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                                                                   EXHIBIT 10.19

                                NEUROMETRIX, INC.

                       STOCK OPTION AGREEMENT (1998 PLAN)

     NeuroMetrix, Inc., a Delaware corporation (the "Company") hereby grants to
Gary L. Gregory, presently of 4951 Mission Hill Place, Tucson, AZ 85718 (the
"Grantee"), an option (the "Option") to purchase 250,000 shares of the Company's
Common Stock, pursuant to the Company's 1998 Equity Incentive Plan (the "Plan"),
a copy of which is attached hereto and is incorporated herein in its entirety by
this reference. The Grantee hereby accepts the Option granted subject to the
terms and provisions set forth in the Plan and the following additional terms
and provisions:

1. The Option is a non-statutory stock option.

2. The price at which shares of Common Stock may be purchased pursuant to the
   Option is $1.50 per share, unless the Company consummates an initial public
   offering of its Common Stock on or before December 31, 2004 ("IPO") in which
   the offering price per share is greater than $1.50 (equitably adjusted in the
   event of any stock split, stock dividend, combination, reclassification,
   recapitalization, reorganization or other similar event), in which case the
   applicable purchase price shall be the IPO price per share. The price and the
   number of shares are also subject to adjustment as provided in the Plan.

3.   (a)  No portion of this Option may be exercised until such portion shall
   have become exercisable. Subject to the provisions of Section (c) hereof, the
   Option shall become exercisable according to the following schedule: (i)
   prior to the first anniversary of the Vesting Start Date (as defined below),
   the Option may not be exercised; and (ii) commencing on the first anniversary
   of the Vesting Start Date, the Option will be exercisable to the extent of
   one sixteenth (1/16th) of the total number of shares covered hereby for each
   full calendar quarter following the Vesting Start Date that Grantee has been
   employed by the Company, or a subsidiary of the Company, less the number of
   shares as to which this Option has been previously exercised. On any given
   date, the portion of the Option that is then exercisable is referred to as
   the "Vested Amount." Notwithstanding any of the other provisions of the
   Option, no portion of the Option may be exercised after the tenth anniversary
   of the Vesting Start Date (the "Expiration Date"). The "Vesting Start Date"
   is June 2, 2004.

     (b)  The Option may be exercised to the extent of the Vested Amount at any
   time on or before the Expiration Date, regardless of whether the Grantee's
   employment with the Company and its subsidiaries has terminated for any
   reason.

     (c)  Notwithstanding the foregoing provisions of this section 3, in the
   event that Grantee is entitled to severance as provided under the heading
   "Severance" in the letter dated June 19, 2002 from the Company to the Grantee
   (the "Offer Letter") and Grantee executes the Release (as defined in the
   Offer Letter), (i) if the first day of the Severance Period (as defined in
   the Offer Letter) is on or prior to the first anniversary of the Vesting
   Start Date, then, as of the first day of the Severance Period, the Vested
   Amount shall be 3/16 of the number of shares covered hereby and (ii) if the
   first day of the Severance Period occurs after the first anniversary of the
   Vesting Start Date, then, as of the first day of the Severance Period, the
   Vested Amount shall be

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   3/16 of the number of shares covered hereby plus an additional 1/16 of the
   number of shares covered hereby for each full calendar quarter following the
   Vesting Start Date that the Grantee has been employed by the Company or a
   subsidiary of the Company; provided, however, that the Vested Amount shall
   not exceed 250,000 shares and the number of shares as to which this Option
   has been previously exercised shall be subtracted from the Vested Amount. The
   Vested Amount shall not increase following the commencement of the Severance
   Period.

   WARNING:  THE OPTION EXERCISE PERIOD MAY BE CUT SHORT IN THE EVENT OF A
   CHANGE IN CONTROL OF THE COMPANY. SEE SECTION 11.4 OF THE PLAN.

4. The Option shall not be exercisable unless either (a) a registration
   statement under the Securities Act of 1933, as amended, with respect to the
   Option and the shares to be issued on the exercise thereof shall have become,
   and continue to be, effective, or (b) the Grantee (i) shall have represented,
   warranted and agreed, in form and substance satisfactory to the Company, at
   the time of exercising the Option, that he or she is acquiring the shares for
   his or her own account, for investment and not with a view to or in
   connection with any distribution, (ii) shall have agreed to restrictions on
   transfer in form and substance satisfactory to the Company and (iii) shall
   have agreed to an endorsement which makes appropriate reference to such
   representations, warranties, agreements and restrictions on the
   certificate(s) representing the shares.

