This invention reveals a heart pulse detector includes a light emitting diode for emitting a short pulse light toward body tissue and a photo sensor for receiving light signal modulated by blood pulse flow through body tissue. The output current of photo sensor is charging a capacitor during pulse light and is discharging the same capacitor during no pulse light for same period of pulse light. The ambient light signal is then cancelled out from the detected light signal. The light current signal is transferred to a voltage signal after sample and hold procession. Finally heart pulse signal is detected out from the voltage signal without the interference of ambient light.本發明提出一種脈搏感測器,包括一個發光二極體供發射短期脈衝光至人體組織,一個光偵測器供接收流過人體組織之血液脈動所調變之光訊號。光偵測器之輸出電流於脈衝光發射時充電於一個電容器,並在脈衝光相同週期之無脈衝光時間內自同一電容器放電。週邊光訊號於是自感測之光訊號被抵消。光電流訊號於取樣及保持程序後被換成電壓訊號。最後,脈搏訊號自電壓訊號測出而無週邊光線之干擾。10...脈搏感測器11...電源調節器12...時脈產生器13...LED驅動器14...光發射及偵測器15...訊號感測器16...訊號放大器17...低通濾波器18...脈衝感測器20...固定電壓源33...光訊號68...感測到之訊號、電壓訊號69...放大訊號70...濾波後之訊號71...脈搏訊號
