Signal Extraction Technology (SET) pulse oximetry

Pulse oximetry uses two light emitting diodes (LEDs), one red and one infrared, to measure the absorption of light and translates that into the percentage of hemoglobin molecules that are bound to oxygen, which is called arterial oxygen saturation (SpO₂). Conventional pulse oximetry assumes that arterial blood is the only blood moving (pulsating) in the measurement site. However, during patient motion, the venous blood also moves, which can cause conventional pulse oximetry to under-read SpO₂ levels because it cannot distinguish between the arterial and venous blood.^[9][10]

SET identifies the venous blood signal (which has a lower oxygen saturation level than arterial blood), isolates it, and uses adaptive filters to extract the arterial signal in order to report accurate SpO₂ and pulse rate. In addition, SET pulse oximetry provides perfusion index (PI) and pleth variability index (PVI). Multiple studies have shown that compared to non-SET pulse oximeters, SET increases the ability to detect life-threatening events and reduces false alarms.^[11][12] Additional studies have also shown the impact of SET on patient outcomes, such as helping clinicians:

• Decrease retinopathy of prematurity (ROP) in neonates^[13][14]
• Increase detection of critical congenital heart disease (CCHD) in newborns^[15]
• Reduce ventilator weaning time by titrating FiO₂ faster and reduce arterial blood gas measurements in the Intensive Care Unit (ICU)^[16]
• Decrease rapid response activations and Intensive Care Unit (ICU) transfers through earlier identification of patients in distress through low SpO₂ and abnormal pulse rate measurements^[17][18]
• Decrease fluid administered during surgery and reduce patient risk^[19]

In 2011, the American Academy of Pediatrics and the U.S. Department of Health and Human Services recommended mandatory screening for all newborns, using "motion-tolerant pulse oximeters that report functional oxygen saturation have been validated in low perfusion conditions".^[20] To make this recommendation, the CCHD workgroup relied on two independent studies that exclusively used SET pulse oximetry to assess newborns. In 2012, Masimo received FDA 510(k) clearance for devices and sensors with labeling for screening newborns for CCHD. It marked the first time the FDA cleared specific labeling indicating the use of pulse oximeters, in conjunction with a physical examination, to screen newborns for CCHD.^[21]

In 2012, the National Health Service (NHS) Technology Adoption Centre in the United Kingdom advised hospitals to use Intraoperative Fluid Management, and included Masimo's PVI among technologies available for helping clinicians manage fluid during surgeries.^[22] In 2013, the French Society for Anaesthesia and Intensive Care (SFAR) added PVI to its guidelines for optimal hemodynamic management of surgical patients.^[23]

Rainbow Pulse CO-Oximetry

Rainbow Pulse CO-Oximetry uses more than seven wavelengths of light to continuously and noninvasively measure hemoglobin (SpHb), carboxyhemoglobin (SpCO), and methemoglobin (SpMet), in addition to oxygen saturation (SpO₂), pulse rate, perfusion index (Pi), and pleth variability index (PVi).^[24] A study at Massachusetts General Hospital showed that SpHb monitoring helped clinicians decrease the frequency of patients receiving blood transfusions during surgery from 4.5% to 0.6%.^[25] Another study from Cairo University showed that SpHb monitoring helped clinicians reduce blood transfusions in high blood loss surgery by an average of 0.9 units per patient.^[26] A study at CHU Limoges in France found that monitoring with SpHb and PVi, integrated into a hospital-wide fluid and blood administration protocol, was associated with earlier transfusion and reduced mortality at 30 and 90 days by 33% and 29%, respectively.^[27] Emergency department studies have shown that SpCO helps clinicians increase the detection of carbon monoxide (CO) poisoning and decreases the time to treatment compared to invasive methods.^[28][29][30] The Pronto-7 device for noninvasive spot checking of hemoglobin, along with SpO₂ and pulse rate, has been recognized with a gold Medical Design Excellence Award.^[31] The World Health Organization called noninvasive hemoglobin an "innovative medical technology for cost-effectively addressing global health concerns and needs".^[32]

