Poor pulse oximetry accuracy.

My wife has a vivosmart 4 and I recently got myself a fenix 6 (now software version 8.10) titanium sapphire and I've been comparing the pulse oximetry of the two devices on both of my wrists followed by my wife's wrists with a professional pulse oximeter and the vivosmart 4 is surprisingly often within 1% accuracy of the professional device. The fenix 6 on the other hand is usually underreading by >= 5% all the time. I'm aware this is not meant to be a medical grade device but the numbers it gives are so much less accurate than the much cheaper device my wife has, and the values are so low that they'd warrant hospital admission or professional sleep studies when they're not warranted. I would not normally pay much attention to the values it gives since they're meant to just be there for trends rather than accuracy, but the much cheaper device being far more accurate is a little disconcerting when they apparently use similar sensors. It hasn't improved in a week of usage. I've tried tightening and loosening the band and on both wrists but the issue persists. I've seen other people posting their oxygen saturations and they're often in the low 90s when healthy young people at normal atmospheric conditions should always be in the high 90s. Do you have any suggestions, or is there any effort being put to improve it? Thanks.

  • As a followup, my saturations often read around 92% but I did some more reading of older forum posts and read that it is more accurate if your wrist is at heart height. Indeed the saturations are higher when I hold my wrist up close to my sternum, usually around 94-96% which is closer to what the medical grade oximeter shows of 97-98%. It's still odd that the vivo active 4 gave reliably better values regardless of where I held my wrist.

  • I have the same issue.. I have a 91 reading but my finger i is oximeter gives a reading of 98. I have has this issue since the time of purchase over a year ago

  • I have the same,  91-92 - Fenix 6 Saphire 

  • Same issue for me. Had the Fenix 6 for over a year and it always shows a rating below 94%, sometimes even below 90%. These would normally be concerning numbers. Have tested with a medical oximeter and a cheap device, both of them always show me as 99. It is also not improving with the various software updates. Seems like the oximeter is a bit of a gimmick in the Fenix6. 

  • This is known since long time. Even Garmin acknowledge this. What is a mystery is why Garmin still puts this energy-devouring, completely useless sensor in their watches.

  • You'll find the same half dozen of users defending that sensor as if it's of any use. They probably got a defective sensor which by mistake gives correct readings. 

    I think the matter should deserve another poll, exactly like the wrong pace issue. I bet it wouldn't receive much praises either. Maybe on Fenix 7 they'll change manufacturer and choose any other one, since any tried instrument is orders of magnitude more reliable than my Fenix 6s Relaxed

  • Yep.  I shut it off as even for acclimation that much bouncing around makes it worthless.  And it DOES gobble the battery.

  • Has anyone tested Pulse Ox on the Elevate 4 sensor? Presumably that's what going on the Fenix 7 (it's already in the new Venu and FR945 LTE). I just turned it off as well on my F6, haven't used it in month.

    One interesting point, I was the hospital last week for a cardio stress test, and they used a little portable fingertip Pulse Ox sensor on me. I was surprised to see it register 89-90% for the first minute on my right forefinger, eventually rising to 99%. Then during the test they had it on my left forefinger and it couldn't get a reading, nor on the left middle finger. 

    So maybe it's not JUST Garmin that can't get it right Confounded 

  • Faulty device? Slight smile Last time I was hospitalized the finger pulsoximeter immediately gave values and they were closer to 99%. 
    I worked years in a huge hospital and I daily heard about electro-medical devices that needed maintenance or to be replaced.

  • I bought a 15 € finger device and never seen going below 97...