Comparison of the EEG between before and during sleeping by the RCE analysis

It is crucial to practically estimate the dozing like the driver dozing, because many people cannot have enough sleeping caused by irregular hour and much stress. In the conventional study, the electroencephalogram (EEG) has been a promising indicator to driver dozing. Furthermore, it is known that frequency of the EEG is highly related to the sleep and the wake conditions. Therefore, we propose to extract frequency components of the EEG from the whole cerebral cortex, by using the rhythmic component extraction (RCE), proposed by Tanaka et al. RCE extracts a component by combining multi-channel signals with weights that are optimally sought for such that the extracted component maximally contains the power in the frequency range of interest and suppresses that in unnecessary frequencies. We found difference between the features obtained by RCE in the sleep and in the wake conditions. This implies that this method is available for analyzing the sleeping.