<PAGE>

                                                                   EXHIBIT 10.31


                              VISION-SCIENCES, INC.

                     PIGGYBACK REGISTRATION RIGHTS AGREEMENT

         This Agreement dated as of January 2, 2001 is entered into by and among
Vision-Sciences, Inc., a Delaware corporation (the "Company"), and the
individuals and entities listed on EXHIBIT A attached hereto (the "Purchasers").

                                    RECITALS

         WHEREAS, the Company has sold to the Purchasers an aggregate of
5,587,418 shares (the `Shares") of Common Stock (as defined below).

         WHEREAS, the Company and the Purchasers desire to provide for certain
arrangements with respect to the registration of shares of capital stock of the
Company under the Securities Act of 1933,

         NOW, THEREFORE, in consideration of the mutual promises and covenants
contained in this Agreement, the parties hereto agree as follows:

         1. CERTAIN DEFINITIONS.

         As used in this Agreement, the following terms shall have the following
respective meanings:

                  "COMMISSION" means the Securities and Exchange Commission, or
any other federal agency at the time administering the Securities Act.

                  "COMMON STOCK" means the common stock, $0.01 par value per
share, of the Company.

                  "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended, or any successor federal statute, and the rules and regulations of the
Commission issued under such Act, as they each may, from time to time, be in
effect.

                   "OTHER HOLDERS" means any holders of securities of the
Company (other than the Stockholders) who are entitled, by contract with the
Company, to have securities included in a registration.

                  "PROSPECTUS" means the prospectus included in any Registration
Statement, as amended or supplemented by an amendment or prospectus supplement,
including post-effective amendments, and all material incorporated by reference
or deemed to be incorporated by reference in such Prospectus.

                  "REGISTRATION STATEMENT" means a registration statement filed
by the Company with the Commission for a public offering and sale of securities
of the Company (other than a registration statement on Form S-8 or Form S-4, or
their successors, or any other form for a


<PAGE>

similar limited purpose, or any registration statement covering only securities
proposed to be issued in exchange for securities or assets of another
corporation).

                  "REGISTRATION EXPENSES" means the expenses described in
Section 2.4.

                  "REGISTRABLE SHARES" means (i) Shares and (ii) any other
shares of Common Stock issued in respect of such Shares (because of stock
splits, stock dividends, reclassifications, recapitalizations, or similar
events); PROVIDED, HOWEVER, that shares of Common Stock which are Registrable
Shares shall cease to be Registrable Shares upon (i) any sale pursuant to a
Registration Statement or Rule 144 under the Securities Act or (ii) any sale in
any manner to a person or entity which, by virtue of Section 3 of this
Agreement, is not entitled to the rights provided by this Agreement.

                  "SECURITIES ACT" means the Securities Act of 1933, as amended,
or any successor federal statute, and the rules and regulations of the
Commission issued under such Act, as they each may, from time to time, be in
effect.

                  "SELLING STOCKHOLDER" means any Stockholder owning Registrable
Shares included in a Registration Statement.

                  "SHARES" shall have the meaning specified in the first
recital.

                  "STOCKHOLDERS" means the Purchasers and any persons or
entities to whom the rights granted under this Agreement are transferred by any
Purchasers, their successors or assigns pursuant to Section 3 hereof.

         2. REGISTRATION RIGHTS

                  2.1 INCIDENTAL REGISTRATION. Whenever the Company proposes to
file a Registration Statement (other than a Registration Statement covering
shares to be sold solely for the account of Other Holders) at any time and from
time to time, it will, prior to such filing, give written notice to all
Stockholders of its intention to do so; provided, that no such notice need be
given if no Registrable Shares are to be included therein as a result of a
determination of the managing underwriter pursuant to Section 2.2. Upon the
written request of a Stockholder or Stockholders given within 20 days after the
Company provides such notice (which request shall state the intended method of
disposition of such Registrable Shares), the Company shall use its best efforts
to cause all Registrable Shares which the Company has been requested by such
Stockholder or Stockholders to register to be registered under the Securities
Act to the extent necessary to permit their sale or other disposition in
accordance with the intended methods of distribution specified in the request of
such Stockholder or Stockholders; provided that the Company shall have the right
to postpone or withdraw any registration effected pursuant to this Section 2
without obligation to any Stockholder.

