Computer evaluation of sleep.

Night sleep registrations were carried out using a portable 4-channel tape recorder (Medilog 4-24 recorder). The evaluation of the sleep stages was done by a computer analysis. One channel was used for EMG, 1 for EOG and 2 channels for EEG. For the analysis of the particular sleep stages the criteria of the Florida modification of the classification of Dement and Kleitman were applied. The computer analysis was based on the estimation of the power spectrum of the 2 EEG channels and the number of REM in the EOG. Automatic artifact detections were fit into the computer program and the individual differences of the EEG of the sleep recordings were taken into consideration.