10 ms·

How on-the-wrist sleep apnea detection works

175 points by brandonb 2y ago

cromka 2y ago
Considering they use accelerometer for it, nothing really stops them from adding this feature to all Apple Watches, potentially even the Series 1, right? Reserving it to Series 10 and 9 really exposes their lack of hardware innovation. I mean, we were talking about them measuring glucose levels for years and this is what we get as a new flagship feature?
- brandonb 2y ago
  I suspect they also need oxygen saturation (introduced in the Apple Watch Series 6 in 2020) in order to make their overall sleep apnea detection algorithm work. Given that it only works with the Series 9 or above, it's possible they're also using the the temperature sensor as another input into their algorithm.
  - jerlam 2y ago
    Did Apple resolve the patent issue that disabled oxygen saturation in the Series 9? Although it's possible that Sleep Apnea detection uses the oxygen saturation sensor but doesn't show its results directly.
    - brandonb 2y ago
      It wouldn't surprise me if they did the latter. The oxygen saturation sensor is fundamentally just another optical sensor with a different wavelength of light -- so if you feed all three wavelengths, plus the accelerometer, into a neural network, you may be able to pick up on oxygen-related physiological signals without explicitly processing an oxygen timeseries.
    - MBCook 2y ago
      No. I was very curious to see if it might be a last minute thing where it came back but the pages for the series 10 clearly don’t list it and if you use the comparison tool it’s highlighted as gone. I hope it’s just still disabled. It would suck for someone to buy a new watch, the fix the dispute in 2 months, and you never get the feature until you buy another new watch. They’re clearly not bending. I don’t know if they’ve given up or waiting on an appeal or maybe home a new administration will tell the ITC to go away or what.
      - _rs 2y ago
        Non-US watch series 10 specification pages mention it still, so it's there and just disabled. I wonder though if they could legally enable it after the fact on watches imported while the ban was in effect
    - skygazer 2y ago
      They're still appealing, but the underlying patent expires in 2028, so maybe they'll wait it out.
  - cromka 2y ago
    They explicitly only mentioned accelerometer. If they used more sensors, in particular temperature sensor, it's hard to imagine they wouldn't mention in, especially that it would justify them limiting the feature to Series 9 and 10. However, reading on PAT (Peripheral arterial tone) and existing FDA-approved devices using that, they indeed use oxygen but not temperature. See for example "WatchPAT ONE" device.
    - dwighttk 2y ago
      Perhaps they aren’t worried about justification
- swatcoder 2y ago
  They absolutely could be segmenting features by generation even if they could introduce them into earlier products and it's pretty normal across the industry to do so, but "well, it seems to use the accelerometer" provides no evidence of that on its own. Without knowing more details about the implementation, it may rely on combining data from other sensors as well, it may need a certain frequency/resolution from a sensor that's not available in earlier generations of hardware, it might place too much demand on compute or power to maintain prior products' expected behavior, etc
  - pdpi 2y ago
    > , it might place too much demand on compute or power to maintain prior products' expected behavior, etc Love it or hate it, this mentality of "the feature is technically possible but we won't enable it because we're not happy with the compromises it demands" is, by design, exactly the sort of logic that Apple is known for.
- mikestew 2y ago
  nothing really stops them from adding this feature to all Apple Watches… I’m confident there’s more to it than just sensor availability. Compute power for starters, as well as the fact that a Series 1 accelerometer may not have the necessary resolution, etc. Reserving it to Series 10 and 9 really exposes their lack of hardware innovation. Ah, the ol’ “Apple didn’t build what I want, ergo, Apple doesn’t innovate” trope.
  - cromka 2y ago
    That's manipulative. I did not mention I expected anything in particular. If anything, your defensive narrative makes you come off as a fanboy.
- a_vanderbilt 2y ago
  Sure it probably comes down to sensor specs, but the same question can be asked about Apple Ingtelligence and the new iPhones. If the model is in a private cloud, why is it restricted to newer iPhones? Surely the preprocessing isn't so intensive that only the latest iPhones can do it. It's artificial segmentation in the interest of driving (historically weakening) sales.
  - cromka 2y ago
