Whoop does sleep tracking, measuring the amount of time you sleep and trying to put a "score" to what that means for your health essentially computing based on time asleep and HRV.

Affectable isn't only measuring. We actively alter your brain activity in real time which increases the restorative function of sleep. You don't sleep longer, it's not about falling asleep faster. Research has shown a 14% increase in HRV during stimulation, we've had 3 positive alzheimer's studies (1 - MCI, 1 - removal of Amyloid, 1 - increasing deep sleep in people with ALZ).

Does that make sense?