Design, development and preliminary assessment of a force sensor for robotized medical applications

This paper presents the design, development and the preliminary assessment of a force sensor designed for robotized medical applications. The requirements and constraints for the force sensor are derived from the targeted application of needle insertion in the context of interventional radiology. These constraints rule out the feasibility of commercially available force sensors necessitating the design of a novel force sensor. A discussion on the various force sensing principles utilized in medical robotics and the choice of a suitable sensible principle is done. Next, the solution principles are offered for the design of the flexural element. Starting from the rigid body equivalent, a compliant model of the flexural element is obtained. Simulation using FEM analysis is utilized to verify that the force sensor indeed satisfies the requirements and the constraints of the targeted application. Finally, the calibration and the experimental validation of the force sensor prototype is done using a realistic force profile showing actual force variation during needle insertion.