A chair situated upon a single wheel in such a relationship to achieve a low center of gravity. The scanning mirror is comprised of a substantially planar member having a movable reflective region and a base region coupled together by a split hinge. The jaw clamp and base mechanisms are laterally symmetrical, in order to provide for both left- and right-hand club heads. Should a paintball jam occur in the vicinity of the impeller, the arm can flex around the jammed ball without breaking it, and help to dislodge it so as to clear the jam. The fluid is configured to produce centrifugal energy. A stimulation system including the DBS lead and a pulse generator is disclosed.