US Patent 10251782 Vitrectomy probe with a counterbalanced electromagnetic drive

According to one example, an ophthalmic surgical probe for treating an eye of a patient includes a body arranged for grasping by a surgeon and a cutting element extending distally from the body. The cutting element includes a sleeve member and an inner member disposed within the sleeve member, the inner member being movable axially with respect to the sleeve member. The probe also includes an actuating element configured to reciprocally move the inner member relative to the sleeve member. The actuating element includes a first coil secured within the body, a first magnet operatively secured to the inner member, and a second magnet that is not secured to the inner member, the second magnet being positioned and arranged to move in an opposite direction of the first magnet upon application of a voltage to the first coil.