    Yeah, I thought the same when they announced it. All in all, I feel that artificial segmentation is more frequent than ever and this can't be good indicator for their future growth, can it?
    - a_vanderbilt 2y ago
      It's definitely a sign of the decline of hardware innovation. It's not for lack of trying, however. Apple has experimented with Touch Bars, VR, and LIDAR cameras, largely to little effect. They just aren't disruptive enough. So how then do they segment if not hardware? Software. I think that growth is going to slow no matter what they do. Western and Japanese markets are saturated, and Chinese markets (once most promising) are bringing fierce competition both from local competition and the government.
  - MBCook 2y ago
    It’s not all in a private cloud. Much is on device, and as we all know AI stuff loves CPU and RAM. They appear to have restricted it to 8 GB of RAM devices or more (when those appear). During The Talk Show interview at WWDC with John Gruber an Apple exec (Joz?) said they did it because of user experience issues, seeming implying speed. And given how hard AI hits hardware I think that’s relatively believable.
- diebeforei485 2y ago
  Probably requires the newer generation accelerometer. There are also other issues like power consumption overnight. Older watches have smaller batteries and slow charging. People will update the software, use the new features, and complain that Apple software updates are killing the battery (waking up to low battery plus slow charing means not being able to charge up before leaving for work). This has the effect of Apple only backporting new features if they don't consume too much battery.
- bamboozled 2y ago
  They're not adding it to the Ultra 1 either, what amazing advancements happened since the Ultra 1 to stop that from happening?
hartator 2y ago
Is it released or they are waiting for fda approval? Little unclear on macrumors.
- peppertree 2y ago
  Waiting for fda.
tootie 2y ago
I wouldn't put a ton of stock into this, but it could still be useful. The WatchPAT device is purpose-built for this test and includes a full fingertip oximeter and while it's FDA-approved, it's still not very accurate. It's also a notoriously tricky condition to diagnose and can't really be done just by looking at numbers. I think there's value in the test being accessible to so many more people, it will likely have a positive outcome on detection and treatment, but I would not expect you to push a button and get a confirmed diagnosis.
- carlmr 2y ago
  >can't really be done just by looking at numbers Depending on the numbers, why not? If it's sensor accuracy a single night might not be enough, but if it detects the condition averaging over a few weeks even unreliable measurements can be made more reliable (given they're just noisy).
  - tootie 2y ago
    Not a doctor, but I was given a diagnosis of severe sleep apnea from an overnight in-lab study. Sought a second opinion who decided it wasn't sleep apnea at all. AHI or T-90 are convenient indicators, but pulmonologists will actually look at the shape of your graph and listen to symptoms. All humans are different and don't always conform to formulas. That being said, your observation that a nightly watch user can collect lots of data is an interesting one. If Apple (or whoever) can come up a more heuristic analysis than just computing AHI, they may end up with something better. Also, not that you asked, but my sleep situation is a bit complicated and I actually ended up with a CPAP anyway.
    - wkat4242 2y ago
      That's why a sleep study is not just done with a watch but with ECG, video, breathing band, finger SpO2 clip etc. I was like a cyborg going to the bathroom, so many wires and devices clipped to me :) it's unreasonable to expect a watch to do the same.
lysace 2y ago
The gatekeeping in the CPAP field is so insane. 1. Yes, we should regulate manufacturers intensely. 2. No, we shouldn't regulate to whom companies should be allowed to sell them. The defaults are good enough for most. Provide an easy to use control for max pressure and people will figure it out. Perhaps a knob? I claim: During the past decade, the risk of being maltreated by a personally set-up CPAP unit has been far, far smaller than the risk of not being treated at all. (Ways to access these menus have been been shared online for 10+ years, many use them.) I wonder how many premature deaths happen every year because of this - including secondary victims from traffic accidents. These things should be $500 mass-market consumer units that you pick up at Target, Walmart, etc.
- a_vanderbilt 2y ago
  The health industry as a whole is insane. I support the use of regulation and law where it ensures safety and efficacy but in the U.S. it's currently a patent and legal minefield. So much of it comes directly from special interests who want gatekeeping to keep out new/disruptive competition.
