Task Control of Minimally Invasive Surgery with Remote Center of Motion Constraint

This paper presents a novel formulation for controlling the task space of the robot with the Remote Center of Motion (RCM) constraint in Minimally Invasive Surgery (MIS). In MIS it is usually required to prevent any lateral motion at the point at which the robot enters the body, called the incision point or the trocar. Therefore, the surgical tool is only allowed to penetrate inside the body or rotate around its axis to avoid more injuries to the patient’s body. The proposed control law considers the RCM constraint at the kinematic level and the convergence of the task space error and regulation of RCM constraint are satisfied, simultaneously. Moreover, the null space of the robot is also exploited effectively within the framework to perform two additional tasks which can limit the RCM movement and optimize the manipulability measure of the robot. A comparative study is finally performed between the proposed approach and a well-known approach used in the literature. To evaluate the efficiency of the approach, a planar robot with 5 degrees of freedom with the trocar constraint is simulated and the results is verified successfully.