Requirements Based Design and End-to-End Dynamic Modeling of a Robotic Tool for Vitreoretinal Surgery

Abstract

Despite several robots having been proposed for vitreoretinal surgery, there is limited information on their dynamic modeling. This gap leads to sub-optimal motor selection and hinders the application of advanced control schemes that would fulfill the goal of micro-precise surgery. This paper presents the design process and a dynamics study of a multi-Degree of Freedom (DoF) robotic system, which is inspired by established co-manipulation architectures. A rigorous kinematics and dynamics analysis of the robot's part that is responsible for manipulating the surgical tool during the retinal surgery phase is provided. In particular, the Euler-Lagrange equations of motion, which describe the dynamics of the 3-link surgical manipulator, are combined with novel analytical models of each link's corresponding transmission mechanism, including an anti-backlash lead screw assembly and a worm drive. The resulting models, transferable to existing manipulators, provide a meticulous analysis of the robot's performance that can be used both for mechanical design and control purposes.