Enhancing the tip positioning of a steerable catheter through quasilinear viscoelastic beam model.

This study introduces a quasilinear viscoelastic (QLV) beam model designed to enhance the tip positioning accuracy of steerable catheters used in minimally invasive surgeries. The catheter is modeled as a QLV beam with multiple segments of varying stiffness to accurately capture its bending behavior. Kinematic equations are presented to calculate the tip position based on the curvature of each segment. Stress relaxation tests are performed to identify the material parameters of the QLV model, and its accuracy is validated through performance tests under random deformations. Comparative performance analysis with elastic and linear viscoelastic models demonstrates that the QLV model achieves superior accuracy. The mean tip position error of the QLV model shows improvements of 80.6% and 30.9% compared to the elastic model and the linear viscoelastic model, respectively. These findings underscore the critical importance of incorporating time-dependent and nonlinear behaviors in accurately modeling the bending of steerable catheters.