心电图中的非线性动力学特征

NONLINEAR DYNAMICS CHARACTERIZATION IN ELECTROCARDIOGRAM

非线性动力学是用来研究复杂系统动力学特性的，心脏是最为复杂的动力系统之一。心电图是反应心脏活动状态的重要信息。本文介绍了几种非线性动力学处理心脏信息的方法，利用ＭＩＴ－ＢＩＨ数据库中的心电数据，对正常心律、起搏心律、室性失常心律和束支传导阻滞心律中的Ｒ波峰、Ｒ－Ｒ间期、Ｒ－Ｒ波峰间波形下的面积和Ｒ－Ｒ波峰间波形曲线长度等序列进行了非线性研究。构造了庞卡莱截面，计算了这些序列的相关维数和相关测度熵。研究结果表明正常心律和异常心律以及这几种异常心律之间，对于庞卡莱截面上点集的分布、相关维数和测度熵是有差异的。

onlinear dynamics was used to study the characteristics of the complex dynamic system. Indeed, ECG is important information which reflect the active states of heart. In this paper several methods of nonlinear dynamics for processing heart information were introduced. Selected 24 data files of ECG from MITBIH database and divided these data into four groups. There were normal ECG, pacing ECG, ECG with premature ventricular contraction, and ECG with bundle branch block. Queues of Rwave peaks, RR intervals, area below wave between Rwave peaks and length of wave between Rwave peaks extracted from these electrocardiograms were analyzed with Poincare section, the correlation dimension and correlation entropy. The results showed that (a) Significant different distributions of point set on Poincare section were found between Rwave peaks, RR intervals, area below wave between Rwave peaks and length between Rwave peaks, of normal ECG, pacing ECG, ECG with premature ventricular contraction, and ECG with bundle branch block. (b) The correlation dimensions of queues of Rwave peaks and RR intervals were different between normal ECG and those of other three pathological states. The dimension of ECG with premature ventricular contraction were smaller than that of normal ECG. (c) Correlation entropy of Rwave peaks and RR intervals of normal ECG was higher than that of other three pathological states. The normal heart lost more information than that of other three pathological states. Used the methods of nonlinear dynamics to extract dynamic characteristics from ECG so as to research active states of heart, thus helping doctors for clinical application of early diagnosis of diseases of heart in the future.