A system and method for generating an electrophysiological map are provided. The system includes an electronic control unit (ECU) configured to receive a signal generated by an electrode disposed at a position on an external surface of the body and indicative of electric potential. The ECU is further configured to identify a surface boundary of an object of interest within the body using an image of the object. The ECU is further configured to identify intervening objects along a pathway between the position on the external surface and the surface boundary of the object of interest from one or more images of the pathway. The ECU is further configured to obtain an impedance value for each of the intervening objects and to determine an electric potential at the surface boundary of the object of interest responsive to the signal from the electrode and the impedance values of the intervening objects.
