Abstract: A cassette and a cassette receptacle assembly are provided for use in an ocular surgical system. The cassette includes a housing which defines an arcuate race. A flexible tube extends across the race and conveys a fluid when compressed by the rollers of a roller pump. A slot is defined by the housing at the point where the tube forms a bend prior to entering the race. The slot has a height which is preferably smaller than the diameter of the tube and therefore prevents the tube from flattening as the rollers urge it away from the slot. The cassette mounting assembly includes a pair of cams which urge the cassette into a locked position with respect to the roller pump.

Abstract: An apparatus and method useful for the removal of a mass of tissue from an animal which includes an elongated instrument, such as a needle, with a sheath device having a sleeve for treatment fluid delivery at the area of operation. The needle can be vibrated at ultrasonic frequency, preferably in the lateral direction, and treatment fluid, along with reduced pieces of tissue mass, can be removed from the area of treatment by means of aspiration through a conduit in the needle.