A non-invasive and invasive fetal electrocardiogram real-time monitoring system

The fetal monitoring system discussed here is battery powered and portable. The system includes and ultra-low noise preamplifier for the non-invasively or invasively obtained signals along with an amplifier for a thoracic electrocardiogram (EGG) that is used to cancel the abdominal maternal electrocardiogram (AMECG) of either of the above signals. The AMECG is suppressed in real-time. The AMECG is canceled by using the thoracic ECG as a trigger for developing an average of the AMECG. This average is then subtracted from the abdominal ECG. The resulting abdominal ECG´s fetal electrocardiogram (FECG) and electromyographic signals are undisturbed by the cancellation. The FECG signal-to-noise ratio is then improved by using FECG averaging and filtering.<>