Sleep wake transition using relative spike amplitude

The transition between the wakefulness-sleep using Electroencephalogram (EEG) signal provides a quantitative indication of asynchronous development of sleep in cortical areas of brain. In order to characterize the transition between wake and sleep, several attempt have been made by neurophysiologists in coordination with bio medical research community. This work attempts to investigate the effect of time-domain attribute, relative spike amplitude on characterizing the first two sleep stages wake and sleep stage-1. EEG´s derived from polysomnography data are segmented into 1 second pattern and variable thresholding is introduced to understand the influence on the relative spike amplitude. The statistical analysis using Wilcoxon model was applied on each group to study whether observed difference is significant from variance obtained. From the simulation study, it was found that the RSA with 50% and 75% thresholding showed significant difference between wake and sleep stage 1 with p<;0.05. The results suggest that RSA can be used as a potential timedomain feature for recognizing the transition between wake and sleep.