正常人心动周期信号的混沌特征随年龄的变化

Variation of Chaotic Characteristics of Heart Period Signal with Age in Normal Subjects

心动周期信号（ＨＰＳ）具有混沌特征，含有重要的生理、病理信息。我们利用自行研制的计算机化心动周期信号混沌分析系统，研究了２７１例正常人心动周期信号的混沌特征参数如相对分散度（ＨＲＤ）、李雅普诺夫指数（ＨＬＥ）和分维数（ＨＦＤ），发现随着年龄的增加，ＨＲＤ、ＨＬＥ、ＨＦＤ逐步降低，即心血管动力学的复杂性逐步降低。

The heart period signal (HPS) has chaotic characteristics and contains abundant information in physiology and pathology. The computerized system analysing chaotic characteristics of HPS, which was made in our laboratry, has been used to investigate 271 normal subjects. The chaotic characteristic parameters include Relative i-cpersion, HRD; Lyapunov exponent, HLE; Fractal Dimension, HFD. The results pointed out that while age increased, HRD, HLE and HFD decreased, that is, while age increased, the complexity of cardiovascular dynamics decreased step by step.