A layer-recursive formula for the medium filter for volume conductor problems in radially symmetric layered media.

Simplified algorithms for the computation of the filter coefficients used in solutions of the forward and inverse volume conductor problems in a multilayered cylindrical geometry are derived. The new algorithms are layer-recursive, as opposed to previous algorithms which were specific for the structure studied. The new algorithms not only eliminate the need to derive algebraically cumbersome filter expressions, but also speed up their numerical evaluation.