关键词: 物理模糊隶属度函数, 改进模糊熵, 改进互模糊熵, 耦合性分析, 心动周期, 收缩间期

Abstract: Previous study indicates that refined fuzzy entropy（rFuzzyEn） based on physical fuzzy membership function, improves significantly in terms of both stability and robustness against additive noise. Its performance in analysing cardiac electro-mechanical time series is further examined by the analysis of RR Interval（RRI） and Systolic Time Interval（STI） series in 5 minutes. Meanwhile, a refined cross fuzzy entropy（rC-FuzzyEn） is developed by substituting the physical fuzzy membership function for the ideal fuzzy membership function in cross fuzzy entropy（C-FuzzyEn） measure. It is used to analyse the coupling of RRI and STI between patients with coronary artery disease（CAD） and healthy volunteers, compared with cross sample entropy（C-SampEn） and cross fuzzy entropy（C-FuzzyEn） simutaneously. The results indicate that rC-FuzzyEn can be used to discriminate between CAD patients and healthy volunteers, it performs better than C-SampEn and C-FuzzyEn in discriminating the two groups.

Key words: physical fuzzy membership function, refined fuzzy entropy, refined cross fuzzy entropy, coupling analysis, RR interval, systolic time interval