Ophthalmic aspirator-irrigator with valve

摘要

An ophthalmic aspirator-irrigator system for use during cataract surgery is disclosed. The system frees both hands of the surgeon for the surgical tasks and leaves the automatic operation of the system to a single control input operated by a foot pedal. The pedal controls both the aspiration and ejection functions as well as their respective speeds. The ophthalmic aspirator-irrigator system essentially comprises a hand-held device, a control box operable by the foot pedal and a power cord connecting the device with the box. A source of fluid is connected via a tube to the device to effect the irrigation function. The control box includes a power source and a circuit coupled to the source and via the cord to the device. Preferably, the circuit includes a bridge output network controlled by a linear motion slide type potentiometer controlled by the foot pedal. The circuit further includes dual DC amplifiers and a pulse-width modulated gate circuit to operate the device bidirectionally with a smooth, continuous and variable speed. The foot pedal has two zero control positions: in its off, non-depressed position and in its off position about midway through the pedal's downward travel. A vacuum limiting valve assembly permits the system readily to be adapted to posterior capsule polishing following the break-up and removal of the cortex.