用于运动监护的心电模拟前端的设计

摘要

The symptoms of coronary heart disease and myocardial ischemia are more likely to appear in the ECG (electrocardiography) during sports,because of the increment of cardiac load.Hence,ECG under the state of motion is more truly reflecting the health status of the heart.In order to detect the ECG signal without using Ag/AgC1 electrodes and conductive gels,which are inconvenience during exercises,a special analog front end is developed.This ECG analog front end characterizes very high input impedance (100‖3GpF) and very low input bias current (70 pA).Additionally,it effectively suppresses the radio frequency interference,power line noise and EMG noise to obtain pure ECG signal.The ECG data is then transmitted through Bluetooth to Smart Phone for data analysis and display.Experimental results show that the front end is efficacious for sport cardiac monitoring,easy to wear and low power cost.%运动状态下,心脏的负荷增大,冠心病、心肌缺血等症状更容易在心电信号中表现出来,所以运动状态下测得的心电信号更能反映心脏的健康状况.设计了一种特殊结构的心电模拟前端,具有很高的输入阻抗(100GΩ‖]3pF)和极小的输入偏置电流(70pA),在不使用贴片电极和导电膏的条件下,实现运动过程中的心电信号采集.该模拟前端能够有效抑制射频干扰、工频干扰和肌电干扰,保证心电信号的质量.采集到的心电数据经蓝牙无线传输到智能手机上,实现心电波形的分析与显示.实验结果表明,该模拟前端具备体积小、佩戴方便、低功耗等优点,与智能手机结合方便地实现运动心电监护的功能.