The present invention relates to a system for measuring the input impedance of a skin/electrode interface and selectively modifying the input impedance of the monitoring circuit to match the measured input impedance. More particularly, a simplified method for correcting for input impedance mismatch between electronic monitoring circuitry and the skin/electrode interface. In accordance with one embodiment of the invention, an input impedance measuring circuit will interface with a microprocessor and a reconfigurable switch network to select the input impedance of the electronic monitoring circuitry, thus eliminating the impedance sensitivity of EMG or EKG instruments.