A system includes an array of N electrode elements configured to be attached to an external region of a patient, and a processing device coupled to the array. The processing device is configured to receive a set of bioelectric data signals from the array, determine from the set of data signals a set of elements of the array that are, according to a predetermined standard, insufficiently attached to the external region, and generate to a display device, in at least two dimensions, a representation of the external region and the spatial positioning of the insufficiently attached set of elements on the external region.
