Reducing vibration in a vitrector

Abstract

Surgical apparatus, including a needle configured to be inserted into an organ of a human subject, a counterweight, and a needle driver. The needle driver includes a cylindrical cam configured to rotate about a cam axis and having a curved circumferential groove extending around a radial surface of the cam. There is a motor coupled to rotate the cylindrical cam about the cam axis. A first follower is mounted to travel in the groove at a first azimuthal location and is coupled to the needle so as to cause the needle to oscillate at a predefined frequency parallel to the cam axis as the cam rotates. A second follower is coupled to the counterweight and is mounted to travel in the groove at a second azimuthal location selected so as to cause the counterweight to oscillate parallel to the cam axis in antiphase to the needle.

Dependencies are inferred from the claim text.