Abstract: An apparatus for providing counteracting force to overcome the off-center weight of a microscope assembly without counterweights. The apparatus is a microscope balance compensator which uses springs or gas pistons to compensate for a change in a moment developed in a microscope assembly when attachments are added or removed or when the tilt angle of the microscope is changed. The microscope balance compensator includes one device for applying counteracting force about a tilt axis and another device for applying counteracting force about a tip axis oriented perpendicular to the tilt axis. Each counteracting force is applied at discrete angles relative to the pivot centers and is adjustable. The apparatus provides balance compensation over a wide range without adding counterweight, thereby minimizing the total weight of the microscope.

Abstract: A phacoemulsification transducer or probe utilizing ultrasonic frequencies to treat cataracts, including a rotatable handle to facilitate repositioning of the needle in the eye during surgery while maintaining a comfortable and secure grip on the instrument. The rotatable handle is comprised of a sleeve portion, irrigation tube and connector member. The sleeve portion is secured to the front of the main body of the probe and the connector member is attached to the distal end thereof.

Abstract: A footswitch apparatus for remotely controlling a surgical instrument. The footswitch apparatus preferably includes a base and a footpedal movably mounted to the base. The footpedal is movable within set upward and downward limits. In one mode of operation, the downward travel of the footpedal is resisted by different springs and different ranges of travel. The footpedal position is sensed and the operation of the surgical instrument is altered depending on which of the ranges the footpedal is in. This gives the operator constant tactile feedback as to which range of travel the footpedal is in. In addition, in a second mode of operation, the multiple springs are decoupled and only a single spring is experienced throughout the range of travel. This provides a flexibility so that the same footswitch apparatus can be used to operate a surgical instrument in a particular mode with linear control throughout the range of footpedal travel.

Abstract: An improved vitrectomy probe for removing vitreous and other fibrous gel materials. A hollow cutting blade is reciprocated within a smooth bore hollow needle of the microsurgical vitrectomy probe across a cutting edge of the outer needle slicing the fibrous material of the vitreous. A pressurized fluid source, diaphragm and spring cooperate to provide for the reciprocation of the blade. A vacuum source removes vitreous material through the hollow needle. A reciprocating suction outlet tube attached to the hollow needle directs vitreous material into a vacuum fitting which is isolated from the motion of the reciprocating outlet tube. An adjustment screw limits the travel of the reciprocating blade as well as the size of the opening in the needle. A dissector head faciitates the separation of vitreous fibers and directs them into the needle opening.