Physiological time-series analysis using approximate entropy and sample entropy

American Journal of Physiology - Heart and Circulatory Physiology - Tập 278 Số 6 - Trang H2039-H2049 - 2000
Joshua Richman1,2, J. Randall Moorman1
1Cardiovascular Division, Department of Internal Medicine, and Department of Molecular Physiology and Biological Physics, and Cardiovascular Research Center, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908; and
2Medical Automation Systems, Charlottesville, Virginia 22903

Tóm tắt

Entropy, as it relates to dynamical systems, is the rate of information production. Methods for estimation of the entropy of a system represented by a time series are not, however, well suited to analysis of the short and noisy data sets encountered in cardiovascular and other biological studies. Pincus introduced approximate entropy (ApEn), a set of measures of system complexity closely related to entropy, which is easily applied to clinical cardiovascular and other time series. ApEn statistics, however, lead to inconsistent results. We have developed a new and related complexity measure, sample entropy (SampEn), and have compared ApEn and SampEn by using them to analyze sets of random numbers with known probabilistic character. We have also evaluated cross-ApEn and cross-SampEn, which use cardiovascular data sets to measure the similarity of two distinct time series. SampEn agreed with theory much more closely than ApEn over a broad range of conditions. The improved accuracy of SampEn statistics should make them useful in the study of experimental clinical cardiovascular and other biological time series.

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Tài liệu tham khảo

10.1103/PhysRevA.29.975

Dawes GS, 1992, Obstet Gynecol, 80, 763

10.1103/RevModPhys.57.617

10.1042/cs0920345

10.1097/00000542-199304000-00011

10.1152/jappl.1994.77.6.2863

10.1016/0375-9601(88)90193-4

10.1103/PhysRevA.28.2591

10.1142/S0218127491000403

10.1161/01.CIR.96.3.842

10.1161/01.CIR.98.5.429

10.1161/01.STR.30.5.1008

10.1016/S0165-1838(97)00028-3

10.1016/S0002-9149(97)00799-6

10.1016/S0735-1097(96)00243-4

10.1203/00006450-199806000-00017

10.1152/ajpheart.1998.274.4.H1099

10.1073/pnas.93.5.2083

10.1073/pnas.88.6.2297

10.1063/1.166092

10.1016/S1043-9471(06)80040-6

10.1152/ajpregu.1993.264.3.R638

10.1007/BF01619355

10.1152/ajpheart.1994.266.4.H1643

10.1073/pnas.93.24.14100

Pincus SM, 1992, Obstet Gynecol, 79, 249

10.1016/0735-1097(94)90177-5

10.1016/S0022-0736(98)90300-4

10.1152/ajpheart.1996.271.1.H244