Ophthalmic needle and method for manufacturing the same

DETAILED DESCRIPTION The present invention comprises an improved irrigation-aspiration needle assembly and a method for manufacturing the same for use with an ophthalmic instrument for extracapsular removal of a cataract.
The needle assembly includes an inner tube essentially coaxially arranged with an outer tube, a pair of essentially side-by-side parallel arranged connector tubes and a tank interposed between said coaxial tubes and said connector tubes.
The inner tube passes through the tank and forms one of the connector tubes extending therefrom.
The outer tube and the second connector tube terminate within the tank but at opposite ends thereof.
The tank provides flow communication between the outer tube and the second connector tube.
At its coaxial portion, the inner tube extends a small distance past the outer tube.
A small opening or port is provided in the side of the inner tube within the portion that extends past the outer tube.
The outer tube is sealingly connected to the outer diameter of the inner tube by a unique swaging technique and forms a tapered transition portion between the tip of the inner tube and the main body of the outer tube.
At least two oppositely disposed ports are provided in the tapered transition portion of the outer tube, with one of the ports being axially aligned with the port in the inner tube.
The needle assembly is uniquely manufactured with the use of a soldering and tube positioning fixture.
The fixture positions the various tube members of the needle assembly and securely holds them in position while sealing of the joints is accomplished.
The fixture includes heat sink means which prevents the sealing means from forming internal flow obstructions.
In other words, it prevents the sealing medium from being internally deposited in areas which would adversely affect irrigation and aspiration flow.
The fixture also correctly positions the irrigation and the aspiration tubes relative to the tank at the interface of the connector tubes and the tank.
A forming die is used to shape and seal the coaxial portion of the needle assembly