A method and system is disclosed for an improved charge pump system. Preferably, the paper layer includes about 10 Wt % to about 30 Wt % of a thermoplastic polymer. The large-diameter shaft portion has an end portion fitted and fixed in the fitting portion of the small-diameter shaft portion. This is especially true in lasers using large amounts of energy. The detector is located so that magnetic flux passes through a detection face of the detector substantially perpendicularly. The invention includes treatment of urge incontinence due to detrusor hyperreflexia.