                  2.2 LIMITATIONS.


                        (a) If the registration for which the Company gives
notice pursuant to Section 2.1 is a registered public offering involving an
underwriting, the Company shall so advise the Stockholders as a part of the
written notice given pursuant to Section 2.1. In such


                                      -2-
<PAGE>

event, the right of any Stockholder to include its Registrable Shares in such
registration pursuant to this Agreement shall be conditioned upon such
Stockholder's participation in such underwriting on the terms set forth herein.
All Stockholders proposing to distribute their securities through such
underwriting shall enter into an underwriting agreement in customary form with
the underwriter or underwriters selected for the underwriting by the Company.
Notwithstanding any other provision of this Section Agreement, if the managing
underwriter determines that the inclusion of all shares requested to be
registered would adversely affect the offering, the Company may limit the number
of Registrable Shares to be included in the registration and underwriting. The
Company shall so advise all holders of Registrable Shares requesting
registration, and the number of shares that are entitled to be included in the
registration and underwriting shall be allocated in the following manner. The
securities of the Company held by holders other than Stockholders and Other
Holders shall be excluded from such registration and underwriting to the extent
deemed advisable by the managing underwriter, and, if a further limitation on
the number of shares is required, the number of shares that may be included in
such registration and underwriting shall be allocated among all Stockholders and
Other Holders requesting registration in proportion, as nearly as practicable,
to the respective number of shares of Common Stock which they held at the time
the Company gives the notice specified in Section 2.1. If any Stockholder or
Other Holder would thus be entitled to include more securities than such holder
requested to be registered, the excess shall be allocated among other requesting
Stockholders and Other Holders pro rata in the manner described in the preceding
sentence. If any holder of Registrable Shares or any officer, director or Other
Holder disapproves of the terms of any such underwriting, such person may elect
to withdraw therefrom by written notice to the Company, and any Registrable
Shares or other securities excluded or withdrawn from such underwriting shall be
withdrawn from such registration.

                        (b) Notwithstanding the foregoing, the Company shall not
be required, pursuant to this Section 2.2, to include any Registrable Shares in
a Registration Statement if such Registrable Shares can then be sold pursuant to
Rule 144(k) under the Securities Act.

                  2.3 REGISTRATION PROCEDURES.

                        (a) If and whenever the Company is required by the
provisions of this Agreement to use its best efforts to effect the registration
of any Registrable Shares under the Securities Act, the Company shall:

                            (i) file with the Commission a Registration
Statement with respect to such Registrable Shares and use its best efforts to
cause that Registration Statement to become effective as soon as possible;

                            (ii) as expeditiously as possible prepare and file
with the Commission any amendments and supplements to the Registration Statement
and the prospectus included in the Registration Statement as may be necessary to
comply with the provisions of the Securities Act (including the anti-fraud
provisions thereof) and to keep the Registration Statement effective for 12
months from the effective date or such lesser period until all such Registrable
Shares are sold;

                                       -3-

<PAGE>

                            (iii) as expeditiously as possible furnish to each
Selling Stockholder such reasonable numbers of copies of the Prospectus,
including any preliminary Prospectus, in conformity with the requirements of the
Securities Act, and such other documents as such Selling Stockholder may
reasonably request in order to facilitate the public sale or other disposition
of the Registrable Shares owned by such Selling Stockholder;

