I don't see how you are going to develop a worthwhile device without wearable hardware. Sure, there are a few metrics you can monitor without, but this limits you to few options. I wear a C-PAP device. It monitors usage time, mask seal, events per hour, and humidifier, mask on/off and then gives you a score from 1 to 100. That's not much, and that's with a mask. When you go for a sleep study, the technicians place stick-on sensors on many locations on your body. The technology may have become more refined since i last had a sleep study, but i'm thinking that the sensors stuck to your body may be a necessity for this sort of thing. Here is a link to the Resmed site that my machine reports to. There's more info there. Good luck. https://www.resmed.com/us/en/index.html