  - smaudet 2y ago
    On the other side, as a consumer, I don't really want "new/disruptive competition" - I want stability and a legal guarantee my rights aren't being trod all over. Large companies e.g. Google/Apple are just inherently untrustworthy in this regards, smaller overseas ones are no better (little to no regulation). So please, no, stay the ** out of my health, thanks.
    - IOT_Apprentice 2y ago
      Google, Meta et al ARE FAR worse than anything might complain about Apple. Between the sleep apnea and hearing aid/hearing loss features you should be applauding these features to the world. As a consumer I have family members that will be leveraging these features immediately, including myself.
    - a_vanderbilt 2y ago
abtinf 2y ago
I’ve always wished I could put Apple Watch into a “constant oxygen monitor mode” for sleep. That seems to be the obvious way to assess sleep apnea. Anyone know why that isn’t the method?
- a_vanderbilt 2y ago
  If I had to venture a guess, maybe it's an industry regulation or power usage issue. Simply being able to assess sleep apnea isn't enough, it has to pass the regulatory burdens as well.
- zwily 2y ago
  They still don't have the regular oxygen monitor mode back yet because of a patent dispute. That might be part of it.
  - tptacek 2y ago
    That's only in the US, right? (My flimsy understanding is that blood oxygen measurement is how at-home sleep studies work?)
    - jrockway 2y ago
      At-home sleep studies measure heart rate (maybe ekg, some probe is on your skin), blood oxygen, sound, and the direction of gravity relative to your testing device (to classify results by "back", "side", "prone", etc.) I did one of these and it was the worst night of sleep I ever had. It's somewhat invasive. Meanwhile, I sleep with my watch every night with no problems.
      - tptacek 2y ago
        Interesting. I keep meaning to get one done. Probes don't seem like that big a deal?
        jrockway 2y ago
GaggiX 2y ago
The new Apple Watch 10 has an 18-hour battery life, so if you use it while you sleep, you won't have much left. I have no idea how some people can charge their smartwatch 1 or more times a day.
- smelendez 2y ago
  People probably use it principally as a fitness (and sleep?) tracker, and charge it while they work
  - GaggiX 2y ago
    I mean it's still a watch so hopefully people are going to use it as a watch.
- a_vanderbilt 2y ago
  I find that integrating it into my routine made my current watch (SE1) battery a non-issue. I wear it starting in the morning, charge it on the way to work, and then to bed. Repeat ad infinitum. Battery usage at night is way lower in my experience, and it usually survives til morning or close to it.
- jerlam 2y ago
  I used to charge my watch every time I took a shower, which was every morning. Never had to think about battery life or charging the watch "out of band". But then again, it wasn't an Apple Watch.
- xyzAbc_ 2y ago
  It is a non-issue for me with the Apple Watch 9. It's charged super quick e.g. if the battery is low after waking up you can plug it in do your morning routine and pick it up. Vice versa in the evening before going to sleep. Also did some bike packing this year and charging it with a power bank was also not an issue. At one point my power bank was empty and my apple watch ran out of power as well - this has been the only time I whined for more battery life.
- 4fterd4rk 2y ago
runjake 2y ago
I'm not an qualified expert, but I spend a lot of time reading about and using this stuff and I'm extremely skeptical sleep apnea detection is very accurate without the pulse oximeter functionality. But gosh, I hope this is accurate across the Watch's wide user base. I wouldn't say it's likely, but I do wonder if the pulse oximeter is being used surreptitiously. In any case, if you could use the pulse oximeter, this functionality would immediately become much more powerful.
- rootusrootus 2y ago
  IIRC the pulse oximeter isn't all that useful for sleep apnea detection anyway, because on the watch it does not run continuously. Just takes measurements every X minutes. I think the oxygen level drop happens on a short enough timescale that you need the continuous monitoring to pick up on it.
  - runjake 2y ago
    I think the pulse oximeter would be most helpful in concert with the accelerometer, as described in the article.
  - TechDebtDevin 2y ago
    Watch Sp02 detection is usually at rather long intervals to conserve battery and typically have not resulted in any sort of detection of low 02 (in my experience, I have very bad sleep apnea)compared to a pretty dependable and accurate $30 on the finger oximeter.
  - lathiat 2y ago
    The watch can ramp the detection up for periods of time if it chooses, such as when doing a workout. But also, people with sleep apnoea tend to have their O2 trend low not just go briefly low.
