To improve an S/N without lowering a positioning resolution, and to reduce the effect of strain of a sensor signal.
In the pulse wave measuring device, a sensor element directly above the artery is determined from the pulse wave measured by a pulse pressure wave sensor composed of a plurality of arranged fine sensor elements. A noise amplitude and a pulse wave amplitude are measured (S201 and 203) by the output signal from the sensor element. And, the present S/N is calculated from the measured result, and difference from or ratio to the necessary S/N is let to a noise reduction target quantity (S205 and 207). And, the output signal from the sensor element is added by calculating a summation number of the sensor elements necessary for reducing a noise by a amount of the target quantity (S211), utilizing the fact that the noise becomes 1/√n by averaging n sensor signals.
Toshio Morita
Yoshihei Nakamura
Yutaka Horii
Hisato Noda
Masayuki Sakai