Shining a light on pulse oximetry

A pulse oximeter is a device that shines light through tissue to measure the oxygen content in the blood. This data can then inform care decisions and support outcomes. Pulse oximetry sensors detect the red and infrared LED light absorbance that shifts in the presence of oxygenated and deoxygenated hemoglobin. Melanin, the natural pigment that gives skin its color, can also impact light absorption — specifically the red LED light used in a pulse oximeter. This can lead to a higher incident of unrecognized hypoxemia in patients with darker skin pigmentation.†,1–4

To assess patient oxygen saturation, our Medtronic Nellcor™ technology uses a form of artificial intelligence called a pattern-matching neural network to recognize and track each patient’s unique pulse.5 We embed a digital memory chip in every sensor matched with individualized calibration curves to help enable higher accuracy and improved performance.6

You can read more about what a pulse oximeter is, how it works, and the history of the device in our Medtronic newsroom.

Oxygen saturation accuracy can be affected by certain environmental, equipment, and patient physiologic conditions that influence readings of SpO2. Please consult the instructions for use and manual for full safety information.

Female patient with pulse oximeter on finger

Nellcor™ pulse oximetry performs better than Masimo for patients with dark skin tones‡,1

A leading hypoxia research laboratory independently tested pulse oximeters made by Medtronic and Masimo. The researchers evaluated devices for their ability to read blood oxygen in patients with dark skin pigmentation and low perfusion. The research showed that the Medtronic Nellcor™ system more frequently identified hypoxemia and more accurately measured oxygen saturation.

These findings show how different technologies perform across skin tones

  • Nellcor™ technology missed 74% fewer hypoxemic events in subjects with dark skin and low perfusion.
  • Nellcor™ pulse oximetry experienced only 10% as many data dropouts as Masimo SET™* pulse oximetry.
  • Nellcor™ pulse oximetry had 31% greater precision in all dark skin readings than Masimo SET™* pulse oximetry.

Accuracy based on study, not funded by Medtronic, that enrolled 146 healthy subjects in the 92-96% saturation range and examined paired readings from Nellcor™ N-595 and Masimo Radical 7™* pulse oximeters generated simultaneously. This study was not designed for head-to-head comparison of the respective devices.

Find webinars, podcasts, and educational courses about equitable monitoring and learn what this can mean for patients.

See independent evaluation at Open Oximetry, where each Nellcor™ system passed preliminary validation for patients of all skin tones.§ The Open Oximetry project was created to improve the safety and precision of pulse oximeters in all populations.

Performs in accordance with 2013 FDA premarket notification submissions guidance and ISO 80601-2-61 (2017). Performance data from healthy volunteers may not accurately represent performance in real world patient populations. The information displayed here shall not be construed as an endorsement by Open Oximetry.

Investing in inclusive clinical evidence

At the Medtronic Clinical Physiology Lab, we’re conducting pulse oximeter clinical studies incorporating the Monk Skin Tone (MST) Scale. The MST scale is a more inclusive 10-pigmentation scale designed to represent a broader range of patient populations. We’re using these new learnings to design the next generation of pulse oximetry technology.

By increasing representation in our research, we help ensure more equitable performance for all patients.



Can technology be blind to skin tone?

Learn more about the inventor of the MST scale, Harvard University sociology professor Dr. Ellis Monk, and his approach to developing the MST. Dr. Monk is an expert on health disparities, ethno-racial inequality, and skin tone.


See the Monk Skin Tone Scale.

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