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Breaking Studies: Masimo SET Pulse Oximetry Technology Again Shown to be Most Effective

New studies presented at last week's 2006 ASA Annual Meeting add to the more than 100 independent studies validating Masimo SET as the gold standard; technology is the foundation that enables Pulse CO-Oximetry

Irvine, California October 27, 2006 - Masimo, the inventor of Pulse CO-Oximetry and read-through motion and low perfusion pulse oximetry, reported that multiple independent studies were presented last week at the 2006 American Society of Anesthesiology (ASA) Annual Meeting in Chicago, each reinforcing the superiority of Masimo SET in providing accurate, reliable pulse oximetry readings. In the studies, Masimo SET was shown to "work better for patient safety" during the most difficult clinical conditions of motion and low peripheral perfusion.

Masimo SET is the foundational technology that allowed the company to introduce Masimo Rainbow SET Pulse CO-Oximetry-the first and only monitoring platform that allows for the continuous and noninvasive measurement of carbon monoxide (COHb), methemoglobin (MetHb), oxygen saturation (O2Hb), pulse rate and perfusion index. Masimo introduced the first bedside monitors, Radical-7, to feature this groundbreaking technology at last week's ASA meeting, and hosted a pre-ASA symposium on clinical implications of noninvasive and continuous monitoring of MetHb and COHb using Masimo Rainbow SET. Specific findings of the studies include:

Masimo shown to be "better for patient safety"

In a study entitled "Comparison of Three New Generation Pulse Oximeters during Motion & Low Perfusion in Volunteers" performed by Nitin Shah, MD and Laverne Estanol, MS at the VA and UC Irvine Medical Centers in Long Beach, CA, the researchers stated that pulse oximeter accuracy is often compromised by low perfusion states and motion artifact that can jeopardize patient safety in the OR, PACU, and ICU, adding that "manufacturers keep improving their technology in an attempt to solve this problem". To asses the effectiveness of the newest technologies, the study compared Masimo SET with the Nellcor N-600 and GE Datex-Ohmeda TruSat, under conditions of low perfusion and motion in hypoxic and normoxic states in volunteers between the ages of 18 and 40 years old.

The results showed that Masimo had the lowest level of false alarms, performing nearly six times better than the Nellcor N600. For the rate of missed true events, the Masimo unit again had the lowest level, performing 17 times better than the Nellcor N600. The researchers concluded that during hypoxic/normoxic and low perfusion states, "Nellcor N-600 and Datex Ohmeda TruSat performed inferior to Masimo Radical with respect to maintaining accurate readings during both machine generated and self generated motions". They added that "it appears from this study that Masimo Radical may work better for patient safety, especially at critical times in OR, PACU, and ICU."1

In a separate report entitled "Impact of Motion and Low Perfusion on SpO2 & Pulse Rate in Three New Generation POs in Volunteers", Shah and Estanol found that the Masimo SET device was within 7 percent of the true saturation measurement 98 percent of the time as compared to 72.7 percent for the Nellcor N-600, concluding that Masimo "performed the best in this vigorous testing schedule for both SpO2 and pulse rate" and added that "Masimo will give reliable SpO2 & PR values for a greater period of time as compared to Datex-Ohmeda TruSat and Nellcor N-600 in the OR, PACU, and ICU". 2

In another abstract, entitled "Failure Rates & Recovery Times of New Generation POs during Motion and Low Perfusion in Volunteers", Shah and Estanol explained that patient movement and low perfusion due to lower temperature is common in the PACU and OR, especially during extubation. They examined the failure rate, the percentage of times that the monitor was more than 7 percent off from the actual SpO2 reading, and the recovery time, the average amount of time taken for the monitor to return to accurate values. The most significant finding was the difference in SpO2 failure rates with Masimo SET was more than 10 times better than Nellcor N-600, concluding that "Masimo may serve better for patient safety."3

Masimo accuracy cited as beneficial to children with cyanotic congenital heart disease

