Robotic Guidance of a Surgical Tool Under Constrained Motions

This letter formulates a generic representation of a path-following controller operating under contained motion, which was developed in the context of surgical robotics. It reports two types of constrained motion: i) Bilateral Constrained Motion, also called Remote Centre Motion (RCM), and ii) Unilaterally Constrained Motion (UCM). To deal with the constrained motion of a surgical tool when performing a path-following task inside a cavity, we investigated methods that combine the two tasks operating in a hierarchical manner. The proposed solutions were successfully evaluated, first on our simulator that mimics realistic conditions of middle ear surgery, then on an experimental platform. Different validation scenarios were carried out experimentally to assess quantitatively and qualitatively each developed approach. Although ultimate precision was not the goal of this letter, our concept is validated with enough accuracy
$(\leq 100 ~\mu m)$
for the ear surgery.