FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * KIANI JOE E   2. Issuer Name and Ticker or Trading Symbol MASIMO CORP [MASI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CEO and Chairman of the Board (Last) (First) (Middle) C/O MASIMO CORPORATION, 40 PARKER 3. Date of Earliest Transaction (Month/Day/Year) 08/05/2008 (Street) IRVINE, CA 92618 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock               3,753,040 D   Common Stock 08/05/2008   S(1)   10,000 D $ 40.0007 9,000 I See Footnote (2) Common Stock               1,680,000 I See Footnote (3) Common Stock               6,689.708 I See Footnote (4)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
KIANI JOE E C/O MASIMO CORPORATION, 40 PARKER IRVINE, CA 92618	X		CEO and Chairman of the Board

Signatures

/s/ Mark P. de Raad, Attorney-in-Fact		08/07/2008
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The shares covered by this Form 4 have been sold pursuant to a Rule 10b5-1 Sales Plan dated as of May 1, 2008, which is intended to comply with Rule 10b5-1 promulgated under the Securities Exchange Act of 1934, as amended.
(2)	Shares held by immediate family member for which Mr. Kiani exercises voting and investment control.
(3)	Shares held in two trusts for which Mr. Kiani is the sole trustee.
(4)	Between February 15, 2008 and May 13, 2008, Mr. Kiani acquired 6,689.708 shares of Masimo Corporation common stock under the Masimo Retirement Savings Plan. The information in this report is based on a plan statement dated as of May 13, 2008.

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