两步式自适应阈值法滤除心电信号中运动伪迹  

ECG Motion Artifact Filtering Based on Two-Stage Adaptive Threshold Rules

作　　者：吕建行 李玉榕[1,2] 陈建国[1,2] 高宁 LÜJian-hang;LI Yu-rong;CHEN Jian-guo;GAO Ning(College of Electrical Engineering and Automation,Fuzhou University,Fuzhou,Fujian 350108,China;Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology,Fuzhou,Fujian 350108,China)

机构地区：[1]福州大学电气工程与自动化学院,福建福州350108 [2]福建省医疗器械和医药技术重点实验室,福建福州350108

出　　处：《电子学报》2024年第10期3493-3506,共14页Acta Electronica Sinica

基　　金：国家自然科学基金(No.62373108)。

摘　　要：心电信号广泛应用于心脏疾病的医学检测中,可穿戴动态心电监测设备可以实现对心律失常的风险识别并预警.相比于静息心电信号,动态心电信号在采集过程中会受到更大运动伪迹的干扰,这些干扰会覆盖心电信号的关键信息,限制其临床应用.本文兼顾心电信号局部和全局特征,利用其周期性,研究了一种将心电信号低频PT波和高频QRS波群分开处理的两步式自适应阈值滤波算法,适用于单通道心电信号中的运动伪迹滤除.第一步先通过多分辨率阈值初步抑制心电信号低频部分中的运动伪迹;第二步,对受运动伪迹影响而不平衡的QRS波进行自适应阈值修复,通过对QRS波形调节,减少心电信号中高频部分运动伪迹,同时设置自适应阈值对心电信号P波、T波对应的小波系数进行处理,超出自适应阈值范围的小波系数通过波形缩放进行调整,进一步抑制低频运动伪迹.研究通过不同心电数据库评估算法的性能.在输入信噪比从-10~10 dB时,心电信号信噪比提升了10.9122 dB和4.3912 dB,滤波后心电信号与纯净心电信号的相关系数分别为0.6876和0.9783,提取的运动伪迹与原运动伪迹相关系数分别为0.9530和0.8529.实验结果表明,算法在不同噪声水平下,利用自适应阈值的优点,能有效复原受运动伪迹污染的心电信号波形特征,最大限度保留心电信号的临床信息,可作为可穿戴心电设备滤除运动伪迹的有效工具.ECG(ElectroCardioGram)signals are widely used in the medical detection of heart disease,and wearable dynamic ECG monitoring devices enable the detection and early warning of cardiac arrhythmias.Compared to resting ECG signals,dynamic ECG signals are more susceptible to interference from motion artifacts during the data acquisition process.These motion artifacts can obscure critical information within the ECG signal,limiting its clinical utility.In this paper,taking into account the local and global characteristics of the ECG signal and using its periodicity,a two-stage adaptive threshold filtering algorithm is investigated to process the low-frequency PT wave and the high-frequency QRS wave group separately,which is suitable for motion artifact filtering in single-channel ECG signal.In the first step,motion artifacts in the low-frequency part of the ECG signal are suppressed by a multi-resolution threshold.In the second step,the imbalanced QRS wave affected by motion artifacts is repaired by adaptive threshold,adjusting the QRS waveform to reduce motion artifacts in the high-frequency portion of the ECG signal,while setting adaptive thresholds to process the wavelet coefficients corresponding to the P-wave and T-wave of the ECG signal.Wavelet coefficients beyond the adaptive threshold range are adjusted via waveform scaling to further suppress the low-frequency motion artifacts.In this paper,the performance of the algorithm is evaluated using different ECG databases.When the input SNR changes from-10~10 dB,the SNR of the ECG signal increases by 10.9122 dB and 4.3912 dB,respectively,and the correlation coefficients between the filtered ECG signal and the pure ECG signal are 0.6876 and 0.9783,respectively,the correlation coefficients between the extracted motion artifacts and the original motion artifacts are 0.9530 and 0.8529,respectively.The experimental results show that under different noise levels,the proposed algorithm can effectively recover the ECG waveform characteristics contaminated by motion artifacts b

关 键 词：心电信号 运动伪迹 小波变换 自适应阈值 信号处理 

分 类 号：TN911.7[电子电信—通信与信息系统] TP274[电子电信—信息与通信工程]