It contains an accelerometer that records your wrist movement. Known as actigraphy, this wrist movement data is used to estimate when you fall asleep and when you wake. For example, if our algorithms detect little movement over a period of time, that period will be recorded as sleep.
Actigraphy is a common and practical method for measuring sleep. And, while proven to be accurate, it’s imperfect. In fact, a clinical comparison of ReadiBand sleep detection versus that from a sleep lab indicated that the ReadiBand has an accuracy rate of 92%. However, since it’s hard to differentiate lying quietly in bed from lying in bed asleep, the algorithm may occasionally overestimate your sleep time.