of this Warrant shall have the right thereafter to receive upon the
exercise hereof the kind and amount of shares of stock or other securities or
property which such Registered Holder would have been entitled to receive if,
immediately prior to any such reorganization, reclassification, consolidation,
merger or sale, as the case may be, such Registered Holder had held the number
of shares of Common Stock which were then

                                      -7-
<PAGE>

purchasable upon the exercise of this Warrant. In any such case, appropriate
adjustment (as reasonably determined in good faith by the Board of Directors of
the Company) shall be made in the application of the provisions set forth herein
with respect to the rights and interests thereafter of the Registered Holder of
this Warrant, such that the provisions set forth in this Section 2 (including
provisions with respect to adjustment of the Purchase Price) shall thereafter be
applicable, as nearly as is reasonably practicable, in relation to any shares of
stock or other securities or property thereafter deliverable upon the exercise
of this Warrant.

          (e)  Adjustment in Number of Warrant Shares.  When any adjustment is
               --------------------------------------
required to be made in the Purchase Price, the number of Warrant Shares
purchasable upon the exercise of this Warrant shall be changed to the number
determined by dividing (i) an amount equal to the number of shares issuable upon
the exercise of this Warrant immediately prior to such adjustment, multiplied by
the Purchase Price in effect immediately prior to such adjustment, by (ii) the
Purchase Price in effect immediately after such adjustment.

          (f)  Certificate of Adjustment.  When any adjustment is required to be
               -------------------------
made pursuant to this Section 2, the Company shall promptly mail to the
Registered Holder a certificate setting forth the Purchase Price after such
adjustment and setting forth a brief statement of the facts requiring such
adjustment. Such certificate shall also set forth the kind and amount of stock
or other securities or property into which this Warrant shall be exercisable
following such adjustment.

     3.   Fractional Shares.  The Company shall not be required upon the
          -----------------
exercise of this Warrant to issue any fractional shares, but shall make an
adjustment therefor in cash on the basis of the Fair Market Value per share of
Common Stock, as determined pursuant to subsection 1(b) above.

     4.   Requirements for Transfer.
          -------------------------

          (a)  This Warrant and the Warrant Shares shall not be sold or
transferred unless either (i) they first shall have been registered under the
Securities Act of 1933, as amended (the "Act"), or (ii) the Company first shall
have been furnished with an opinion of legal counsel, reasonably satisfactory to
the Company, to the effect that such sale or transfer is exempt from the
registration requirements of the Act.

          (b)  Notwithstanding the foregoing, no registration or opinion of
counsel shall be required for (i) a transfer by a Registered Holder which is a
partnership to a partner of such partnership or a retired partner of such
partnership who retires after the date hereof, or to the estate of any such
partner or retired partner, if the transferee agrees in writing to be subject to
the terms of this Section 4, or (ii) a transfer made in accordance with Rule 144
under the Act.

                                      -8-
<PAGE>

          (c)  Each certificate representing Warrant Shares shall bear a legend
substantially in the following form:

               "The securities represented by this certificate have
               not been registered under the Securities Act of 1933,
               as amended, and may not be offered, sold or otherwise
               transferred, pledged or hypothecated unless and until
               such securities are registered under such Act or an
               opinion of counsel satisfactory to the Company is
               obtained to the effect that such registration is not
               required."

The foregoing legend shall be removed from the certificates representing any
Warrant Shares, at the request of the holder thereof, at such time as they
become eligible for resale pursuant to Rule 144(k) under the Act.

     5.   No Impairment. The Company will not, by amendment of its charter or
          -------------
through reorganization, consolidation, merger, dissolution, sale of assets or
any other voluntary action, avoid or seek to avoid the observance or performance
of any of the terms of this Warrant, but will at all times in good faith assist
in the carrying out of all such terms and in the taking of all such action as
may be necessary or appropriate in order to protect the rights of the holder of
this Warrant against impairment.

