Jiao Qing, Guo Yongxin, Zhang Zhengguo
Department of Radiology, Taishan University, Taian 271016, China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2009 Jun;26(3):676-80.
Chaos and fractals are ubiquitous phenomena of nature. A system with fractal structure usually behaves chaos. As a complicated nonlinear dynamics system, heart has fractals structure and behaves as chaos. The deeper inherent mechanism of heart can be opened out when the chaos and fractals theory is utilized in the research of the electrical activity of heart. Generally a time series of a system was used for describing the status of the strange attractor of the system. The indices include Poincare plot, fractals dimension, Lyapunov exponent, entropy, scaling exponent, Hurst index and so on. In this article, the basic concepts and the methods of chaos and fractals were introduced firstly. Then the applications of chaos and fractals theories in the study of electrocardial signal were expounded with example of how they are used for ventricular fibrillation.
混沌和分形是自然界中普遍存在的现象。具有分形结构的系统通常表现出混沌行为。心脏作为一个复杂的非线性动力学系统，具有分形结构且表现为混沌状态。将混沌和分形理论应用于心脏电活动的研究中，可以揭示心脏更深层次的内在机制。通常，一个系统的时间序列用于描述该系统奇异吸引子的状态。这些指标包括庞加莱图、分形维数、李雅普诺夫指数、熵、标度指数、赫斯特指数等。本文首先介绍了混沌和分形的基本概念及方法。然后以心室颤动为例，阐述了混沌和分形理论在心电图信号研究中的应用。
