Estimates of current density distributions: I. Applying the principle of cross-entropy minimization to electrographic recordings

Abstract
We consider the generalized bioelectromagnetic inverse problem (the evaluation of expressions for the unknown current densities that give rise to experimentally measurable field/surface potential readings). We apply the principle of cross-entropy minimization to compute new expressions for the expected means and convariances of the current densities. The new expressions are shown by computer simulations to offer better results than the existing methods in those cases when only partial information about the source is available. Our expressions are general enough to be equally valid for the biomagnetic, bioelectric or combined bioelectromagnetic inverse problems.