2020 年 25 巻 1 号 p. 40-49
This paper clarified the basic characteristics of a new prototype of a sheet type piezoelectric sensor. And we discovered that the frequency characteristics of this sheet type piezoelectric sensor change depending on the input impedance of the connected preamplifier. Furthermore, we have proved that this sheet type piezoelectric sensor can actually measure heartbeat signals. We propose a new heartbeat signal measurement method with unconstrained using a sheet type piezoelectric sensor. In this new measurement method, two signals of the cardioballistic and the phonocardia are measured simultaneously by one sensor. It is expected to improve the problem that heartbeat signals cannot be measured due to the effects of ambient noise and body movement.