ECG and heart rate detection of prenatal cattle foetus using adaptive digital filtering

A method for detecting the electrocardiogram and heart rate of prenatal cattle foetus is described. The foetal electrocardiogram is picked up from the body surface of a pregnant cow by disposable surface electrodes noninvasively. Using an adaptive digital filter, foetal ECG is enhanced from the corrupted measurement that is contaminated by maternal ECG. Foetal QRS complexes are detected from the enhanced foetal ECG by a digital matched filter. The heart rate is then calculated by known R-R intervals. The method was verified in nine pregnant cows with gestation period from 136 days to 224 days. The results showed that although it was difficult to monitor foetal heart rate from raw measured signal due to maternal ECG and EMG interferences, the proposed method was effective in detecting foetal ECG from the raw measurement mixing maternal and foetal signals. It is also noticed that the detected signal quality of a foetal ECG depends on the lead positions and gestation period. The method is considered useful in monitoring cattle´s health status in order to prevent premature birth, abortion and seize a symptom of apparent death