Blood oxygen readings wildly inaccurate!

[Tikatika]

I received my wonderful new S6 today and have been tracking my blood oxygen. I have asthma and one of my Reasons (excuses 😄) for upgrading my S4 was for this specific reason. My watch readings have ranged from 85!!-95. I have loosened and tightened my band. Placed it in different areas on my wrist. No difference!

The photos were taken after readings done at the same exact time! I’m not certain where I go from here.

 

[Lumpydog]

I have a pulse oximeter. So far the Apple Watch 6 and the finger reader/device have only varied +/-2

 

[michsu]

Maybe it is close to the right reading.. just like your heart beat.. it varies every minute and every second.. if you are in the same setting when measuring, then it is worth looking into..

you never know.. those finger ones can be lying too..

 

[edhchoe]

Eye for an eye.
Finger tip for a finger tip.
Try the watch on the finger. And. Report back.

 

[Madonepro]

I received my wonderful new S6 today and have been tracking my blood oxygen. I have asthma and one of my Reasons (excuses 😄) for upgrading my S4 was for this specific reason. My watch readings have ranged from 85!!-95. I have loosened and tightened my band. Placed it in different areas on my wrist. No difference!

The photos were taken after readings done at the same exact time! I’m not certain where I go from here.

A finger SPO2 monitor records, using infra red light, by sending light through your finger. Wrist based SPO2 monitors work similar to ultrasound, by reflecting back the light sent. The finger is much more accurate.
However, Oxygen saturation is not a good indication of how bad your asthma flare-up is. Asthmatics are notoriously good oxygen compensators and can have near normal or completely normal oxygen stats during the midst of a severe asthma attack. Asthma is a disease of the airways, not the little air sacs (alveoli) where the gas exchange itself takes place. So even if your airways are very constricted and tight, often enough oxygen is able to pass through to your blood and therefore show a normal or near normal oxygen saturation.

 

[Mercenary]

We also see different results on different fingers. The one you are using is widely seen as the most accurate but others may give results more in line with the watch. But yes, there is a high chance the watch is not right and guessing.

 

[Monkswhiskers]

If you are monitoring a serious condition, I would not throw to much weight on the readings of a smartwatch.

 

[The Game 161]

I think if people are in need of using this then i don’t think they will be measuring on the watch.

 

[Zanton68]

I take the readings in the same way I take the step count, heart rate etc. I’m not too concerned with the accuracy of the reading but look at the variances. e.g. if the watch always says 95% to 98% and then suddenly drops to 80% that’s a big drop even if 95% and 98% is wrong in the first place. Does that make sense?

 

[Julien]

It is really about the overall average and not a one time reading since it is a consumer device (not medical grade). I got a 90% and was calling the morgue but checked again and got 99% in the same minute.

 

[ShadowGuardian87]

Yea I agree the readings are pretty random sometimes. I guess that's why Apple stated it isn't for medical use and just used as a general tool to help/monitor wellness.

 

[michaelb5000]

I also see variation in my values, but this is not something I have ever monitored before. So that variation may be perfectly normal; or this is error +/- 3 or so in the readings. But I also see that the SPO2 readings include the barometric pressure from the watch. Pressure is falling for me today in those readings. This must be used to compare the blood o2 to the atmosphere. Some folks have reported errors or variation in their elevation/pressure readings, so I wonder if issues with the barometer sensor could also result in errors or variation in the SPO2 reading?

 

[WitchDoktor]

Mine doesn't show much variance between a fingertip sensor I have here and the watch. Maybe +/- 2% or so. As long as the baseline is over 95% I'm fine.

 

[Tikatika]

Eye for an eye.
Finger tip for a finger tip.
Try the watch on the finger. And. Report back.
View attachment 963741

WOW! 97. Five times! I guess I need to wear my watch on my finger 😂. Thanks everybody for responding. My asthma is very well controlled and I would Never rely on the watch reading.. I just thought it would be convenient to have away from home.

 

[Expos of 1969]

Yea I agree the readings are pretty random sometimes. I guess that's why Apple stated it isn't for medical use and just used as a general tool to help/monitor wellness.

Yep, the FDA did not have to certify it as it falls under the "fun" and "general wellness" categories. In other words, a gimmick, a toy and marketing scheme to draw in unsuspecting and gullible buyers.

 

[1rottenapple]

So basically knock one reason to buy series 6. Brighter AOD and 20% faster charger speed, slightly faster processor. Not very compelling.