                            (iv) as expeditiously as possible use its best
efforts to register or qualify the Registrable Shares covered by the
Registration Statement under the securities or Blue Sky laws of such states as
the Selling Stockholders shall reasonably request, and do any and all other acts
and things that may be necessary or desirable to enable the Selling Stockholders
to consummate the public sale or other disposition in such states of the
Registrable Shares owned by the Selling Stockholder; PROVIDED, HOWEVER, that the
Company shall not be required in connection with this paragraph (iv) to qualify
as a foreign corporation or execute a general consent to service of process in
any jurisdiction;

                            (v) as expeditiously as possible, cause all such
Registrable Shares to be listed on each securities exchange or automated
quotation system on which similar securities issued by the Company are then
listed;

                            (vi) promptly provide a transfer agent and registrar
for all such Registrable Shares not later than the effective date of such
registration statement;

                            (vii) promptly make available for inspection by the
Selling Stockholders, any managing underwriter participating in any disposition
pursuant to such Registration Statement, and any attorney or accountant or other
agent retained by any such underwriter or selected by the Selling Stockholders,
all financial and other records, pertinent corporate documents and properties of
the Company and cause the Company's officers, directors, employees and
independent accountants to supply all information reasonably requested by any
such seller, underwriter, attorney, accountant or agent in connection with such
Registration Statement;

                            (viii) as expeditiously as possible, notify each
Selling Stockholder, promptly after it shall receive notice thereof, of the time
when such Registration Statement has become effective or a supplement to any
Prospectus forming a part of such Registration Statement has been filed; and

                            (ix) as expeditiously as possible following the
effectiveness of such Registration Statement, notify each seller of such
Registrable Shares of any request by the Commission for the amending or
supplementing of such Registration Statement or Prospectus.

                        (b) If the Company has delivered a Prospectus to the
Selling Stockholders and after having done so the Prospectus is amended to
comply with the requirements of the Securities Act, the Company shall promptly
notify the Selling Stockholders and, if requested, the Selling Stockholders
shall immediately cease making offers of Registrable Shares and return all
Prospectuses to the Company. The Company shall promptly provide the Selling
Stockholders with revised Prospectuses and, following receipt of the revised

                                      -4-
<PAGE>

Prospectuses, the Selling Stockholders shall be free to resume making offers of
the Registrable Shares.

                        (c) In the event that, in the judgment of the Company,
it is advisable to suspend use of a Prospectus included in a Registration
Statement due to pending material developments or other events that have not yet
been publicly disclosed and as to which the Company believes public disclosure
would be detrimental to the Company, the Company shall notify all Selling
Stockholders to such effect, and, upon receipt of such notice, each such Selling
Stockholder shall immediately discontinue any sales of Registrable Shares
pursuant to such Registration Statement until such Selling Stockholder has
received copies of a supplemented or amended Prospectus or until such Selling
Stockholder is advised in writing by the Company that the then current
Prospectus may be used and has received copies of any additional or supplemental
filings that are incorporated or deemed incorporated by reference in such
Prospectus.

                  2.4 ALLOCATION OF EXPENSES. The Company will pay all
Registration Expenses for all registrations under this Agreement. For purposes
of this Section, the term "Registration Expenses" shall mean all expenses
incurred by the Company in complying with this Agreement, including, without
limitation, all registration and filing fees, exchange listing fees, printing
expenses, fees and expenses of counsel for the Company, state Blue Sky fees and
expenses, and the expense of any special audits incident to or required by any
such registration, but excluding underwriting discounts, selling commissions and
the fees and expenses of Selling Stockholders' own counsel.

