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                                                                     EXHIBIT 4.9

THE OFFER AND SALE OF THE WARRANT REPRESENTED BY THIS CERTIFICATE AND THE SHARES
ISSUABLE UPON EXERCISE THEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT
OF 1933, AS AMENDED (THE "SECURITIES ACT") NOR QUALIFIED UNDER ANY APPLICABLE
STATE SECURITIES OR BLUE SKY LAWS. THIS WARRANT HAS BEEN ACQUIRED FOR INVESTMENT
AND NOT WITH A VIEW TO, OR FOR SALE IN CONNECTION WITH, ANY DISTRIBUTION THEREOF
WITHIN THE MEANING OF THE SECURITIES ACT AND ANY APPLICABLE STATE SECURITIES OR
BLUE SKY LAWS. THIS WARRANT AND THE SHARES ISSUABLE UPON EXERCISE THEREOF MAY
NOT BE SOLD OR OFFERED FOR SALE IN THE ABSENCE OF AN EFFECTIVE REGISTRATION
STATEMENT UNDER THE SECURITIES ACT AND COMPLIANCE WITH ANY APPLICABLE STATE
SECURITIES OR BLUE SKY LAWS OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY
TO THE EFFECT THAT SUCH REGISTRATION AND COMPLIANCE ARE NOT REQUIRED.

W-[ ]                                               Warrant to Purchase
                                                    [   ] Shares of
                                                    Common Stock
                                                    As Herein Described

                       WARRANT TO PURCHASE COMMON STOCK OF
                           CARDIAC SCIENCE CORPORATION

      This is to certify that, for value received, [PERSEUS ENTITY] (the
"HOLDER"), is entitled to purchase from CARDIAC SCIENCE CORPORATION, a Delaware
corporation (the "COMPANY"), having its principal place of business at 3303
Monte Villa Parkway, Bothell, Washington 98021, at any time during the period
from the date hereof (the "COMMENCEMENT DATE") to 5:00 p.m., California time, on
[     ] (the "EXPIRATION DATE"), at which time this Warrant shall expire and
become void, and subject to vesting and other provisions of this Warrant,
[   (     )   ]shares ("WARRANT SHARES") of the Company's Common Stock (the
"COMMON STOCK"). This Warrant shall be exercisable at $[     ] per share (the
"EXERCISE PRICE"). The number of shares of Common Stock to be received upon
exercise of this Warrant and the Exercise Price shall be adjusted from time to
time as set forth below. This Warrant also is subject to the following terms and
conditions:

1.    VESTING: EXERCISE AND PAYMENT; EXCHANGE

      (a)   [Intentionally omitted.]

      (b) This Warrant may be exercised in whole or in part at any time from and
after the date hereof and before the Expiration Date, but if such date is a day
on which federal or

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state chartered banking institutions located in the State of
California are authorized to close, then on the next succeeding day which shall
not be such a day. Exercise shall be by presentation and surrender to the
Company at its principal office, or at the office of any transfer agent
designated by the Company, of (i) this Warrant, (ii) the attached exercise form
properly executed, and (iii) either (A) a certified or official bank check for
the Exercise Price for the number of Warrant Shares specified in the exercise
form; or (B) other securities of the Company owned by the Holder and having a
fair market value determined as set forth in SECTION 3 hereof equal to the
Exercise Price for the number of Warrant Shares specified in the exercise form
or (C) any combination of the consideration specified in the foregoing clauses
(A) and (B). If this Warrant is exercised in part only, the Company or its
transfer agent shall, upon surrender of the Warrant, execute and deliver a new
Warrant evidencing the rights of the Holder to purchase the remaining number of
Warrant Shares purchasable hereunder. Upon receipt by the Company of this
Warrant in proper form for exercise, accompanied by payment as aforesaid, the
Holder shall be deemed to be the holder of record of the Common Stock issuable
upon such exercise, notwithstanding that the stock transfer books of the Company
shall then be closed or that certificates representing such Warrant Shares shall
not then be actually delivered by the Holder.

