Four Regional Oximetry Monitoring Options

Cerebral desaturation in cardiac surgery is common1 and can lead to an array of adverse events.2 Regional oximetry monitors need to be highly responsive to changes in cerebral blood oxygen saturation so they can serve as a “first alert” for hemodynamic changes and deteriorating patient conditions.2 These monitors use near infrared spectroscopy (NIRS) to detect signs of hypoxia in the brain and other tissues. A well-protected brain may act as an index organ for how well other organs are perfused and oxygenated.2

Medtronic, Edwards, Masimo, and Nonin are all suppliers of regional oximetry monitors in the United States. In this blog post, we’ll compare the INVOS regional oximetry monitor to other available monitors for use in the OR, ICU, and ECMO applications.

While not an exhaustive list of every cerebral oximetry system available, this blog presents each product in the manufacturer’s own words. You may validate all features listed by checking the manufacturers’ websites or contacting their sales representatives.

Related: Get the facts about cerebral oxygen desaturation, which is common, costly, and debilitating.

Selecting a cerebral oximetry system

Not all regional oximeters perform the same way. In side-by-side comparisons, devices from different manufacturers exhibit significant variations in:3

  • Responsiveness
  • Sensitivity to hemodynamic changes
  • Depth of response
  • Correlation to physiological changes

To select the right system, it’s important to consider how each manufacturer’s sensor design and algorithm can make them unique in how they respond to change.

Difference in response times is an important factor, as cerebral desaturation can occur within seconds. Every second counts toward patient safety and outcomes. In a clinical study it was found that the INVOS™ system reached 80 percent3 threshold faster than other monitors:

  • Nonin system responded 25 seconds slower
  • Edwards LifeSciences system responded 151 seconds slower
  • Masimo system responded 183 seconds slower

Related: Find out what the costs and benefits of a regional oximetry solution are for your hospital. Read the blog post here.

Medtronic Regional Oximetry System

Our clinically tested INVOS™ algorithm is at the heart of the INVOS™ 7100 system. And we’ve enhanced it with next-generation features that make it easier to monitor patients across the care continuum.

When the INVOS™ 7100 system is used in your OR and ICU, it can help improve your ability to intervene when patients need you most. The INVOS™ system is not only the most widely used regional oximetry system — it’s also the most studied. In fact, no other cerebral oximetry technology is backed by a comparable volume of published, peer-reviewed clinical research.

INVOS™ technology is engineered to respond to each patient’s unique physiology because normal cerebral saturation levels can vary widely — from 58 to 82 percent.8,9

The INVOS™ system displays changes in regional saturation from the patient’s baseline. That’s significant because studies have shown that intervening based on a relative drop of cerebral oxygen saturation from baseline can improve patient outcomes.9,10

With the INVOS™ 7100 system, you get:

  • A redesigned user interface that saves time customizing the monitor
  • Touchscreen functionality that makes reviewing and marking patient data faster
  • Auto baseline that eliminates the need for manual setup and ensures the baseline is set
  • A portable, tablet-style monitor to keep an eye on patients — wherever they are
  • Sensor identification that enables quick identification and adjustment of sensors
  • Sensor-off detection that lets you know if sensors have become detached
  • Perforated sensor design to keep sensor in place
  • Reduced sensor size to fit alongside BIS™ monitoring sensors without overlapping
  • Third-party OEM capability
  • Three-year warranty

*The INVOS™ monitoring system should not be used as the sole basis for diagnosis or therapy and is intended only as an adjunct in patient assessment.

Related: Read clinical study summaries that describe the study objectives, populations, results, and more.

Edwards Lifesciences Regional Oximetry System

The FORE-SIGHT™* Elite tissue oximetry system continuously and noninvasively monitors oxygen saturation. The FORE-SIGHT™* Elite system is now available on the HemoSphere™* advanced monitoring platform, giving you a view of tissue oximetry and advanced hemodynamics on one monitor.

The FORE-SIGHT™* Elite system offers the following features:

  • Five precise wavelengths of near infrared light (NIRS) enabling highly accurate performance
  • A thoughtfully validated and patented algorithm to compensate for patient tissue properties and the effects of melanin
  • Sensors to accommodate anatomical differences of each unique patient
  • Pediatric-specific mode
  • Exclusive availability with the HemoSphere™* advanced monitoring platform so you can view tissue oximetry and advanced hemodynamics on one monitor11

Masimo Regional Oximetry Monitors

Root™* with O3™* Regional Oximetry monitors the regional hemoglobin oxygen saturation of blood (rSO2) in the cerebral region for infant, neonatal, pediatric, and adult patients. With their flexible design, O3 sensors allow for ergonomic application on foreheads of all sizes.

