Addendum 1 To The Oem Purchase Agreement

Exhibit 10.2


Confidential Materials omitted and filed separately with the
Securities and Exchange Commission. Asterisks denote omissions.


ADDENDUM 1
OEM-Purchase Agreement


Addendum 1 to the agreement dated the 1st day of September 2000 (the "Agreement"), by and between Aspect Medical Systems, Inc. ("Aspect") and Datex-Ohmeda Division, Instrumentarium Corporation ("D-O").


Per section 5 of the Agreement, Prices and Terms of Payment, Aspect is reducing the list price on the Aspect BIS Module Kit (exclusive of royalty) from $[**] to $[**]. For the purpose of calculating the volume discount for the calendar year 2003, all BIS Module Kits shipped from January 1, 2003 through December 31, 2003 will be included in the total volume discount calculation.


In addition, Aspect is reducing the list price for the BIS Sensors. Volume pricing will be based on [**] and pricing adjustments based on [**] versus [**] will be calculated and compensated as detailed in Section 5.4 of the Agreement.


The attached Appendix 1, dated February 19, 2003, replaces Appendix 1 in the Agreement.


Please indicate your acceptance of this Addendum by signing below.


Aspect Medical Systems, Inc. Datex-Ohmeda Division, Instrumentarium
Corporation


By: /s/ J. Neal Armstrong By: Unreadable Anntti Ritvos
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Title: CFO Title: Director Director


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