      (c) Exchange of Warrant for Common Stock. In addition to and without
limiting the rights of the Holder under the terms of this Warrant, the Holder
shall have the right, Upon its written request delivered or transmitted to the
Company together with this Warrant, to exchange this Warrant, in whole or in
part at any time or from time to time on or prior to the Expiration date, for
the number of shares of Common Stock having an aggregate fair market value
(determined as set forth in SECTION 3 hereof) on the date of such exchange equal
to the difference between (i) the aggregate fair market value on the date of
such exchange (determined as set forth in SECTION 3 hereof) of a number of
Warrant Shares designated by the Holder and (ii) the aggregate Exercise Price
the Holder would have paid to the company to purchase such designated number of
Warrant Shares, and, if a balance of purchasable Warrant Shares remains after
such exchange, the Company shall execute and deliver to the Holder a new Warrant
evidencing the right of the Holder to purchase such balance of Warrant Shares.
No payment of any cash or other consideration shall be required. Such exchange
shall be effective upon the date of receipt by the Company of the original
Warrant surrendered for cancellation and a written request from the Holder that
the exchange pursuant to this Subsection be made, or at such later date as may
be specified in such request.

      (d) Conditions to Exercise or Exchange. The restrictions in SECTION 7
shall apply, to the extent applicable by their terms, to any exercise or
exchange of this Warrant permitted by this SECTION 1.

2.       RESERVATION OF SHARES

      The Company shall, at all times until the expiration of this Warrant,
reserve for issuance and delivery upon exercise of this Warrant the number of
Warrant Shares which shall be required for issuance and delivery upon exercise
of this Warrant.

                                      -2-
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3.    FRACTIONAL INTERESTS

      The Company shall not issue any fractional shares or script representing
fractional shares upon the exercise or exchange of this Warrant. With respect to
any fraction of a share resulting from the exercise or exchange hereof, the
Company shall pay to the Holder an amount in cash equal to such fraction
multiplied by the number of shares of Common Stock into which each share of
Common Stock is then convertible, multiplied by the current fair market value
per share of Common Stock. The current fair market value shall be the last
reported sale price of the Common Stock on The Nasdaq National Market on the
last business day prior to the date of exercise of this Warrant or if no such
sale is made on such day, the mean of the closing bid and asked prices for such
day on The Nasdaq National Market;

4.    NO RIGHTS AS STOCKHOLDERS

      This Warrant shall not entitle the Holder to any rights as a stockholder
of the Company, either at law or in equity. The rights of the Holder are limited
to those expressed in this Warrant and are not enforceable against the Company
except to the extent set forth herein.

5.    ADJUSTMENTS IN NUMBER AND EXERCISE PRICES OF WARRANT SHARES

      5.1 The number of shares of Common Stock for which this Warrant may be
exercised and the Exercise Prices therefor shall be subject to adjustment as
follows:

            (a) If the Company is recapitalized through the subdivision or
combination of its outstanding shares of Common Stock into a larger or smaller
number of shares, the number of shares of Common Stock for which this Warrant
may be exercised shall be increased or reduced, as of the record date for such
recapitalization in the same proportion as the increase or decrease in the
outstanding shares of Common Stock, and the exercise price shall be adjusted so
that the aggregate amount payable for the purchase of all of the Warrant Shares
issuable hereunder immediately after the record date for such recapitalization
shall equal the aggregate amount so payable immediately before such record date.

                                      -3-
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            (b) If the Company declares a dividend or distribution on Common
Stock payable in Common Stock or securities convertible into Common Stock, the
number of shares of Common Stock for which this Warrant may be exercised shall
be increased as of the record date for determining which holders of Common Stock
shall be entitled to receive such dividend, in proportion to the increase in the
number of outstanding shares (and shares of Common Stock issuable upon
conversion of all such securities convertible into Common Stock) of Common Stock
as a result of such dividend, and the Exercise Price shall be adjusted so that
the aggregate amount payable for the purchase of all the Warrant Shares issuable
hereunder immediately after the record date for such dividend shall equal the
aggregate amount so payable immediately before such record date.

