The potential distribution generated by surface electrodes in inhomogeneous volume conductors of arbitrary shape

The use of the boundary-element technique in the computation of the potential distribution within isotropic inhomogeneous volume conductors of arbitrary shape set up by current injected through surface electrodes is presented. The derived algorithm is validated by comparing its solution to analytical solutions in the case of a concentric bipolar electrode configuration on a homogeneous, spherical volume conductor. This problem is essentially a mixed boundary value problem. It is shown that approximations that involve treating this problem as a Neumann problem, which have recently appeared in the literature, are valid for remote field points only. Applications to the modeling of the field of cardiac defibrillation electrodes are presented.