Analysis and simulation of large deflection of a multi-segmented catheter tube under wire tension

Tip positioning of a wire-driven catheter tube is a great challenge during surgeries and it is a significant problem. In order to successfully position the tip to the desired location, a reliable simulation has to be developed. With simulation, determining the required tension force to accurately position the tip of the tube is possible. We examined the general structure of a wire-driven catheter tube. The equations for analyzing the nonlinear large deformation of the tube were derived based on the Euler-Bernoulli law. The Matlab simulation of the deflected catheter tube was developed according to the derived equations. An experiment capturing the actual shape of deflected catheter under various pull wire tensions of up to about 11 N involved measuring the displacement of the pre-selected five points along the catheter tube. The location of the points was compared to the location of the corresponding points of the simulation results. Both shapes resulted in similar curve shapes with maximum error around 3 mm, which corresponds to 1 % error. Thus, the simulation reliability was verified.