초록 ▼

A pulsed fluid jet surgical instrument includes a cannula extending from a handpiece, the cannula emitting a pulsed fluid jet for cutting and emulsification purposes, and also providing suction for aspiration and evacuation of the fluid and tissue. A pressure intensifier piston arrangement receives

A pulsed fluid jet surgical instrument includes a cannula extending from a handpiece, the cannula emitting a pulsed fluid jet for cutting and emulsification purposes, and also providing suction for aspiration and evacuation of the fluid and tissue. A pressure intensifier piston arrangement receives fluid at relatively low pressure, and operates reciprocally and reiteratively to pump the fluid through the jet needle in a series of high pressure pulses, each having a nearly rectangular pressure waveform. The pressure intensifier piston is T-shaped, including a broad end which divides a drive bore into a driving chamber and a retracting chamber. A bistable valve is connected to admit high pressure gas into the actuating chamber, driving the piston to translate. The narrow end of the piston is disposed in a fluid pumping chamber connected to a supply of fluid. The translating piston drives the fluid from the pumping chamber through a first check valve into a fluid jet needle, which directs the high pressure fluid pulse to a tissue target. The bistable valve switches to admit pressurized gas to the retracting chamber, driving the piston retrograde and allowing the pumping chamber to refill with fluid through a second check valve. There is no high pressure fluid supplied to the handpiece, and only the pressure intensifying pumping action of the piston creates a high pressure fluid pulse. The gas supply to drive the piston is at a relatively low pressure, so that gas pressure cannot comprise a safety risk to the patient. Thus failure of the piston mechanism cannot result in the emission of a stream of high pressure fluid, and the instrument is inherently safer than prior art instruments that are connected to a high pressure fluid source.

대표청구항 ▼

[ I claim:] [1.] A method for performing ocular surgery, comprising the steps of:puncturing the eye capsule with a needle probe, the probe including a needle cannula extending from a handle, the handle being connected to a source of low pressure fluid and including a pressure amplifying mechanism di

[ I claim:] [1.] A method for performing ocular surgery, comprising the steps of:puncturing the eye capsule with a needle probe, the probe including a needle cannula extending from a handle, the handle being connected to a source of low pressure fluid and including a pressure amplifying mechanism disposed in the handle;supplying low pressure fluid to the handle from the fluid source;activating the pressure amplifying mechanism;generating high pressure fluid pulses from the low pressure fluid by the pressure amplifying mechanism for delivery to the needle cannula; andimpinging the fluid pulses upon a tissue target.