Just as Apple is forced to remove blood oxygen tracking from top Apple Watch models in the US, Garmin is doubling down on making its SpO2 readings more accurate.
In a new filing, Garmin has patented technology that will take measurements by using three different light sources. Its new method will compare the respective percentages of oxygen detected in the blood for more accurate measurements.
Currently, Garmin uses a combination of red and infrared LED lights and sensors to determine the percentage of the total oxygen capacity circulating through the bloodstream.
Garmin
The improved system would activate a third LED light source, on a third wavelength, to further validate the accuracy of the readings.
“A second embodiment of the disclosure is broadly directed to an apparatus for determining the validity of a measured in-blood percentage of oxygenated hemoglobin,” the filing with the USPTO reads.
The technical document goes on to say the array would comprise a “first pulse oximetry channel comprising: a first light emitting diode producing light having a first wavelength and a first current, a second light emitting diode producing light having a second wavelength and a second current, a third light emitting diode producing light having a third wavelength and a third current, a first photodiode configured to selectively detect light from the first pulse oximetry channel light emitting diodes…”
From here, Garmin claims the first and second readings would be compared, the first and third readings would be compared, and the second and third readings would be compared, to ensure a more holistic reading and a truer picture.
Or, as Garmin puts it in more technical language:“Determining that a signal quality of the first estimated in-blood percentage of oxygenated hemoglobin exceeds a predetermined validity threshold, and based on the determination, indicating that the first estimated in-blood percentage is valid.”
The patent points out that on the first and second readings, the bloody oxygen percentage reading could be affected by “noise” like motion, so a third pass would provide a big assist.
Garmin
The percentage of oxygen in the blood has become a reliable overall health metric for wearable device owners. A reading of over 95% SpO2 is a normal measure, and under 90% is low. It’s a great tool for monitoring your recovery from strain or illness, or for those acclimatizing to high altitude.
While Garmin cautions its pulse ox features aren’t designed to be used in a medical context, the company says: “Being aware of your SpO2 can help you understand how your body reacts to various situations and can serve as an indication of important changes in your health.”
Wareable has contacted Garmin for comment on whether this patented technology is likely to make it into a fitness watch or tracker any time soon.
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By Chris Smith
Chris has more than decade of experience writing for the UK's foremost technology publications including TechRadar, T3 and more.
A freelance journalist based near Miami, Florida, Chris has written for Wareable since its inception in 2014. From reviews of the latest fitness devices, and in-depth features on bleeding-edge wearable devices, to future-gazing interviews with some of the industry's brightest minds, Chris covers the lot. He also writes about sport for The Guardian and is the author of many technology guide books, while also dabbling in film, music, beer, travel and political commentary.
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