Newly Published Study Confirms Accuracy of Masimo Noninvasive and Continuous Hemoglobin Monitor

November 10, 2010

IRVINE, Calif., Nov. 10, 2010 /PRNewswire via COMTEX/ -- Masimo (Nasdaq: MASI) announced today that a new study published online in the international peer-reviewed academic journal,Anesthesia & Analgesia, shows that Masimo noninvasive and continuous hemoglobin (SpHb®) monitoring technology is "accurate within 1.0 g/dL" at one standard deviation, compared to invasive blood sampling and laboratory analysis in subjects undergoing hemodilution. (1) In the study, which will appear in the December 2010 print issue, researchers highlight the potential benefits of continuous noninvasive hemoglobin monitoring as "hastening the detection of postoperative bleeding, preventing the over-transfusion of blood products during surgery, reducing phlebotomy-induced anemia in the intensive care unit, and increasing patient safety and comfort in all care areas where hemoglobin testing is done."

Citing a "large potential benefit if a validated noninvasive method were available," researchers from Loma Linda University (Loma Linda, California) compared simultaneous measurements of hemoglobin using Masimo SpHb (obtained noninvasively and continuously via a Masimo Radical-7 Pulse CO-Oximeter) and laboratory CO-oximetry (tHb, obtained via an invasive blood draw of 500mL) obtained from 20 test subjects undergoing hemodilution. After initial blood draws, subjects received crystalloid IV fluid until they reached the goal of 30% reduction in hemoglobin or a max of 30mL/kg of fluid. Analyzing 355 paired measurements of noninvasive SpHb and invasive tHb, researchers found that the average difference between the two was -0.15 g/dL, 1 SD of the difference was 0.92 g/dL, and the average root-mean-square difference was 0.94 g/dL. The difference between SpHb and tHb was <2.0 g/dL for 97% of all measurements and when tHb was 7 to 10 g/dL (N=79), the difference between SpHb and tHb was <1.5 g/dL 99% of the time.

Noting that an intradevice comparison of different laboratory CO-Oximeters yielded "a range of 0.1 to 1.3 g/dL difference and an average standard deviation of 0.5 g/dL," study findings indicate that Masimo SpHb measurements obtained noninvasively have clinically-acceptable accuracy and "would offer many advantages in the assessment of both acute and chronic anemic status in a variety of clinical settings."

(1) Macknet, M., Allard, M., Applegate, R., Rook, J. "The Accuracy of Noninvasive and Continuous Total Hemoglobin Measurement by Pulse CO-Oximetry in Human Subjects Undergoing Hemodilution" Anesth & Analg, Dec. 2010, vol 112. Available online here.

About Masimo

Masimo (NASDAQ: MASI) is the global leader in innovative noninvasive monitoring technologies that significantly improve patient care--helping solve "unsolvable" problems. In 1995, the company debuted Measure-Through Motion and Low Perfusion pulse oximetry, known as Masimo SET®, which virtually eliminated false alarms and increased pulse oximetry's ability to detect life-threatening events. More than 100 independent and objective studies demonstrate Masimo SET provides the most reliable SpO2 and pulse rate measurements even under the most challenging clinical conditions, including patient motion and low peripheral perfusion. In 2005, Masimo introduced rainbow® SET Pulse CO-Oximetry™ technology, allowing noninvasive and continuous monitoring of blood constituents that previously required invasive procedures, including total hemoglobin (SpHb®), oxygen content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), and Pleth Variability Index (PVI®), in addition to SpO2, pulse rate, and perfusion index (PI). In 2008, Masimo introduced Patient SafetyNet™, a remote monitoring and wireless clinician notification system designed to help hospitals avoid preventable deaths and injuries associated with failure to rescue events. In 2009, Masimo introduced rainbow Acoustic Monitoring™, the first-ever noninvasive and continuous monitoring of acoustic respiration rate (RRa™). Masimo's rainbow SET technology platform offers a breakthrough in patient safety by helping clinicians detect life-threatening conditions and helping guide treatment options. In 2010, Masimo acquired SEDLine®, a pioneer in the development of innovative brain function monitoring technology and devices. Masimo SET and Masimo rainbow SET technologies can be also found in over 100 multiparameter patient monitors from over 50 medical device manufacturers around the world. Founded in 1989, Masimo has the mission of "Improving Patient Outcomes and Reducing Cost of Care... by Taking Noninvasive Monitoring to New Sites and Applications®." Additional information about Masimo and its products may be found at http://www.masimo.com/.

Forward Looking Statements

This press release includes forward-looking statements as defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, in connection with the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based on current expectations about future events affecting us and are subject to risks and uncertainties, all of which are difficult to predict and many of which are beyond our control and could cause our actual results to differ materially and adversely from those expressed in our forward-looking statements as a result of various risk factors, including, but not limited to: risks related to our assumptions regarding the repeatability of clinical results, as well as other factors discussed in the "Risk Factors" section of our most recent reports filed with the Securities and Exchange Commission ("SEC"), which may be obtained for free at the SEC's website at www.sec.gov. Although we believe that the expectations reflected in our forward-looking statements are reasonable, we do not know whether our expectations will prove correct. All forward-looking statements included in this press release are expressly qualified in their entirety by the foregoing cautionary statements. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of today's date. We do not undertake any obligation to update, amend or clarify these forward-looking statements or the "Risk Factors" contained in our most recent reports filed with the SEC, whether as a result of new information, future events or otherwise, except as may be required under the applicable securities laws.

Media Contacts:

Dana Banks

Phone: (949) 297-7348

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