<PAGE>

                                                                   EXHIBIT 10.20

                                CataPULSE INC.

                      STAND-ALONE STOCK OPTION AGREEMENT


I.       NOTICE OF STOCK OPTION GRANT
         ----------------------------

         Michael T. Devlin

         Address: ___________________________

         ____________________________________



         You have been granted a Nonstatutory Stock Option to purchase shares
(the "Shares") of Common Stock of the Company, subject to the terms and
conditions of this Agreement, as follows:

         Date of Grant                               December 6, 1999

         Vesting Commencement Date                   December 6, 1999

         Exercise Price per Share                    $0.03

         Total Number of Shares Granted              21,111,111

         Total Exercise Price                        $633,333.33

         Term/Expiration Date:                       December 6, 2009

         Vesting Schedule:
         ----------------


         This Option shall vest and may be exercised (in accordance with Section
3), in whole or in part, in accordance with the following schedule:

         1/48/th/ of the Shares (439,814.8125 Shares) subject to the Option
shall vest each month after the Vesting Commencement Date, so that the Option
shall be fully vested four (4) years from the Date of Grant, subject to the
Optionee continuing to be a Service Provider on such dates.

         All of the remaining Shares subject to the Option shall vest
immediately prior to the closing of a change of control. A "change of control"
shall mean a merger or consolidation of the Company with or into another
corporation, entity or person (where the stockholders of the Company immediately
prior to such merger or consolidation hold less than 50% of the capital stock of
the surviving corporation immediately following the merger or consolidation), or
the sale of all or substantially all of the Company's assets to another
corporation, entity or person. In addition, all of the remaining Shares subject
to the Option shall vest if Optionee is not elected as a member of the
<PAGE>

Company's Board of Directors, is removed (other than for cause) from the Board
of Directors or is not reelected to the Board of Directors, unless, in either
event, Optionee has voluntarily resigned as an employee of the Company;
provided, however that a voluntary resignation from the Board of Directors by
Optionee or Optionee's voluntary election to not stand for election to the Board
of Directors shall not cause the remaining Shares subject to the Option to vest.

         Termination Period
         ------------------

         This Option may be exercised, to the extent it is then vested, within
three (3) months after Optionee ceases to be a Service Provider in accordance
with Section 8 of this Agreement. Upon the death or Disability of the Optionee,
this Option may be exercised, to the extent it is then vested, within twelve
(12) months after the Optionee ceases to be a Service Provider in accordance
with Sections 9 and 10 of this Agreement. In no event shall this Option be
exercised later than the Term/Expiration Date provided.

II.      AGREEMENT
         ---------

         1.   Definitions.  As used herein, the following definitions shall
              -----------
apply:

              (a) "Agreement" means this stock option agreement between the
                   ---------
Company and Optionee evidencing the terms and conditions of this Option.

              (b) "Applicable Laws" means the requirements relating to the
                   ---------------
administration of stock options under U.S. state corporate laws, U.S. federal
and state securities laws, the Code, any stock exchange or quotation system on
which the Common Stock is listed or quoted and the applicable laws of any
foreign country or jurisdiction that may apply to this Option.

              (c) "Board" means the Board of Directors of the Company or any
                   -----
committee of the Board that has been designated by the Board to administer this
Agreement.

              (d) "Code" means the Internal Revenue Code of 1986, as amended.
                   ----

              (e) "Common Stock" means the common stock of the Company.
                   ------------

              (f) "Company" means CataPULSE Inc., a Delaware corporation.
                   -------

              (g) "Consultant" means any person, including an advisor, engaged
                   ----------
by the Company or a Parent or Subsidiary to render services to such entity.

              (h) "Director" means a member of the Board.
                   --------

              (i) "Disability" means total and permanent disability as defined
                   ----------
in Section 22(e)(3) of the Code.

              (j) "Employee" means any person, including Officers and Directors,
                   --------
employed by the Company or any Parent or Subsidiary of the Company. A Service
Provider shall not cease to be an Employee in the case of (i) any leave of
absence approved by the Company or (ii) transfers

                                      -2-
<PAGE>

between locations of the Company or between the Company, its Parent, any
Subsidiary, or any successor.

               (k)  "Exchange Act" means the Securities Exchange Act of 1934, as
                     ------------
amended.

