How does a sensor detect the levels of sleep and rapid eyes movement? How does it detect the levels of stresses?
How does a sensor detect the levels of sleep and rapid eyes movement? How does it detect the levels of stresses?
I think it finds out sleep phases using heart rate and movement detection. The level of stress is determined using heart rate variability (HRV), and it seems to be working well.
It can't detect REM. Just as all other manufacturers that track sleep, it's "guessing" what stage of sleep you're in using averages based on sleep studies.