- m463 2y ago
  > sleep apnea detection I don't think it has to be as accurate as other things like blood glucose levels, because with those people might use the results to inject insulin. Detecting sleep apnea might be more like afib detection. It just tells someone they should be checked out.
jrockway 2y ago
This is a neat feature. I read Reddit and r/applewatch shows up in my feed a lot. 99% of the questions are "do I have sleep apnea?" At least the watch can give them my cut-n-paste response "you should talk to your doctor about a sleep study" now.
breck 2y ago
If you're interested in this, I'd recommend reading the 1870 [public domain] book "Shut Your Mouth and Save your Life". Internet Archive has it: https://archive.org/details/b28114450 https://archive.org/details/b28114450 Also look into "mouth taping".
- VeejayRampay 2y ago
  mouth taping is dangerous for many reasons, you should not be advocating it in a public forum
  - breck 2y ago
    You are right, on the list of things that are dangerous, you would find mouth taping, probably right next to using a fork.
    - mikestew 2y ago
      You’re right, medical advice from the 1870s and TikTok videos, what could go wrong? But I did “look into ‘mouth taping’” as you suggested, and I’ll bet half the page titles were “Mouth-taping: is it safe?” or “…does it work?” At what point does Betteridge’s Law of Headlines[0] kick in? [0] https://en.wikipedia.org/wiki/Betteridge's_law_of_headlines https://en.wikipedia.org/wiki/Betteridge's_law_of_headlines
      - breck 2y ago
        > You’re right, medical advice from the 1870s and TikTok videos, what could go wrong? Have you read the book? Do you think I'd be recommending something that didn't have a very strong dataset backing it? > At what point does Betteridge’s Law of Headlines[0] kick in? Nothing is easier to manipulate than digital symbols. Thus, when talking about patterns one finds in digital symbols, one much be very very careful to build a trusthworthy dataset. Do you have a trusthworthy dataset on Betterridge's headlines?
        2y ago
pjohri 2y ago
I used a PAT device that showed mild apnea. I then used an at home sleep study that came back negative.
deleted 2y ago
[deleted]
eh_why_not 2y ago
>Undiagnosed sleep apnea affects more than 23.5 million people in the US alone, leading to $150B of wasted medical spend every year. What do they mean by "wasted medical spend" here? (1) Patients incorrectly spending money on a misdiagnosis, or (2) apnea solution providers not making money off people when they could?
- brandonb 2y ago
  (OP here) a third category: downstream complications of sleep apnea, primarily car crashes and heart attacks. Diagnosing and treating people with undiagnosed sleep apnea would prevent these entirely, which is obviously much healthier for the person and reduces medical cost for the entire system (including the patient themselves for co-pays, taxpayers for government costs, etc).
  - eh_why_not 2y ago
    Thanks, I think it would be informative if you put this spelling out in the article. People like myself not immersed in health fields won't immediately know what you mean without it.
    - brandonb 2y ago
      Just updated the article to spell that out. Thanks for the feedback!
dave333 2y ago
Amazing that you can get much the same functionality in a off brand $30 watch these days - at least monitors sleep and blood oxygen - although it explicitly does not do medical diagnosis. Still every senior should have one for many reasons.
- TechDebtDevin 2y ago
  I have extremely severe sleep apnea with 60-100 events per minute, and baseline blood oxygen is low to start with because I live at altitude. I'm very into wearables and have tested most of the top SpO2 capable watches and none of them detect my sleep apnea outside a very rare detection of low O2.
  - tmoertel 2y ago
    > 60-100 events per minute Do you mean per hour?
- emporas 2y ago
  Sleep apnea is very easily fixed. You have to increase blood pressure on the head by a lot, for a little bit of time each day, half an hour to an hour and it is 100% fixable. Additionaly increasing blood pressure on the head helps for sleeping more. I do that and sleep for an average of 10 hours a day. 12 hours or 14 hours/day of sleep for me, is not rare either. Also increasing the blood pressure on the head helps fix myopia 100%, like that woman astronaut who returned to earth and her eyes worked perfectly again.
  - dave333 2y ago
    Raising the foot end of the bed eg with a few thick books under the mattress is supposed to give health benefits by stopping the blood pooling in the lower legs where DVT blood clots most likely occur. Wondering if it also benefits by increasing blood pressure in the head?
    - emporas 2y ago

