Abstract: A system for assisting a user with navigating a set of stairs includes a pulley system positioned adjacent to the stairs, the pulley system including a first pulley, a second pulley, and an elongated member coupled to and looped around the first pulley and the second pulley. The system further includes a motor coupled to the first pulley, a sensing assembly operatively coupled to the pulley system, the sensing assembly being structured and configured to sense that a force is being applied to or that is about to be applied to the elongated member by the user, and a controller coupled to the motor and the sensing assembly. The controller is structured and configured to, responsive to the sensing assembly sensing the force, turn the motor on to drive the first pulley.

Abstract: There is described a battery driven atomizer in which an alternating voltage is applied to a piezoelectric actuation element to cause it to expand and contract and vibrate an atomizing orifice plate. The alternating voltage is controlled to produce a high amplitude vibration during a first portion of a drive period, to initiate atomization, and thereafter to produce a lower amplitude vibration to sustain atomization during the remainder of the drive period. The frequency of the alternating voltage is swept repeatedly during each drive period.