Automatic REM detection: modifications on an existing system and preliminary normative data.

This paper describes hardware changes and additions to a previously reported sleep rapid eye movement (REM) automatic detection system. Specifically, it describes the design philosophy of a new and optimum analogue bandpass prefilter, new detection criteria based on a detailed study of the waveform distortion due to AC coupling and bandpass prefiltering and the implementation of an artifact detection system for a more accurate detection of seemingly REM-related electro-oculographic (EOG) waveforms. Preliminary normative data on phasic REM patterns from young adults, detected by the described system, are also presented.