Fig. 4From: Classifying blinking and winking EOG signals using statistical analysis and LSTM algorithma EOG measurement of a non-intentional blink (NB) showing one peak. b First derivative (FD) of a non-intentional blink (NB) showing two tips of one minimum and one maximum. c Digitized first derivative (FD) of a non-intentional blink (NB) showing three clearly separated values + 1, −1 and zeroBack to article page