Computing Electrode Contact Signal Quality for Non-Invasive Electrocardiography Signals in Fetal Heart Rate Monitoring

Non-invasive fetal electrocardiogram (NIFECG) from maternal abdominal electrocardiogram (aECG) is an effective method for external fetal monitoring to predict the fetal risk timely. The aECG typically contains a high level of noise which makes it difficult to obtain the fetal heartbeat detection with high accuracy. In this paper, we propose a method called Electrode Contact Signal Quality (ECS) to check the signal quality of the electrode contact with the abdominal skin before performing each session to improve the fetal heart rate (FHR) accuracy. This approach is based on the combination of denoising techniques, Teager-Kaiser energy operator (TKEO) and Short-time Fourier Transform (STFT) Power Cepstrum. We used our Femom device to collect data with specific scenarios, in hospital and home monitoring to find out the suitable parameter values. FHR accuracy is increased from 60% to 81% with applying ECS method.