摘 要：心电图是反映心脏内兴奋产生、传导和恢复过程中的电位变化的综合波形。它不仅与单个心肌细胞动作电位的曲线有明显的不同，而且因测量的电极放置的位置和连接方式的不同而有所差异。传统的心电监测仪价格昂贵，体积庞大，不便于移动且主要集中在大医院而无法实时监测患者的病情。未来的心电监测系统会具有成本低、体积小、可靠性高、操作简单等优点，并且会继续向全信息、固态记录、多导联同步采集等方向发展。本心电监测系统以AT89C51单片机为核心，把采集到心电信号进行处理，经过放大滤波整形电路后，由ADC0808转化成数字信号，通过显示电路让经过单片机处理的信号显示在液晶屏上。通过仿真实验能实现本系统对人体的心电监测，并将心电图实时的在液晶屏上显示出来。基于单片机的心电监测系统可以方便快捷的进行心电监测，消除患者不安的心理状态以及心理压力，有利于提前预防和及早诊断部分心脏病。78180

毕业论文关键词： AT89C51；ADC0808；A/D转换电路

Abstract: Electrocardiogram(ECG) is a comprehensive waveform that reflects the variation of electric potentials, which happen during the process of the occurrence, transference and recovery of stimulation in heart。 It not only differs from the curve of action potential of single myocardial cell, but the results will be variety, which contributed by the different positions or the connection type of electrodes。 The traditional electrocardioscanner is quite expensive, huge volume, not easy to move and can not monitor the patients’ circumstances in time on account of being mainly located in big hospitals。 The ECG monitoring system in future would be low cost, small volume, more reliable, easy to control and so on。  Also, it is supposed to develop in various aspects, such as perfect information, solid state, multi lead synchronization acquisition and so forth。 This ECG monitoring system is based on AT89C51,  which handles the gathered signals, and then it transforms the signals into digital ones  through ADC0808。 Finally, the processed signals would be displayed on LCD。 The design can successfully realize the ECG monitoring of people through simulation experiment, and  displayed the diagrams on LCD。 The ECG monitoring system would do ECG monitoring conveniently, which plays an significant role in erasing the nervous minds of patients。 Last but not least, it is in favor of preventing and diagnosing some kinds of cardiopathy。

Keywords: AT89C51; ADC0808; LCD display; A/D conversion circuit

目   录

1 绪论 4

1。1 课题的研究背景和意义 4

1。2 心电监测系统的发展现状 4

2 心电监测系统的设计 5

2。1 心电监测系统的设计方案 5

2。2 心电监测系统的设计方案对比 5

2。3 系统设计的方案实施 6

3 系统硬件电路设计 7

3。1 心电信号采集电路的设计 7

3。2 前置放大电路的设计 8

3。3 补偿电路的设计 9

3。4 滤波电路的设计 10

3。5 主放大电路的设计 12

3。6 同相加法器电路的设计 12

3。7 ADC0808转换电路的设计