Blink artifacts and power noise are constantly found:to strongly iufluence the acquisition and analysis of EEG signals.In this paper

by comparing the efficiencies of two ICA algorithms—Infomax-ICA and Extended-Infomax-ICA methods in extracting blink artifacts and power noise in the EEG signals

it was shown that ICA algorithms were insensitive to disturbance in the conditions of low signal-noise-ratio

and ICA algorithms demonstrated a strong robustness in processing non-stationary signals.Though blink slow waves could be extracted by infomax algorithm

but power noise was unlikely to be removed by it.Therefore

Extended-Infomax ICA algorithm should be used.By applying Extended-Infomax algorithms

blink artifacts and power noise contained in the 16-channel EEG signals of Alzheimer-disease patients were removed successfully(the lowest signal-noise-ratio for power noise can be -40dB).Meanwhile

it proved by calculating approximation entropy (ApEn) that ICA algorithms could preserve the nonlinear characteristics of EEG after removing the interference.