Abstract: The present invention relates to an improved needle for use in the surgical emulsification of tissue such as cataracts, wherein the inner surface of the needle comprises one or more concave recesses. Such recesses are referred to herein as "cavitation generators". During the emulsification process, the cavitation generator produces a focus of cavitation bubbles directed toward a point interior to the body of the needle, thereby facilitating the emulsification of tissue within the needle as well as the aspiration of fluid from the operative field, while simultaneously protecting surrounding tissues from cavitation bubble-mediated damage. In preferred embodiments of the invention, a plurality of cavitation generators are located within the distal end of the surgical emulsification needle. Such cavitation generators may be incorporated into any existing emulsification needle (including but not limited to phacoemulsification needle) design.

Abstract: An ultrasonic instrument including a stack of laminations having acoustic impedance transformer connected and a housing which fits over the stack and at least a part of the transformer in which the housing has a portion of a material having a low coefficient of friction which makes contact with the acoustic impedance transformer.

Abstract: A surgical instrument for removing objects from the body of a human or animal in vitro in which a hook type implement is utilized to grasp a portion of the object to be removed and to bring it into a relationship with a cutting surface of another portion of the instrument to provide a combined crushing and cutting action. In the preferred embodiment of the invention, suction pressure and irrigation fluid is supplied through the instrument with the cut material being removed from the area by the suction pressure.

Abstract: A cutter body for a surgical instrument having at least one blade surface thereon which rotates relative to a fixed blade surface. The cutter body and the rotatable blade are shaped to minimize the stress and wear of the rotatable cutter blade.

Abstract: A cutter body for a surgical instrument having at least one blade surface thereon which rotates relative to a fixed blade surface. The cutter body is shaped to minimize the stress and wear of the rotatable cutter blade.

Abstract: A system for controlling the infusion of fluid to an operating field at a selected predetermined pressure, as a counterpart to an instrument for severing material of an object in the field, and for evacuating through a passage the severed material from the field in a suspension or emulsion of the infusion fluid. The system provides a means for maintaining a constant differential pressure between the operating field and its infusion line and the pressure in the line communicating with the passage through which material is being evacuated at the time a reverse fluid flow mode of operation is initiated in the system to send fluid down the passage through which the severed material is normally evacuated.