Abstract: A system and method for estimating a property of a neural or cardial source using inverse problem solving including a forward numerical model comprises a selection means for selecting at least one subset of a plurality of measurement channels, the selection taking into account the sensitivity of the measurement channel results to conductivity in the forward numerical model for the neural or cardial source. The system also includes a calculation means for determining a property of the neural or cardial source based on said at least one selected subset of measurement channel results. A corresponding computer program product and a controller adapted for controlling a system accordingly, are described.