<PAGE>   1
                                                                 EXHIBIT 10.81

                                 LEASE SCHEDULE

Lease Schedule No: 003
to Master Lease Agreement No: 0001E

Lessor:  Aberlyn Capital Management       Lessee:  American BioMed, Inc.
         Limited Partnership                       10077 Grogan's Mill Road
         1000 Winter Street                        Suite 100
         Waltham, MA 02154                         The Woodlands, TX 77380
         (617) 895-1144

1.  Lessor and Lessee have entered into a Master Lease Agreement dated as of
January 4, 1993, including this Lease Schedule (collectively, the "Lease"),
pursuant to which Lessor and Lessee have agreed to lease the equipment
described in Exhibit A hereto (the "Equipment"). the Lessor and Lessee
acknowledge and agree that for United States federal income tax purposes, this
Lease shall be treated as a conditional sale transaction, and both parties (and
their successors or assigns) hereby agree to report to all relevant tax
authorities that this Lease transaction is a conditional sale transaction. For
this purpose, (i) this Lease is, and shall consistently be treated as, a
financing transaction, rather than a sale, (ii) Lessee will be the owner of the
Equipment to be delivered under this Agreement, for tax purposes, (iii) Lessee
will not claim any rental deduction for the amounts paid to the Lessor under
the Lease, (iv) Lessor will not claim amortization or depreciation deduction
with respect to the Equipment delivered under the lease, (v) neither party will
at any time take any action, directly or indirectly, or file any returns,
or other documents inconsistent with the foregoing, and (vi) the parties will
file such returns, take such actions and execute such documents as may
be reasonable and necessary to facilitate the accomplishment of the intent
expressed in subparagraph (i) through (v) of this Section 1.

2.  The Acquisition Cost of the Equipment is $285,823.00.

3.  a.  Lease Term: The Lease Term is 24 months commencing on the "Lease Term
Commencement Date" as defined in the Acceptance Certificate, plus any partial
period between the date on which Lessor, at the request of the Lessee, acquires
an interest in or incurs any obligation with respect to such Equipment and the
Lease Term Commencement Date.



                                       1

<PAGE>   2
        b.  Rent: Lessee shall pay Lessor 24 Rent payments in the following
amounts commencing on the date set forth in the Acceptance Certificate with
respect to the Equipment (the "Rent Payment Commencement Date") and on the same
day of each month thereafter for the entire Lease Term:


        Rent Payment Nos:  1-5     Rent Payment Amount: $ 6,612.00 each
        Rent Payment No:   6       Rent Payment Amount: $22,039.00
        Rent Payment Nos:  7-11    Rent Payment Amount: $ 6,612.00 each
        Rent Payment No:  12       Rent Payment Amount: $22,039.00
        Rent Payment Nos: 13-17    Rent Payment Amount: $ 6,612.00 each
        Rent Payment No:  18       Rent Payment Amount: $55,097.00
        Rent Payment Nos: 19-23    Rent Payment Amount: $11,019.00 each
        Rent Payment No:  24       Rent Payment Amount: $94,767.00

In the event that the Rent payments set forth in any Acceptance Certificate
hereto differ from those set forth in this Section 3(b), the Rent Payments
shall be as set forth in the Acceptance Certificate. If a Rent payment date
shall fall on a day that is not a business day, the Rent due and payable on
such day shall be made on the business day next succeeding such Rent payment
date.

        c.  Intentionally Omitted

        d.  Taxes: Lessee shall be responsible for the payment of all taxes or
other impositions, including sales tax if applicable, as more fully set forth
in the Lease.

4.  Purchase Option: Notwithstanding any provision contained in the Lease to
the contrary, Lessee shall have the option to purchase from Lessor all of
Lessor's rights, title and interest in and to all, but not less than all, of
the Equipment at the expiration of the stated Lease Term, which is June 1, 1998
(the "Purchase Option Date") with respect thereto, provided that Lessee is not
in default hereunder, for a purchase price equal to $1.00.

