抑制心电信号中工频干扰的滤波采样系统设计

摘要

针对心电信号采集过程中易受工频信号干扰的问题,设计了一种高衰减倍数的滤波采样系统.以XC3SD3400A芯片为主控单元,陷波模块和滤波模块依次对心电信号滤波,采用16位AD7656采样滤波,并将数据缓存后通过通用串口总线(USB)传输至上位机处理.定性和定量分析结果表明:系统能够将工频噪声衰减300倍,且输出信噪比有较大的提升,具有噪声高衰减、有用信息低损失、高精度采样等优点.%Electrocardiogram(ECG)signals are vulnerable to interfere with power frequency signals,which has always been a problem in signal acquisition.Aiming at the above problem,design a sam-pling system with high attenuation.The system uses XC3SD3400A as core control-ler.The ECG signals are filtered through the notch and filtering modules,and are sampled and filtered with the 16-bit AD7656.The sampling data are cached,transmitted through the USB,and processed in the upper computer.Qualitative and quantitative analysis prove that with the designed system,the frequency signals are attenuated by 300 times,and the output signal to noise ratio(SNR)is greatly improved.To sum up,this system has the advantages of high noise attenuation,low useful information loss and high-precision sampling.