現今社會，由於醫療科技的進步，人口老化是無法避免的社會問題，因此醫療資源越來越珍貴。在衰老疾病研究中，大量的研究集中在心血管的健康上，而心臟是心血管疾病最重要的指標，因此相關研究報告持續被發表出來，這些研究報告若以信號擷取方式分類，包括了心電圖(Electrocardiography，ECG)、光體積變化描記圖法(Photoplethysmography，PPG)、心音圖(phonocardiography，PCG)、超音波等。

本論文提出使用三個壓電薄膜感測器(PVDF)設計一套使用三個端點的多重PVDF感測器心率量測系統，利用三個壓電薄膜感測器(PVDF)元件收集心音信號，並透過自行開發之三輸入放大電路板將信號放大並且使用Butterworth 低通濾波器及微分電路去除不必要雜訊後，再使用微分方程式及自動增益來同步多個心音信號，改善原始信號的信噪比(SNR)，平均可提升7.7dB，最後將三組資料整合後尋找每一個心跳的峰值，找出心跳峰值真正的位置，計算出平均心率，其準確度可達98.6%。

經過實驗結果可證實，藉由本論文所提出的方法，可以改善單一感測器因擺放位置不同而造成心跳訊號過小無法判斷的問題，並強化所需要的心跳信號且移除不必要的雜訊，更準確地偵測到每一個心跳信號，提高心率量測的準確度。

In today’s world, due to medical advancement, population aging is an inevitable social problem; therefore, medical resources become increasingly important. Among previous research on aging diseases, substantial research focuses on cardiovascular health since the heart is the most vital organ in the human body. Previous research is mainly classified by the signal extraction methods, including electrocardiography (ECG), photo plethysmography (PPG), phonocardiography (PCG), sonography, etc.

In this study, we propose to design a multi-sensor heart sound detection system with multiple piezoelectric film sensors (PVDF). Multiple sensor elements are utilized to collect heart sound signals while the differential equations and the automatic gain are applied to synchronize multiple heart sound signals. Besides, we improve the signal-to-noise ratio (SNR) by 7.7dB on average. In addition, our algorithm can accurately find the peak value of each heartbeat and calculate the correct heart rate, and thus the heart rate detection accuracy can reach 98.6%.

The experimental results prove that using multiple sensors can improve the heart signal detection. In addition, we enhance the heartbeat signal and remove unnecessary noise to detect each heartbeat signal accurately and better the accuracy of heart rate measurement.

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