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by hh3k0 1944 days ago
There's a device with app which can reliably determine if you are in REM: https://dreem.com/.

I have sleep apnea and bought it in order to keep track of the quality of my sleep.

3 comments

I'd be interested in hearing about your experience with Dreem. We're building a similar product at https://soundmind.co

Though Apnea is not in our initial target group, we'll be looking into ways we can resolve apnea in the future. I have central apnea (brain stops breathing).

Do you continue to use your Dreem? How does knowing the "quality of your sleep" help you? We're more interested in improving the quality of your sleep than in just giving you the data.

Details are in my profile if you feel like reaching out.

But it doesn't send a signal so I don't think it will help the poster.

Tracking REM sleep seems to be fairly easy. My Xiaomi wristband seems to reliably detect when I go into REM, even though the device is very cheap.

Out of curiosity : how do you know it reliably detects it?

I have a polar watch that also tracks my sleep and presents it in a nice plot. I have no way to check whether that plot is a good representation of my night, or whether they just randomly put in a few blocks and mark them as REM.

I don't mean to imply that I don't trust the device or anything. I'm just saying I have no way to verify how reliable it really is.

Because every time I wake up after having a dream, I see it being properly registered. Conversely, if I wake up without having dreamt right before waking, then I see that the device didn't register REM.
> I don't mean to imply that I don't trust the device or anything. I'm just saying I have no way to verify how reliable it really is.

Dreem 2, for example, has a few studies to back it up:

> The aim of this study was to assess the signal acquisition and the performance of the automatic sleep staging algorithms of a reduced-montage dry-electroencephalographic (EEG) device (Dreem headband, DH) compared to the gold-standard polysomnography (PSG) scored by five sleep experts.

And the relevant results:

> The algorithm achieved an overall accuracy comparable to human-level performance of 85.76% (N1: 56%, N2: 88%, N3: 85%, REM: 92%, and Wake: 85%).

https://academic.oup.com/sleep/article/43/11/zsaa097/5841249

I am less skeptical about an EEG-based device like the Dreem than I am about a wristband.

Most wristbands have a heart rate monitor and an accelerometer. Is there a pattern in the heart rate that shows REM sleep versus deep or light sleep? Or do they use the accelerometer to detect twitches you make during REM sleep? How do they discriminate that from my cat jumping onto the bed?

Compare that to EEG-based devices : I think it is well known that sleep phases can be read in an EEG. The Dreem has fewer channels than a medical EEG, and maybe a little less accuracy, but that is beside the point : it is measuring the relevant signals for sleep phase detection.

I've worked on detecting sleep stages from accelerometer data and it should work in theory (loss of muscle tone) but it doesn't in practice (still there are muscle twitches).

You need more modalities like heart rate, and a very sensitive heart rate monitor (the one in my Xiaomi/Amazfit is nowhere near the quality needed).

On the other hand, you can make quite good guesses based on the recurring pattern of REM sleep (in healthy subjects). Because REM sleep is quite prevalent in the later stages, your accuracy when guessing will be quite high.

What do you do with the data? After knowing the quality, how do you improve it?
I can try to make lifestyle changes and see how it impacts my sleep, for example.

Additionally, I can also quite reliably see when my CPAP needs adjusting by my doctor.

The Dreem 2 has two functions I'm rather fond of:

1) It can wake you up in light sleep within a specific timeframe you've set. That made me less groggy and grumpy in the mornings.

2) It can generate pink noise which is said to enhance the quality of your deep sleep (there are a handful of studies about it).

Both features work well for me but I think the pink noise function is not available in the US for some FDA-related terminology reason.

I find pink noise relaxing when working.