Abboud S, Sadeh D
Comput Biomed Res. 1984 Jun;17(3):258-66. doi: 10.1016/s0010-4809(84)80017-8.
The cross-correlation function for alignment of ECG waveforms and rejection of artifacts was studied. ECG waveforms were recorded and digitized (10-bit resolution) at 1.28 KHz and were processed with a CDC 6600 computer. The cross-correlation function was calculated using the cross spectrum and the fast Fourier transform algorithm. The maximum value of the cross-correlation function and the time location of that value were searched for (a) the similarity between the waveforms (for elimination of extrasystoles), and (b) measuring the relative time delay (for the waveform's alignment in the averaging process) between the ECG waveforms. Prior to the correlation procedure each of the ECG waveforms was filtered through a nonrecursive digital bandpass filter. Experiments with various filters indicated that when low-frequency cutoff at 30 Hz and high-frequency cutoff at 250 Hz were used the maximum value of the cross-correlation function was higher than 0.9 for most of our recorded waveforms and more accurate results were obtained.
研究了用于心电图波形对齐和伪迹去除的互相关函数。心电图波形在1.28千赫兹下进行记录并数字化（10位分辨率），然后用一台CDC 6600计算机进行处理。互相关函数使用互谱和快速傅里叶变换算法进行计算。搜索互相关函数的最大值及其时间位置，用于（a）波形之间的相似性（以消除早搏），以及（b）测量心电图波形之间的相对时间延迟（用于平均过程中波形的对齐）。在进行相关程序之前，每个心电图波形都通过一个非递归数字带通滤波器进行滤波。使用各种滤波器的实验表明，当低频截止频率为30赫兹且高频截止频率为250赫兹时，对于我们记录的大多数波形，互相关函数的最大值高于0.9，并且能获得更准确的结果。
