EX-24. 2 rrd183919_207556.htm POWER OF ATTORNEY rrd183919_207556.html
Know all by these presents, that the undersigned hereby constitutes and appoints Mark de Raad,
signing individually, the undersigned's true and lawful attorneys-in-fact and agents to:
      (1)	execute for and on behalf of the undersigned, an officer, director
and/or holder of 10% or more of a registered class of securities of Masimo
Corporation, a Delaware corporation (the "Company"), Forms 3, 4 and 5 in
accordance with Section 16(a) of the Securities Exchange Act of 1934, as
amended (the "Exchange Act"), and the rules promulgated thereunder;
      (2)	do and perform any and all acts for and on behalf of the undersigned
that may be necessary or desirable to complete and execute such Forms 3, 4 and
5, complete and execute any amendment or amendments thereto, and timely file
such forms or amendments with the United States Securities and Exchange
Commission and any stock exchange or similar authority, as required; and
      (3)	take any other action of any nature whatsoever in connection with
the foregoing which, in the opinion of any such attorney-in-fact, may be of
benefit, in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.
The undersigned hereby grants to each such attorney-in-fact full power and authority to do and
perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the
exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact, or such attorney-in-
fact's substitute or substitutes, shall lawfully do or cause to be done by virtue of this power of
attorney and the rights and powers herein granted.  The undersigned acknowledges that the
foregoing attorneys-in-fact, in serving in such capacity at the request of the undersigned, are not
assuming, nor is the Company assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Exchange Act.
This Power of Attorney shall remain in full force and effect with respect to the undersigned until
the earliest to occur of (a) the undersigned is no longer required to file Forms 3, 4 and 5 with
respect to the undersigned's holdings of and transactions in securities issued by the Company, or
(b) revocation by the undersigned in a signed writing delivered to the Company and each of the
foregoing attorneys-in-fact. This Power of Attorney shall terminate with respect to a foregoing
attorney-in-fact, individually, at such time as such attorney-in-fact is no longer employed by the
Company or any of its subsidiaries.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of
this 5th day of May, 2008.
/s/ Olivier Berthon
Olivier Berthon

LEGAL_US_W # 54547056.1