                  2.5 INDEMNIFICATION AND CONTRIBUTION.

                        (a) In the event of any registration of any of the
Registrable Shares under the Securities Act pursuant to this Agreement, the
Company will indemnify and hold harmless each Selling Stockholder, each
underwriter of such Registrable Shares, and each other person, if any, who
controls such Selling Stockholder or underwriter within the meaning of the
Securities Act or the Exchange Act against any losses, claims, damages or
liabilities, joint or several, to which such Selling Stockholder, underwriter or
controlling person may become subject under the Securities Act, the Exchange
Act, state securities or Blue Sky laws or otherwise, insofar as such losses,
claims, damages or liabilities (or actions in respect thereof) arise out of or
are based upon any untrue statement or alleged untrue statement of any material
fact contained in any Registration Statement under which such Registrable Shares
were registered under the Securities Act, any preliminary prospectus or final
prospectus contained in the Registration Statement, or any amendment or
supplement to such Registration Statement, or arise out of or are based upon the
omission or alleged omission to state a material fact required to be stated
therein or necessary to make the statements therein not misleading; and the
Company will reimburse such Selling Stockholder, underwriter and each such
controlling person for any legal or any other expenses reasonably incurred by
such Selling Stockholder, underwriter or controlling person in connection with
investigating or defending any such loss, claim, damage, liability or action;
PROVIDED, HOWEVER, that the Company will not be liable in any such case to the
extent that any such loss, claim, damage or liability arises out of or is based
upon any untrue statement or omission made in such Registration Statement,
preliminary prospectus or prospectus, or any such amendment or supplement, in
reliance upon and in conformity with

                                      -5-
<PAGE>

information furnished to the Company, in writing, by or on behalf of such
Selling Stockholder, underwriter or controlling person specifically for use in
the preparation thereof.

                        (b) In the event of any registration of any of the
Registrable Shares under the Securities Act pursuant to this Agreement, each
Selling Stockholder, severally and not jointly, will indemnify and hold harmless
the Company, each of its directors and officers and each underwriter (if any)
and each person, if any, who controls the Company or any such underwriter within
the meaning of the Securities Act or the Exchange Act, against any losses,
claims, damages or liabilities, joint or several, to which the Company, such
directors and officers, underwriter or controlling person may become subject
under the Securities Act, Exchange Act, state securities or Blue Sky laws or
otherwise, insofar as such losses, claims, damages or liabilities (or actions in
respect thereof) arise out of or are based upon any untrue statement or alleged
untrue statement of a material fact contained in any Registration Statement
under which such Registrable Shares were registered under the Securities Act,
any preliminary prospectus or final prospectus contained in the Registration
Statement, or any amendment or supplement to the Registration Statement, or
arise out of or are based upon any omission or alleged omission to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading, if the statement or omission was made in reliance upon
and in conformity with information relating to such Selling Stockholder
furnished in writing to the Company by or on behalf of such Selling Stockholder
specifically for use in connection with the preparation of such Registration
Statement, prospectus, amendment or supplement; PROVIDED, HOWEVER, that the
obligations of a Selling Stockholder hereunder shall be limited to an amount
equal to the net proceeds to such Selling Stockholder of Registrable Shares sold
in connection with such registration.

                        (c) Each party entitled to indemnification under this
Section (the "Indemnified Party") shall give notice to the party required to
provide indemnification (the "Indemnifying Party") promptly after such
Indemnified Party has actual knowledge of any claim as to which indemnity may be
sought, and shall permit the Indemnifying Party to assume the defense of any
such claim or any litigation resulting therefrom; PROVIDED, that counsel for the
Indemnifying Party, who shall conduct the defense of such claim or litigation,
shall be approved by the Indemnified Party (whose approval shall not be
unreasonably withheld); and, PROVIDED, FURTHER, that the failure of any
Indemnified Party to give notice as provided herein shall not relieve the
Indemnifying Party of its obligations under this Section except to the extent
that the Indemnifying Party is adversely affected by such failure. The
Indemnified Party may participate in such defense at such party's expense;
PROVIDED, HOWEVER, that the Indemnifying Party shall pay such expense if
representation of such Indemnified Party by the counsel retained by the
Indemnifying Party would be inappropriate due to actual or potential differing
interests between the Indemnified Party and any other party represented by such
counsel in such proceeding; PROVIDED FURTHER that in no event shall the
Indemnifying Party be required to pay the expenses of more than one law firm per
jurisdiction as counsel for the Indemnified Party. The Indemnifying Party also
shall be responsible for the expenses of such defense if the Indemnifying Party
does not elect to assume such defense. No Indemnifying Party, in the defense of
any such claim or litigation shall, except with the consent of each Indemnified
Party, consent to entry of any judgment or enter into any settlement which does
not include as an unconditional term thereof the giving by the claimant or
plaintiff to such Indemnified Party of a release from all liability in respect
of such claim or litigation, and no Indemnified Party shall consent to entry of
any