            (c) If the Company distributes to holders of its Common Stock, other
than as part of its dissolution or liquidation or the winding up of its affairs,
any evidence of indebtedness or any of its assets (other than cash, Common Stock
or securities convertible into Common Stock), the Company shall give written
notice to the Holder of any such distribution at least fifteen days prior to the
proposed record date in order to permit the Holder to exercise this Warrant on
or before the record date. There shall be no adjustment in the number of shares
of Common Stock for which this Warrant may be exercised, or in the Exercise
Price, by virtue of any such distribution.

            (d) If the Company offers rights or warrants to the holders of
Common Stock which entitle them to subscribe to or purchase additional Common
Stock or securities convertible into Common Stock, the Company shall give
written notice of any such proposed offering to the Holder at least fifteen days
prior to the proposed record date in order to permit the Holder to exercise this
Warrant on or before such record date. There shall be no adjustment in the
number of shares of Common Stock for which this Warrant may be exercised, or in
the Exercise Price, by virtue of any such distribution.

            (e) If the event, as a result of which an adjustment is made under
paragraph (a) or (b) above, does not occur, then any adjustments in the Exercise
Price or number of shares issuable that were made in accordance with such
paragraph (a) or (b) shall be adjusted to the Exercise Price and number of
shares as were in effect immediately prior to the record date for such event.

      5.2 In the event of any reorganization or reclassification of the
outstanding shares of Common Stock (other than a change in par value or from no
par value to par value, or from par value to no par value, or as a result of a
subdivision or combination) or in the event of any consolidation or merger of
the Company with another entity after which the Company is not the surviving
entity, at any time prior to the expiration of this Warrant, upon subsequent
exercise of this Warrant the Holder shall have the right to receive the same
kind and number of shares of Common Stock and other securities, cash or other
property as would have been distributed to the Holder upon such reorganization,
reclassification, consolidation or merger had the Holder exercised this Warrant
immediately prior to such reorganization, reclassification, consolidation or
merger, appropriately adjusted for any subsequent event described in this
SECTION 5. The Holder shall pay upon such exercise the Exercise Price that

                                      -4-
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otherwise would have been payable pursuant to the terms of this Warrant. If any
such reorganization, reclassification, consolidation or merger results in a cash
distribution in excess of the then applicable Exercise Price, the holder may, at
the Holder's option exercise this Warrant without making payment of the Exercise
Price, and in such case the Company shall, upon distribution to the Holder,
consider the Exercise Price to have been paid in full, and in making settlement
to the Holder, shall deduct an amount equal to the Exercise Price from the
amount payable to the Holder. In the event of any such reorganization, merger or
consolidation, the corporation formed by such consolidation or merger or the
corporation which shall have acquired the assets of the Company shall execute
and deliver a supplement hereto to the foregoing effect, which supplement shall
also provide for adjustments which shall be as nearly equivalent as may be
practicable to the adjustments provided in this Warrant.

      5.3 If the Company shall, at any time before the expiration of this
Warrant, dissolve, liquidate or wind up its affairs, the Holder shall have the
right to receive upon exercise of this Warrant, in lieu of the shares of Common
Stock of the Company that the Holder otherwise would have been entitled to
receive, the same kind and amount of assets as would have been issued,
distributed or paid to the Holder upon any such dissolution, liquidation or
winding up with respect to such Common Stock receivable upon exercise of this
Warrant on the date for determining those entitled to receive any such
distribution. If any such dissolution, liquidation or winding up results in any
cash distribution in excess of the Exercise Price provided by this Warrant, the
Holder may, at the Holder's option, exercise this Warrant without making payment
of the Exercise Price and, in such case, the Company shall, upon distribution to
the Holder, consider the Exercise Price to have been paid in full and, in making
settlement to the Holder, shall deduct an amount equal to the Exercise Price
from the amount payable to the Holder.

