The History of Masimo SET® Pulse Oximetry

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 200 million patients in healthcare settings around the world,1 and is the primary pulse oximetry technology at 9 of the top 10 hospitals listed in the 2019-2020 U.S. News & World Report Best Hospitals Honor Roll.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

Masimo Today


Today, Masimo is publicly traded and employs over 5,300 people worldwide, with annual revenues of more than $900 million. Licensing agreements allow Masimo technology to work inside monitoring devices from a host of manufacturers, including Philips, Atom, Mindray North America, GE Medical, Spacelabs, and Zoll. Throughout its more than 30-year journey, Masimo’s mission – to improve patient outcomes and reduce the cost of care – has remained strong.

Masimo rainbow® Technology

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:


Perfusion Index


Pleth Variability Index

Versatile Devices

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-97®, as well as a multitude of sensors, including the RD collection and the tetherless Radius PPG™. These highly versatile devices 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 and in the case of Rad-97, for home use.

Complementing devices that primarily monitor continuously, Masimo spot-check devices such as Rad-67® and MightySat® Rx, and allow physician offices, EMS responders, and others to measure oxygen saturation and other valuable measurements. MightySat, alongside the smart device-enabled iSpO2®, is also available for personal use for general health and wellness applications.

Alongside a variety of sidestream and mainstream capnography products, Masimo offers ventilation solutions powered by TNI softFlow® technology, which provides nasal high-flow therapy for spontaneously breathing adult patients in both hospital and home-care environments.

Expanding Monitoring with Root

Expanding Monitoring with Root


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:

Next Generation SedLine® Brain Function Monitoring

SedLine helps clinicians monitor the state of the brain under anesthesia with bilateral data acquisition and processing of four leads of electroencephalogram (EEG) signals. Next Generation SedLine brain function monitoring features an enhanced processed EEG index (PSi, a processed EEG parameter related to the effect of anesthetic agents) with less susceptibility to EMG interference and improved performance in low power EEG cases.

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 noninvasive blood pressure and temperature measurements, combined with Root's advanced connectivity, automate vital sign documentation in hospital electronic medical records (EMRs). Rad-97 is similarly available in a configuration with integrated noninvasive blood pressure.

NomoLine® Capnography Solutions

ISA™ capnography with sidestream CO2 and gas monitoring features NomoLine technology for extended monitoring and cost-effective consumables.

Early Warning Scores

Integrated Early Warning Scores (EWS) help to simplify workflows with automatic, device-based calculations using up to 14 Root-measured and manually entered contributors. EWS protocols can be customized based on hospital protocol. Root's ability to display EWS trends allows clinicians to quickly visualize changes in patient status over time, and automated electronic charting allows them to push EWS calculations to hospital EMRs at the touch of a button.

Vital Signs Check

Vital Signs Check on Root helps clinicians streamline vital signs workflows by automating clinician-patient and patient-data association at the bedside; centralizing the collection of both integrated measurement and manually entered data, including early warning scores, on a single device; and facilitating immediate electronic charting from the bedside, with the ability to send comprehensive spot-check data to the EMR at the touch of a button and to store up to 1,000 spot-check sessions with unique patient identifiers locally.


Pathway is a newborn oxygenation visualization mode for Root that provides clinicians with a way to visualize a hospital’s recommended resuscitation protocol for a newborn’s oxygen saturation while providing continuous monitoring during the first ten minutes after birth. Pathway is intended to help streamline clinician workflow and improve protocol adherence during this critical period.

Connecting Devices and Data, Patients and Clinicians

Connecting Devices and Data, Patients and Clinicians


Joining the expanding set of monitoring possibilities are redefined and extended connectivity and automation solutions driven by the Iris® platform. Masimo Iris Gateway® gathers medical data from devices throughout the hospital, including bedside Masimo and third-party devices and ADT systems, and converts and transfers them to a central repository, the EMR, automating clinician access to a more complete picture of each patient. To those abilities, Masimo Patient SafetyNet™** with Replica™ adds hospital-wide monitoring and two-way remote clinician notification from a central server, customizable view stations, and mobile devices. Halo ION™ aggregates trend data from multiple physiologic parameters into a single, continuous score for each patient, configured according to hospital policy and displayed and dynamically updated at Patient SafetyNet central view stations and on Replica devices.

Masimo also offers solutions designed to help care teams remotely manage large quantities of low-acuity patients—for example during the COVID-19 surge in patient volume—such as Masimo SafetyNet™. Masimo SafetyNet is an economically scalable, cloud-based patient management telehealth solution that combines SET® tetherless pulse oximetry with a remote data capture and surveillance platform accessible from the patient’s smartphone and a web-based clinician dashboard. Clinicians can also create, relay, and manage treatment plans for more than 150 types of care, including COPD, heart failure, and oncology, providing a complete end-to-end home care solution.


  1. 1.

    Estimate: Masimo data on file.

  2. 2.


  3. 3.

    Shah N et al. J Clin Anesth. 2012 Aug;24(5):385-91.

  4. ** The use of the trademark PATIENT SAFETYNET is under license from University HealthSystem Consortium.

Masimo SafetyNet and TNI softFlow 50 are not licensed for sale in Canada.

Corporate Headquarters

Masimo Corporation
52 Discovery
Irvine, CA 92618
(949) 297-7000