Inverse Problem Solution to Evaluate the Bioelectric Field of Fetal Heart Muscle: Remarks on Electrodes Placement

It is well know that the evaluation of the bioelectric field generated by the human heart allows an accurate monitoring of the cardiac activity. In fact the human heart can be assimilated to an electric dipole that changes its amplitude and its orientation during the depolarization and repolarization processes of the heart muscle cell: this is the theoretic basis of the modern electrocardiogram (ECG). In fact the ECG is a recording of the electric potential, generated by the electric activity of the heart, on the surface of the thorax. Thus, it is used in cardiological diagnosis, like tachycardia, arrhythmia and other disorders in the heart activation. Recent works have shown that the ECG technique could be employed to evaluate the effects of the bioelectric field generated by a fetal heart muscle in order to obtain the so-called fetal electrocardiogram (fECG). The fECG could be a very efficient way for in utero fetal heart monitoring and pathology detection during the pregnancy. In the last years many authors have studied signal processing techniques in order to obtain the fECG in a non-invasive way, but no-reflection has been shown about the bioelectric field generated by the fetal heart. The goal of this paper is to discuss the bioelectric potential distribution that the fetal heart produces on the mother abdomen during the pregnancy. The authors also show that the electrodes placement on the mother abdomen can be optimized to evaluate the fECG using blind source separation technique.