Method and apparatus for continuous detection not conscious of heart frequency by pletismography of impedance with hidden electrodes. (Machine-translation by Google Translate, not legally binding)

摘要

Method and apparatus for continuous non-conscious detection of heart rate by impedance plethysmography with hidden electrodes. A method for measuring heart rate by electric impedance plethysmography is proposed, with the subject sitting and not being aware of the measurement. Four electrodes of parallel conductive strips are hidden under the seat upholstery. An alternating current of between 10 khz and 250 khz is injected with the two external electrodes and the voltage drop between the two inner electrodes is measured. The recorded signal has periodic peaks whose frequency coincides with the heart rate. The waveform and its sensitivity to changes in impedance depend on the position and relative dimensions of the detection electrodes with respect to the injection electrodes. The heart rate is obtained by an algorithm based on the detection of the slope of the signal. (Machine-translation by Google Translate, not legally binding)