用于去除心电信号工频干扰的多阶自适应滤波器阶数确定策略研究

工频干扰是微弱生物信号采集过程的常见噪音源之一,特别会造成像心电之类信号的信噪比的显著下降.自适应滤波技术对于去除心电信号工频干扰噪音有着显著的效果,但自适应滤波技术中的自适应滤波器阶数确定是关键问题.本文提出了多阶自适应滤波器中适于去除心电信号的阶数选择策略.在以单路正弦波为模拟工频干扰信号源进行实验中,根据提出的阶数选择策略,确定5阶自适应滤波器对心电信号的工频干扰有着明显的抑制效果.同时,实验还证明,与自适应滤波器中的对消器相比,策略所确定的5阶自适应滤波器具有更快的收敛速度,并且还能在工频波动处取得更好的处理增益.

Order selection strategy in multiple adaptive filter for power line interference elimination in ECG signals

Power line interference is one of ordinary noise sources along with biological signal collecting procedure. It leads to the dramatic decline of SNR in the biological signal, like ECG （Electrocardiogram）. Adaptive filter is effective in the suppression the power line interference in ECG signals, but it is an essential problem to select proper order of the adaptive filter to get the best filtering result. We came up with the method to select proper order through using single sine wave as the reference sig- nal in the adaptive filter and it turned out that the fifth-order was effective to suppress the power line interference in the ECG signal. Through the experiment we concluded that comparing with the self-interference canceller the fifth-order adaptive filter has the faster convergence speed, wider effective bandwidth and higher processing gain.