175 points by brandonb 2y ago

Considering they use accelerometer for it, nothing really stops them from adding this feature to all Apple Watches, potentially even the Series 1, right? Reserving it to Series 10 and 9 really exposes their lack of hardware innovation. I mean, we were talking about them measuring glucose levels for years and this is what we get as a new flagship feature?

brandonb 2y ago
I suspect they also need oxygen saturation (introduced in the Apple Watch Series 6 in 2020) in order to make their overall sleep apnea detection algorithm work. Given that it only works with the Series 9 or above, it's possible they're also using the the temperature sensor as another input into their algorithm.
- jerlam 2y ago
  Did Apple resolve the patent issue that disabled oxygen saturation in the Series 9? Although it's possible that Sleep Apnea detection uses the oxygen saturation sensor but doesn't show its results directly.
  - brandonb 2y ago
    It wouldn't surprise me if they did the latter. The oxygen saturation sensor is fundamentally just another optical sensor with a different wavelength of light -- so if you feed all three wavelengths, plus the accelerometer, into a neural network, you may be able to pick up on oxygen-related physiological signals without explicitly processing an oxygen timeseries.
  - MBCook 2y ago
    No. I was very curious to see if it might be a last minute thing where it came back but the pages for the series 10 clearly don’t list it and if you use the comparison tool it’s highlighted as gone. I hope it’s just still disabled. It would suck for someone to buy a new watch, the fix the dispute in 2 months, and you never get the feature until you buy another new watch. They’re clearly not bending. I don’t know if they’ve given up or waiting on an appeal or maybe home a new administration will tell the ITC to go away or what.
    - _rs 2y ago
      Non-US watch series 10 specification pages mention it still, so it's there and just disabled. I wonder though if they could legally enable it after the fact on watches imported while the ban was in effect
  - skygazer 2y ago
    They're still appealing, but the underlying patent expires in 2028, so maybe they'll wait it out.
- cromka 2y ago
  They explicitly only mentioned accelerometer. If they used more sensors, in particular temperature sensor, it's hard to imagine they wouldn't mention in, especially that it would justify them limiting the feature to Series 9 and 10. However, reading on PAT (Peripheral arterial tone) and existing FDA-approved devices using that, they indeed use oxygen but not temperature. See for example "WatchPAT ONE" device.
  - dwighttk 2y ago
    Perhaps they aren’t worried about justification
swatcoder 2y ago
They absolutely could be segmenting features by generation even if they could introduce them into earlier products and it's pretty normal across the industry to do so, but "well, it seems to use the accelerometer" provides no evidence of that on its own. Without knowing more details about the implementation, it may rely on combining data from other sensors as well, it may need a certain frequency/resolution from a sensor that's not available in earlier generations of hardware, it might place too much demand on compute or power to maintain prior products' expected behavior, etc
- pdpi 2y ago
  > , it might place too much demand on compute or power to maintain prior products' expected behavior, etc Love it or hate it, this mentality of "the feature is technically possible but we won't enable it because we're not happy with the compromises it demands" is, by design, exactly the sort of logic that Apple is known for.
mikestew 2y ago
nothing really stops them from adding this feature to all Apple Watches… I’m confident there’s more to it than just sensor availability. Compute power for starters, as well as the fact that a Series 1 accelerometer may not have the necessary resolution, etc. Reserving it to Series 10 and 9 really exposes their lack of hardware innovation. Ah, the ol’ “Apple didn’t build what I want, ergo, Apple doesn’t innovate” trope.
- cromka 2y ago
  That's manipulative. I did not mention I expected anything in particular. If anything, your defensive narrative makes you come off as a fanboy.
a_vanderbilt 2y ago
Sure it probably comes down to sensor specs, but the same question can be asked about Apple Ingtelligence and the new iPhones. If the model is in a private cloud, why is it restricted to newer iPhones? Surely the preprocessing isn't so intensive that only the latest iPhones can do it. It's artificial segmentation in the interest of driving (historically weakening) sales.
- cromka 2y ago
  Yeah, I thought the same when they announced it. All in all, I feel that artificial segmentation is more frequent than ever and this can't be good indicator for their future growth, can it?
  - a_vanderbilt 2y ago
    It's definitely a sign of the decline of hardware innovation. It's not for lack of trying, however. Apple has experimented with Touch Bars, VR, and LIDAR cameras, largely to little effect. They just aren't disruptive enough. So how then do they segment if not hardware? Software. I think that growth is going to slow no matter what they do. Western and Japanese markets are saturated, and Chinese markets (once most promising) are bringing fierce competition both from local competition and the government.
- MBCook 2y ago
  It’s not all in a private cloud. Much is on device, and as we all know AI stuff loves CPU and RAM. They appear to have restricted it to 8 GB of RAM devices or more (when those appear). During The Talk Show interview at WWDC with John Gruber an Apple exec (Joz?) said they did it because of user experience issues, seeming implying speed. And given how hard AI hits hardware I think that’s relatively believable.
diebeforei485 2y ago
Probably requires the newer generation accelerometer. There are also other issues like power consumption overnight. Older watches have smaller batteries and slow charging. People will update the software, use the new features, and complain that Apple software updates are killing the battery (waking up to low battery plus slow charing means not being able to charge up before leaving for work). This has the effect of Apple only backporting new features if they don't consume too much battery.
bamboozled 2y ago
They're not adding it to the Ultra 1 either, what amazing advancements happened since the Ultra 1 to stop that from happening?

