A method for temporarily widening a gingival sulcus. In one form of the invention, at high motor speeds, an inverter is requested to deliver a pseudo-sinusoidal voltage having peak-to-peak value which a vehicle battery cannot attain. A ringlike frame defined by frame elements extend along edges of the substrate. from about 2000 Oe to about 10000 Oe, to one or more heavy atom ion bombardments of gaseous ions, e. An algorithm determines whether to use the last atrial event in a cycle or whether an earlier atrial event occurred and would provide a more accurate PR value. Methods for use with the system are also disclosed.