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EXHIBIT 10.20

                    PROMISSORY NOTE SECURED BY DEED OF TRUST

         FOR VALUE RECEIVED, Kenneth Sumner and Linda Sumner (collectively,
"Maker") promise to pay to Nellcor Incorporated, a Delaware corporation
("Holder"), or order, at 4280 Hacienda Drive Pleasanton, California, or any
other place designated by Holder, the principal sum of ONE HUNDRED TWENTY FIVE
THOUSAND DOLLARS ($125,000) plus interest according to the terms contained in
this Note.

         Interest only at the annual rate of 7.55% (the "Note Rate") on the
principal sum of this Note, shall be due and payable in arrears in semi-annual
installments on or before May 16 and November 16 of each year. All payments
shall be applied first to interest on the principal balance of the Note, and any
balance shall be applied to reduction of principal, and interest shall
thereafter cease to accrue on the principal so paid. The entire principal
outstanding together with all accrued and unpaid interest shall be due and
payable on the Maturity Date.

         "Maturity Date" shall mean the date on which this Note shall be due and
payable in full, and shall be the earlier of (i) the sale of the residence of
Maker, which property is encumbered by a Deed of Trust securing this Note and is
located at 18 Rima Court, Danville, California 94526 (ii) the resignation or
termination of Maker's employment with Holder, or (iii) November 16, 2004.

         MAKER HEREBY ACKNOWLEDGES AND AGREES THAT THE ENTIRE PRINCIPAL BALANCE
OF THIS NOTE MAY BE UNPAID AND SHALL BE DUE AND PAYABLE ON THE MATURITY DATE.

         This Note may be prepaid at any time, in whole or in part, without any
prepayment penalty. Maker waives diligence, presentment and demand, notice of
protest, and demand, of nonpayment, of dishonor and of maturity and agrees that
time is of the essence of every provision hereof.

         Anything herein to the contrary notwithstanding, the obligations of
Maker under this Note shall be subject to the limitation that payments of
interest shall not be required to the extent that payment hereof would be
contrary to applicable provisions of law limiting rates of interest which may be
charged or collected by Holder.

         This Note may not be amended or modified orally in any manner. This
Note may be amended or modified only by a writing duly executed by Maker and
Holder. No provision of this Note may be waived by Holder, except in writing
executed by Holder, and which expressly refers to this Note. No such express
written waiver shall affect any other provision of this Note, or cover any
default or time period or event, other than the matter as to which an express
written waiver has been given hereunder, as specified in such written waiver.

         Maker agrees to pay all costs of collection when incurred, including
but not limited to reasonable attorneys' fees. If any suit or action is
instituted to enforce this Note, Maker promises to pay, in addition to the costs
and disbursements otherwise allowed by law, such sum as the court may adjudge
reasonable attorneys' fees in such suit or action. Maker agrees to pay any
additional attorneys' fees incurred in enforcing any such judgment, separately
from and in addition to any other attorneys' fees herein.

                  This Note will be governed by California law.


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         This Note is secured by a Deed of Trust of even date herewith, executed
by Maker in favor of Holder.

         IN WITNESS WHEREOF, Maker has executed this Note as of November 16,
1994.

                                    -------------------------
                                    Kenneth Sumner

                                    -------------------------
                                    Linda Sumner



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