hartator 2y ago

Is it released or they are waiting for fda approval? Little unclear on macrumors.

peppertree 2y ago
Waiting for fda.

tootie 2y ago

I wouldn't put a ton of stock into this, but it could still be useful. The WatchPAT device is purpose-built for this test and includes a full fingertip oximeter and while it's FDA-approved, it's still not very accurate. It's also a notoriously tricky condition to diagnose and can't really be done just by looking at numbers. I think there's value in the test being accessible to so many more people, it will likely have a positive outcome on detection and treatment, but I would not expect you to push a button and get a confirmed diagnosis.

carlmr 2y ago
>can't really be done just by looking at numbers Depending on the numbers, why not? If it's sensor accuracy a single night might not be enough, but if it detects the condition averaging over a few weeks even unreliable measurements can be made more reliable (given they're just noisy).
- tootie 2y ago
  Not a doctor, but I was given a diagnosis of severe sleep apnea from an overnight in-lab study. Sought a second opinion who decided it wasn't sleep apnea at all. AHI or T-90 are convenient indicators, but pulmonologists will actually look at the shape of your graph and listen to symptoms. All humans are different and don't always conform to formulas. That being said, your observation that a nightly watch user can collect lots of data is an interesting one. If Apple (or whoever) can come up a more heuristic analysis than just computing AHI, they may end up with something better. Also, not that you asked, but my sleep situation is a bit complicated and I actually ended up with a CPAP anyway.
  - wkat4242 2y ago
    That's why a sleep study is not just done with a watch but with ECG, video, breathing band, finger SpO2 clip etc. I was like a cyborg going to the bathroom, so many wires and devices clipped to me :) it's unreasonable to expect a watch to do the same.

lysace 2y ago

The gatekeeping in the CPAP field is so insane. 1. Yes, we should regulate manufacturers intensely. 2. No, we shouldn't regulate to whom companies should be allowed to sell them. The defaults are good enough for most. Provide an easy to use control for max pressure and people will figure it out. Perhaps a knob? I claim: During the past decade, the risk of being maltreated by a personally set-up CPAP unit has been far, far smaller than the risk of not being treated at all. (Ways to access these menus have been been shared online for 10+ years, many use them.) I wonder how many premature deaths happen every year because of this - including secondary victims from traffic accidents. These things should be $500 mass-market consumer units that you pick up at Target, Walmart, etc.