Details of the Root™* with O3™* Regional Oximetry include:

  • Seamless integration with the Root platform alongside SedLine™Brain Function Monitoring (available for adult and pediatric patients) for a more complete brain monitoring solution
  • Plug-and-play monitoring with Masimo Open Connec™* (MOC-9™*) modules via the Root patient monitoring and connectivity hub
  • Viewability with Masimo SET™* pulse oximetry on Root™*, providing clinicians with expanded visibility of a patient’s oxygenation status.
  • One-year warranty12

Nonin Regional Oximetry System

EQUANOX™* regional oximetry systems are designed for cerebral and somatic use. They can be used for spot-checking or continuous monitoring of neonatal, pediatric, or adult patients in hospitals, long-term care, medical facilities, sleep laboratories, and sub-acute environments.

The EQUANOX™* regional oximetry systems include:

  • Patented dual emitter/dual detector sensor architecture to enhance measurement accuracy that is minimally affected by intervening tissue or surface effects
  • Displays rSO2, SpO2, and pulse for up to six sites
  • Bluetooth®* connectivity for wireless data transfer via the portable, easy-to-operate SenSmart X-100 monitor
  • A reusable sensor with a disposable patient interface via the Sensmart 8006 Hybrid sensor — reducing cost per procedure
  • Three-year warranty13


1. Schoen J, Husemann L, Tiemeyer C, et al. Cognitive function after sevoflurane- vs propofol-based anaesthesia for on-pump cardiac surgery: a randomized controlled trial. Br J Anaesth. 2011;106(6):840–850.
2. Avery EG. Cerebral oximetry is frequently a “first alert” indicator of adverse outcomes. Internal white paper. 2010.
3. Tomlin KL, Neitenbach AM, Borg U. Detection of critical cerebral desaturation thresholds by three regional oximeters during hypoxia: a pilot study in healthy volunteers. BMC Anesthesiol. 2017;17(1):6. doi: 10.1186/s12871-016-0298-7
4. Hongo K, Kobayashi S, Okudera H, Hokama M, Nakagawa F. Noninvasive cerebral optical spectroscopy: depth-resolved measurements of cerebral haemodynamics using indocyanine green. Neurol Res. 1995;17(2):89–93.
5. Kim MB, Ward DS, Cartwright CR, et al. Estimation of jugular venous O2 saturation from cerebral oximetry or arterial O2 saturation during isocapnic hypoxia. J Clin Monit Comput. 2000;16(3):191–199.
6. Redford D, Paidy S, Kashif F. Absolute and trend accuracy of a new regional oximeter in healthy volunteers during controlled hypoxia. Anesth Analg. 2014;119(6):1315–1319.
7. Bickler PE, Feiner JR, Rollins MD. Factors affecting the performance of 5 cerebral oximeters during hypoxia in healthy volunteers. Anesth Analg. 2013;117(4):813–823.
8. Murkin JM, Adams SJ, Novick RJ, et al. Monitoring brain oxygen saturation during coronary bypass surgery: a randomized, prospective study. Anesth Analg. 2007;104:51–58.
9. Edmonds HL Jr, Ganzel BL, Austin EH 3rd. Cerebral oximetry for cardiac and vascular surgery. Semin Cardiothorac Vasc Anesth. 2004;8(2):147–166.
10. Colak Z, Borojevic M, Bogovic A, Ivancan V, Biocina B, Majeric-Kogler V. Influence of intraoperative cerebral oximetry monitoring on neurocognitive function after coronary artery bypass surgery: a randomized, prospective study. Eur J Cardiothorac Surg. 2015;47(3):447–454.
11. Edwards Lifesciences. ForeSight Elite tissue oximetry system. https://www.edwards.com/devices/hemodynamic-monitoring/ForeSight. Accessed August 2020.
12. Masimo. O3 Regional Oximetry monitors. https://www.masimo.com/siteassets/us/documents/pdf/plm_11661c_brochure_o3_series_us.pdf. Accessed August 2020.
13. Nonin. Cerebral and tissue oximetry. https://www.nonin.com/technologies/cerebral-tissue-oximetry/. Accessed August 2020.

About the Author

Vance Curro is an operating room specialist for the Medtronic Respiratory and Monitoring Solutions portfolio. He provides consultation on the McGRATH™ MAC video laryngoscope, BIS™ brain monitoring system, and INVOS™ regional oximeter to healthcare facilities in Central and Eastern North Carolina.