[Long term recording of motor activity: its use in research and clinical situations]

A method is described for long-term recording of motor activity with a wrist-worn solid-state activity monitor. Movement-induced signals are integrated over predetermined periods (usually 7.5 min) and stored in the memory (1024 8-bit words) of the device. At 5-day intervals the data are transferred into a minicomputer and plotted in graph form. The technique may be used for studying the rest activity cycle and motor activity during sleep under normal life conditions. Sleep disorders and pharmacological effects on sleep can be objectified from the activity plots. Various applications in clinical medicine and in research are illustrated and discussed.