Masimo Announces FDA 510(k) Clearance of Radius Tº™ for Prescription and Over-the-Counter (OTC) Use

The Radius Tº Wearable Continuous Body Temperature Thermometer Is Now Available for Use in Hospital and at Home

Masimo Radius Tº™ (Photo: Business Wire)

IRVINE, Calif.--()--Masimo (NASDAQ: MASI) announced today that Radius Tº™, a wearable, wireless thermometer that measures body temperature continuously and noninvasively, has received FDA 510(k) clearance for both prescription and over-the-counter (OTC) use on patients and consumers five years and older. Featuring continuously trending temperature measurements and Bluetooth® connectivity, Radius Tº automates remote, continuous body temperature status for clinicians through its paired connection to a Masimo patient monitoring or telehealth solution, and for consumers through the Masimo Radius Tº smartphone application. Radius Tº is part of the growing family of tetherless Masimo technologies that includes Radius PPG™, which offers Masimo SET® Measure-through Motion and Low Perfusion pulse oximetry, and Radius PCG™, which provides mainstream capnography.

For prescription use, Radius Tº is compatible with both the Root® Patient Monitoring and Connectivity Hub and the Rad-97® patient monitor for use in the hospital, as part of the Masimo Hospital Automation™ platform. Radius Tº can also be paired to a patient’s smartphone using the Masimo SafetyNet™ app, for remote patient management from the home or other care location. The wireless thermometer is designed to help streamline workflows, with its convenient wearability, continuous measurements, and wireless connectivity, reducing the need for intermittent manual temperature checks with traditional probes that require a clinician’s presence at the bedside. Each Radius Tº wireless thermometer is single-patient use, to reduce the risk of cross-contamination between patients, with an 8-day battery life and shower-proof adhesive, reducing the need to remove or replace the sensor—thus supporting a hospital’s or caregiver’s temperature monitoring and infection control workflow.

Using a proprietary algorithm, Radius Tº provides continuous body temperature measurements that are approximations of sublingual temperatures captured from an oral probe. Radius Tº supports continuous body temperature performance that goes beyond simple skin surface temperature measurements, and remains reliable even when environmental temperatures are fluctuating. Radius Tº provides trended data to help clinicians manage and review a patient’s high fever risks and fever progress over time.

Radius Tº is easily integrated into the Masimo Hospital Automation platform, through Root or Rad-97, allowing automatic transfer of continuous body temperature data to a hospital’s electronic medical records (EMRs) or surveillance monitoring solution, thus streamlining clinicians’ ability to gain a more insightful picture of each patient’s physiological status, regardless of the clinician’s physical location.

For consumers, Radius Tº represents a paradigm shift in thermometry by making it continuous, wearable, and hassle-free. Traditional periodic and invasive methods depend on the user repeatedly conducting a series of steps that can interrupt daily activities, including sleep, and can miss body temperature trends and patterns. With a traditional thermometer, a person may only notice a spike in temperature hours after a spike has occurred, or may not even become aware of it if it is during sleep. By contrast, Radius Tº continuously measures temperatures and seamlessly transmits data and customizable temperature notifications to the Masimo Radius Tº app on the user’s smartphone – helping caregivers, such as parents, monitor loved ones’ temperatures even while they sleep and providing continuous insight into changes and trends in their temperature. In addition, Radius Tº is applied comfortably on the upper chest, avoiding the potential discomfort of other wearable devices that rely on placement in the armpit.

Joe Kiani, Founder and CEO of Masimo, said, “Radius Tº was first made available in the U.S. under an FDA COVID-19 enforcement policy for thermometers as part of Masimo SafetyNet – where it quickly demonstrated its value in improving clinician workflows through its continuous, remotely accessible body temperature measurements for patients recovering or quarantined at home. Now, with the FDA 510(k) clearance, the availability of the Radius Tº is being expanded for use by both clinicians and consumers to help monitor and track body temperatures in all thermometer applications.”

