滤除ECG中肌电和宽频率范围工频干扰的小波算法

目的 设计小波去除噪声方法消除心电内肌电和宽频率范围的工频干扰。方法 根据QRS波群含有的最高频率成分较高，T波和P波含有的最高频率成分较低的特性，选取双正交小波将原始信号分解，将各尺度上系数重新组合，然后再重构，得到消噪后的心电。结果 受肌电干扰的心电信号分别叠加幅度为20%的49Hz和61Hz工频干扰的心电信号，经小波消噪算法后49Hz至61Hz工频干扰和肌电干扰已消除，结论 该方法可以很好地去除肌电干扰和工频干扰的基频和谐波成分，而对工频干扰的频率变化并不敏感，对于50/60Hz的工频干扰可用同样的算法。

The Algorithm Based on Wavelet for Canceling Muscle Electricity and Wide Range Frequency of Power Line Hum in ECG

Objective To develop a wavelet noise canceller that cancels muscle electricity and power line hum in wide range of frequency. Mothod According to the feature that the QRS complex has higher frequency components, and the T, P wave have lower frequency components, the biortho-gonal wavelet was selected to decompose the original signals. An interference-eliminated signal ECG was formed by reconstruction from the changed coefficients of wavelet. Result By using the canceller, muscle electricity and power line interference between 49 Hz and 61 Hz were eliminated from the ECG signals. Conclusion This canceller works well in canceling muscle electricity, and basic and harmonic frequencies of power line hum. The canceller is also insensitive to the frequency change of power line, the same procedure is good for both 50 and 60 Hz power line hum.