A wrist-mounted activity and pulse recording system

A wrist movement and arterial pulse recording system has been developed for continuous data acquisition in studies of activity/rest time periods, sleep quantity and quality, general activity level, resting heart rate and circadian rhythms. The system employs a wrist-mounted optical sensor, low-power 8-bit single chip microcomputer and a compact flash memory. The microcomputer detects whether the wrist is moving or inactive; if it is moving, activity signals are recorded by the compact flash memory. If the wrist is at rest, the arterial pulse waveform is continuously recorded