               (l)  "Fair Market Value" means, as of any date, the value of
                     -----------------
Common Stock determined as follows:

                    (i)   If the Common Stock is listed on any established stock
exchange or a national market system, including without limitation The Nasdaq
National Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its
Fair Market Value shall be the closing sales price for such stock (or the
closing bid, if no sales were reported) as quoted on such exchange or system for
the last market trading day prior to the time of determination, as reported in
The Wall Street Journal or such other source as the Administrator deems
reliable;

                    (ii)  If the Common Stock is regularly quoted by a
recognized securities dealer but selling prices are not reported, its Fair
Market Value shall be the mean between the high bid and low asked prices for the
Common Stock on the last market trading day prior to the day of determination;
or
                    (iii) In the absence of an established market for the Common
Stock, the Fair Market Value thereof shall be determined in good faith by the
Board.

               (m)  "Nonstatutory Stock Option" means an Option not intended
                     -------------------------
to qualify as an incentive stock option within the meaning of Section 422 of the
Code and the regulations promulgated thereunder.

               (n)  "Notice of Grant" means the written notice, in Part I of
                     ---------------
this Agreement, evidencing certain the terms and conditions of this Option. The
Notice of Grant is part of the Agreement.

               (o)  "Officer" means a person who is an officer of the Company
                     -------
within the meaning of Section 16 of the Exchange Act and the rules and
regulations promulgated thereunder.

               (p)  "Option" means this stock option.
                     ------

               (q)  "Optioned Stock" means the Common Stock subject to this
                     --------------
Option.

               (r)  "Optionee" means the person named in the Notice of Grant
                     --------
or such person's successor.

               (s)  "Parent" means a "parent corporation," whether now or
                     ------
hereafter existing, as defined in Section 424(e) of the Code.

               (t)  "Service Provider" means an individual that serves as
                     ----------------
either an Employee, Director or Consultant (as requested by the Company) for at
least twenty-five (25) percent of such individual's time.

                                      -3-
<PAGE>

                   (u) "Share" means a share of the Common Stock, as adjusted in
                        -----
accordance with Section 11 of this Agreement.

                   (v) "Subsidiary" means a "subsidiary corporation", whether
                        ----------
now or hereafter existing, as defined in Section 424(f) of the Code.

         2.   Grant of Option. The Board hereby grants to the Optionee named in
              ---------------
the Notice of Grant, attached as Part I of this Agreement, the Option to
purchase the number of Shares, as set forth in the Notice of Grant, at the
exercise price per share set forth in the Notice of Grant (the "Exercise
Price"), subject to the terms and conditions of this Agreement.

         3.   Exercise of Option.
              ------------------

              (a) Right to Exercise.
                  -----------------

                  (i)   Subject to subsections 3(a)(ii) and 3(a)(iii) below,
this Option shall be exercisable cumulatively according to the Vesting Schedule
set forth in the Notice of Grant. Alternatively, at the election of the
Optionee, this Option may be exercised in whole or in part at any time as to
Shares that have not yet vested. For purposes of this Agreement, Shares subject
to the Option shall vest based on continued employment of Optionee continuing to
be a Service Provider with the Company. Vested Shares shall not be subject to
the Company's repurchase right (as set forth in the Restricted Stock Purchase
Agreement, attached hereto as Exhibit C-1).
                              -----------

                  (ii)  As a condition to exercising this Option for unvested
Shares, the Optionee shall execute the Restricted Stock Purchase Agreement.

                  (iii) This Option may not be exercised for a fraction of a
Share.


              (b) Method of Exercise. This Option is exercisable by delivery of
                  ------------------
an exercise notice, in the form attached as Exhibit A (the "Exercise Notice"),
                                            ---------
which shall state the election to exercise the Option, the number of Shares in
respect of which the Option is being exercised (the "Exercised Shares"), and
such other representations and agreements as may be required by the Company. The
Exercise Notice shall be completed by the Optionee and delivered to Secretary of
the Company. The Exercise Notice shall be accompanied by payment of the
aggregate Exercise Price as to all Exercised Shares. This Option shall be deemed
to be exercised upon receipt by the Company of such fully executed Exercise
Notice accompanied by such aggregate Exercise Price.

              (c) Legal Compliance. No Shares shall be issued pursuant to the
                  ----------------
exercise of this Option unless such issuance and exercise complies with
Applicable Laws. Assuming such compliance, for income tax purposes the Exercised
Shares shall be considered transferred to the Optionee on the date the Option is
exercised with respect to such Exercised Shares.

