| 摘要 |
<p>Apparatus for reducing signal noise in a fetal ECG signal obtained by using a unipolar ECG lead configuration (1), (3) thereby detecting a predominant T wave vector and avoiding changes in ECG waveform shape due to fetal rotation through the birth canal. The ECG signal is transmitted by means of a first signalling link (5) to the signal noise reducing components which include a conventional analogue filter (7), a digital high pass filter (9) for attenuating low frequencies and with a predetermined cut-off frequency, the cut-off frequency being essentially between 0.2 and 1.7 Hz, and a further digital filter (11). The filtered ECG signal is arranged as output signal from the electrical arrangement by means of a second signalling link (13).</p> |
