Actigraphy is a technique that uses activity data collected by an accelerometer to assess the quality of sleep. While commercial wrist actigraphic devices are useful, a detailed methodology for the derivation of sleep parameters is usually lacking. In order to better understand and explain the strengths and weaknesses of these devices and the technical factors that underlie them, we reverse-engineered the algorithms for two widely used actigraph devices. As a result, we found that a handy and common accelerometer is able to derive the sleep parameters consistent with the actigraphy devices.
Learn about actigraphy's advantages/disadvantages over other sleep assessment methods, clinically-relevant actigraphic measures, history, clinical indications (specifically focused on sleep medicine), and limitations.
We reverse-engineered the algorithm for the Philips Actiwatch 2 and found that an affordable, consumer wearable such as Vivosmart 4 can reproduce the results from a more expensive, medical-grade actigraphic device.