              (d) Buyout Provisions. The Board may at any time offer to buy out
                  -----------------
for a payment in cash or Shares an Option previously granted based on such terms
and conditions as the Board shall establish and communicate to the Optionee at
the time that such offer is made.

         4.   Optionee's Representations. In the event the Shares have not been
              --------------------------
registered under the Securities Act of 1933, as amended, at the time this Option
is exercised, the Optionee shall, if

                                      -4-
<PAGE>

required by the Company, concurrently with the exercise of all or any portion of
this Option, deliver to the Company his or her Investment Representation
Statement in the form attached hereto as Exhibit B.
                                         ---------

         5.   Method of Payment. Payment of the aggregate Exercise Price shall
              -----------------
be by any of the following, or a combination thereof, at the election of the
Optionee:

              (a) cash or check;

              (b) consideration received by the Company under a cashless
exercise program implemented by the Company; or

              (c) surrender of other Shares which (i) in the case of Shares
acquired upon exercise of an option, have been owned by the Optionee for more
than six (6) months on the date of surrender, and (ii) have a Fair Market Value
on the date of surrender equal to the aggregate Exercise Price of the Exercised
Shares.

              (d) delivery of Optionee's promissory note (the "Note") in the
form attached hereto as Exhibit E, in the amount of the aggregate Exercise Price
                        ---------
of the Exercised Shares together with the execution and delivery by the Optionee
of the Security Agreement attached hereto as Exhibit D. The Note shall bear
                                             ---------
interest at the "applicable federal rate" prescribed under the Code and its
regulations at time of purchase, and shall be secured by a pledge of the Shares
purchased by the Note pursuant to the Security Agreement.

         6.   Non-Transferability of Option. This Option may not be transferred
              -----------------------------
in any manner otherwise than by will or by the laws of descent or distribution
and may be exercised during the lifetime of Optionee only by the Optionee. The
terms of this Agreement shall be binding upon the executors, administrators,
heirs, successors and assigns of the Optionee.

         7.   Term of Option. This Option may be exercised only within the term
              --------------
set out in the Notice of Grant, and may be exercised during such term only in
accordance with the terms of this Agreement.

         8.   Termination of Relationship as a Service Provider. If the Optionee
              -------------------------------------------------
ceases to be a Service Provider (other than for death or Disability), this
Option may be exercised for a period of three (3) months after the date of such
termination (but in no event later than the expiration date of this Option as
set forth in the Notice of Grant) to the extent that the Option is vested on the
date of such termination. To the extent that the Optionee does not exercise this
Option within the time specified herein, the Option shall terminate.

         9.   Disability of Optionee. If the Optionee ceases to be a Service
              ----------------------
Provider as a result of the Optionee's Disability, this Option may be exercised
for a period of twelve (12) months after the date of such termination (but in no
event later than the expiration date of this Option as set forth in the Notice
of Grant) to the extent that the Option is vested on the date of such
termination. To the extent that Optionee does not exercise this Option within
the time specified herein, the Option shall terminate.

                                      -5-
<PAGE>

         10.  Death of Optionee. If the Optionee dies while a Service Provider,
              -----------------
the Option may be exercised at any time within twelve (12) months following the
date of death (but in no event later than the expiration date of this Option as
set forth in the Notice of Grant), by the Optionee's estate or by a person who
acquired the right to exercise the Option by bequest or inheritance, but only to
the extent that the Option is vested on the date of death. If, after death, the
Optionee's estate or a person who acquired the right to exercise the Option by
bequest or inheritance does not exercise the Option within the time specified
herein, the Option shall terminate.

         11.  Adjustments Upon Changes in Capitalization, Dissolution, Merger or
              ------------------------------------------------------------------
Asset Sale.
----------
              (a) Changes in Capitalization. Subject to any required action by
                  -------------------------
the stockholders of the Company, the number of shares of Common Stock covered by
this Option, as well as the price per share of Common Stock covered by this
Option, shall be proportionately adjusted for any increase or decrease in the
number of issued shares of Common Stock resulting from a stock split, reverse
stock split, stock dividend, combination or reclassification of the Common
Stock, or any other increase or decrease in the number of issued shares of
Common Stock effected without receipt of consideration by the Company; provided,
however, that conversion of any convertible securities of the Company shall not
be deemed to have been "effected without receipt of consideration." Such
adjustment shall be made by the Board, whose determination in that respect shall
be final, binding and conclusive. Except as expressly provided herein, no
issuance by the Company of shares of stock of any class, or securities
convertible into shares of stock of any class, shall affect, and no adjustment
by reason thereof shall be made with respect to, the number or price of shares
of Common Stock subject to this Option.

