Remote fetal monitoring system ensures a continuous healthcare for high-risk pregnancy patients, whose hospitalization results in in psychological discomfort and a high cost of long hospital stay. In the developed system the bioelectrical fetal signals, recorded indirectly from maternal abdomen, are the source of diagnostic information. Monitoring using mobile instrumentation MI (signal recorder and tablet PC) takes place at patient’s home from where the data are transmitted in online mode to the surveillance center (SC).
The software running in MI is responsible for obtaining the fetal electrocardiogram (FECG) of good quality, which is a basis for determination of the fetal heart rate and analysis of QRS morphology. When analysing the abdominal FECG the most crucial is efficient suppression of dominating maternal electrocardiogram. Depending on a noise level a less or more advanced signal analysis software is required to obtain a good quality FECG. Therefore, dedicated signal quality measures control an adaptive modification of the analysis range in the MI. The surveillance center carries out the analysis of variability of the fetal heart rate signal delivered by MI’s, and the analysis results provide the final interpretation of the fetal state basing on the so called non-stress test. When the fetal wellbeing is not confirmed, the signal classification process is supported by additional information on QRS morphology changes in the FECG. The amount and content of data transmitted through remote channels to the SC can be managed to ensure the most reliable assessment of the fetal state, while minimizing the MI power consumption.