Current studies into sleep disorders involve the simultaneous measurement of a combination of physical parameters. These include EEG, EMG, heart rate, core temperature, and brain temperature. CPB (Clinical Psycho- Biology) is presently investigating sleep disorders using animal models. Rats display sleep behavior similar to humans and are used in this investigation. A signal interface system has been designed which processes thermistor inputs as well as RF transmitted temperature signals. A microcomputer is used to linearize and calibrate the temperature signals. With the use of factory calibrated thermistors, the software converts the measured signals directly into degrees Centigrade for storage and display. Two Metrabyte A/D cards are run in background mode to acquire 16 channels of 'fast' signals (EEG's, EMG's etc.) and 16 channels of 'slow' signals (temperature and heart rate) . We use the timers on the Metrabyte cards to synchronize the two cards and yet still operate them at different sampling rates.
