Kinematic modeling and task-based design of a URRR-URR parallel mechanism for percutaneous interventions

Abstract

International audiencePercutaneous interventions, including biopsies, thermal ablations, and regional anesthesia, involve the insertion of an instrument into the patient's body to remove tissue or manage pain. In this context, the use of a robotic assistant is suitable to guide the medical gestures, leading to a more time effective intervention and better patient care. For this purpose, this paper introduces a novel URRR-URR parallel mechanism. The constraint and mobility analysis of the mechanism is performed using screw theory. A methodology for determining the solution to its Direct and Inverse Geometric Models is presented. The forward and inverse kinematic Jacobian matrices of the mechanism are then expressed. Some singularities of the mechanism are identified and illustrated. Additionally, the design problem of the parallel manipulator (PM) under study is formulated as a bi-objective optimization problem. The first objective function is expressed in terms of the condition number of the forward and inverse Jacobian matrices. The second objective function deals with the mechanism size. Lastly, the non-dominated Pareto-optimal solutions are obtained and three Pareto-optimal solutions are detailed