AN ONLINE AUTOMATED SLEEP-WAKE CLASSIFICATION-SYSTEM FOR LABORATORY-ANIMALS

A computerized sleep-wake classification program is presented that is capable of classifying sleep-wake states on-line in four animals simul taneously. Every 10 s the classification algorithm assigns sleep-wake states on the basis of the power spectrum of an EEG signal and the sta ndard deviation of an EMG signal. The system was developed specificall y for long-term circadian rhythm experiments and can run uninterrupted for an unlimited period of time. To validate the system a total of 57 60 sleep-wake epochs from 4 rats was classified both visually and by c omputer. The results show a good agreement between visual and computer automated (kappa = 0.770) sleep-wake scoring. Therefore, the presente d sleep-wake classification system can be regarded as a reliable and t ime saving alternative for visual scoring in sleep research.