Comparison of Different EHG Feature Selection Methods for the Detection of Preterm Labor

D Alamedine,M Khalil,C Marque

doi:10.1155/2013/485684

Abstract

Numerous types of linear and nonlinear features have been extracted from the electrohysterogram (EHG) in order to classify labor and pregnancy contractions. As a result, the number of available features is now very large. The goal of this study is to reduce the number of features by selecting only the relevant ones which are useful for solving the classification problem. This paper presents three methods for feature subset selection that can be applied to choose the best subsets for classifying labor and pregnancy contractions: an algorithm using the Jeffrey divergence (JD) distance, a sequential forward selection (SFS) algorithm, and a binary particle swarm optimization (BPSO) algorithm. The two last methods are based on a classifier and were tested with three types of classifiers. These methods have allowed us to identify common features which are relevant for contraction classification.

Highlights

Preterm birth, that is, birth before the 37th week of pregnancy, remains a major problem in obstetrics
We notice that the two features 3 and 5 marked in bold font in Table 2 are always selected by the two algorithms (BPSO and sequential forward selection (SFS)) whatever the mean m1 and m2 (m1#m2) and whatever the classifier
time reversibility (Tr) Lyapunov exponent (LE) sample entropy (SE) variance entropy (VarEn) W1 W2 W3 W4 W5 D1 D2 D3 D4 D5 decile 6 (D6) decile 7 (D7) decile 8 (D8) decile 9 (D9) MPF peak frequency (PF) Figure 4: Selection vector representing the best parameters for the discrimination between pregnancy and labor

Summary

Introduction

That is, birth before the 37th week of pregnancy, remains a major problem in obstetrics. Children born before term present a high risk of mortality as well as health and development problems [1]. According to the World Health Organization (WHO), preterm birth rates range between 5% and 12% of births and perinatal mortality occurs in 3% to 47% of these cases in even the most developed parts of the world [2]. Delivery occurs after the onset of regular and effective uterine contractions, which cause dilation of the cervix and expulsion of the fetus. The evolution of uterine contractions, from weak and ineffective during pregnancy to strong and effective during labor, is related to an increase in cellular excitability to an increase in the synchronization of the entire uterus [3]

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Conclusion