The History of Masimo SET® Pulse Oximetry

Masimo (NASDAQ: MASI) is a global medical technology company that develops and manufactures innovative noninvasive patient monitoring technologies, medical devices, and a wide array of sensors. We believe that Masimo SET® helps clinicians monitor in excess of approximately 100 million patients in healthcare settings around the world,1 and is the pulse oximeter technology used by 17 of the top 20 hospitals on the U.S. News & World Report Best Hospitals Honor Roll for the 2016-2017 year.2

Joe Kiani founded Masimo in 1989 as a private “garage start-up” company because he was convinced that the use of adaptive signal processing in the measurement of physiological parameters could solve the problems of low perfusion and motion, which had long plagued in-vivo monitoring and especially pulse oximetry, the measurement of the oxygen saturation of arterial blood. His solution, Masimo SET® Measure-through Motion and Low Perfusion pulse oximetry, was shown in a study comparing three pulse oximetry technologies to demonstrate the highest sensitivity and specificity in identifying desaturation events during conditions of motion and low perfusion.3

Masimo Today

Today, Masimo is publicly traded and employs over 4,000 people worldwide, with annual revenues of approximately $700 million.  Licensing agreements allow Masimo technology to work inside monitoring devices from a host of manufacturers, including Philips, Atom, Datascope, GE Medical, Medtronic, Spacelabs, and Zoll. Throughout its more than 25-year journey, Masimo’s mission – to improve patient outcomes and reduce the cost of care by taking noninvasive monitoring to new sites and applications – has remained strong.

Masimo rainbow® Technology

rainbow®, introduced in 2005, allows additional parameters to be noninvasively and continuously monitored. Advanced signal processing algorithms and unique adaptive filters work together to isolate, identify, and quantify various types of hemoglobin.

rainbow SET measurements include:

Masimo - Rainbow Measurements

Versatile Devices

Masimo SET® and rainbow® technologies, collectively known as rainbow SET, fuel medical monitoring devices such as Root®, Radical-7®, Radius-7®, and Rad-57® as well as a multitude of sensors, including the RD collection. These highly-versatile monitors are configurable for use in a variety of high- and low-acuity hospital settings, from ICUs and surgical suites to post-operative floors, as well as in long-term care facilities.

Complementing devices that primarily monitor continuously, Masimo spot-check devices such as Pronto®, MightySat Rx, and MightySat allow EMS responders and consumers, respectively, to measure oxygen saturation and other valuable measurements.

Expanding Monitoring

Masimo continues to expand what can be monitored and how. Root, for example, was built from the ground up to be as flexible and expandable as possible, with Iris ports and Masimo Open Connect (MOC-9) to facilitate the addition of other Masimo and third-party monitoring technologies. Key Masimo additions include:

SedLine® Brain Function Monitoring
SedLine helps clinicians monitor the state of the brain with bilateral data acquisition and processing of electroencephalogram signals, using four simultaneous channels of frontal EEG waveforms, and displaying in addition a Density Spectral Array (an easy-to-interpret, high-resolution display of bi-hemispheric activity and EEG power) and the Patient State Index (PSi; a processed EEG parameter related to the effect of anesthetic agents).

O3 Regional Oximetry
O3 may help clinicians monitor cerebral oxygenation in situations in which pulse oximetry alone may not be fully indicative of the oxygen in the brain.

Noninvasive Blood Pressure and Temperature
Integrated NIBPT measurements automate vital sign documentation in hospital EMRs.

Capnography Solutions
ISA CO2 capnography for sidestream monitoring featuring Nomoline technology for extended monitoring and cost-effective consumables.

Connecting Devices and Data, Patients and Clinicians

Joining the expanding set of monitoring possibilities are redefined and extended connectivity and automation. Masimo Iris Gateway gathers medical data from devices throughout the hospital, including ADT, and converting and transferring them to a central repository, the EMR, thus automating clinician access to a more complete picture of each patient. To those abilities, Masimo Patient SafetyNet* adds hospital-wide monitoring and remote clinician notification from a central server and customizable view stations. The wearable Masimo Radius-7 allows for the tetherless monitoring of mobile patients, communicating alarms wirelessly back to Root and Patient SafetyNet.


  • 1 Estimate: Masimo data on file.
  • 2
  • 3 Shah N et al. J Clin Anesth. 2012 Aug;24(5):385-91.