a_vanderbilt 2y ago
The health industry as a whole is insane. I support the use of regulation and law where it ensures safety and efficacy but in the U.S. it's currently a patent and legal minefield. So much of it comes directly from special interests who want gatekeeping to keep out new/disruptive competition.
- smaudet 2y ago
  On the other side, as a consumer, I don't really want "new/disruptive competition" - I want stability and a legal guarantee my rights aren't being trod all over. Large companies e.g. Google/Apple are just inherently untrustworthy in this regards, smaller overseas ones are no better (little to no regulation). So please, no, stay the ** out of my health, thanks.
  - IOT_Apprentice 2y ago
    Google, Meta et al ARE FAR worse than anything might complain about Apple. Between the sleep apnea and hearing aid/hearing loss features you should be applauding these features to the world. As a consumer I have family members that will be leveraging these features immediately, including myself.
  - a_vanderbilt 2y ago

abtinf 2y ago

I’ve always wished I could put Apple Watch into a “constant oxygen monitor mode” for sleep. That seems to be the obvious way to assess sleep apnea. Anyone know why that isn’t the method?

a_vanderbilt 2y ago
If I had to venture a guess, maybe it's an industry regulation or power usage issue. Simply being able to assess sleep apnea isn't enough, it has to pass the regulatory burdens as well.
zwily 2y ago
They still don't have the regular oxygen monitor mode back yet because of a patent dispute. That might be part of it.
- tptacek 2y ago
  That's only in the US, right? (My flimsy understanding is that blood oxygen measurement is how at-home sleep studies work?)
  - jrockway 2y ago
    At-home sleep studies measure heart rate (maybe ekg, some probe is on your skin), blood oxygen, sound, and the direction of gravity relative to your testing device (to classify results by "back", "side", "prone", etc.) I did one of these and it was the worst night of sleep I ever had. It's somewhat invasive. Meanwhile, I sleep with my watch every night with no problems.
    - tptacek 2y ago
      Interesting. I keep meaning to get one done. Probes don't seem like that big a deal?
      - jrockway 2y ago

GaggiX 2y ago

The new Apple Watch 10 has an 18-hour battery life, so if you use it while you sleep, you won't have much left. I have no idea how some people can charge their smartwatch 1 or more times a day.

smelendez 2y ago
People probably use it principally as a fitness (and sleep?) tracker, and charge it while they work
- GaggiX 2y ago
  I mean it's still a watch so hopefully people are going to use it as a watch.
a_vanderbilt 2y ago
I find that integrating it into my routine made my current watch (SE1) battery a non-issue. I wear it starting in the morning, charge it on the way to work, and then to bed. Repeat ad infinitum. Battery usage at night is way lower in my experience, and it usually survives til morning or close to it.
jerlam 2y ago
I used to charge my watch every time I took a shower, which was every morning. Never had to think about battery life or charging the watch "out of band". But then again, it wasn't an Apple Watch.
xyzAbc_ 2y ago
It is a non-issue for me with the Apple Watch 9. It's charged super quick e.g. if the battery is low after waking up you can plug it in do your morning routine and pick it up. Vice versa in the evening before going to sleep. Also did some bike packing this year and charging it with a power bank was also not an issue. At one point my power bank was empty and my apple watch ran out of power as well - this has been the only time I whined for more battery life.
4fterd4rk 2y ago

runjake 2y ago

I'm not an qualified expert, but I spend a lot of time reading about and using this stuff and I'm extremely skeptical sleep apnea detection is very accurate without the pulse oximeter functionality. But gosh, I hope this is accurate across the Watch's wide user base. I wouldn't say it's likely, but I do wonder if the pulse oximeter is being used surreptitiously. In any case, if you could use the pulse oximeter, this functionality would immediately become much more powerful.

rootusrootus 2y ago
IIRC the pulse oximeter isn't all that useful for sleep apnea detection anyway, because on the watch it does not run continuously. Just takes measurements every X minutes. I think the oxygen level drop happens on a short enough timescale that you need the continuous monitoring to pick up on it.
- runjake 2y ago
  I think the pulse oximeter would be most helpful in concert with the accelerometer, as described in the article.
- TechDebtDevin 2y ago
  Watch Sp02 detection is usually at rather long intervals to conserve battery and typically have not resulted in any sort of detection of low 02 (in my experience, I have very bad sleep apnea)compared to a pretty dependable and accurate $30 on the finger oximeter.
- lathiat 2y ago
  The watch can ramp the detection up for periods of time if it chooses, such as when doing a workout. But also, people with sleep apnoea tend to have their O2 trend low not just go briefly low.
m463 2y ago
> sleep apnea detection I don't think it has to be as accurate as other things like blood glucose levels, because with those people might use the results to inject insulin. Detecting sleep apnea might be more like afib detection. It just tells someone they should be checked out.