                                      -6-

<PAGE>

judgment or settle such claim or litigation without the prior written consent of
the Indemnifying Party, which consent shall not be unreasonably withheld.

                        (d) In order to provide for just and equitable
contribution in circumstances in which the indemnification provided for in this
Section 2.5 is due in accordance with its terms but for any reason is held to be
unavailable to an Indemnified Party in respect to any losses, claims, damages
and liabilities referred to herein, then the Indemnifying Party shall, in lieu
of indemnifying such Indemnified Party, contribute to the amount paid or payable
by such Indemnified Party as a result of such losses, claims, damages or
liabilities to which such party may be subject in such proportion as is
appropriate to reflect the relative fault of the Company on the one hand and the
Selling Stockholders on the other in connection with the statements or omissions
which resulted in such losses, claims, damages or liabilities, as well as any
other relevant equitable considerations. The relative fault of the Company and
the Selling Stockholders shall be determined by reference to, among other
things, whether the untrue or alleged untrue statement of material fact related
to information supplied by the Company or the Selling Stockholders and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such statement or omission. The Company and the Selling
Stockholders agree that it would not be just and equitable if contribution
pursuant to this Section 2.5 were determined by pro rata allocation or by any
other method of allocation which does not take account of the equitable
considerations referred to above. Notwithstanding the provisions of this
paragraph of Section 2.5, (a) in no case shall any one Selling Stockholder be
liable or responsible for any amount in excess of the net proceeds received by
such Selling Stockholder from the offering of Registrable Shares and (b) the
Company shall be liable and responsible for any amount in excess of such
proceeds; PROVIDED, HOWEVER, that no person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation. Any party entitled to contribution will, promptly
after receipt of notice of commencement of any action, suit or proceeding
against such party in respect of which a claim for contribution may be made
against another party or parties under this Section, notify such party or
parties from whom contribution may be sought, but the omission so to notify such
party or parties from whom contribution may be sought shall not relieve such
party from any other obligation it or they may have thereunder or otherwise
under this Section. No party shall be liable for contribution with respect to
any action, suit, proceeding or claim settled without its prior written consent,
which consent shall not be unreasonably withheld.

                  2.6 INFORMATION BY HOLDER. Each Selling Stockholder shall
furnish to the Company such information regarding such holder and the
distribution proposed by such holder as the Company may reasonably request in
writing and as shall be required in connection with any registration,
qualification or compliance referred to in this Agreement.

                  2.7 "STAND-OFF" AGREEMENT; CONFIDENTIALITY OF NOTICES. Each
Selling Stockholder, if requested by the Company and the managing underwriter of
an underwritten public offering by the Company of Common Stock, shall not sell
or otherwise transfer or dispose of any Registrable Shares or other securities
of the Company held by such Stockholder for a period of 90 days following the
effective date of a Registration Statement. The Company may impose stop-transfer
instructions with respect to the Registrable Shares or other securities subject
to the foregoing restriction until the end of such 90-day period.

                                      -7-

<PAGE>

         Any Stockholder receiving any written notice from the Company regarding
the Company's plans to file a Registration Statement shall treat such notice
confidentially and shall not disclose such information to any person other than
as necessary to exercise its rights under this Agreement.

