Foetal ECG display and evaluation procedure - uses changes in individual signal channels, with variable amplification or attenuation for separate channels

摘要

The display and evaluation of the foetal electrocardiogram uses derivation of abdominal, or abdominal and dorsal electrocardiogram of the pregnant woman. At least three signal derivations are used which are convertible in separate signal channels at least as far as their amplitude is concerned. The derivations are additively superimposed, in order to eliminate the mother heartbeat waveform QRS-complex. The conversion in the individual signal channels takes place by variable amplification or attenuation for each channel separatley, independently of the geometric arrangement of the measuring electrodes (2-7). Pref. the amplitude changes in the individual channels are separate events. The signal, resulting from the additive superimposition, may be submitted to a mean value formation by sectional summation and storage. The change of amplitude and/or sign of the individual derived signal is carried out by computer operated evaluation of the QRS-complexes. The circuit includes a resistance network (9) and a display unit (12).