5.  Intentionally Omitted

6.  Intentionally Omitted

7.  The Equipment will be located at the locations specified in Exhibit A
hereto.




                                       2




<PAGE>   3
8.  Further, Lessor's obligations under this Schedule, including Lessor's
obligation to purchase and participate in the financing of any Equipment to be
leased hereunder, are conditioned upon Lessor having received: (i) evidence as
to due compliance with the insurance provisions hereof; and (ii) UCCs and all
other filings and recordings with respect to the transactions contemplated
thereunder which are necessary or appropriate to establish, protect, perfect
or give first priority to Lessor's title in the Equipment leased hereunder.

9.  Intentionally Omitted

By execution hereof, the undersigned certifies that he has read, accepted and
duly executed this Lease Schedule to the Master Lease Agreement on behalf of
Lessee.

LESSOR:                                        LESSEE:
Aberlyn Capital Management                     American BioMed, Inc.
Limited Partnership
By its: General Partner
Aberlyn Capital Management Company, Inc.


By:    /s/ DIANA M SPANO                       By:    /s/ STEVEN B. RASH
       --------------------------                     -------------------------
Name:  Diana M Spano                            Name:  Steven B. Rash
       --------------------------                     -------------------------
Title: Vice President                          Title: President and CEO
       --------------------------                     -------------------------
Date:                                          Date:  6-01-96
       --------------------------                     -------------------------




                                     3


<PAGE>   4

                                   Schedule B
                                       to
              Patent Schedule No. 002 dated ____________ __, 1996

               Patent Assignment and License Agreement No. 0001P
                            dated December 31, 1992

                        License Terms and Base Royalties

Term:  The stated Term is twenty-four (24) months.

Effective Date:  Commencing on ______________ __, 1996.

Base Royalty Effective Date:  Commencing on June 1, 1996.

Base Royalty:  Licensee shall pay Company, in advance, 24 Royalty payments
("Base Royalty") in the following amounts:


        Royalty Payment Nos:   1-5   Royalty Payment Amount: $  8,388.00 each
        Royalty Payment No:    6     Royalty Payment Amount: $ 27,961.00
        Royalty Payment Nos:   7-11  Royalty Payment Amount: $  8,388.00 each
        Royalty Payment No:   12     Royalty Payment Amount: $ 27,961.00
        Royalty Payment Nos:  13-17  Royalty Payment Amount: $  8,388.00 each
        Royalty Payment No:   18     Royalty Payment Amount: $ 69,903.00
        Royalty Payment Nos:  19-23  Royalty Payment Amount: $ 13,981.00 each
        Royalty Payment No:   24     Royalty Payment Amount: $120,233.00

Base Royalty Payment Commencement Date: Commencing on June 1, 1996 and on the
same day of each month thereafter for the entire Term. If a Base Royalty
payment date shall fall on a day that is not a business day, the Base Royalty
due and payable on such day shall be made on the business day next succeeding
such Base Royalty payment due:

Last Base Royalty Payment Date:  May 1, 1998

Purchase Option:  Notwithstanding any provision contained in the Agreement to
the contrary, Licensee shall have the option to purchase from the Company all
of the Company's rights, title and interest in and to all, but not less than
all, of the Patents at the expiration of the stated Term, which is June 1, 1998
(the "Purchase Option Date") with respect thereto, provided that Licensee is
not in default hereunder, for a purchase price equal to $1.00.



                                       3

<PAGE>   5

                               EQUIPMENT LOCATION


Lease Schedule and
Acceptance Certificate No. 003
to Master Lease Agreement No: 0001E


Lessee:              American BioMed, Inc.
Address:             10077 Grogan's Mill Road
                     Suite 100
                     The Woodlands, TX 77380

Equipment Location:  American BioMed, Inc.
                     10077 Grogan's Mill Road
                     Suite 100
                     The Woodlands, TX 77380

Equipment Location:  American BioMed, Inc.
                     Buildings B-8 and B-9
                     2408 Timberloch Place
                     The Woodlands, TX 77380


       [See attached 6 pages including the equipment location cover page]