摘要:心臟，在人體的血液循環(huán)系統(tǒng)中起著核心作用，是重要的動力器官。它承擔著血液運輸?shù)墓δ堋Ｈ欢S著生活節(jié)奏的日益加快，過重的壓力，不健康的生活、飲食習慣等都給心臟帶來了負荷。據(jù)了解，心血管疾病嚴重地威脅了人們的生命，對此類疾病的防治已成為醫(yī)學上的重、難點問題。因而能夠準確獲取和即時檢測人體的心電信號具有重要的意義。便攜式心電儀就是一種方便人們隨身攜帶，有助于提早對心血管疾病做出預警的電子設(shè)備。

　　　心電信號頻率極低，一般在0.05~100Hz之間。同時它的微弱性使得其十分容易受到其他信號的干擾。心電信號幅度大約為10μV~5mV。在對采集到的心電信號進行放大之后，需要將低通和高通濾波器串聯(lián)起來組成帶通濾波器，接著對干擾信號進行濾除，同時使用陷波器對50Hz的工頻干擾作進一步濾除，從而得到失真度小且高質(zhì)量的心電信號。最后利用帶有A/D轉(zhuǎn)換功能的STC系列51單片機將最終結(jié)果顯示在液晶屏上。

　　　本論文針對人體心電信號的特點，設(shè)計了一種簡易實用、性能穩(wěn)定的便攜式心電儀。無論是在室內(nèi)還是戶外都能夠?qū)π碾娦盘栠M行實時監(jiān)測，應用前景相當廣闊。

關(guān)鍵詞 心電信號；便攜式；心電儀；STC12C5410AD

Abstract:The heart, in the body's blood circulation system, is an important power organ which plays a central role. It assumes the function of blood transportation. However, with the accelerated pace of life, too much stress, unhealthy life, eating habits brought heart load. Learned, cardiovascular diseases seriously threaten the lives of people. To prevent and control this kind of disease has become a heavy and difficult problem in medical. Thus obtaining the accurate and real-time detection of the human body has the vital significance of ECG signals. Portable heart is one kind of device which can be portable and help warn cardiovascular disease early. 

　　　The frequency of ECG signal is very small, generally between 0.05 ~ 100 Hz. The weakness of the signal at the same time makes it very vulnerable to the interference of other signals. Amplitude of ECG signal is approximately 10μV ~ 5 mV. After amplifying the collected ECG signal, we need to group a low-pass and high-pass filter together. They form a band-pass filter, and then it begins to filter the interference signal. At the same time, we use the trap on the interference of 50 Hz frequency for further filtering. Thus pure and high quality of the ECG signal is obtained. Finally we use the function of A/D conversion on STC12C5410AD. Then the result will display on the LCD screen. 

　  According to the characteristics of human’s ECG signal, this paper designs a simple and practical, reliable, portable heart instrument. In the indoor and outdoor place we can monitor ECG signal all the times. It has a certain development prospects.

Keywords   ECG signal   portable   electrocardiogram equipment   STC12C5410AD

　　　本論文基于51單片機，設(shè)計了一款簡易的便攜式心電儀。根據(jù)心電信號的特點，設(shè)定了一系列的放大濾波電路，包括前置放大電路、后級放大、帶通濾波和帯阻濾波。在查閱了大量的資料之后，弄清了硬件設(shè)計的原理，終于完成了硬件的制作。

　　　經(jīng)過多次調(diào)試，基本能夠顯示出穩(wěn)定的心電圖波形。在器件的選擇上，盡量保證較高的性價比，保證波形盡可能的不失真。此次單片機的選擇上也頗有創(chuàng)新，選擇了一款帶有AD轉(zhuǎn)換功能的單片機，實現(xiàn)了系統(tǒng)最小化，便捷化。

當然設(shè)計還有相當多的不足之處。所設(shè)計的心電儀原定有報警裝置，即當心率超過一定正常值時，系統(tǒng)將發(fā)出報警。多次嘗試失敗后，在控制電路板上焊上了一個LED指示燈，用來指示心跳的頻率，根據(jù)輸出信號的大小呈現(xiàn)明暗閃爍。最終設(shè)計的成品只實現(xiàn)了顯示人體心跳的波形圖，當有信號時，呈現(xiàn)心跳式的抖動，無信號輸入則呈現(xiàn)滿格狀態(tài)。