Prenatal care signal filtering

Abstract

This contribution describes methods of processing signals measured by special body belt which is used to monitor pregnant women. As a part of previous research a belt dedicated to clasp belly of pregnant women with potential problems during the gravidity was designed. The task is to monitor movement of the belly with focus on catching the moment and length of contraction. Output data are values of belt tension measured by strain gages placed at the ends of belt. These raw data has to be filtered first and than analyzed to find the contractions. For this task three simple filter algorithms were proposed. After their testing it was found, that best results are obtained from their mutual combination. After filtering is done the data are processed by special algorithm to determine whether we found contraction and eventually in what period the contractions are repeating. All above mentioned algorithms are implemented in an experimental program which also performs reading data from belt memory and simple visualization. This paper aimed to describe methods of data filtering algorithm.