Modeling fetal cardiac valve intervals and fetal-maternal interactions

Despite the advances in fetal healthcare, in Australia around 9-10 out of 1000 babies die in perinatal period, which is defined as starting from 22 weeks of pregnancy and extending to the first week after birth. This mortality rate is three to four times higher in some developing countries. Furthermore, false alarms produced by the current fetal surveillance technology impose unnecessary interventions, which involve additional costs and potential maternal and fetal risks. Therefore there is a critical need for more accurate fetal assessment methods for reliable identification of fetal risks. Fetal heart assessment is one of the main concerns in fetal healthcare and provides significant information about the fetal development and well-being. The aim of this research is to develop automated and accurate fetal heart assessment methods using noninvasive and less specialized techniques. In this research, automated methods were developed for estimation of the fetal cardiac valve intervals which are fundamental and clinically significant part of the fetal heart physiology. For this purpose simultaneous recordings of one dimensional Doppler Ultrasound (1-D DUS) signal and noninvasive fetal Electrocardiography (fECG) were used. New methods were developed for decomposition of the DUS signal into the component manifesting the valves’ motion. Opening and closing of the valves were then identified automatically based on the features of the DUS component, their temporal order and duration from the R-peak of fECG. Result of evaluating the cardiac intervals over healthy gestational ages and in heart anomaly cases, showed evidences of their effectiveness in assessing fetal development and well-being. Fetal heart activity is influenced by not only the fetal conditions and maturation, but also the maternal psychological and physiological conditions. Therefore this research