Development of Novel Techniques for Fetal ECG Extraction in Early Pregnancy

Abstract

Congenital heart defects are among the most common birth defects and the leading newlinecause of birth defect-related deaths. Most cardiac defects have some manifestation in the newlinemorphology of cardiac electrical signals. The non invasive study of fetal cardiac signals can newlineprovide an effective means of monitoring the well-being of the fetal heart. This may be used newlinefor the early detection of cardiac abnormalities. The electrocardiogram (ECG) signal is the newlinegraphical recording of the electrical potential generated in association with heart activity. It is newlineone of the physiological signals commonly used in clinical aspects. As in adults, the wellbeing newlineand the status of the fetus can be assessed from a fetal electrocardiogram (FECG) newlinesignal. newlineNon invasive techniques of fetal monitoring are Doppler ultrasound, fetal newlineelectrocardiography and fetal magneto cardiography. Among these methods the most newlinecommonly used is Doppler ultrasound because it is simple to use and cheap. However this newlinemethod produces an averaged heart rate and therefore cannot give beat to beat variability. newlineFetal electrocardiogram offers the advantage of monitoring beat to beat variability. There are newlinemany technical problems with non invasive extraction of FECG. The FECG signal is newlinecorrupted by different sources of interferences such as maternal electrocardiogram (MECG) newlinematernal electromyogram (MEMG), 50 Hz power line interference and base line wander. newlineThe low amplitude of the signals, the different types of noise and overlapping frequencies of newlinemother and fetal ECG make the extraction of FECG a difficult task. newlineExtraction and analysis of the fetal ECG signal are the primary objectives of newlineelectronic fetal monitoring. In extracting the fetal ECG signal, the digital signal processing newlinetechniques have played a significant role. The primary assumption is that the abdominal ECG newlineiv newlinesignal (AECG) is a non linear combination of the maternal ECG, fetal ECG signal and other newlineinterference signal.