| 摘要: | 臨床上，心衰竭病人的心輸出能力，相較於正常人而言更加「力不從心」。若要及早發現心輸出能力的缺陷，監測心輸出量（Cardiac Output, CO）是勢在必行，但是市面上較為精密的醫療監測儀器，皆有體積龐大、價格昂貴的缺點，且侵入式量測亦有感染風險，即使如心臟超音波（Echocardiography）[1]、都普勒心臟排血量監測（Doppler Echocardiography, DE）[2]等非侵入式量測技術，也都需要具備專業知識人員才能操作。
因此，本研究將開發一套攜帶式且非侵入式的心電聽診系統，將臨床上的聽診器數位化，同時整合心電圖（Electrocardiogram, ECG）[3]及心音圖（Phonocardiogram, PCG）[4]量測的功能於數位聽診器上，分別透過單導程心電圖收取心電訊號、電容式麥克風收取心音訊號，經由類比電路上的濾波器處理後，於兩組類比數位轉換器（A-D Converter, ADC）取樣並編碼後，將轉換後的訊號傳輸至微控制器（Microcontroller, MCU）。將資料儲存於本地端microSD卡的同時，由低功耗藍芽（Bluetooth Low-Energy, BLE）無線傳輸技術輸出資料至手機APP端即時顯示。最後，可透過心電圖的特徵R波，對齊心音圖的特徵第一心音S1，將兩訊號做時間序列上的同步，計算兩者的時間差，獲得射血前期（Pre-Ejection Period, PEP）和左心室射血時間（Left Ventricular Ejection Time, LVET）[5]等心輸出量指標。更重要的是，此裝置同時配有肺音、廔管音的量測功能，能夠全面性的監測心臟輸出能力、血流動力和肺臟的相關生理機能。
本系統不僅為非侵入式的量測方式，除了具有低成本、體積小、易攜帶和易操作的優點，且於臨床上也能提供更多初步診斷的依據，更重要的是能夠有利於個人居家監測的普及化。
;Compare to healthy ones, patients with Heart Failure (HF) have more awful ability on Cardiac Output. If we want to discover the problem at early age, monitoring cardiac output is an imperative work. Nevertheless, the medical devices those which could monitor precisely have some inevitable problems. No matter using invasive or non-invasive monitor techniques, both of them will face some challenges.
This study will develop a wearable and non-invasive Electrocardiac-Stethoscope System. By using a digital stethoscope, we measure the single lead ECG signal and PCG signal with capacitive microphone. After filtering, sampling and encoding the both signal through A-D Converter (ADC), the signals are transmitted to microcontroller (MCU). Then, the signal will simultaneously save in microSD card and transmit to APP on smartphone by Bluetooth Low-Energy (BLE) wireless technique. At the end, align S1 peak with R-peak for synchronizing the time series. By calculating time delay between peaks, we will get two important parameter for cardiac output, Pre-Ejection Period (PEP) and Left Ventricular Time (LVET). What’s more, the device can measure lung sound, vascular sound as well, which is able to monitor cardiac and pulmonary function.
The system has not only utilize a non-invasive method, but is also low-cost, small size and wearable. It will also provide lots of merits clinically and personally. |