              (b) Dissolution or Liquidation. In the event of the proposed
                  --------------------------
dissolution or liquidation of the Company, the Board shall notify Optionee as
soon as practicable prior to the effective date of such proposed transaction.
The Board in its discretion may provide for the Optionee to have the right to
exercise his or her Option until fifteen (15) days prior to such transaction as
to all of the Optioned Stock covered thereby, including Shares as to which the
Option would not otherwise be exercisable. The Board may permit the Option to be
exercised contingent upon this transaction. To the extent it has not been
previously exercised, the Option will terminate immediately prior to the
consummation of such proposed action.

         12.  Lock-Up Period. Optionee agrees, in connection with the Company's
              --------------
initial public offering of the Company's securities, (i) not to sell, make short
sales of, loan, grant any options for the purchase of, or otherwise dispose of
any shares of Common Stock of the Company held by Optionee (other than those
shares included in the registration) without the prior written consent of the
Company or the underwriters managing such initial underwritten public offering
of the Company's securities for up to one hundred eighty (180) days from the
effective date of such registration and (ii) further agrees to execute any
agreement reflecting (i) above as may be requested by the underwriters at the
time of the public offering.

         13.  Notices. Any notice to be given to the Company hereunder shall be
              -------
in writing and shall be addressed to the Company at its then current principal
executive office or to such other address as the Company may hereafter designate
to the Optionee by notice as provided in this Section. Any notice to be given to
the Optionee hereunder shall be addressed to the Optionee at the address set
forth beneath his signature hereto, or at such other address as the Optionee may
hereafter

                                      -6-
<PAGE>

designate to the Company by notice as provided herein. A notice shall be deemed
to have been duly given when personally delivered or mailed by registered or
certified mail to the party entitled to receive it.

         14.  Tax Consequences. Some of the federal tax consequences relating to
              ----------------
this Option, as of the date of this Option, are set forth below. THIS SUMMARY IS
NECESSARILY INCOMPLETE, AND THE TAX LAWS AND REGULATIONS ARE SUBJECT TO CHANGE.
THE OPTIONEE SHOULD CONSULT A TAX ADVISER BEFORE EXERCISING THIS OPTION OR
DISPOSING OF THE SHARES.

              (a) Exercising the Option. The Optionee may incur regular federal
                  ---------------------
income tax liability upon exercise of a Nonstatutory Stock Option (an "NSO").
The Optionee will be treated as having received compensation income (taxable at
ordinary income tax rates) equal to the excess, if any, of the Fair Market Value
of the Exercised Shares on the date of exercise over their aggregate Exercise
Price. If the Optionee is an Employee or a former Employee, the Company will be
required to withhold from his or her compensation or collect from Optionee and
pay to the applicable taxing authorities an amount in cash equal to a percentage
of this compensation income at the time of exercise, and may refuse to honor the
exercise and refuse to deliver Shares if such withholding amounts are not
delivered at the time of exercise.

              (b) Disposition of Shares. If the Optionee holds NSO Shares for at
                  ---------------------
least one year, any gain realized on disposition of the Shares will be treated
as long-term capital gain for federal income tax purposes.

              (c) Section 83(b) Election for Unvested Shares Purchased Pursuant
                  -------------------------------------------------------------
to Options. With respect to the exercise of this Option for unvested Shares, an
----------
election may be filed by the Optionee with the Internal Revenue Service, within
                                                                         ------
30 days of the purchase of the Shares, electing pursuant to Section 83(b) of the
-------
Code to be taxed currently on any difference between the purchase price of the
Shares and their Fair Market Value on the date of purchase. This will result in
a recognition of taxable income to the Optionee on the date of exercise,
measured by the excess, if any, of the Fair Market Value of the Shares, at the
time the Option is exercised over the purchase price for the Shares. Absent such
an election, taxable income will be measured and recognized by Optionee at the
time or times on which the Company's repurchase option lapses. Optionee is
strongly encouraged to seek the advice of his or her own tax consultants in
connection with the purchase of the Shares and the advisability of filing of the
Election under Section 83(b) of the Code. A form of Election under Section 83(b)
is attached hereto as Exhibit C-5 for reference.
                      -----------

