ECG Data Acquisition And Preprocessing System Based On Single Chip Micyoco

Heart disease has become one of the main diseases that harm the health of human beings. On statistics, cardiovascular disease is the major illness threatening human's life and the death rate of heart disease is still the highest in the world. Thus, the medicine circles all over the world always attach importance to diagnose and cure cardiovascular disease. It is an important and meaningful task to extract ECG precisely and provide auxiliary analytical measures for doctors. With the rapid development of electronic technology, medical electronic monitoring system gradually applied in the clinical diagnosis in recent years.Firstly, this thesis introduces the ECG detection circuit and gives ECG acquisition circuit, especially the specific design and some circuits. It adopts the linear photo-electricity coupling amplifier to segregate prepositional operation amplifier circuit from postpositional one, which depresses various kinds of interference effectively.Secondly, the research is mainly about AT89C52 Low Power MCU-based portable ECG monitor and its system. According to the ECG human characteristics, we design excellent ECG data acquisition system and select low-power 8-bit MCU AT89C52 and large-capacity flash memory of the ECG signal to record, analyze and process the ECG data. The monitoring system with LCD display can show ECG waveform. The keyboard is provided with the friendly Chinese menu, simple and convenient, and ECG data can be transmitted through the RS-232 interface to host computer. The monitoring equipment can do their work continuously, reliably and stably in the long term. In addition, it has other advantages, e.g. small in size, large storage capacity, low power consumption, easy to carry and use.Thirdly, more and more researchers find that the majority of cardiovascular diseases have close relationship to ECG ST segment changes. So this passage studies preprocessing methods: 4-point moving average filter, first order differential and second order differential. Bsaed on the second-order differential variable threshold detection method, the R wave of ECG waveform, a more accurate calculation of the value of HR can be detected. Designing characteristics of the ECG waveform on locating points, calibration points and determination of ST level migration, thus the real-time analysis of the ST segment can be realized. In addition, the use on the basic principles of adaptive coherent template of a real-time ECG signal interference and noise filtering achieves the desired results.Finally, the author points out some shortcomings about the system and gives more prospects to cardiac systems.