   SHARES ISSUED UPON EXERCISE OF THE OPTION WILL BE SUBJECT TO ALL RESTRICTIONS
   ON TRANSFER IMPOSED BY THE COMPANY'S CERTIFICATE OF INCORPORATION, AS
   AMENDED, OR BY-LAWS, AS AMENDED, BY STOCKHOLDERS AGREEMENT, OR BY APPLICABLE
   STATE OR FEDERAL SECURITIES LAWS.

5. The Option may be exercised, subject to such conditions as the Company's
   Board of Directors may require in accordance with the Plan, by the giving of
   written notice, by certified or registered mail, to the Company's Treasurer
   at its principal place of business in Cambridge, Massachusetts, of the
   election to purchase shares pursuant hereto, which notice shall specify the
   number of shares to be so purchased, accompanied by full payment for the
   shares purchased, together with any tax or excise due in respect of issue of
   such shares, in cash or by certified or bank cashier's cheek.

6. Notwithstanding anything to the contrary contained herein, no shares shall be
   issued to the Grantee pursuant to the Option until the Company and the
   Grantee have made appropriate arrangements for the withholding of applicable
   income taxes, if any, attributable to the exercise of the Option with respect
   to such shares, and the Company may require the Grantee to make a cash
   payment to the Company in the amount of such taxes required to be withheld.

7. In the event the Company proposes an initial public offering of any of its
   equity securities pursuant to a registration statement under the Securities
   Act (whether for its own account or the account of others), and if requested
   in writing by the Company and an underwriter of the proposed offering of
   common stock or other securities of the Company to sign any "Lock-Up
   Agreement (the "Lock-Up Agreement"), the Grantee shall agree to sign the
   Lock-Up Agreement whereby he or she shall not sell, grant any option or right
   to buy or sell, or otherwise transfer or dispose of in any manner, to the
   public in open market transactions, any

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   Shares or other equity securities of the Company acquired upon exercise of
   this Option and held by such Grantee during whatever time period is requested
   by the Company and the underwriter for restrictions on trading or transfer
   (the "Lock-Up Period") following the effective date of the registration
   statement of the Company filed under the Securities Act. The Company may
   impose stop-transfer instruction with respect to the securities subject to
   the foregoing restrictions until the end of the Lock-Up Period. Such Lock-Up
   Period shall not exceed 180 days in length.

THE OPTION IS NOT TRANSFERABLE BY THE GRANTEE OTHERWISE THAN BY WILL OR THE LAWS
OF DESCENT AND DISTRIBUTION AND, DURING THE LIFETIME OF THE GRANTEE, MAY BE
EXERCISED ONLY BY THE GRANTEE.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement
effective as of June 21, 2004.

                                       NEUROMETRIX, INC.


                                       By: /s/ Shai N. Gozani
                                           ------------------
                                           Authorized Signature

                                       ACCEPTED:

                                       /s/ Gary L. Gregory
                                       -------------------
                                       Gary L. Gregory, Grantee

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                                NEUROMETRIX, INC.

                           1998 EQUITY INCENTIVE PLAN

                              OPTION EXERCISE FORM


TO:       Treasurer, NEUROMETRIX, INC.

FROM:     ___________________________


I elect to exercise my option to purchase shares of NEUROMETRIX, INC., common
stock as follows:

     Date of Option Grant: _______________

     Exercise Price: __________________

     Number of Shares to be Purchased: _____________________

     Total Exercise Price Enclosed: $________________________

Full payment, in cash, certified check or bank cashier's check, for the shares I
am electing to purchase is enclosed with this notice. I understand that issuance
of the purchased shares may be conditioned on my payment of any tax or excise
due thereon and on fulfillment of requirements specified in Section 6 of the
Stock Option Agreement between NEUROMETRIX, INC., and me.


                                       ---------------------------------------
                                       Optionholder's Signature


                                       Date:
                                             ---------------------------------

Received by:


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Date:
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