基于形态滤波的心电信号基线矫正算法

An Algorithm Based on morphological filter for Baseline Normalization of ECG

基线矫正是心电(EGG)信号预处理中的一个重要步骤。本文提出了一个基于形态滤波的ECC信号基线矫正算法。首先,对原始输入ECG信号进行基于相同结构元素的形态开闭-闭开滤波,抑制其中的QRS波群;然后,采用两个不同宽度的结构元素,对去除QRS波群后的ECG信号进行广义形态开-闭滤波,分离出基线漂移信号;最后,用原始ECG信号减去估计出的基漂信号,得到经过基线矫正的ECG信号。仿真实验与实际应用结果表明,本文方法不仅可以有效去除ECG信号中的基漂干扰,而且较好地保持了ECG信号的原有特征形态,处理效果明显优于以往算法。

Baseline normalization is an important step in ECG signal preprocessing. This paper presents a morphological filter algorithm for the elimination of baseline drift in ECG signal. First, QRS complexes of the input ECG signal are suppressed using an average of open-closing and close-opening operations with the same structuring element. Then, in the QRS-removed signal, a general open-closing filtering operation with two structuring elements of different size is carried out to estimate baseline drift. Finally, the baseline-normalized ECG signal is obtained by subtracting the baseline drift signal from the input ECG signal. The performance of the algorithm is evaluated with simulated and real ECG signals. And it shows that the proposed method performs better than other existing morphological methods, especially in reducing distortion of the baseline drift in any part of the signal.