Recording human activity is known as actigraphy and is important to the study of sleep disorders, exercising, atheletic performance, geriatrics, and other sciences related to human movement. An actigraph, or actimetry sensor, measures the movements made by the patient. The simplest actigraph is a pedometer, which counts the gross cyclic movement of the body. However, a pedometer doesn’t record when a movement occured, to what extent the movement was made, or the direction of the movement.
I have one of these devices and have just begun exploring its potential. I got it for a work application, but am thinking of all sorts of other applications. Quite sophisticated technology for a relatively low price.