Application of decision tree in determining the importance of surface electrohysterography signal characteristics for recognizing uterine contractions

Dongmei Hao,Qian Qiu,Xiya Zhou,Yang An,Jin Peng,Lin Yang,Dingchang Zheng

doi:10.1016/j.bbe.2019.06.008

Abstract

The aims of this study were to apply decision tree to classify uterine activities (contractions and non-contractions) using the waveform characteristics derived from different channels of electrohysterogram (EHG) signals and then rank the importance of these characteristics. Both the tocodynamometer (TOCO) and 8-channel EHG signals were simultaneously recorded from 34 healthy pregnant women within 24h before delivery. After preprocessing of EHG signals, EHG segments corresponding to the uterine contractions and non-contractions were manually extracted from both original and normalized EHG signals according to the TOCO signals and the human marks. 24 waveform characteristics of the EHG segments were derived separately from each channel to train the decision tree and classify the uterine activities. The results showed the Power and sample entropy (SamEn) extracted from the un-normalized EHG segments played the most important roles in recognizing uterine activities. In addition, the EHG signal characteristics from channel 1 produced better classification results (AUC=0.75, Sensitivity=0.84, Specificity=0.78, Accuracy=0.81) than the others. In conclusion, decision tree could be used to classify the uterine activities, and the Power and SamEn of un-normalized EHG segments were the most important characteristics in uterine contraction classification.

Highlights

Uterine contraction provides physiological information of the uterine activity and plays an important role in monitoring the health of mother and fetus during pregnancy
It helps clinicians to distinguish the normal contraction from the contraction that may lead to preterm labor
Tocodynamometer (TOCO) and internal uterine pressure (IUP) catheter are conventionally used to monitor the uterine contraction during pregnancy and labor

Summary

Introduction

Uterine contraction provides physiological information of the uterine activity and plays an important role in monitoring the health of mother and fetus during pregnancy. It helps clinicians to distinguish the normal contraction from the contraction that may lead to preterm labor. The process of labor and delivery can be monitored by regular uterine contraction and cervical dilation [1]. Uterine contraction becomes more and more synchronized, which leads to the expulsion of fetus [4]. Tocodynamometer (TOCO) and internal uterine pressure (IUP) catheter are conventionally used to monitor the uterine contraction during pregnancy and labor. In terms of IUP measurement, it monitors the IUP changes during uterine activities [5,6], and provides reliable information about the uterine dynamics [7]. It cannot be routinely used to monitor the uterine contraction

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Methods

Results