Link A, Endt P, Oeff M, Trahms L
Physikalisch-Technische Bundesanstalt, Berlin, Germany.
IEEE Trans Biomed Eng. 2001 Feb;48(2):133-42. doi: 10.1109/10.909634.
The variability of electric and magnetic signals from the heart during the depolarization phase is investigated. A signal processing method is developed, which provides estimates for the beat-to-beat variability of the QRS-complex. The method is based on the decomposition of the depolarization signal into bandpass signals by means of the Morlet wavelet transform. The beat variability of the depolarization signal is estimated by normalized variances of the envelope and instantaneous frequency of bandpass signals. Time intervals of the bandpass filtered depolarization signals having a high signal-to-noise ratio are selected applying an analysis based on phase statistics. The method was tested by computer simulation and experimental data taken from electrocardiographic and magnetocardiographic measurements of healthy persons and patients prone to malignant ventricular tachycardia (VT) or ventricular fibrillation (VF). Results suggest that the calculated variance parameters permit the characterization of beat variable depolarization signals and distinguish VT/VF patients from healthy persons.
研究了心脏去极化阶段电信号和磁信号的变异性。开发了一种信号处理方法，该方法可提供QRS复合波逐搏变异性的估计值。该方法基于通过Morlet小波变换将去极化信号分解为带通信号。通过带通信号包络和瞬时频率的归一化方差来估计去极化信号的搏动变异性。应用基于相位统计的分析方法，选择具有高信噪比的带通滤波去极化信号的时间间隔。该方法通过计算机模拟以及从健康人和易发生恶性室性心动过速（VT）或心室颤动（VF）的患者的心电图和心磁图测量中获取的实验数据进行了测试。结果表明，计算出的方差参数能够表征搏动可变的去极化信号，并区分VT/VF患者和健康人。
