Instantaneous measurement of electrical parameters in palm during electrodermal activity

The determination of impedance is performed by means of frequency domain analysis or time domain analysis. The latter has an advantage of being able to measure instantaneously the whole frequency characteristics of impedance. The method is hence powerful to obtain biological impedance which changes with time. An instantaneous measuring method by using time domain analysis has been developed. Fast Fourier transformation of the initial response of a current applied to the skin can determine the palm impedance. This method can enable the determination of the parameters of the palm skin impedance during a galvanic skin reflex, which is impossible by means of frequency domain analysis