标题：Is Cross-sample Entropy a Valid Measure of Synchronization between Sequences of RR Interval and Pulse Transit Time?
作者：Liu, Chengyu; Zheng, Dingchang; Li, Peng; Zhao, Lina; Liu, Changchun; Murray, Alan
作者机构：[Liu, Chengyu; Zheng, Dingchang; Murray, Alan] Newcastle Univ, Inst Cellular Med, Newcastle Upon Tyne NE1 4LP, Tyne & Wear, England.; [Liu, Chengyu; 更多
会议名称：40th Annual Meeting on Computing in Cardiology (CinC)
会议日期：SEP 22-25, 2013
来源：2013 COMPUTING IN CARDIOLOGY CONFERENCE (CINC)
摘要：Synchronization provides an insight into mechanisms underlying the interaction among bivariate physiological signals where their coupling is not known a priori. Cross-sample entropy (C-SampEn) has been used to quantify their synchronization. However, traditional C-SampEn has a poor statistical stability because a rigid decision rule is applied to define the similarity between two vectors. In this study, a fuzzy membership function was implemented to redefine the decision rule in C-SampEn with its performance evaluated using simulated and real cardiovascular coupling signals (RR interval and pulse transit time sequences from 10 normal subjects and 10 heart failure patients).; Simulation results verified the decrease of both C-SampEn with increasing coupling degree. The analysis of cardiovascular coupling signals demonstrated a significant difference between normal and heart failure patients (normal 1.17 +/- 0.09 vs. heart failure 1.02 +/- 0.10, P<0.01) with the improved C-SampEn, but not the traditional C-SampEn. Our improved C-SampEn provides a better understanding of the different cardiovascular coupling between normal subjects and heart failure patients.