No wonder they discontinue series 5 b/c most would likely buy that over the 6 at a discount if given the choice.

 

[ShadowGuardian87]

So basically knock one reason to buy series 6. Brighter AOD and 20% faster charger speed, slightly faster processor. Not very compelling.

No wonder they discontinue series 5 b/c most would likely buy that over the 6 at a discount if given the choice.

Yea they did the same with the iphone X after the announcement of the iPhone XS.

 

[1rottenapple]

Yea they did the same with the iphone X after the announcement of the iPhone XS.

I wonder what it would take for me to upgrade to my next apple watch. I got the titanium so having paid 2x as much I need my next apple watch to ge super compelling. I'll probably u/g in 4 years.

 

[Apple_Robert]

I received my wonderful new S6 today and have been tracking my blood oxygen. I have asthma and one of my Reasons (excuses 😄) for upgrading my S4 was for this specific reason. My watch readings have ranged from 85!!-95. I have loosened and tightened my band. Placed it in different areas on my wrist. No difference!

The photos were taken after readings done at the same exact time! I’m not certain where I go from here.

As has been stated, consistent long term readings are more beneficial. Check the watch results once a day. After a month, compare it to the finger tip readings of the same time.

The watch is meant to give a general overview of one’s well being. The feature is not meant to be medically accurate much less at every test done. Look for a consistent differential of 1 - 2% between the two devices.

Having the band too tight or too loose can affect the reading as can tattoos and placement on the arm.

 

[ShadowGuardian87]

I wonder what it would take for me to upgrade to my next apple watch. I got the titanium so having paid 2x as much I need my next apple watch to ge super compelling. I'll probably u/g in 4 years.

Next ones might have extended battery and a redesign and other new features.

 

[1rottenapple]

I don't know I feel like they might stay for another period with the current design given these watches aren't exactly stagnating sales wise. I would love super fast charging. 15 min, 80% charge, corresponds to someone taking a shower and getting ready.

 

[1rottenapple]

As has been stated, consistent long term readings are more beneficial. Check the watch results once a day. After a month, compare it to the finger tip readings of the same time.

The watch is meant to give a general overview of one’s well being. The feature is not meant to be medically accurate much less at every test done. Look for a consistent differential of 1 - 2% between the two devices.

Having the band too tight or too loose can affect the reading as can tattoos and placement on the arm.

I agree maybe that's where the value lies. I was blown away when i downloaded a new app to track my workout and I saw my exercise calories since 2018. I can see my progress through time and how much i'm working out now compared to back then.

 

[Aspasia]

Precisely why I opted to buy a pulse oximeter versus upgrading my AW5 to 6.

 

[Madonepro]

WOW! 97. Five times! I guess I need to wear my watch on my finger 😂. Thanks everybody for responding. My asthma is very well controlled and I would Never rely on the watch reading.. I just thought it would be convenient to have away from home.

Precisely why I opted to buy a pulse oximeter versus upgrading my AW5 to 6.

Oxygen saturation is not a good indication of how bad your asthma flare-up is. Asthmatics are notoriously good oxygen compensators and can have near normal or completely normal oxygen stats during the midst of a severe asthma attack. Asthma is a disease of the airways, not the little air sacs (alveoli) where the gas exchange itself takes place. So even if your airways are very constricted and tight, often enough oxygen is able to pass through to your blood and therefore show a normal or near normal oxygen saturation.

 

[RemE]

The technology of pulse oximetry was based on resolving the blood flow pulse in a finger tip (or other extremity) with two colors of Infra-red light. They use two led light emitters and two light detectors. They chose the finger because that's a great place to measure arterial blood oxygen as blood pumps thru the capillary bed of the fingertip. Monitoring the pulse waveform and measuring at the peak of the pulse gives the most accurate measurement. Most pulse oximeters display the waveform during use so that the operator can visually see if the blood flow is good, by the shape of the displayed pulse, and if compromised in some way they can re-position the arm etc.

The Apple watch blood oxygen measurement, on the back of the wrist, is not at all optimal to measure SPO2. I'm pretty sure that is why they don't show the waveform as I suspect it may not look like a classic crisp pulse ox waveform from a finger. They take a 15 sec measurement and probably have an algorithm to compensate for the measurement location. All that said, decent job in my opinion, good enough for a personal trend measurement. SPO2 is a "boring" measurement as we are all normally 95% and higher. When it's lower than this, one would want to use a certified device to monitor before administering any form of treatment.