A Microcomputer System for the Measurement of Avian Heart Rate

A system is described for measuring changes in avian heart rate in response to auditory stimuli using an Apple II microcomputer. Heart beat signals and auditory stimuli are filtered and then recorded on a stereo cassette tape. These recorded signals are subsequently processed by computer interface hardware. The physiological signal passes through a simple feature detection circuit designed to discriminate between heart beats and physiological 'noise', while the auditory signal is shaped and passed through a Schmitt trigger and one-shot. Software programs then count heart beats for specified periods, and specially label counts obtained during auditory stimulus periods for later analysis.