         15.  Entire Agreement; Governing Law. This Agreement constitutes the
              -------------------------------
entire agreement of the parties with respect to the subject matter hereof and
supersedes in its entirety all prior undertakings and agreements of the Company
and Optionee with respect to the subject matter hereof, and may not be modified
adversely to the Optionee's interest except by means of a writing signed by the
Company and Optionee. This agreement is governed by the internal substantive
laws, but not the choice of law rules, of California

         16. NO GUARANTEE OF CONTINUED SERVICE. OPTIONEE ACKNOWLEDGES AND AGREES
             ---------------------------------
THAT THE VESTING OF SHARES PURSUANT TO THE VESTING SCHEDULE HEREOF IS EARNED
ONLY BY CONTINUING AS A SERVICE PROVIDER AT

                                      -7-
<PAGE>

THE WILL OF THE COMPANY (AND NOT THROUGH THE ACT OF BEING HIRED, BEING GRANTED
AN OPTION OR PURCHASING SHARES HEREUNDER). OPTIONEE FURTHER ACKNOWLEDGES AND
AGREES THAT THIS AGREEMENT, THE TRANSACTIONS CONTEMPLATED HEREUNDER AND THE
VESTING SCHEDULE SET FORTH HEREIN DO NOT CONSTITUTE AN EXPRESS OR IMPLIED
PROMISE OF CONTINUED ENGAGEMENT AS A SERVICE PROVIDER FOR THE VESTING PERIOD,
FOR ANY PERIOD, OR AT ALL, AND SHALL NOT INTERFERE WITH OPTIONEE'S RIGHT OR THE
COMPANY'S RIGHT TO TERMINATE OPTIONEE'S RELATIONSHIP AS A SERVICE PROVIDER AT
ANY TIME, WITH OR WITHOUT CAUSE.

         By your signature and the signature of the Company's representative
below, you and the Company agree that this Option is granted under and governed
by the terms and conditions of this Agreement. Optionee has reviewed this
Agreement in its entirety, has had an opportunity to obtain the advice of
counsel prior to executing this Agreement and fully understands all provisions
of this Agreement. Optionee hereby agrees to accept as binding, conclusive and
final all decisions or interpretations of the Board upon any questions relating
to this Agreement. Optionee further agrees to notify the Company upon any change
in the residence address indicated below.


OPTIONEE                                    CATAPULSE INC.

/s/ Michael T. Devlin                       /s/ Paul D. Levy
-----------------------------------         -----------------------------------
Signature                                   Paul D. Levy
                                            Chief Executive Officer
Michael T. Devlin
-----------------------------------
Print Name

___________________________________
Residence Address

___________________________________

___________________________________

                                      -8-
<PAGE>

                               CONSENT OF SPOUSE


     The undersigned spouse of Optionee has read and hereby approves the terms
and conditions of this Agreement. In consideration of the Company's granting his
or her spouse the right to purchase Shares as set forth in this Agreement, the
undersigned hereby agrees to be irrevocably bound by the terms and conditions of
this Agreement and further agrees that any community property interest shall be
similarly bound. The undersigned hereby appoints the undersigned's spouse as
attorney-in-fact for the undersigned with respect to any amendment or exercise
of rights under this Agreement.

                                    /s/ Bobbie Devlin
                                    -------------------------------------------
                                    Spouse of Optionee
<PAGE>

                                   EXHIBIT D
                                   ---------

                              SECURITY AGREEMENT


     This Security Agreement is made as of December 6, 1999, between CataPULSE
Inc., a Delaware corporation ("Pledgee"), and Michael T. Devlin ("Pledgor").


