FuzzyEn Compared to SampEn for Evaluation of Dynamic Complexity

Figures

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  Figure 1. Comparison of SampEn and FuzzyEn. (a) Heaviside (denoted as ‘H’) and exponential (denoted as ‘E’) functions for vectors distance; (b) flowchart of SampEn and FuzzyEn.

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  Figure 2. The FuzzyEn and SampEn of the Henon series and its surrogate data under different noise levels, with arrows pointing to magnified graphical results for the SNR ranging from 1 dB to 3 dB.

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  Figure 3. Determination of parameter of FuzzyEn and SampEn (mean ± standard error) based on PO5. (a) Selection of dimension when τ = 1, r = 0.25; (b) selection of delay based on m = 3, r = 0.25; (c) control parameter of tolerance when m = 3, τ = 3. ‘Depr-R’ and ‘Depr-V’ denote depressed EEGs in rest and visual-stimulated learning states, and ‘Ctrl-R’ and ‘Ctrl-V’ denote those of healthy control.

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  Figure 4. SampEn and FuzzyEn of depressed EEGs with m = 3, τ = 3 and r = 0.15. Circled PO7, PO5 and PO3 in left occipital lobes are shown due to optimal discrimination. ‘Depr-R’ and ‘Depr-V’ denote depressed EEGs in rest and visual-stimulated learning states, and ‘Ctrl-R’ and ‘Ctrl-V’ denote those of healthy control. ‘*’ represents case in which entropy of EEGs is significantly different from that of others (Bonferroni-corrected p < 0.01).

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  Figure 5. SampEn and FuzzyEn of depressed EEGs (mean ± standard error) in α (8–13 Hz) bands. SampEn brain topography maps are presented below. Electrode locations 1–60 in x-coordinate represent FP1, FPZ, FP2, AF3, AF4, F7, F5, F3, F1, FZ, F2, F4, F6, F8, FT7, FC5, FC3, FC1, FCZ, FC2, FC4, FC6, FT8, T7, C5, C3, C1, CZ, C2, C4, C6, T8, TP7, CP5, CP3, CP1, CPZ, CP2, CP4, CP6, TP8, P7, P5, P3, P1, PZ, P2, P4, P6, P8, PO7, PO5, PO3, POZ, PO4, PO6, PO8, O1, OZ, and O2 respectively.

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  Figure 6. FuzzyEn and SampEn of depressed EEGs (mean ± standard error) in alpha-low (8–10 Hz) and alpha-high (10–13 Hz) bands. Electrode locations 1–60 in x-coordinate are same as those in Figure 5.