Heartbeat interval monitoring by PZT/PZT flexible piezoelectric film sensor

摘要

Sol-gel composite flexible piezoelectric sensors was attempt for heartbeat interval monitoring because of flexibility, relatively low dielectric constant and less ringing effect. Lead zirconate titanate (PZT)/PZT was chosen as piezoelectric film because of high piezoelectricity and high dielectric constant, respectively. 150 μrn thick PZT/PZT films were fabricated onto 200, 500 and 1,000 μrn thick stainless steel substrate. The sensors were fixed around the human wrist by a commercial sport-type watch wristband. Voltage change caused by pulse was monitored and it was recorded by an oscilloscope. Electrocardiogram (ECG) measurement was also carried out simultaneously for validation purpose and in the best case, the maximum heartbeat interval difference between piezoelectric film sensor results and ECG was 0.003 s and it could be useful for heartbeat interval fluctuation monitoring.