Prototyping of a fetal ECG monitoring system.

The fetal heart rate (fHR) and fetal electrocardiogram (fECG) are important parameters for diagnosing fetal well-being. Currently, the fECG can only be accurately recorded during labor using an electrode connected directly to the fetal scalp. Another possibility to obtain the fECG is by positioning contact electrodes on the maternal abdomen. The signals recorded by these electrodes are however corrupted by other electrophysiological signals and noise. The maternal electrocardiogram (mECG) is the predominant corruption, which has to be removed to enable detection of the fHR. In this paper a novel technique to remove the mECG from abdominal recordings has been implemented in a prototype fECG monitoring system. Moreover, a novel technique to detect the fHR and subsequently calculate an average fECG complex has been implemented as well. Implementation is performed to enable real-time monitoring of the fHR and fECG. The fHR detected from the maternal abdomen is validated by comparison to the fHR detected by a simultaneously performed recording from the fetal scalp. Preliminary results show a correlation coefficient of 0.98 between the fHR traces.