Aspects of EMF topology in the time domain have been studied by re­searchers looking at the influence on biological systems from combined AC and DC EMFs in superposition [58-61]. It has been shown that the cellular response to the orientation of the fields is distinct depending whether the AC and DC fields are perpendicular and parallel to each other. It was found that the perpendicular orientation is dominant in an intensity — dependent non-linear manner [61]. There is a fundamental difference in the spatial pattern of cellular response between DC and pulsed stimulation [62]. Several studies report that the relative orientation of AC and DC magnetic fields appears to be critical for a number of calcium-dependent cell processes. The data suggests that DC magnetic fields influence bio­logical membranes in a somewhat different manner than low frequency AC magnetic fields [1].