                                   Recitals
                                   --------

     Pursuant to Pledgor's election to purchase shares of Pledgee's common stock
("Common Stock") under the Stand-Alone Stock Option Agreement dated December 6,
1999 (the "Option"), between Pledgor and Pledgee, and Pledgor's election under
the terms of the Option to pay for such shares with his promissory note (the
"Note"), Pledgor has purchased 21,111,111 shares of Pledgee's Common Stock (the
"Shares") at a price of $0.03 per share, for a total purchase price of
$633,333.33. The Note and the obligations thereunder are as set forth in Exhibit
                                                                         -------
E to the Option.
-

     NOW, THEREFORE, it is agreed as follows:

     1.   Creation and Description of Security Interest. In consideration of the
          ---------------------------------------------
transfer of the Shares to Pledgor under the Option Agreement, Pledgor, pursuant
to the California Commercial Code, hereby pledges all of such Shares (herein
sometimes referred to as the "Collateral") represented by certificate number 3,
duly endorsed in blank or with executed stock powers, and herewith delivers said
certificate to the Secretary of Pledgee ("Pledgeholder"), who shall hold said
certificate subject to the terms and conditions of this Security Agreement.

     The pledged stock (together with an executed blank stock assignment for use
in transferring all or a portion of the Shares to Pledgee if, as and when
required pursuant to this Security Agreement) shall be held by the Pledgeholder
as security for the repayment of the Note, and any extensions or renewals
thereof, to be executed by Pledgor pursuant to the terms of the Option, and the
Pledgeholder shall not encumber or dispose of such Shares except in accordance
with the provisions of this Security Agreement.

     2.   Pledgor's Representations and Covenants. To induce Pledgee to enter
          ---------------------------------------
into this Security Agreement, Pledgor represents and covenants to Pledgee, its
successors and assigns, as follows:

          (a)  Payment of Indebtedness. Pledgor will pay the principal sum of
               -----------------------
the Note secured hereby, together with interest thereon, at the time and in the
manner provided in the Note.

          (b)  Encumbrances. The Shares are free of all other encumbrances,
               ------------
defenses and liens, and Pledgor will not further encumber the Shares without the
prior written consent of Pledgee.

          (c)  Margin Regulations. In the event that Pledgee's Common Stock is
               ------------------
now or later becomes margin-listed by the Federal Reserve Board and Pledgee is
classified as a "lender" within the meaning of the regulations under Part 207 of
Title 12 of the Code of Federal Regulations
<PAGE>

("Regulation G"), Pledgor agrees to cooperate with Pledgee in making any
amendments to the Note or providing any additional collateral as may be
necessary to comply with such regulations.

     3.   Voting Rights. During the term of this pledge and so long as all
          -------------
payments of principal and interest are made as they become due under the terms
of the Note, Pledgor shall have the right to vote all of the Shares pledged
hereunder.

     4.   Stock Adjustments. In the event that during the term of the pledge any
          -----------------
stock dividend, reclassification, readjustment or other changes are declared or
made in the capital structure of Pledgee, all new, substituted and additional
shares or other securities issued by reason of any such change shall be
delivered to and held by the Pledgee under the terms of this Security Agreement
in the same manner as the Shares originally pledged hereunder. In the event of
substitution of such securities, Pledgor, Pledgee and Pledgeholder shall
cooperate and execute such documents as are reasonable so as to provide for the
substitution of such Collateral and, upon such substitution, references to
"Shares" in this Security Agreement shall include the substituted shares of
capital stock of Pledgor as a result thereof.

     5.   Options and Rights. In the event that, during the term of this pledge,
          ------------------
subscription Options or other rights or options shall be issued in connection
with the pledged Shares, such rights, Options and options shall be the property
of Pledgor and, if exercised by Pledgor, all new stock or other securities so
acquired by Pledgor as it relates to the pledged Shares then held by
Pledgeholder shall be immediately delivered to Pledgeholder, to be held under
the terms of this Security Agreement in the same manner as the Shares pledged.

     6.   Default. Pledgor shall be deemed to be in default of the Note and of
          -------
this Security Agreement in the event:

          (a)  Payment of principal or interest on the Note shall be delinquent
for a period of 10 days or more; or

          (b)  Pledgor fails to perform any of the covenants set forth in the
Option or contained in this Security Agreement for a period of 10 days after
written notice thereof from Pledgee.

          In the case of an event of Default, as set forth above, Pledgee shall
have the right to accelerate payment of the Note upon notice to Pledgor, and
Pledgee shall thereafter be entitled to pursue its remedies under the California
Commercial Code.

