5 ms·

How accurate are those devices without a blood sample?

hausen 5y ago
FDA-cleared pulse oximeters must be accurate to ±4% SpO2. https://www.fda.gov/medical-devices/safety-communications/pulse-oximeter-accuracy-and-limitations-fda-safety-communication https://www.fda.gov/medical-devices/safety-communications/pu...
- wlesieutre 5y ago
  Notably, the Apple Watch S6 sensor does not have FDA approval. It's for "wellness." https://www.theverge.com/2020/10/7/21504023/apple-watch-ekg-blood-oxygen-fda-clearance https://www.theverge.com/2020/10/7/21504023/apple-watch-ekg-... > Blood oxygen monitors, or pulse oximeters, are considered Class II medical devices by the FDA. Generally, any company that wants to sell one in the United States has to submit documentation to the agency confirming that its product works just as well as other versions of the same product already on the market. There’s a workaround, though: if the company says that the product is just for fun, or for general “wellness,” they don’t have to go through that process. They can’t claim that it can diagnose or treat any medical conditions, but they can put it up for sale. You might still use that as a cue that you should get tested for sleep apnea, but the watch itself isn't considered a medical device for measuring blood oxygen.
Baeocystin 5y ago
The full set of arterial blood gasses requires a blood draw, but just oxygen saturation is easily and accurately done via a simple light sensor. The FDA requirement is that the finger/light sensors be within 2-3% of the measured blood gas value.
jvans 5y ago
It's worth noting that sleep apnea can disrupt your sleep without oxygen desaturation. Typical at home sleep tests cannot return a negative result, they can either be positive or inconclusive. EEG monitoring for arousals is necessary to rule out sleep apnea which most at home tests don't include.
nradov 5y ago
Under ideal circumstances they are accurate to within a couple percent. But accuracy varies widely based on watch band tightness, skin color, hair, etc.

FDA-cleared pulse oximeters must be accurate to ±4% SpO2. https://www.fda.gov/medical-devices/safety-communications/pulse-oximeter-accuracy-and-limitations-fda-safety-communication https://www.fda.gov/medical-devices/safety-communications/pu...

wlesieutre 5y ago
Notably, the Apple Watch S6 sensor does not have FDA approval. It's for "wellness." https://www.theverge.com/2020/10/7/21504023/apple-watch-ekg-blood-oxygen-fda-clearance https://www.theverge.com/2020/10/7/21504023/apple-watch-ekg-... > Blood oxygen monitors, or pulse oximeters, are considered Class II medical devices by the FDA. Generally, any company that wants to sell one in the United States has to submit documentation to the agency confirming that its product works just as well as other versions of the same product already on the market. There’s a workaround, though: if the company says that the product is just for fun, or for general “wellness,” they don’t have to go through that process. They can’t claim that it can diagnose or treat any medical conditions, but they can put it up for sale. You might still use that as a cue that you should get tested for sleep apnea, but the watch itself isn't considered a medical device for measuring blood oxygen.

Baeocystin 5y ago

The full set of arterial blood gasses requires a blood draw, but just oxygen saturation is easily and accurately done via a simple light sensor. The FDA requirement is that the finger/light sensors be within 2-3% of the measured blood gas value.

jvans 5y ago

It's worth noting that sleep apnea can disrupt your sleep without oxygen desaturation. Typical at home sleep tests cannot return a negative result, they can either be positive or inconclusive. EEG monitoring for arousals is necessary to rule out sleep apnea which most at home tests don't include.

nradov 5y ago

Under ideal circumstances they are accurate to within a couple percent. But accuracy varies widely based on watch band tightness, skin color, hair, etc.