Abstract: An electrophysiological sensing device, such as a helmet, that can be fitted to a living subject. The device includes a set of electrodes for detecting electromagnetic signals and inputting the signals to a processor. The set of electrodes includes working electrodes having at least one acquisition electrode in a selected position on the subject, and an additional electrode to be connected to the processor as a floating ground. An output of each working electrode is equipped with a first impedance adapter. A common electrical supply is provided for these first impedance adapters. A circuit capable of maintaining an intermediate electrical potential, dependant from the electrical supply, is provided at the electrical potential of the additional electrode.

Abstract: A method and an apparatus for measuring the variations of the foetal heart rate particularly during labor. According to this method, an average value is determined from zones where no deceleration occurs. In order to avoid variations due to small parasitic signals, this average value is compared with a filtered value, corresponding to the average value during a small number of periods of the electrocardiogram. This apparatus allows a practitioner to obtain a binary indication on the decelerations of foetal heart rate and accordingly an indication on the possible foetal stress.