Device for measuring and indicating changes in the resistance of a living body

摘要

An apparatus for measuring and indicating changes in the resistance of a living body in which all changes in the resistance of the living body are displayed automatically by the apparatus. The apparatus includes a bridge network to which the resistance of the body is coupled. An amplifier is coupled to the bridge network for sensing the output voltage thereof and for providing an output signal to a meter for displaying small changes in the resistance of the body. A meter registration controller detects instances wherein the amplifier output signal is outside the range of the meter and causes a position counter to be incremented or decremented accordingly. The digital output of the position counter is converted to a non-linear analog voltage which is applied to the bridge network to automatically balance the same. The apparatus also includes a digital display for indicating the relative magnitude of the resistance of the body.