An interface device for delivering a flow of a treatment gas to an airway of a patient includes: a conductive element positioned on a surface such that the conductive element directly contacts the patient when the interface device is positioned on the patient for delivering the flow of the treatment gas to the airway of the patient; and a conductive pathway extending from a first end which is electrically connected to the conductive element to an opposite second end which is structured to be electrically connected to earth ground.