Fig. 1

Upper figure (1-a); A schema of the BP pulsation and time course. The ordinate represents pressure in mmHg, and the abscissa represents time course. t: the interval for one pulse.

Middle figure (1-b); A schema of the photoplethysmographic pulsation and time course. The ordinate represents transmitted light signals, and the abscissa represents time course. t: the interval for one pulse.

Lower figure (1-c); A probe applied to the tissue, which was composed of a clipping applier like as a forceps for a finger or an earlobe, a red photo-emitter (644 nm) and a photo-receiver. A: finger or earlobe, B: light emitting diode, C: photodiode, D: A probe to clip the tissue.