Wavelet packet energy entropy analysis of EEG signals evoked by acupuncture

To reveal the effects of acupuncture on brain activities, experiment is designed that electroencephalograph (EEG) signals are recorded under different brain states (before, during and after acupuncture at `Zusanli´ acupoint). The corresponding EEG signals are analyzed by the wavelet packet transform (WPT) and the wavelet packet energy entropy (WPEE). Rhythms of the EEG signals are extracted by using WPT and the relative WPEE reflects the energy distribution among rhythms during acupuncture. Effects of acupuncture on rhythms and order of brain activities are investigated by these methods. The results show that `Zusanli´ acupoint has selectivity of different functional regions and rhythms of the brain.