The study seems small. Really small. 125ish nights worth of data?. The results came back very comparable from all devices. It's almost like when someone falls

The study seems small. Really small. 125ish nights worth of data?. The results came back very comparable from all devices. It's almost like when someone falls asleep it's pretty obvious. I wish this study did a few things, like get more into depth on the sleep cycle. I own an oura 2. I perused the study, but didn't read it word for word start to finish, so I missed whether it was an oura 1, 2 or 3. How accurate can these devices tell what stage of sleep the body is in? That's a more relevant question for 2023