A system for generating an electrophysiological map of a surface boundary of an object of interest of a body, comprising: an electrode of a plurality of electrodes disposed at a position on an external surface of the body for determining an electric potential on said external surface at said position; an electronic control unit electrically connected to said electrode, the electronic control unit configured to: receive an image from an imaging system of the object of interest and a tissue density and tissue type at a plurality of locations between the object of interest and the external surface of the body; receive a signal generated by said electrode, said signal indicative of the electric potential measured at said position; identify the surface boundary of an object of interest within said body using the image of said object of interest, and the electronic control unit being characterized by being configured to: obtain an impedance value from the tissue density and tissue type at each of the plurality of locations along pathways between said position on said external surface of said body and said surface boundary of said object of interest; and determine an electric potential at said surface boundary of said object of interest from said electrode by correcting the signal generated by the electrode by using a total impedance value which is the summed total impedances measured along each of the pathways between the electrode and the surface boundary. an electrode of a plurality of electrodes disposed at a position on an external surface of the body for determining an electric potential on said external surface at said position; an electronic control unit electrically connected to said electrode, the electronic control unit configured to: receive an image from an imaging system of the object of interest and a tissue density and tissue type at a plurality of locations between the object of interest and the external surface of the body; receive a signal generated by said electrode, said signal indicative of the electric potential measured at said position; identify the surface boundary of an object of interest within said body using the image of said object of interest, and the electronic control unit being characterized by being configured to: obtain an impedance value from the tissue density and tissue type at each of the plurality of locations along pathways between said position on said external surface of said body and said surface boundary of said object of interest; and determine an electric potential at said surface boundary of said object of interest from said electrode by correcting the signal generated by the electrode by using a total impedance value which is the summed total impedances measured along each of the pathways between the electrode and the surface boundary. receive an image from an imaging system of the object of interest and a tissue density and tissue type at a plurality of locations between the object of interest and the external surface of the body; receive a signal generated by said electrode, said signal indicative of the electric potential measured at said position; identify the surface boundary of an object of interest within said body using the image of said object of interest, and the electronic control unit being characterized by being configured to: obtain an impedance value from the tissue density and tissue type at each of the plurality of locations along pathways between said position on said external surface of said body and said surface boundary of said object of interest; and determine an electric potential at said surface boundary of said object of interest from said electrode by correcting the signal generated by the electrode by using a total impedance value which is the summed total impedances measured along each of the pathways between the electrode and the surface boundary. obtain an impedance value from the tissue density and tissue type at each of the plurality of locations along pathways between said position on said external surface of said body and said surface boundary of said object of interest; and determine an electric potential at said surface boundary of said object of interest from said electrode by correcting the signal generated by the electrode by using a total impedance value which is the summed total impedances measured along each of the pathways between the electrode and the surface boundary.