Apparatus for destroying calculi

Claim 1

Apparatus for destroying calculi in a living body, comprising: a) a plurality of ultrasonic transducers; b) actuating means for actuating said ultrasonic transducers to produce beams of ultrasonic waves; c) supporting means for supporting said ultrasonic transducers plate with their axes inclined in such a manner that the axes of said ultrasonic beams meet at a focal point spaced a predetermined distance away from said supporting means so that energy from said ultrasonic beams is concentrated at the focal point, wherein said supporting means comprises a plate-like member recesses to provide a plurality of holes, in each of which one of said ultrasonic transducers is fitted, each of said recesses having a bottom face which is so inclined that the axes of said ultrasonic beams produced by all said transducers meet at said focal point when said transducers are supported in said recesses; and d) liquid-containing means for supporting said living body above said ultrasonic transducers so that a calculus in said living body may be positioned at said focal point; wherein said actuating means comprises: a plurality of high-voltage pulse generators each connected to one of said ultrasonic transducers; a main controller for producing a series of pulses; and a plurality of delay circuits each connected between said main controller and one of said high-voltage pulse generators, said delay circuits providing different delay times such that said series of pulses produced by said main controller cause said high-voltage pulse generators to actuate said ultrasonic transducers in such a manner that the phases of the ultrasonic waves produced by said ultrasonic transducers coincide at said focal point.