Comparison of different threshold values r for approximate entropy: application to investigate the heart rate variability between heart failure and healthy control groups
Comparison of different threshold values r for approximate entropy: application to investigate the heart rate variability between heart failure and healthy control groups
复制标题
DOI：
10.1088/0967-3334/32/2/002
复制
发表时间：
2011-02-01
影响因子：
3.2
通讯作者：
Liu, Feng
中科院分区：
文献类型：
--
作者：
Liu, Chengyu;Liu, Changchun;Liu, Feng
近似熵（ApEn）被广泛接受为心率变异性（HRV）信号的复杂性度量，但是选择阈值r的标准是有争议的。本文旨在验证Chon预测r（max）的方法是否适用于HRV信号。记录120例受试者仰卧位10 min的标准肢体导联ECG信号。受试者分为两组：心力衰竭组（22名女性和38名男性，中位年龄62.4 ± 12.6岁）和健康对照组（33名女性和27名男性，中位年龄51.5 ± 16.9岁）。计算了三种类型的近似熵：使用推荐常数r = 0.2的近似熵（0.2），使用Chon方法的近似熵（chon）和使用真实r（max）的近似熵（max）。Wilcoxon秩和检验显示，两组之间的ApEn（0.2）（p = 0.267）和ApEn（max）（p = 0.813）无统计学差异，而ApEn（chon）（p = 0.040）有统计学差异。我们生成了一个合成数据库，以研究两个影响因素（信号长度N和短期和长期变异性的比值sd（1）/sd（2））对Chon方法中经验公式的影响（Chon et al 2009 IEEE Eng.Med.Biol.Mag.28 18-23）。结果表明，Chon等人提出的经验公式是分析随机信号的一种很好的方法，但不适合分析非线性信号，如Logistic或HRV信号。
Approximate entropy (ApEn) is widely accepted as a complexity measure of the heart rate variability (HRV) signal, but selecting the criteria for the threshold value r is controversial. This paper aims to verify whether Chon's method of forecasting the r(max) is an appropriate one for the HRV signal. The standard limb lead ECG signals of 120 subjects were recorded for 10 min in a supine position. The subjects were divided into two groups: the heart failure (22 females and 38 males, median age 62.4 +/- 12.6) and healthy control group (33 females and 27 males, median age 51.5 +/- 16.9). Three types of ApEn were calculated: the ApEn(0.2) using the recommended constant r = 0.2, the ApEn(chon) using Chon's method and the ApEn(max) using the true r(max). A Wilcoxon rank sum test showed that the ApEn(0.2) (p = 0.267) and the ApEn(max) (p = 0.813) had no statistical differences between the two groups, while the ApEn(chon) (p = 0.040) had. We generated a synthetic database to study the effect of two influential factors (the signal length N and the ratio of short-and long-term variability sd(1)/sd(2)) on the empirical formula in Chon's method (Chon et al 2009 IEEE Eng. Med. Biol. Mag. 28 18-23). The results showed that the empirical formula proposed by Chon et al is a good method for analyzing the random signal, but not an appropriate tool for analyzing nonlinear signals, such as the logistic or HRV signals.