     7.   Release of Collateral. Subject to any applicable contrary rules under
          ---------------------
Regulation G, there shall be released from this pledge a portion of the pledged
Shares held by Pledgeholder hereunder upon payments of the principal of the
Note. The number of the pledged Shares which shall be released shall be that
number of full Shares which bears the same proportion to the initial number of
Shares pledged hereunder as the payment of principal bears to the initial full
principal amount of the Note.

     8.   Withdrawal or Substitution of Collateral. Pledgor shall not sell,
          ----------------------------------------
withdraw, pledge, substitute or otherwise dispose of all or any part of the
Collateral without the prior written consent of Pledgee.
<PAGE>

     9.   Term. This pledge of Shares shall continue until the payment of all
          ----
indebtedness secured hereby, at which time the remaining pledged stock shall be
promptly delivered to Pledgor, subject to the provisions for prior release of a
portion of the Collateral as provided in paragraph 7 above.

     10.  Insolvency. Pledgor agrees that if a bankruptcy or insolvency
          ----------
proceeding is instituted by or against it, or if a receiver is appointed for the
property of Pledgor, or if Pledgor makes an assignment for the benefit of
creditors, the entire amount unpaid on the Note shall become immediately due and
payable, and Pledgee may proceed as provided in the case of default.

     11.  Pledgeholder Liability. In the absence of willful or gross negligence,
          ----------------------
Pledgeholder shall not be liable to any party for any of his acts, or omissions
to act, as Pledgeholder.

     12.  Invalidity of Particular Provisions. Pledgor and Pledgee agree that
          -----------------------------------
the enforceability or invalidity of any provision or provisions of this Security
Agreement shall not render any other provision or provisions herein contained
unenforceable or invalid.

     13.  Successors or Assigns. Pledgor and Pledgee agree that all of the terms
          ---------------------
of this Security Agreement shall be binding on their respective successors and
assigns, and that the term "Pledgor" and the term "Pledgee" as used herein shall
be deemed to include, for all purposes, the respective designees, successors,
assigns, heirs, executors and administrators.

     14.  Governing Law. This Security Agreement shall be interpreted and
          -------------
governed under the internal substantive laws, but not the choice of law rules,
of California.
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the day and year first above written.


PLEDGOR                                      /s/ Michael T. Devlin
                                             -----------------------------------
                                             Signature

                                             Michael T. Devlin
                                             -----------------------------------
                                             Print Name

                                   Address:  ___________________________________

                                             ___________________________________


PLEDGEE                                      CATAPULSE INC.,
                                             a Delaware corporation


                                             /s/ Paul D. Levy
                                             -----------------------------------
                                             Paul D. Levy
                                             Chief Executive Officer


PLEDGEHOLDER                                 /s/ Michael Charney
                                             -----------------------------------
                                             Assistant Secretary of
                                             CataPULSE Inc.
<PAGE>

                                   EXHIBIT E
                                   ---------

                                     NOTE


$633,333.33
                                                           Cupertino, California

December 6, 1999

     FOR VALUE RECEIVED, Michael T. Devlin promises to pay to CataPULSE Inc., a
Delaware corporation (the "Company"), or order, the principal sum of Six Hundred
Thirty Three Thousand Three Hundred Thirty Three Dollars and Thirty Three Cents
($633,333.33), together with interest on the unpaid principal hereof from the
date hereof at the rate of 6.11 percent (6.11%) per annum, compounded
                                         -----
semiannually.

     Principal and interest shall be due and payable on December 6, 2004.
Payment of principal and interest shall be made in lawful money of the United
States of America.

     The undersigned may at any time prepay all or any portion of the principal
or interest owing hereunder.

     This Note is subject to the terms of the Stand-Alone Stock Option
Agreement, dated as of December 6, 1999. This Note is secured in part by a
pledge of the Company's common stock under the terms of a Security Agreement of
even date herewith and is subject to all the provisions thereof.

     The holder of this Note shall have full recourse against the undersigned,
and shall not be required to proceed against the collateral securing this Note
in the event of default.

     In the event the undersigned shall cease to be an employee, director or
consultant of the Company for any reason, this Note shall, at the option of the
Company, be accelerated, and the whole unpaid balance on this Note of principal
and accrued interest shall be immediately due and payable.

     Should any action be instituted for the collection of this Note, the
reasonable costs and attorneys' fees therein of the holder shall be paid by the
undersigned.


                                             /s/ Michael T. Devlin
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                                             Michael T. Devlin