Actigraphy

Actigraphy is a method that measures “non-invasively” gross body movements. It is based on a device (the actigraph) that is worn on the wrist and records arms, legs, and body movements. The device itself is based on one or more sensors working as accelerometers, recording accelerations in different directions (x, y, z as an example). The accelerations/movements are thus converted into electrical signals, sampled over a predetermined time and then analyzed in a computer.