     6.   Liquidating Dividends. If the Company pays a dividend or makes a
          ---------------------
distribution on the Common Stock payable otherwise than in cash out of earnings
or earned surplus (determined in accordance with generally accepted accounting
principles) except for a stock dividend payable in shares of Common Stock (a
"Liquidating Dividend"), then the Company will pay or distribute to the
Registered Holder of this Warrant, upon the exercise hereof, in addition to the
Warrant Shares purchased upon such exercise, the Liquidating Dividend which
would have been paid to such Registered Holder if it or he had been the owner of
record of such Warrant Shares immediately prior to the date on which a record is
taken for such Liquidating Dividend or, if no record is taken, the date as of
which the record holders of Common Stock entitled to such dividends or
distribution are to be determined.

     7.   Notices of Record Date, etc.  In case:
          ---------------------------

          (a)  the Company shall take a record of the holders of its Common
Stock (or other stock or securities at the time deliverable upon the exercise of
this Warrant) for the purpose of entitling or enabling them to receive any
dividend or other distribution, or to receive any right to subscribe for or
purchase any shares of stock of any class or any other securities, or to receive
any other right; or

                                      -9-
<PAGE>

          (b)  of any capital reorganization of the Company, any
reclassification of the capital stock of the Company, any consolidation or
merger of the Company with or into another corporation (other than a
consolidation or merger in which the Company is the surviving entity), or any
transfer of all or substantially all of the assets of the Company; or

          (c)  of the voluntary or involuntary dissolution, liquidation or
winding-up of the Company,

then, and in each such case, the Company will mail or cause to be mailed to the
Registered Holder of this Warrant a notice specifying, as the case may be, (i)
the date on which a record is to be taken for the purpose of such dividend,
distribution or right, and stating the amount and character of such dividend,
distribution or right, or (ii) the effective date on which such reorganization,
reclassification, consolidation, merger, transfer, dissolution, liquidation or
winding-up is to take place, and the time, if any is to be fixed, as of which
the holders of record of Common Stock (or such other stock or securities at the
time deliverable upon the exercise of this Warrant) shall be entitled to
exchange their shares of Common Stock (or such other stock or securities) for
securities or other property deliverable upon such reorganization,
reclassification, consolidation, merger, transfer, dissolution, liquidation or
winding-up. Such notice shall be mailed at least ten (10) days prior to the
record date or effective date for the event specified in such notice.

     8.   Reservation of Stock.  The Company will at all times reserve and keep
          --------------------
available, solely for issuance and delivery upon the exercise of this Warrant,
such number of Warrant Shares and other stock, securities and property, as from
time to time shall be issuable upon the exercise of this Warrant.

     9.   Exchange of Warrants.  Upon the surrender by the Registered Holder of
          --------------------
any Warrant or Warrants, properly endorsed, to the Company at the principal
office of the Company, the Company will, subject to the provisions of Section 4
hereof, issue and deliver to or upon the order of such Holder, at the Company's
expense, a new Warrant or Warrants of like tenor, in the name of such Registered
Holder or as such Registered Holder (upon payment by such Registered Holder of
any applicable transfer taxes) may direct, calling in the aggregate on the face
or faces thereof for the number of shares of Common Stock called for on the face
or faces of the Warrant or Warrants so surrendered.

     10.  Replacement of Warrants.  Upon receipt of evidence reasonably
          -----------------------
satisfactory to the Company of the loss, theft, destruction or mutilation of
this Warrant and (in the case of loss, theft or destruction) upon delivery of an
indemnity agreement (with surety if reasonably required) in an amount reasonably
satisfactory to the Company, or (in the case of mutilation) upon surrender and
cancellation of this Warrant, the Company will issue, in lieu thereof, a new
Warrant of like tenor.

