Systems and methods for providing security to a user of an electronic device are provided. The improved apparatus generally comprises one or more electrode assemblies or patches affixed to the skin of the subject in the vicinity of the thoracic cavity. Two connecting members are connected respectively and fixedly to the slidable elements, and are disposed outwardly of the left and right sliding rails. A sound deflection unit that deflects a sound wave which is output by at least one of the piezoelectric vibrators may be further included. A power combining circuit is provided.