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zubikov

macrumors 6502
Original poster
Sep 3, 2014
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The series 6 blood oxygen readout is so inaccurate, it may just do more harm than good. Sudden blood oxygen level drops have devastating and potentially fatal impacts on human health. These levels are also on a scale where a few percent variability could mean the difference between normal function, COPD, heavy smoking and critically low lung function due to COVID.

Apple jammed through this update seemingly without giving false measurements much consideration. I just did four measurements on my wrist within a couple of mins:

#1 - 89% - omg, am I hypoxic? Do I have COPD?
#2 - 98% - whew, I'm in the clear
#3 - 100% - wow, go me!
#4 - 94% - i give up

I have no tattoos, don't smoke, I'm in decent shape and have thankfully never been diagnosed with pulmonary or heart issues before. It's just so unreliable that it defeats the purpose of having such a sensor. Apple will quickly confuse their customers with noise, lose credibility and render the blood oxygen function useless.

Anyone else seeing crazy levels of variability like this??
 
Yep, will do this weekend. Already ordered a $15 pulse oximeter on Amazon.

Trust me, this is not a purchase regret rant. It's a genuine concern for millions of people getting false information.
 
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Yep, will do this weekend. Already ordered a $15 pulse oximeter on Amazon.

Trust me, this is not a purchase regret rant. It's a genuine concern for millions of people getting false information.
Apple did not state the Blood Oxygen sensor is medical grade and FDA cleared like the ECG.

I have used the test since i got the watch on the 21, and I have had consistent manual and automatic test results.
 
There are many of us that are getting virtually 100% accuracy. Tighten up the watch, rest your arm on something that has a lot of support, do not move whatsoever, and you’ll get a good reading. I have COPD so I can compare it to my readings that I get at the hospital, and my finger pulse ox device.
 
This is not a medical device and should be used for tracking trends only. Run multiple measurements within same timeframe to get an average.
 
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There is a lot of volatility in the readings, especially the ones that are taken automatically throughout the day or night. You can get it pretty accurate if you are focusing on it (higher up the wrist, tighten up, stay still), but let's not kid ourselves about its accuracy. Attached my readings since I got the watch on launch day:

CA42B69D-2B54-409A-B9A5-F5B93C215C20.jpeg
 
I have a Fitbit charge 3 and since I just got my first Apple Watch yesterday I moved the Fitbit to my opposite wrist as I wanted to compare what each provided. My heart rate seems to be the same on both. I do think it depends on how you wear the watch (too loose, too tight, too high on wrist)

Don’t have anything to compare oxygen levels to.
 
Tried with a couple of different adjustable straps...huge difference. The tighter the fit, the more consistent were the readings. Hoping the folks at Apple tweak the algorithm over time for more consistent readings.
 
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Yes, I think the band tightness is an issue and not necessarily fixable. For people that don’t like their watch band super tight and like even a bit of play it is quite possible that when an automatic measurement is silently taken (as they are) the wearer is standing up with his/her arms at their side and the base of the watch is at a very slight angle away from the skin. That seems to be what is happening to me. When I take a manual reading and obey the prompt to keep my wrist flat and still I get a reading of 98% to 100% but my automated readings are usually in the 85% to 95% range. I do suspect it’s because I’m mostly inadvertently not obeying the correct “wrist protocol” when the automated readings happen to be taken.
 
Tried with a couple of different adjustable straps...huge difference. The tighter the fit, the more consistent were the readings. Hoping the folks at Apple tweak the algorithm over time for more consistent readings.
Isn’t that what Apple has been telling you all along?
 
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Isn’t that what Apple has been telling you all along?

Yes, but I got a series 6 with a solo loop that was...not adjustable. Even though I thought the fit was decent, it clearly wasn't enough and caused fluctuations in the readouts; even if I held my hand totally still. So first chance I got, I tried a tight fit w/ a Milanese and an old sport band.

Thanks for the tips guys.
 
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Pretty happy with what I’m seeing from my AW6. Numbers are well within range of what I know and expect. Fun extra: was on a few flights this week and it accurately marked some of my lower numbers as high altitude environments.

I do wear my watch with no slack in the band.
 

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Pretty happy with what I’m seeing from my AW6. Numbers are well within range of what I know and expect. Fun extra: was on a few flights this week and it accurately marked some of my lower numbers as high altitude environments.

I do wear my watch with no slack in the band.
I didn’t know the watch could automatically detect lower saturation based on higher altitude. That is very cool tech indeed.
 
My range is consistent as well, except when my watch is loose fitting... then usually the watch will not record (background readings) or the recordings are a bit off.

Fingertip pulse ox readers that are not placed properly / hanging off your finger don't work either.
 
Yep, will do this weekend. Already ordered a $15 pulse oximeter on Amazon. Trust me, this is not a purchase regret rant. It's a genuine concern for millions of people getting false information.
I don’t expect a $15 oximeter from Amazon to be more precise and accurate.
 
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I just got mine yesterday, wearing it with a Sport Loop atm, quite tight but not too tight. Realistic readings, during night 96-99%. Just checked manually with 99%, my medical proved 50$ Pulsoximeter says the same. Can't complain. But I think it needs to have a good fit. So a Sports Loop or Milanese Loop would be the best, that is my guess.

My Garmins have PulseOX like forever and not matter which watch I wore I always got lower readings. Never used a Loop with them, don't own one, and I think they measured it all the time, the AW measures it when not moving. Better results. First night AW6 96-99%, Garmin always had readings from 85-95%, and I do a lot of sport and have no sickness or anything else, no problems whatsoever. I had to turn it off. Don't need inaccurate readings.

I will follow the readings in the next days, but first night top!
 
In fairness professional blood ox monitors can also screw up even in the most controlled hospital settings. When my mum was taken into hospital after a fall they did her blood ox in the emergency room and it came out really low (can't remember what but I think something crazy like 65%). The doctor said "that can't be right" and they (the doctor and a nurse) fiddled with the sensor and measured it again and got a more sensible value. (Sadly for my mum then followed up by taking arterial blood gas readings using a syringe which is apparently quite an unpleasant procedure.)
 
Apple watch: $399.
Oximeter: $15.
Missing out on everything else Apple watch has to offer all because of O2 Sat% variability when OP has no lung issues: Priceless.

Must feel great to put down total strangers on message boards, for reasons you can’t fathom. I have an older watch, and was contemplating whether this pulse ox and always on face were a worthy update.
 
Must feel great to put down total strangers on message boards, for reasons you can’t fathom. I have an older watch, and was contemplating whether this pulse ox and always on face were a worthy update.
For me, it will be a valuable update from my S4. I’m asthmatic, and high risk COVID. My ox sat is watched very closely. And yes, I have a $15 pulse ox from Amazon, but it is not always with me. I can’t wait for my S6 to get here 😁
 
Must feel great to put down total strangers on message boards, for reasons you can’t fathom. I have an older watch, and was contemplating whether this pulse ox and always on face were a worthy update.
Agree and in the same boat; in-fact, I will rather upgrade to SE, save some $$ that I can spend on iPhone 12, may be buy a higher storage device..

Honestly, before covid I didn't even know about this pulse ox meter; I was good before then and if I keep Covid away from me, then I hope I continue to stay good after covid as well :eek:)))
 
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Just remember that any band that has the word “solo“ in it, may be problematic with blood ox, they simply can’t get tight enough.
 
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