Deep brain stimulation (DBS) is presently the most used method of surgical treatment because it does not destroy brain tissue, it is reversible, and it can be tailored to individuals at their particular stage of disease. DBS employs three hardware components: a neurostimulator, also called an implanted pulse generator (IPG), which generates electrical impulses used to modulate neural activity, a lead wire which directs the impulses to a number of metallic electrodes towards the tip of the lead near the stimulation target, and an extension wire that connects the lead to the IPG. The IPG, which is battery-powered and encased in titanium, is traditionally implanted under the collarbone, and is connected by the subcutaneous extension to the lead, which extends from outside the skull under the scalp down into the brain to the target of stimulation. The IPG, or the entire three-component system, are sometimes referred to as a brain pacemaker, due to the precedence and renown of cardiac pacemakers and similarities in the components of both types of systems.