Additional studies presented at the ASA included "The Accuracy of Masimo SET and Nellcor N-595 in Children with Cyanotic Congenital Heart Disease" conducted by Yuichiro Toda, M.D., Mamoru Takeuchi, M.D., Tatsuo Iwasaki, M.D., Kazuyoshi Shimizu, M.D., Kiyoshi Morita, M.D. from Okayama University Medical School in Japan. In this study, the researchers compared the performance of Masimo SET and specifically Masimo's Blue sensor to the Nellcor 595 and the Max-I Sensor on infants with cyanotic congenital heart disease, a patient population with a reputation for causing erroneous pulse oximetry readings. The Masimo Blue sensor was specifically designed for this patient population. The researchers found that overall, the bias (error) of the Nellcor sensor was approximately 18 times that of Masimo's, but on the sickest patients with the lowest blood flow, the Nellcor bias (error) was more than 21 times that of the Masimo Blue Sensor prompting the researchers to conclude "Masimo blue sensor presented smaller bias compared with Nellcor sensor" and that "Nellcor presented wider bias during low perfused state than that at normal perfusion". They concluded that of the two technologies, "Masimo blue sensor provides the accurate measurement of pulse oximetry in patients with cyanotic congenital heart disease". 4

These and all the studies referencing the superiority of Masimo technology were presented in abstract form at the ASA Annual Meeting and are available for viewing on the ASA website at

Joe E. Kiani, Chairman & CEO of Masimo stated; "It is gratifying to see so many independent researchers taking the time to evaluate Masimo SET and to communicate the positive impacts on patient care and safety that can be realized through its use. We are confident that the introduction of Masimo Rainbow SET will further enable clinicians to do what's right for patient care by giving them a more accurate picture of their patients' status with the continuous and noninvasive monitoring of oxyhemoglobin, methemoglobin, carboxyhemoglobin, perfusion index and pulse rate."

About Masimo

Masimo develops innovative monitoring technologies that significantly improve patient care-helping solve "unsolvable" problems. In 1995, the company debuted Read-Through Motion and Low Perfusion pulse oximetry, known as SET, and with it virtually eliminated false alarms and increased pulse oximetry's ability to detect life-threatening events. More than 100 independent clinical studies have confirmed that Masimo SET technology allows clinicians to accurately monitor blood oxygen saturation in critical care situations- establishing the technology as the "gold standard" pulse oximetry and substantially contributing to improved patient outcomes. In 2005 Masimo introduced Masimo Rainbow SET Pulse CO-Oximetry, which, for the first time, noninvasively monitors the level of carbon monoxide and methemoglobin in the blood, allowing early detection and treatment of potentially life-threatening conditions. Masimo, founded in 1989, has the mission of "Improving Patient Outcome 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

  1. Nitin Shah, M.D., Laverne Estanol, M.S. Anesthesiology, Long Beach VA Medical Center; UC Irvine Medical Center, Long Beach, California. Anesthesiology 2006; 105: A929
  2. Nitin Shah, M.D., Laverne Estanol, M.S. Anesthesiology, Long Beach VA Medical Center; UC Irvine Medical Center, Long Beach, California. Anesthesiology 2006; 105: A1433
  3. Nitin Shah, M.D., Laverne Estanol, M.S. Anesthesiology, Long Beach VA Medical Center, UC Irvine Medical Center, Long Beach, California. Anesthesiology 2006; 105: A242
  4. Yuichiro Toda, M.D., Mamoru Takeuchi, M.D., Tatsuo Iwasaki, M.D., Kazuyoshi Shimizu, M.D., Kiyoshi Morita, M.D., Dept. of Anesthesiology and Intensive care medicine, Okayama University Medical School, Okayama-shi, Okayama-ken, Japan. Anesthesiology 2006; 105: A1704

Tom McCall
Masimo Corporation

Masimo, SET, Signal Extraction Technology, Rainbow, Radical, APOD, SpCO, and Improving and Reducing Cost of Care by Taking Noninvasive Monitoring to New Sites and Applications are registered trademarks of Masimo Corp. Radical-7, Rad-57, SpMet and Pulse CO-Oximeter are trademarks of Masimo Corp.

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