<PAGE>

                                     TRANSFER OF
                                 TECHNOLOGY AGREEMENT


    This Transfer of Technology Agreement ("Agreement") by and between  Project
Heart Limited Partnership, a Minnesota limited partnership (the "Partnership"),
and LexTen, Inc., a Minnesota  corporation ("LexTen") shall be deemed to be
effective as of the 30th day of September, 1997.

                                 W I T N E S S E T H:

    WHEREAS, LexTen is the general partner of the Partnership and Larry
Rasmusson, the president of LexTen, Inc., was, but no longer is, a limited
partner of the Partnership;

    WHEREAS, Larry A. Rasmusson ("Rasmusson") and LexTen sold, assigned and
transferred all of their right, title and interest in and to certain processes
or devices for inhibiting rejection in connection with heart transplant patient
procedures, as described in Exhibit A (the "Concept") attached hereto and made a
part hereof, to the Partnership pursuant to the terms of an Assignment dated
October 31, 1990, attached hereto as Exhibit B;

    WHEREAS, the Partnership has been since the date of the Assignment
described above and is now the sole owner of the Concept;

    WHEREAS, the undersigned general partner and limited partners have decided
to dissolve the Partnership and return all of the cash on hand, which is the
only asset of the Partnership other than the Concept, to the limited partners
and to distribute the Concept to the general partner to facilitate the
dissolution of the Partnership;

    WHEREAS, the limited partners have approved the transfer and distribution
of the Concept to the general partner, LexTen, and have authorized the general
partner to effect such transfer and distribution pursuant to the terms of this
Agreement.

    NOW THEREFORE, in consideration of the recitals set forth above and the
terms and conditions set forth below, the parties hereto agree as follows:

    1.   TRANSFER OF CONCEPT.  The Partnership hereby sells, transfers, assigns
and distributes to LexTen all past, present and future rights, title and
interests of the Partnership in and to the Concept, including, without
limitation, any applications for Letters Patent and any all divisions,
continuations and reissues thereof, and any and all Letters Patent of the United
States and foreign countries which may be granted therefor, the same to be held
and enjoyed by LexTen for its own use and benefit, and for the use and benefit
of its successors, assigns or other legal representatives.  The Partnership
further authorizes LexTen to execute and deliver any and all papers on behalf of
the Partnership that may be necessary or desirable to perfect the title of said
invention or inventions in and to such Letters Patent as may be applied for or
granted therefor


<PAGE>

and to sign all papers, make all rightful oaths and do all lawful acts requisite
for the filing of such applications.

    2.   CONSIDERATION.  The consideration for the transfer, assignment and
distribution described herein is the acceptance of the Concept by LexTen in full
and complete satisfaction and in consideration of the liquidation of LexTen's
interest in the Partnership and LexTen's consent to the distribution of cash to
the limited partners.

    3.   OWNERSHIP INTEREST.  The Partnership represents and warrants that it
has not advanced the research and development of the Concept by research or
development or otherwise and has not granted an interest in and to the Concept
to any third parties and has not communicated, divulged or disclosed the
specifics of the Concept to any third party or parties.

    4.   GENERAL PROVISIONS.

         4.1  This Agreement is the entire Agreement between the parties
              concerning the subject matter herein and supersedes and replaces
              any existing Agreement between the parties hereto relating to
              such subject matter.

         4.2  No provisions of this Agreement may be modified, waived, or
              discharged unless in a writing signed by LexTen and the
              Partnership.

         4.3  It is further agreed and understood by the parties hereto that if
              any part, term or provision of this Agreement is held
              unenforceable, this Agreement shall be construed as if not
              containing the invalid provision or provisions.  Invalidity or
              unenforceability of any portion or provision of this Agreement
              shall not affect the validity or enforceability of the remaining
              provisions of this Agreement, which shall remain in full force
              and effect and shall govern the rights and obligations of the
              parties hereto.

         4.4  This Agreement shall be construed and enforced in accordance with
              the laws of the State of Minnesota.  By executing this Agreement,
              the parties do hereby agree and submit to personal jurisdiction
              in the State of Minnesota for the purposes of any suit or
              proceeding brought to enforce the terms and conditions of this
              Agreement and agree that any such suit or proceeding shall be
              venued in Minnesota.

         4.5  The terms, conditions and covenants herein shall be binding upon
              the successors or assigns of the Partnership and/or LexTen or any
              subsidiary or affiliate of the Partnership and/or LexTen.

         4.6  This Agreement may be executed in one or more counterparts, each
              of which shall be deemed to be an original, but all of which
              together shall constitute one and the same contract.

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<PAGE>

         4.7  In the event that any legal action must be taken by either party
              to enforce this Agreement, all costs and expenses of the
              prevailing party in connection with any such action, including,
              but not limited to, reasonable attorney's fees and legal expenses
              shall be paid on demand and presentation of appropriate evidence
              by the nonprevailing party.

    IN WITNESS WHEREOF, the parties hereto have executed this Agreement
effective as of the date set forth above.


LEXTEN, INC.


By  /s/ Larry Rasmusson
  ----------------------------
  Its  President
     -------------------------
Date:      11/23       , 1997;
     ------------------

PROJECT HEART LIMITED PARTNERSHIP
LexTen, Inc., General Partner

By /s/ Larry Rasmusson
  --------------------------------------
  Its   President
     -----------------------------------

Date:     11/23    , 1997
     ---------------

Consented and agreed by the undersigned Limited Partners of Project Heart
Limited Partnership:

OXBORO MEDICAL INTERNATIONAL, INC.

By  /s/ Larry Rasmusson
  -------------------------------------------
   Its     CEO
      ---------------------------------------
Date:     11/23  , 1997
     ------------

/s/ Keith Olson                   11-19-97
--------------------------------------------
Keith Olson                         Date


/s/ Harley Haase                  11/19/97
--------------------------------------------
Harley Haase                        Date


/s/ Randie Lundberg               11-24-97
--------------------------------------------
Randie Lundberg                     Date


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