7 ms·

> Wrist watches can't really detect sleep stages. As someone else noted, the paper you linked to is from 2015. Apple Watch couldn't do it until watchOS 9 (2022

> Wrist watches can't really detect sleep stages. As someone else noted, the paper you linked to is from 2015. Apple Watch couldn't do it until watchOS 9 (2022, 7 years later), but can now do this pretty reliably. You might find the "Algorithm Development and Validation" section of this whitepaper interesting: https://www.apple.com/healthcare/docs/site/Estimating_Sleep_Stages_from_Apple_Watch_Sept_2023.pdf https://www.apple.com/healthcare/docs/site/Estimating_Sleep_...

pkoird 3y ago
Thanks for linking this. I always did wonder how they did it. From a cursory read, it looks like the basic approach is to collect accelerometer data and train it to predict ground truth labels generated via a consumer EEG device. Not sure if each epochs (30s) were considered iids. I'd assume that the overall sequence of activity would be much more informative than a single 30s activity considered independently.
- cj 3y ago
  Sometimes at work I’m concentrating so hard my Apple Watch logs a sleep session… Definitely not 100% accurate but as someone who checks their sleep log (and time in each stage using the Pillow app) daily, it seems pretty accurate and I can correlate how I feel on a given day back to that day’s sleep report with pretty good correlation. Definitely not perfect but better than nothing. If you’ve ever been on medication that suppresses REM sleep, Apple Watch detects REM rebound very clearly.
  - pkoird 3y ago
    I won't be surprised. The accelerometers seem to be pretty sensitive. Enough to measure any variations in heart rates and breathing patterns which are likely highly correlated with sleep patterns.
  - astrange 3y ago
    I didn't think it tracked sleep unless you put it into Sleep mode explicitly.
    - fingerlocks 3y ago
      Yeah likewise. If I fall asleep during normal wake hours, such as an unexpected nap, it will vibrate and remind me to stand up because I’ve been inactive for too long.
      - euroderf 3y ago
        There should be a toggle for this.
        fingerlocks 3y ago
        There is. But it’s easy to forget because it’s an unexpected nap
genewitch 3y ago
i have purchased 2 amazfits and they work fine for sleep records, they use the zepp app. I've had 2 other watches that had sleep tracking, but the amazfit seems better, then again, it is much newer.

pkoird 3y ago

Thanks for linking this. I always did wonder how they did it. From a cursory read, it looks like the basic approach is to collect accelerometer data and train it to predict ground truth labels generated via a consumer EEG device. Not sure if each epochs (30s) were considered iids. I'd assume that the overall sequence of activity would be much more informative than a single 30s activity considered independently.

cj 3y ago
Sometimes at work I’m concentrating so hard my Apple Watch logs a sleep session… Definitely not 100% accurate but as someone who checks their sleep log (and time in each stage using the Pillow app) daily, it seems pretty accurate and I can correlate how I feel on a given day back to that day’s sleep report with pretty good correlation. Definitely not perfect but better than nothing. If you’ve ever been on medication that suppresses REM sleep, Apple Watch detects REM rebound very clearly.
- pkoird 3y ago
  I won't be surprised. The accelerometers seem to be pretty sensitive. Enough to measure any variations in heart rates and breathing patterns which are likely highly correlated with sleep patterns.
- astrange 3y ago
  I didn't think it tracked sleep unless you put it into Sleep mode explicitly.
  - fingerlocks 3y ago
    Yeah likewise. If I fall asleep during normal wake hours, such as an unexpected nap, it will vibrate and remind me to stand up because I’ve been inactive for too long.
    - euroderf 3y ago
      There should be a toggle for this.
      - fingerlocks 3y ago
        There is. But it’s easy to forget because it’s an unexpected nap

genewitch 3y ago

i have purchased 2 amazfits and they work fine for sleep records, they use the zepp app. I've had 2 other watches that had sleep tracking, but the amazfit seems better, then again, it is much newer.