Cosserat Rods for Modeling Tendon-Driven Robotic Catheter Systems

TL;DR

This paper introduces a novel mechanical model of tendon-driven robotic catheters using Cosserat rods, validated against experiments, enabling precise control and interaction modeling for minimally invasive cardiac procedures.

Contribution

It presents the first fully-validated Cosserat rod model for both catheter and tendons in robotic catheter systems, enhancing accuracy in simulation and control.

Findings

Model accurately predicts catheter deformation under large loads.

Tendon constraints effectively simulated with penalty forces.

Validated against experimental data for physical fidelity.

Abstract

Tendon-driven robotic catheters are capable of precise execution of minimally invasive cardiac procedures including ablations and imaging. These procedures require accurate mathematical models of not only the catheter and tendons but also their interactions with surrounding tissue and vasculature in order to control the robot path and interaction. This paper presents a mechanical model of a tendon-driven robotic catheter system based on Cosserat rods and integrated with a stable, implicit Euler scheme. We implement the Cosserat rod as a model for a simple catheter centerline and validate its physical accuracy against a large deformation analytical model and experimental data. The catheter model is then supplemented by adding a second Cosserat rod to model a single tendon, using penalty forces to define the constraints of the tendon-catheter system. All the model parameters are defined by the catheter properties established by the design. The combined model is validated against experimental data to confirm its physical accuracy. This model represents a new contribution to the field of robotic catheter modeling in which both the tendons and catheter are modeled by mechanical Cosserat rods and fully-validated against experimental data in the case of the single rod system.