Design Of ECG Signal Acquisition And ST Segment Real-Time Analysis System

Heart disease has become the one of major disease, which does harm to human health. According to statistics, cardiovascular disease is the major disease of threatening human life. The death rate of heart disease still takes the first place around the world, so the diagnose and treatment for cardiovascular disease is paid much attention by the medical circle around the world. Accurately extracting ECG signal and providing effective method of auxiliary analyses is a very meaningful task. Along with quick development of electronics technique, Medical electron monitoring system has been applied to the clinical diagnosis in the recent years. Firstly, electro-cardio signal collective module, including ECG signal preamplifier, linear photo-electric coupler amplifier circuit, high-pass filter, second order Butterworth filter, 50 Hz double T trap filter with adjustable Q value, circuit with adjustable gain, A/D conversion circuit and etc, has been designed. Secondly, more and more researchers have found that the change of ST segment in Electrocardiogram has close relations to the majority of the cardiovascular disease, so electrocardiogram signal pretreatment methods, including 4 point averaging filter, slide averaging filter, first difference, second difference, have been designed; With this foundation, detection method based on the second difference variable threshold to detect R wave in electrocardiogram has been designed, and heart rate has been calculated accurately. The design of electrocardiogram analysis algorithm is to mark for the feature point of waveform, and measure ST segment level offset. Finally, Studying whole design scheme of the system primarily, this paper presents the model of host computer and slave system. The slave system is the core of handling and analyzing ECG data. The slave system sends the ECG data and results to the host computer by serial communication. Microcomputer, as the host computer, is programmed by Visual Basic. It displays the ECG wave and the analyzed and handled result and realizes the playback functions of ECG data. In this paper,The circuit designed have effectively restrained various disturbance and detected good ECG signal; Based on this, this paper has realized the recognition of ECG wave and the real-time calculation of heart rate and ST segment offset. The studies of this paper basically arrive at the demand of design and have established a good basis for the future development.