In October 2014, Masimo announced CE Marking of Oxygen Reserve Index or ORi, the company's 11th noninvasive parameter, which provides real-time visibility to oxygenation status. ORi is intended to supplement, not replace, oxygen saturation (SpO₂) monitoring and partial pressure of oxygen (PaO₂) measurements. ORi can be trended and has optional alarms to notify clinicians of changes in a patient's oxygen reserve, and may enable proactive interventions to avoid hypoxia and unintended hyperoxia.

SafetyNet

Patient SafetyNet is a remote monitoring and notification system designed for patients on medical/surgical care floors.^[33] A large study by Dartmouth-Hitchcock Medical Center showed Patient SafetyNet helped clinicians achieve a 65% reduction in distress codes and rescue activations and a 48% decrease in patient transfers to intensive care units (ICU), yielding a savings of 135 Intensive Care Unit (ICU) days annually for an annual opportunity-cost savings of $1.48 million.^[34][35]

In 2020, Dartmouth-Hitchcock published a retrospective study showing that over ten years of using Patient SafetyNet, there were zero patient deaths and no patients were harmed by opioid-induced respiratory depression while continuous monitoring with Masimo SET was in use.^[36] ECRI Institute gave Dartmouth its Health Devices Achievement Award for its use of Patient SafetyNet to prevent "severe patient harm".^[37] Masimo has introduced Halo ION in the Patient SafetyNet system, combining multiple physiologic parameters into one number to help clinicians assess overall patient status.^[38]

In 2020, amid the COVID-19 pandemic, the company released Masimo SafetyNet—a telehealth system for remote patient monitoring via sensors connected to smartphones. The mobile apps transmit this data to a HIPAA-compliant cloud server, allowing it to be monitored by physicians.^[39]

Rainbow acoustic monitoring

Rainbow acoustic monitoring provides non-invasive and continuous measurement of respiration rate using an adhesive sensor with an integrated acoustic transducer that is applied to the patient's neck.^[40][41] Researchers have evaluated acoustic respiration rate (RRa) and found the acceptable accuracy and significantly fewer false alarms than traditional respiration rate monitoring methods, end-tidal carbon dioxide (EtCO₂) and impedance pneumography.^[42]

SedLine brain function monitoring

In 2010, Masimo began offering brain function monitoring to measure the effects of anesthesia and sedation by monitoring both sides of the brain's electrical activity (EEG). Studies have shown this results in more individualized titration and improved care.^[43]

Capnography and gas monitoring

Masimo began offering ultra-compact mainstream and sidestream capnography as well as multigas analyzers for end-tidal carbon dioxide (CO₂), nitrous oxide (N₂O), oxygen (O₂), and anesthetic agents, for use in the operating room, procedural sedation, and in intensive care units (ICU).^[44] A multi-center study at Cincinnati Children's Hospital Medical Center, University Medical Center (Tucson, Arizona), and Children's Medical Center (Dallas), found that respiratory rate measured from noninvasive, acoustic monitoring had similar accuracy and precision as nasal capnography, the current standard of care when used in pediatric patients.^[45]

Opioid monitoring and treatments

In June 2020, the company released Bridge, a medical device intended to reduce symptoms of opioid withdrawal via neuromodulation.^[46]

In April 2023, the company received FDA approval for a pulse oximetry-based device for preventing opioid overdose by providing alerts of respiratory depression. The device—which was the subject of an innovation challenge issued by the FDA—received a De Novo classification allowing it to be distributed over-the-counter and through prescription^[47]

Smartwatches

In 2022, Masimo released the W1, a smartwatch that includes continuous health monitoring features and integrated with Masimo's other product lines. It was released in a limited public launch in the U.S., and to telehealth providers internationally.^[48]