| 摘要 |
<p>1,120,019. Measuring contact potentials. COMMISSARIAT A L'ENERGIE ATOMIQUE. Feb.9, 1967 [Feb. 22, 1966], No.6299/67. Heading G1N. In the measurement of the potential of a human organ, e.g. heart, brain, muscles &c., in which contact electrodes are placed on the skin, the potential drift due to the polarization of the electrodes is compensated for by subtracting from the measured potential a linearly increasing potential equal to the polarization potential. The potential across the electrodes 1, 2, Fig. 2, is fed to the input of a differential amplifier 3 whose second input 14 is provided by the attenuated output from an amplifier 5, connected in parallel with a capacitor 6, whose input is provided either by the output of amplifier 3, via switch 9, or the voltage on the slider of a potentiometer 12, via switch 11. For setting the zero of the amplifier 3, switch 9 is closed either manually or automatically; capacitor 6 is charged to the level of the output from the amplifier 3, equal to the potential initially existing between the electrodes. When switch 9 is opened the capacitor discharges applying the voltage to the input of the amplifier 3 via attenuator 7 which is reset to give zero output. In use with switch 11 closed and switch 9 open, a linearly increasing voltage is applied to input 14, whose slope is arranged to be equal to that of the polarization potential by alteration of the slider of the potentiometer 12.</p> |
