Design of a Remote Center-of-Motion Parallel Mechanism for Percutaneous Interventions

Abstract Percutaneous intervention procedures require the insertion and manipulation of a puncture instrument within the patient’s body. In this context, a remote center-of-motion (RCM) parallel mechanism, termed PercuCob-RCM, is designed to support clinicians during needle-based interventions by securely holding the puncture instrument and enabling a translational motion along the direction of the needle and rotational motions about a fixed insertion point. A key challenge in developing this mechanism lies in the actuation of its universal joint. This work investigates three alternative actuation schemes and evaluates them to guide the construction of a suitable prototype. The prototype design is formulated as a biobjective optimization problem. The first objective function represents the overall size of the mechanism, while the second captures the motor torques required to sustain a specified axial tool force. For each actuation scheme, the set of nondominated Pareto-optimal solutions is computed and analyzed. Based on the comparative assessment of the Pareto fronts, a preferred design configuration is selected, and a functional prototype is developed.