                  2.8 TERMINATION. All of the Company's obligations to register
Registrable Shares under this Agreement shall terminate two years after the date
hereof.

         3. TRANSFERS OF RIGHTS. This Agreement, and the rights and obligations
of each Purchaser hereunder, may be assigned by such Purchaser to (i) any person
or entity to which at least 50,000 Shares are transferred by such Purchaser (or
all of the Shares held by such Purchaser, if such Purchaser holds less than
50,000 shares) or (ii) to any partner, stockholder or affiliate of such
Purchaser, and such transferee shall be deemed a "Purchaser" for purposes of
this Agreement; provided that the transferee provides written notice of such
assignment to the Company and agrees in writing to be bound hereby.

         4. GENERAL.

                        (a) SEVERABILITY. The invalidity or unenforceability of
any provision of this Agreement shall not affect the validity or enforceability
of any other provision of this Agreement.

                        (b) SPECIFIC PERFORMANCE. In addition to any and all
other remedies that may be available at law in the event of any breach of this
Agreement, each of the parties shall be entitled to specific performance of the
agreements and obligations of the other parties hereunder and to such other
injunctive or other equitable relief as may be granted by a court of competent
jurisdiction.

                        (c) GOVERNING LAW. This Agreement shall be governed by
and construed in accordance with the internal laws of the Commonwealth of
Massachusetts (without reference to the conflicts of law provisions thereof).

                        (d) NOTICES. All notices, requests, consents, and other
communications under this Agreement shall be in writing and shall be deemed
delivered (i) two business days after being sent by registered or certified
mail, return receipt requested, postage prepaid or (ii) one business day after
being sent via a reputable nationwide overnight courier service guaranteeing
next business day delivery, in each case to the intended recipient as set forth
below:

         If to the Company, at 9 Strathmore Road, Natick, Massachusetts 01760,
Attention: President, or at such other address or addresses as may have been
furnished in writing by the Company to the Purchasers, with a copy to Mark G.
Borden, Hale and Dorr LLP, 60 State Street, Boston, Massachusetts 02109; or

         If to a Purchaser, at his or its address set forth on EXHIBIT A, or at
such other address or addresses as may have been furnished to the Company in
writing by such Purchaser.

         Any party may give any notice, request, consent or other communication
under this Agreement using any other means (including, without limitation,
personal delivery, messenger

                                      -8-

<PAGE>

service, telecopy, first class mail or electronic mail), but no such notice,
request, consent or other communication shall be deemed to have been duly given
unless and until it is actually received by the party for whom it is intended.
Any party may change the address to which notices, requests, consents or other
communications hereunder are to be delivered by giving the other parties notice
in the manner set forth in this Section.

                        (e) COMPLETE AGREEMENT. This Agreement constitutes the
entire agreement and understanding of the parties hereto with respect to the
subject matter hereof and supersedes all prior agreements and understandings
relating to such subject matter.

                        (f) AMENDMENTS AND WAIVERS. Any term of this Agreement
may be amended or terminated and the observance of any term of this Agreement
may be waived with respect to all parties to this Agreement (either generally or
in a particular instance and either retroactively or prospectively), with the
written consent of the Company and the holders of at least a majority of the
Registrable Shares held by all of the Stockholders. Notwithstanding the
foregoing, this Agreement may be amended or terminated, and any right hereunder
may be waived with respect to all parties to this Agreement with the consent of
the holders of less than all Registrable Shares only in a manner which applies
to all such holders in the same fashion. Any such amendment, termination or
waiver effected in accordance with this Section 4(f) shall be binding on all
parties hereto, even if they do not execute such consent and the Company. No
waivers of or exceptions to any term, condition or provision of this Agreement,
in any one or more instances, shall be deemed to be, or construed as, a further
or continuing waiver of any such term, condition or provision.

                        (g) PRONOUNS. Whenever the context may require, any
pronouns used in this Agreement shall include the corresponding masculine,
feminine or neuter forms, and the singular form of nouns and pronouns shall
include the plural, and vice versa.

