A method is provided for treating heart failure in a subject in need of such treatment, including applying a stimulating current to parasympathetic nervous tissue of the subject, selected from the group consisting of: a vagus nerve and an epicardial fat pad. The rotating pressurized heads are counterbalanced throughout the inventive process, and the lapping platen is continuously conditioned by simultaneously rotating the concentric conditioning rings over the lapping platen. Then, deactivating a signal reception unit that receives the signal if the hysteresis comparator output signal corresponds to a DC signal; or, activating the signal reception unit if the hysteresis comparator output signal corresponds to an AC signal.