An implanted electrical signal generator delivers a novel exogenous electrical signal to a vagus nerve of a patient. A beam is optically coupled to an optical conduit, and the optical conduit is made to bend. The reading unit reads in an EXI grammar form. In this manner, pool water can circulate from the lower end of the second section, through the second and first sections and into the skimmer intake. Accordingly, the foreign bodies can be substantially removed from the surface of the substrate without corroding a metal.