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About Masimo

Masimo (NASDAQ: MASI) is a global medical technology company that develops and produces a wide array of industry-leading monitoring technologies, including innovative measurements, sensors, patient monitors, and automation and connectivity solutions. Our mission is to improve patient outcomes, reduce the cost of care, and take noninvasive monitoring to new sites and applications. Masimo SET® Measure-through Motion and Low Perfusion™ pulse oximetry, introduced in 1995, has been shown in over 100 independent and objective studies to outperform other pulse oximetry technologies.1 Masimo SET® has also been shown to help clinicians reduce severe retinopathy of prematurity in neonates,2 improve CCHD screening in newborns,3 and, when used for continuous monitoring with Masimo Patient SafetyNet™ in post-surgical wards, reduce rapid response team activations, ICU transfers, and costs.4-7 Masimo SET® is estimated to be used on more than 200 million patients in leading hospitals and other healthcare settings around the world,8 and is the primary pulse oximetry at 9 of the top 10 hospitals according to the 2020-21 U.S. News and World Report Best Hospitals Honor Roll.9 Masimo continues to refine SET® and in 2018, announced that SpO2 accuracy on RD SET® sensors during conditions of motion has been significantly improved, providing clinicians with even greater confidence that the SpO2 values they rely on accurately reflect a patient’s physiological status. In 2005, Masimo introduced rainbow® Pulse CO-Oximetry technology, allowing noninvasive and continuous monitoring of blood constituents that previously could only be measured invasively, including total hemoglobin (SpHb®), oxygen content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), Pleth Variability Index (PVi®), RPVi™ (rainbow® PVi), and Oxygen Reserve Index (ORi™). In 2013, Masimo introduced the Root® Patient Monitoring and Connectivity Platform, built from the ground up to be as flexible and expandable as possible to facilitate the addition of other Masimo and third-party monitoring technologies; key Masimo additions include Next Generation SedLine® Brain Function Monitoring, O3® Regional Oximetry, and ISA™ Capnography with NomoLine® sampling lines. Masimo’s family of continuous and spot-check monitoring Pulse CO-Oximeters® includes devices designed for use in a variety of clinical and non-clinical scenarios, including tetherless, wearable technology, such as Radius-7® and Radius PPG™, portable devices like Rad-67®, fingertip pulse oximeters like MightySat® Rx, and devices available for use both in the hospital and at home, such as Rad-97®. Masimo hospital automation and connectivity solutions are centered around the Masimo Hospital Automation™ platform, and include Iris® Gateway, iSirona™, Patient SafetyNet, Replica™, Halo ION™, UniView®, UniView :60™, and Masimo SafetyNet™. Additional information about Masimo and its products may be found at Published clinical studies on Masimo products can be found at

ORi and RPVi have not received FDA 510(k) clearance and are not available for sale in the United States. The use of the trademark Patient SafetyNet is under license from University HealthSystem Consortium.


  1. Published clinical studies on pulse oximetry and the benefits of Masimo SET® can be found on our website at Comparative studies include independent and objective studies which are comprised of abstracts presented at scientific meetings and peer-reviewed journal articles.
  2. Castillo A et al. Prevention of Retinopathy of Prematurity in Preterm Infants through Changes in Clinical Practice and SpO2 Technology. Acta Paediatr. 2011 Feb;100(2):188-92.
  3. de-Wahl Granelli A et al. Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns. BMJ. 2009;Jan 8;338.
  4. Taenzer A et al. Impact of pulse oximetry surveillance on rescue events and intensive care unit transfers: a before-and-after concurrence study. Anesthesiology. 2010:112(2):282-287.
  5. Taenzer A et al. Postoperative Monitoring – The Dartmouth Experience. Anesthesia Patient Safety Foundation Newsletter. Spring-Summer 2012.
  6. McGrath S et al. Surveillance Monitoring Management for General Care Units: Strategy, Design, and Implementation. The Joint Commission Journal on Quality and Patient Safety. 2016 Jul;42(7):293-302.
  7. McGrath S et al. Inpatient Respiratory Arrest Associated With Sedative and Analgesic Medications: Impact of Continuous Monitoring on Patient Mortality and Severe Morbidity. J Patient Saf. 2020 14 Mar. DOI: 10.1097/PTS.0000000000000696.
  8. Estimate: Masimo data on file.

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 include, among others, statements regarding the potential effectiveness of Masimo Radius Tº™. 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; risks related to our belief that Masimo's unique noninvasive measurement technologies, including Masimo Radius Tº, contribute to positive clinical outcomes and patient safety; risks related to our belief that Masimo noninvasive medical breakthroughs provide cost-effective solutions and unique advantages; risks related to COVID-19; 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 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 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.


Evan Lamb

Release Summary

Masimo Radius Tº™, a wearable, wireless continuous body temperature thermometer, has received FDA 510(k) clearance for prescription and OTC use.


Evan Lamb