jrockway 2y ago

This is a neat feature. I read Reddit and r/applewatch shows up in my feed a lot. 99% of the questions are "do I have sleep apnea?" At least the watch can give them my cut-n-paste response "you should talk to your doctor about a sleep study" now.

breck 2y ago

If you're interested in this, I'd recommend reading the 1870 [public domain] book "Shut Your Mouth and Save your Life". Internet Archive has it: https://archive.org/details/b28114450 https://archive.org/details/b28114450 Also look into "mouth taping".

VeejayRampay 2y ago
mouth taping is dangerous for many reasons, you should not be advocating it in a public forum
- breck 2y ago
  You are right, on the list of things that are dangerous, you would find mouth taping, probably right next to using a fork.
  - mikestew 2y ago
    You’re right, medical advice from the 1870s and TikTok videos, what could go wrong? But I did “look into ‘mouth taping’” as you suggested, and I’ll bet half the page titles were “Mouth-taping: is it safe?” or “…does it work?” At what point does Betteridge’s Law of Headlines[0] kick in? [0] https://en.wikipedia.org/wiki/Betteridge's_law_of_headlines https://en.wikipedia.org/wiki/Betteridge's_law_of_headlines
    - breck 2y ago
      > You’re right, medical advice from the 1870s and TikTok videos, what could go wrong? Have you read the book? Do you think I'd be recommending something that didn't have a very strong dataset backing it? > At what point does Betteridge’s Law of Headlines[0] kick in? Nothing is easier to manipulate than digital symbols. Thus, when talking about patterns one finds in digital symbols, one much be very very careful to build a trusthworthy dataset. Do you have a trusthworthy dataset on Betterridge's headlines?
      - 2y ago

pjohri 2y ago

I used a PAT device that showed mild apnea. I then used an at home sleep study that came back negative.

deleted 2y ago

[deleted]

eh_why_not 2y ago

>Undiagnosed sleep apnea affects more than 23.5 million people in the US alone, leading to $150B of wasted medical spend every year. What do they mean by "wasted medical spend" here? (1) Patients incorrectly spending money on a misdiagnosis, or (2) apnea solution providers not making money off people when they could?

brandonb 2y ago
(OP here) a third category: downstream complications of sleep apnea, primarily car crashes and heart attacks. Diagnosing and treating people with undiagnosed sleep apnea would prevent these entirely, which is obviously much healthier for the person and reduces medical cost for the entire system (including the patient themselves for co-pays, taxpayers for government costs, etc).
- eh_why_not 2y ago
  Thanks, I think it would be informative if you put this spelling out in the article. People like myself not immersed in health fields won't immediately know what you mean without it.
  - brandonb 2y ago
    Just updated the article to spell that out. Thanks for the feedback!

dave333 2y ago

Amazing that you can get much the same functionality in a off brand $30 watch these days - at least monitors sleep and blood oxygen - although it explicitly does not do medical diagnosis. Still every senior should have one for many reasons.

TechDebtDevin 2y ago
I have extremely severe sleep apnea with 60-100 events per minute, and baseline blood oxygen is low to start with because I live at altitude. I'm very into wearables and have tested most of the top SpO2 capable watches and none of them detect my sleep apnea outside a very rare detection of low O2.
- tmoertel 2y ago
  > 60-100 events per minute Do you mean per hour?
emporas 2y ago
Sleep apnea is very easily fixed. You have to increase blood pressure on the head by a lot, for a little bit of time each day, half an hour to an hour and it is 100% fixable. Additionaly increasing blood pressure on the head helps for sleeping more. I do that and sleep for an average of 10 hours a day. 12 hours or 14 hours/day of sleep for me, is not rare either. Also increasing the blood pressure on the head helps fix myopia 100%, like that woman astronaut who returned to earth and her eyes worked perfectly again.
- dave333 2y ago
  Raising the foot end of the bed eg with a few thick books under the mattress is supposed to give health benefits by stopping the blood pooling in the lower legs where DVT blood clots most likely occur. Wondering if it also benefits by increasing blood pressure in the head?
  - emporas 2y ago