提升小波和平滑滤波在心电信号快速滤波中的研究

Investigation of Fast Filter of ECG Signals with Lifting Wavelet and Smooth Filter

利用提升小波将原始心电信号(ECG)按频率特性分解为低频的逼近信号和高频的细节信号,舍弃前几层细节信号,采用自适应平滑滤波器选择合适的阈值对逼近信号进行滤波,从而避免平滑滤波对QRS波的损伤,再用提升小波逆变换重建保留的逼近信号,进而实现对心电信号中三种主要噪声的抑制。实验表明该方法计算量小,实时性强。

The lifting wavelet is used to decompose the original ECG signals and separate them into the approach signals with low frequency and the detail signals with high frequency, based on frequency characteristic. Parts of the detail signals are ignored according to the frequency characteristic. To avoid the distortion of QRS Complexes, the approach signals are filtered by an adaptive smooth filter with a proper threshold value. Through the inverse transform of the lifting wavelet, the reserved approach signals are reconstructed, and the three primary kinds of noise are limited effectively. In addition, the method is fast and there is no time delay between input and output.