Okay, first night with my S+.
First a couple thoughts, I have read around the net people complaining that ResMed has not integrated this with their CPAPs, at least allowing a connection to share the data. I think that will never happen. The CPAPs are medical devices and I expect there are a lot of regulations concerning reliability and accuracy. I am certain this is a "consumer" level device (at < $100) and it's accuracy is too unreliable to class as a medical device. Allowing the two to share data would certainly open ResMed up to legal complications if for no other reason that implied accuracy and reliability.
I have mild to moderate OSD and possibly mild restless legs... I have not received my CPAP machine yet, and so the following is purely opinion and is not based on comparing the S+ with my CPAP data for the same period, I will do that when the CPAP gets here.
1. REM sleep states shown are "doubtful", in my sleep study I had 1 all night - so, I am suspicious of this statistic. It might be that I had a good night last night maybe, and I will have to see how it compares to my CPAP data to be certain.
2. I don't understand why they swapped light and REM in order, probably from a consumer point of view light is before deep ? Anyway, the light sleep is what I would expect from my sleep study. Lots of short duration light sleep levels achieved.
3. Deep Sleep seems possible, probably right, I seem to recall on my original sleep study (a couple weeks ago) that I had 1 or 0 of them.
4. Waking events also seems at least in the ball park with 6. I believe it should be closer to 10 or so waking events and many more arousal events which this does not detect, but maybe I had a good night
5. 6 hours of sleep in a 8 hour period roughly seems about right.
I noticed that the device is VERY sensitive to movement, you can watch your "breathing" waveform in realtime on your phone or tablet. Moving will cause a lot of "noise" in wild fluctuations. Obviously they filter out most of the wild fluctuations to come to their conclusions. However that probably explains why they have a disclaimer that people with restless legs will see a reduction in accuracy. It also explains why they say you should not have pets in bed with you, since they will move around during the night and decrease the accuracy.
So, my first impression is that it does something. It is at least in the ball park for what I would expect my sleep pattern to look like. I will not know how accurate it is until I get my CPAP, and I may put together a quick and dirty DIY EEG to compare brain waves with it also.
Of course the one BIG advantage this has is that it is non-contact. No wires, no sound, it will not disturb your sleep, unless you are paranoid about having a low power RADAR system monitoring your every movement in bed and transmitting those movements to a company somewhere...
(I don't know if you can turn off the remote data uploading yet, and some people have complained that it burns through their limited data plans, so beware of that. It connects via wifi to the internet)
Oh, this is the screen shot from my iPAD. You also can go to their mysplus.com page and log in and see more charts, graphs and details about your data over days, weeks or months.
EDIT: Oh, forgot to mention, my wife was sharing the bed, and they say that will not interfere with the measurements. I watched for a while and her movements did not seem to impact the waveform at all.