      5.4 The Company may retain a firm of independent public accountants of
recognized standing (who may be any such firm employed by the Company) to make
any computation required under this SECTION 5, and a certificate signed by such
firm shall be conclusive evidence of the correctness of any computation made
under this SECTION 5.

      5.5 Whenever the number of Warrant Shares or Exercise Price shall be
adjusted as required by the provisions of this SECTION 5, the Company forthwith
shall file in the custody of its secretary or an assistant secretary, at its
principal office, an officer's certificate showing the adjusted number of
Warrant Shares and Exercise Price and setting forth in reasonable detail the
circumstances requiring the adjustment. Each such officer's certificate shall be
made available at all reasonable times during reasonable hours for inspection by
the Holder.

6.    NOTICES TO HOLDER

      So long as this Warrant shall be outstanding (a) if the Company shall pay
any dividends or make any distribution upon the Common Stock otherwise than in
cash or (b) if the Company shall offer generally to the holders of Common Stock
the right to subscribe to or purchase any shares of any class of Common Stock or
securities convertible into Common

                                      -5-
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Stock or any similar rights or (c) if there shall be any capital reorganization
of the Company in which the Company is not the surviving entity,
recapitalization of the capital stock of the Company, consolidation or merger of
the Company with or into another corporation, sale, lease or other transfer of
all or substantially all of the property and assets of the Company, or voluntary
or involuntary dissolution, liquidation or winding up of the Company, then in
such event, the Company shall cause to be mailed to the Holder, at least thirty
days prior to the relevant date described below (or such shorter period as is
reasonably possible if thirty days is not reasonably possible), a notice
containing a description of the proposed action and stating the date or expected
date on which a record of the Company's stockholders is to be taken for the
purpose of any such dividend, distribution of rights, or such reclassification,
reorganization, consolidation, merger, conveyance, lease or transfer,
dissolution, liquidation or winding up is to take place and the date or expected
date, if any is to be fixed, as of which the holders of Common Stock of record
shall be entitled to exchange their shares of Common Stock for securities or
other property deliverable upon such event.

7.    TRANSFER, EXERCISE, EXCHANGE, ASSIGNMENT OR LOSS OF WARRANT, WARRANT
      SHARES OR OTHER SECURITIES

      7.1 This Warrant may be transferred, exercised, exchanged or assigned
("TRANSFERRED"), in whole or in part, subject to the following restrictions.
This Warrant and the Warrant Shares or any other securities ("OTHER SECURITIES")
received upon exercise of this Warrant or the conversion of the Warrant Shares
shall be subject to restrictions on transferability unless registered under the
Securities Act of 1933, as amended (the "SECURITIES ACT"), or unless an
exemption from registration is available. Until this Warrant and the Warrant
Shares or Other Securities are so registered, this Warrant and any certificate
for Warrant Shares or Other Securities issued or issuable upon exercise of this
Warrant shall contain a legend on the face thereof, in form and substance
satisfactory to counsel for the Company, stating that this Warrant, the Warrant
Shares or Other Securities may not be sold, transferred or otherwise disposed of
unless, in the opinion of counsel satisfactory to the Company, which may be
counsel to the Company, that the Warrant, the Warrant Shares or Other Securities
may be transferred without such registration. This Warrant and the Warrant
Shares or Other Securities may also be subject to restrictions on
transferability under applicable state securities or blue sky laws. Until the
Warrant and the Warrant Shares or Other Securities are registered under the
Securities Act, the Holder shall reimburse the Company for its expenses,
including attorneys' fees, incurred in connection with any transfer or
assignment, in whole or in part, of this Warrant or any Warrant Shares or Other
Securities.

      7.2 Until this Warrant, the Warrant Shares or other Securities are
registered under the Securities Act, the Company may require, as a condition of
transfer of this Warrant, the Warrant Shares, or other Securities that the
transferee (who may be the Holder in the case of an exercise or exchange)
represent that the securities being transferred are being acquired for
investment purposes and for the transferee's own account and not with a view to
or for sale in connection with any distribution of the security. The Company may
also require that transferee provide written information adequate to establish
that the transferee is an "accredited investor" within the meaning of Regulation
D issued under the Securities Act, or

                                      -6-
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otherwise meets all qualifications necessary to comply with exemptions to the
Securities Act and any applicable securities or blue sky laws, all as determined
by counsel to the Company.

