多尺度熵反映了单个时间序列在多个尺度上的复杂性,本研究提出了多尺度交叉熵的概念和算法,并探索两个时间序列在多个尺度上的耦合行为。首先,将其应用到一个混沌动力学系统的分析中,即Henon-Henon映射。然后,应用多尺度交叉熵分析清醒和麻醉两种状态下血压与肾交感神经活动的非线性耦合模式。结果表明,肾神经活动和血压之间耦合可能具有分形动力学的特征,其复杂度在麻醉后显著降低,而且两种状态下的耦合模式具有明显的差异。
Multiscale entropy reflects the complexity of single sequence on multiscale. In this paper, we proposed a method based on the concenpt of multiscale cross entropy (MSCE) to detect nonlinear coupling behavior between two sequences on muhiscale. First, MSCE was applied in the analysis of of Henon-Henon map which was a chaotic dynamical system. Secondly, the MSCE was used to measure the coupling complexity between renal sympathetic nerve activity (RSNA) and blood pressure (BP) in conscious and anesthetized Wistar rats, respectively. Experimental results demonstrated that MSCE was a simple parameter for quantification of fractal dynamical characteristics. It was found that the coupling complexity between RSNA and BP decreased significantly after anesthesia. There was a significant difference of coupling patterns for BP and RSNA between conscious and anesthetized states.