Title: Modified multiscale entropy in HRV for automatic selection of threshold value r

Authors: Butta Singh; Dilbag Singh

Addresses: Department of Electronics and Communication Engineering, Guru Nanak Dev University, Regional Campus, Jalandhar, Punjab 144 001, India. ' Department of Instrumentation and Control Engineering, National institute of Technology, Jalandhar, Punjab 144 001, India

Abstract: The multiscale entropy (MSE), a technique, to analyse heart rate variability at different time-scales, requires priori determination of pattern length (m) to be compared and tolerance threshold value (r) to accept the similarity between the patterns. Conventionally recommended value of r, 0.1 to 0.2 times the standard deviation of original time series, found inappropriate for accurate MSE at higher scales. Finding true maximum MSE (MSE_max), by evaluating all values of r from 0 to 1 is a better index of coarse-grained time series complexity, but it is very cumbersome. Automatic selection method of r proposed by Lu et al, has been extended to find MSE_max of RR interval time series for ten healthy subjects with data length N = 900 and m = 2. The burden of finding MSE_max has been averted by the proposed modified multiscale entropy and lead to a more appropriate representation of the complexity than the conventional method.

Keywords: heart rate variability; HRV; multiscale entropy; modified MSE; MMSE; threshold values; threshold value selection.

DOI: 10.1504/IJMEI.2012.045303

International Journal of Medical Engineering and Informatics, 2012 Vol.4 No.1, pp.55 - 65

Published online: 11 Aug 2014 *

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