The recorded EOG data were first preprocessed to extract
0.53-15 Hz signals using finite impulse response (FIR)
filter. Secondly, we extracted the EOG segment of 800ms
from the time that the fixation cross was appeared on the
screen, and EOG segment of 800ms during resting state
through visual inspection. In addition, we removed the segments
that have obvious artifacts through visual inspection.
In this study, we employed three features of eye blink signals.
One is the vertical peak amplitude of EOG signals,
another is the horizontal peak amplitude of EOG signals
and the other is maximum cross correlation between vertical
EOG signals and the template signal of DOUBLE blink
prepared preliminary