一种基于提升小波的膈肌肌电信号在线去噪方法

An On-line Denoising Method for Diaphragmatic Electromyogram Signals Based on Lifting Wavelet

膈肌肌电信号传递着膈肌生理状态和呼吸系统的功能等重要信息,但用食道电极采集该信号常受到心电信号的强烈干扰。本研究以提升小波为基础,针对膈肌肌电信号与心电干扰的特征,提出了一种新的膈肌肌电信号在线去噪方法。该方法由于采用了提升小波变换和简单的阈值滤波,运算速度较传统小波方法大为提高。模拟信号的仿真实验中,用该方法去噪后的信号相对于原纯净信号其功率谱相对误差很小。将该方法应用于临床采样数据时,也能达到比较理想的去噪效果。

Diaphragmatic electromyographic（EMGdi） signals contain important information about the status of diaphragm and the respiratory system functions.However,EMGdi signals measured with an esophageal catheter are always contaminated by electrocardiogram（ ECG ）.Based on the characteristics of EMGdi and ECG interference,this paper proposed a novel online EMGdi denoising method by employing lifting wavelet.Owing to lifting wavelet transform and simple threshold filtering,the proposed method outperformed the traditional wavelet ones on operation speed.The simulation results showed that the relative error of power spectral density between the denoised signal and the pure EMGdi signal was very small.Furthermore,this method also achieved satisfying denoising performance when applied to real EMGdi signals.