An assembly of devices that non-invasively disintegrates stones (i.e., calculi) by sending focused shock waves from outside the body produced by a spark-gap generator. The generator delivers shock waves when an electrical discharge between two electrodes submerged in water or in electrolytes causes explosive vaporization; the shock wave expands from the gap between the electrodes and is focused at the stone by an ellipsoidal reflector. This system also includes a treatment table, an imaging system, and an operator's console. This [extracorporeal shock wave lithotripsy (ESWL)] system is used to disintegrate stones located in the kidneys, urinary tract, gallbladder, or bile/pancreatic ducts.