Abstract: A valve assembly is provided which includes a seat structure and a cage structure. A valve member is movable between open and closed positions and includes an upstream side adapted to engage the seat structure with the valve member in its closed position and a downstream side connected to the cage struture. The cage structure includes a manifold communicating with the valve member downstream side. A pilot valve is provided for selectively venting the manifold to an area of low fluid pressure whereby the valve member is held in its open position.

Abstract: An internally sterile pulsatile infusor system comprises an elastic reservoir or bulb connected to a closed, sterile source of a liquid infusion solution. A check valve is connected between the source and bulb to prevent reflux of the solution therepast and a reciprocating piston is arranged to intermittently compress the bulb to create a pulsating discharge of solution through a cannula. In the preferred embodiment of this invention, controls are provided to vary the rate of compressions of the bulb and to also modulate the force of the pulsating discharge through the cannula. The pulsatile infusor system is useful in many areas in the fields of medicine and surgery, including extracapsular cataract extraction and intravenous infusion procedures wherein bloodclots and like blockages must be removed from the cannula.