                                      -10-
<PAGE>

     11.  Transfers, etc.
          --------------

          (a)  The Company will maintain a register containing the names and
addresses of the Registered Holders of this Warrant.  Any Registered Holder may
change its or his address as shown on the warrant register by written notice to
the Company requesting such change.

          (b)  Subject to the provisions of Section 4 hereof, this Warrant and
all rights hereunder are transferable, in whole or in part, upon surrender of
this Warrant with a properly executed assignment (in the form of Exhibit II
                                                                 ----------
hereto) at the principal office of the Company.

          (c)  Until any transfer of this Warrant is made in the warrant
register, the Company may treat the Registered Holder of this Warrant as the
absolute owner hereof for all purposes; provided, however, that if and when this
                                        --------  -------
Warrant is properly assigned in blank, the Company may (but shall not be
obligated to) treat the bearer hereof as the absolute owner hereof for all
purposes, notwithstanding any notice to the contrary.

     12.  Mailing of Notices, etc.  All notices and other communications from
          -----------------------
the Company to the Registered Holder of this Warrant shall be mailed by first-
class certified or registered mail, postage prepaid, to the address furnished to
the Company in writing by the last Registered Holder of this Warrant who shall
have furnished an address to the Company in writing. All notices and other
communications from the Registered Holder of this Warrant or in connection
herewith to the Company shall be mailed by first-class certified or registered
mail, postage prepaid, to the Company at its principal office set forth below.
If the Company should at any time change the location of its principal office to
a place other than as set forth below, it shall give prompt written notice to
the Registered Holder of this Warrant and thereafter all references in this
Warrant to the location of its principal office at the particular time shall be
as so specified in such notice.

     13.  No Rights as Stockholder.  Until the exercise of this Warrant, the
          ------------------------
Registered Holder of this Warrant shall not have or exercise any rights by
virtue hereof as a stockholder of the Company.

     14.  Change or Waiver.  Any term of this Warrant may be changed or waived
          ----------------
only by an instrument in writing signed by the party against which enforcement
of the change or waiver is sought.

     15.  Headings.  The headings in this Warrant are for purposes of reference
          --------
only and shall not limit or otherwise affect the meaning of any provision of
this Warrant.

                                      -11-
<PAGE>

     16.  Governing Law.  This Warrant will be governed by and construed in
          -------------
accordance with the laws of the Commonwealth of Massachusetts.


                                   Nitinol Medical Technologies, Inc.


                                   By: /s/ Thomas M. Tully
                                       ---------------------------------------

[Corporate Seal]                   Name:  Thomas M. Tully
                                   Title: President and Chief Executive Officer

                                      -12-
<PAGE>

                                                                       EXHIBIT I
                                                                       ---------


                                 PURCHASE FORM
                                 -------------


To:_________________                                          Dated:____________


     The undersigned, pursuant to the provisions set forth in the attached
Warrant (No. ___), hereby irrevocably elects to purchase _____ shares of the
Common Stock covered by such Warrant.  The undersigned herewith makes payment of
$____________, representing the full purchase price for such shares at the price
per share provided for in such Warrant.  Such payment takes the form of (check
applicable box or boxes):

[_]  $______ in lawful money of the United States; and/or

[_]  The cancellation of such portion of the attached Warrant as is exercisable
     for a total of _____ Warrant Shares (using a Fair Market Value of $_____
     per share for purposes of this calculation).

Signature:_____________________

                                                         Address:_______________

                                                               _________________
<PAGE>

                                                                      EXHIBIT II
                                                                      ----------


                                ASSIGNMENT FORM
                                ---------------


     FOR VALUE RECEIVED, ________________________________________ hereby sells,
assigns and transfers all of the rights of the undersigned under the attached
Warrant (No. ____) with respect to the number of shares of Common Stock covered
thereby set forth below, unto:

Name of Assignee                    Address                  No. of Shares
----------------                    -------                  -------------



Dated:_____________________         Signature:________________________________

Dated:_____________________         Witness:_________________________________