Motor event frequency recording, actigraphy, is a technology useful in studies of sleep disorders, circadian function, activity patterns of adults and infants, and depressive disorders. Widespread utilization of this monitoring technology in health applications has been delayed by the lack of an affordable activity monitoring instrument and integrated system for data mangement, analysis and presentation. This proposal is for engineering design, construction of a prototypical Actigraph system suitable for us in offices and institutions. The system consists of a self-contained sensor, data storage unit, readout unit, operational test unit and system software. Sensitivity to activity will encompass the range from sleep to hyperkinesis with constant relative precision with minimal artifact from extracorporeal vibration. Analysis software will be prepared using a highly efficient, transportable language ("C"), that is compilable for MS-DOS, CP/M, and Apple microcomputer systems. Evaluation of Actigraphy for diagnostic, utility and therapeutic regimen management requires that a standardized data collection and analysis system be commercially available to diverse investigators. Actigraphy is a realizable technology that holds great promise for moving diagnostic and management activities into the natural environments of the patient in a manner that is both medically sound and consistent with cost containment goals.