Maternal heart signal noise removal for ECG signals - by storing shape of interference pulse for subtraction from subsequent pulses

摘要

The noise reduction system removes the maternal heart signals in abdominally derived foetal-maternal electro-cardiogram signals. It detects interference occuring at intervals and stores its amplitude shape in a memory (5). When further similar interference occurs later in the wanted signal the stored interference is subtracted from it with the correct phase. similar interference signals that are subject to time variations are removed by continually adapting the amplitude shape of the stored signal to the actual shape of the interference signal.