      7.3 Any transfer permitted hereunder shall be made by surrender of this
Warrant to the Company at its principal office or to its transfer agent at its
offices with a duly executed request to transfer the Warrant, which shall
provide adequate information to effect such transfer and shall be accompanied by
funds sufficient to pay any transfer taxes applicable. Upon satisfaction of all
transfer conditions, the Company or its transfer agent shall, without charge,
execute and deliver a new Warrant in the name of the transferee named in such
transfer request, and this Warrant promptly shall be cancelled.

      7.4 Upon receipt by the Company of evidence satisfactory to it of loss,
theft, destruction or mutilation of this Warrant and, in the case of loss, theft
or destruction, of reasonable satisfactory indemnification, or, in the case of
mutilation, upon surrender of this Warrant, the Company will execute and
deliver, or instruct its transfer agent to execute and deliver, a new Warrant of
like tenor and date, any such lost, stolen or destroyed Warrant thereupon shall
become void.

      7.5 Each Holder of this Warrant, the Warrant Shares and any Other
Securities shall indemnify and hold harmless the Company, its directors and
officers, and each other person, if any, who controls the Company, against any
losses, claims, damages or liabilities, joint or several, to which the Company
or any such director, officer or any such person may become subject under the
Securities Act, any applicable state securities or blue sky laws or any statute
or common law, insofar as such losses, claims, damages or liabilities or actions
in respect thereof, arise out of or are based upon the disposition by such
Holder of the Warrant, the Warrant Shares or Other Securities in violation of
this Warrant.

8.    NO IMPAIRMENT

      The Company will not, by amendment of its Certificate of Incorporation or
otherwise, 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, take all such
action as may be necessary or appropriate in order to protect the rights of the
Holder against impairment.

9.    NOTICES

      Notices and other communications to be given to the Holder shall be deemed
sufficiently given if delivered by hand, or two business days after mailing if
mailed by registered or certified mail, postage prepaid, addressed in the name
and at the address of such Holder appearing on the records of the Company.
Notices or other communications to the Company shall be deemed to have been
sufficiently given if delivered by hand or two business days after mailing if
mailed by registered or certified mail, postage prepaid, to the Company at:

                                      -7-
<PAGE>

              3303 Monte Villa Parkway
              Bothell, Washington  98021
              Attention:  Chief Financial Officer

Either party may change the address to which notices shall be given by notice
pursuant to this SECTION 9.

10.   GOVERNING LAW

      This Warrant shall be governed by and construed in accordance with the
laws of the State of California.

      IN WITNESS WHEREOF, the Company has caused this Warrant to be executed on
its behalf by one of its officers thereunto duly authorized.

                                            CARDIAC SCIENCE CORPORATION

                                            By:________________________________
                                            Name:______________________________
                                            Its:_______________________________

Original Issuance Date: [      ]
Replacement Warrant Date:   , 2005

                                      -8-
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                                                                         Annex A

                                FORM OF EXERCISE
                    (To be executed upon exercise of Warrant)

      The undersigned hereby irrevocably elects to exercise the right,
represented by this Warrant Certificate, to purchase _______________ shares of
Common Stock and herewith tenders payment for such shares of Common Stock to the
order of Cardiac Science Corporation the amount of $__________ in accordance
with the terms hereof. The undersigned requests that a certificate for such
shares of Common Stock be registered in the names of _______________, whose
address is __________________.

Dated:_______________________                Signature:________________________
                                             (Signature must conform in all
                                             respects to name of holders as
                                             specified on the face of the
                                             Warrant Certificate.)

_____________________________________________
(Insert Social Security or Taxpayer Identification
Number of Holder.)