Features of pulse plethysmography and a comparison with impedance plethysmography

The features of current pulse plethysmography are given. The skin capacitance and resistance are depending upon pulse duration but not the internal resistance. The internal resistance changes depend of arteries volume changes. A comparison between pulsed plethysmography and sine-wave plethysmography is discussed. The advantages of pulsed plethysmography like much lower current load through the tissue, higher sensitivity and less noise in the recorded signal versus impedance sine-wave plethysmography is pointed out.