Abstract
Long-term fetal heart rate (FHR) monitoring is necessary in order to early detection of fetal dysfunction. However, current fetal heart rate monitoring technology based on the Doppler method is not suitable for long-term monitoring over the perinatal period because FHR cannot measure outside hospital since the device is large and expensive and sensor-head is necessary to adjust the position depending on fetal movements. Therefore, a FHR monitoring device with a maternity-girdle-type-Electrocardiogram (ECG) sensor-head using conductive fabric electrodes has been developed in this study to obtain fetal ECG signals from abdominal wall potential of pregnant women, achieving non-invasive monitoring of FHR, easy attaching by people under monitoring themselves, robustness in fetal movements, and so on.
Maternal abdominal wall potentials of women at 34 and 36 weeks pregnant were measured for one minute using the developed device. The fetal R-waves were observed together with the maternal R-waves but the fetal ones were about 6 times smaller than the maternal ones and buried partially in the noises due to contact failures between the electrodes and the skin of maternal abdomen in maternal body movements.