                        (h) COUNTERPARTS; FACSIMILE SIGNATURES. This Agreement
may be executed in any number of counterparts, each of which shall be deemed to
be an original, and all of which together shall constitute one and the same
document. This Agreement may be executed by facsimile signatures.

                        (i) SECTION HEADINGS. The section headings are for the
convenience of the parties and in no way alter, modify, amend, limit or restrict
the contractual obligations of the parties.


                  [Remainder of page intentionally left blank.]







                                      -9-
<PAGE>


         Executed as of the date first written above.

                                        COMPANY:

                                        VISION-SCIENCES, INC.

                                        By: /s/ James A. Tracy
                                           -----------------------------------

                                        Name: James A. Tracy
                                             ---------------------------------

                                        Title: VP Finance
                                              --------------------------------


                                        PURCHASERS:


                                        /s/ Katsumi Oneda
                                        ------------------------------------
                                        Katsumi Oneda


                                        /s/ Gerald B. Lichtenberger
                                        ------------------------------------
                                        Gerald B. Lichtenberger


                                        /s/ Karl P. Klein
                                        ------------------------------------
                                        Karl P. Klein


                                        /s/ Craig M. Shumate
                                        ------------------------------------
                                        Craig M. Shumate


                                        /s/ Richard Podell
                                        ------------------------------------
                                        Richard Podell


                                        /s/ Patricia Podell
                                        ------------------------------------
                                        Patricia Podell


                                        PRUDENTIAL SECURITIES c/f
                                        RALPH E. WEIL IRA


                                        By:  /s/ Ralph E. Weil
                                           ---------------------------------
                                        Title:   IRA Custodian
                                              ------------------------------


                                        /s/ Karen Weil
                                        ------------------------------------
                                        Karen Weil




                                      -10-
<PAGE>

                                        /s/ Leonard Schwartz
                                        ------------------------------------
                                        Leonard Schwartz



                                        BHS HOLDING LTD.

                                        By:  /s/ Shlomo Ben-Haim
                                           ---------------------------------
                                        Title: President
                                              ------------------------------


                                        /s/ Lewis Pell
                                        ------------------------------------
                                        Lewis Pell


                                        /s/ Anaka Prakash, M.D.
                                        ------------------------------------
                                        Anaka Prakash, M.D.


                                        /s/ Kenneth W. Anstey
                                        ------------------------------------
                                        Kenneth W. Anstey







                                      -11-

<PAGE>


                                                                     EXHIBIT A

                                   PURCHASERS

    NAME AND ADDRESS

         Katsumi Oneda
         33 Stone Tower Drive
         Alpine, NJ 07620

         Gerald B. Lichtenberger
         11 Heather Hill Way
         Mendon, NJ 07945

         Karl P. Klein
         22 Hilltop Road
         Mendham, NJ 07945

         Craig M. Shumate
         29 Hilltop Road
         Mendham, NJ  07945

         Richard & Patricia Podell, as joint tenants
         253 Dale Road
         Short Hills, NJ  07078

         Prudential Securities c/f
         Ralph E. Weil IRA
         17758 Litten Drive
         Boca Raton, FL  33498

         Karen Weil
         17758 Litten Drive
         Boca Raton, FL 33498

         Leonard Schwartz
         10 Falmouth Street
         Brooklyn, NY  11235



                                      A-1

<PAGE>



         BHS Holding Ltd.
         8 Efroni St. Cluster 10
         POB 42
         Cessaria, 38900
         Israel

         Lewis Pell
         34 Old Meadow Bend
         West Hampton, NY 11978


         Anaka Prakash, M.D.
         3 Ekert Farm Road
         Saddle River, NJ  07458

         Kenneth W. Anstey
         c/o Oratec Interventions
         3700 Haven Court
         Menlo Park, CA  94025















                                      A-2