Title: Towards retinal membrane peeling with a handheld robotic instrument

Abstract:

Vitreoretinal surgery procedures demand high precision and have to be performed with limited visualization and access. One such procedure is membrane peeling, which involves peeling of the 5-10 µm thick internal limiting membrane around macular holes. Using virtual fixtures in conjunction with robotic surgery has the potential to improve the safety and accuracy of these procedures. We develop virtual fixtures for membrane peeling using an actuated handheld instrument. A cornerstone of many of the proposed virtual fixtures is a reconstruction of the retinal surface with respect to the surgical tool, which is difficult to obtain due to the inadequacy of traditional stereo vision techniques in the intact eye. A structured-light technique using an aiming beam interfaced with the handheld instrument has been proposed to combat this problem, but it only provides a reconstruction at the start of the procedure; it cannot update it as the eye moves during surgery. We propose updating the initial estimate of the retinal plane a single point at a time, by continued detection of a laser aiming beam in each camera frame, as in the initial structured-light approach. Membrane peeling experiments aided by the virtual fixtures are carried out using the instrument in an artificial phantom and we find a significant reduction in the forces applied at the phantom during the robot-aided trials. The efficacy of the retinal plane update method is demonstrated by tracking a plane in an open-sky experiment and finding points on the plane in saline water.

Committee:
Cameron Riviere (advisor)

John Galeotti

Chengqian Che