Single channel analysis of sleep EEG: An adaptive database method

An automatic procedure for the spectral analysis of an all-night sleep electroencephalogram (EEG) is presented. This method relies on a fixed database initializing a procedure which adapts parameters so that they match to the signal to be analyzed. Parameters coming from database are normalized power spectra in predefined frequency bands. The novelty of our approach is to use flexible sleep stage patterns rather than fixed ones, these patterns being iteratively updated (thanks to a short/long term analysis) in order to cope with the EEG variability. The main part of the procedure, performed on-line, is followed by a very short off-line processing yielding a real time implementation. The procedure adaptation ability is shown on detection of Rapid Eyes Movement (REM) events, the latter being well known for their inter as well as for their intra individual extreme variability.