Area 1 approximate entropy: empirical validation of the tool

• Grant number: 14/08842-3
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2014
• End date: April 30, 2016
• Field of knowledge: Engineering - Biomedical Engineering
• Principal Investigator: José Guilherme de Souza Chaui Mattos Berlinck
• Grantee: José Guilherme de Souza Chaui Mattos Berlinck
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Jose Eduardo Pereira Wilken Bicudo

Abstract

Approximate Entropy ( ApEn ) is an extremely popular tool for nonlinear analysis. However, due to the arbitrary choice of parameters for the application of the tool, the results may lose consistency: two clearly distinct series can be classified in opposite ways depending on the choice made by the observer. It can be found two attempts to overcome this lack of consistency. One of these, pApEn, computes the peak value of ApEn for a vector of tolerances. The other, vApEn, is based on a double summation of ApEn values over all windows and possible tolerances for a given time series. pApEn is much more robust than ApEn. Nevertheless, due to the choice of window, it maintains subjectivity in the analysis. Moreover, recent tests by our group indicate that certain inconsistencies may occur. On the other hand, vApEn is of very high computational demand and analyses become prohibitive for more than 400 points in a series, even on powerful conventional platforms. Thus, there is still need for improvement in the original tool. Recently, our group developed another approach, based on the area obtained with window 1 ( a1ApEn ). The approach showed to be more consistent and robust than previous ones. In this sense, a validation of the a1ApEn tool, made in real time series obtained experimentally, is still lacking. This project aims to do such a validation through analysis of heart rate data obtained under very controlled conditions . (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SOUBHIA NATALI, JOSE EDUARDO; STARZYNSKI, PAULO NOGUEIRA; CHAUI-BERLINCK, JOSE GUILHERME. Oscillatory patterns in heart rate variability and complexity: A meta-analysis. Biomedical Signal Processing and Control, v. 33, p. 66-71, MAR 2017. (14/08842-3)