Patent ID: 8265745

Claim:
A method for performing a medical procedure, comprising the steps of: guiding a catheter to an internal patient location, wherein the catheter includes at least first and second electrodes; providing first and second separate electrical signals having equal frequency and phase to the first and second electrodes, respectively, wherein an amplitude of one of the first and second electrical signals is adjustable relative to an amplitude of the other of the first and second electrical signals; monitoring the first and second electrical signals as applied to the first and second electrodes, respectively, to identify first and second input responses; adjusting the amplitude of at least one of the first and second electrical signals as applied to a corresponding one of the electrodes to generate an initial relative response of the first and second electrodes; identifying a level of the initial relative response; identifying a change in the initial relative response; scaling the change based on the level of the initial relative response to generate a scaled change of response; and generating an output based on the scaled change of response.