Abstract: An improved valve utilizes a ball or sphere positioned within a housing which is movable by source of magnetic force external to the housing, the housing having a fluid inlet and a fluid outlet, and a sealing member positioned within the housing adjacent the fluid inlet or the fluid outlet. A modular control valve apparatus is provided having at least one or a plurality of valves in the housing, each having a fluid inlet and a fluid outlet, and a passage from a source of fluid or aspiration to an instrument or other device to direct and/or utilize the fluid or aspiration. Control is provided by including one or more pressure monitors, such as diaphragms positioned in recesses in a surface of the housing, coupled to passageways connected to passageways leading to fluid flow conduits. Variations in pressure in the conduits are transmitted from the diaphragm to a sensor such as a transducer to generate a signal, which activates a correcting electronic circuit which in turn controls a pump for a vacuum system.

Abstract: An invasive lithotripter includes a pair of electrodes having rectangular cross sections, and having flat faces of rectangular configuration confronting one another. An insulating member is interposed between the electrodes and spaces them apart a predetermined distance. The insulating member at its forward edge is relieved to provide portions of the electrode flat faces exposed and confronting one another to permit an electrical spark to jump between the exposed portions of the electrode faces. The relieved portion comprises a reflector having a focus point. The portions of the electrodes facing one another across the relieved area are provided with protuberances aligned with the focus point. A spark across the exposed portions of the faces of the electrodes in an aqueous medium generates a shockwave that is focused by the reflector. A shield surrounds and extends beyond the electrode and the insulating member to inhibit radial propagation of shockwave energy while enhancing axial propagation thereof.