Three dimensional modeling of an MRI actuated steerable catheter system

Abstract

This paper presents the three dimensional kinematic modeling of a novel steerable robotic ablation catheter system. The catheter, embedded with a set of current-carrying micro-coils, is actuated by the magnetic forces generated by the magnetic field of the MRI scanner. This paper develops a 3D model of the MRI actuated steerable catheter system by using finite differences approach. For each finite segment, a quasi-static torque-deflection equilibrium equation is calculated using beam theory. By using the deflection displacements and torsion angles, the kinematic modeling of the catheter system is derived. The proposed models are evaluated by comparing the simulation results of the proposed model with the experimental results of a proof-of-concept prototype.

Iterative Jacobian-Based Inverse Kinematics and Open-Loop Control of an MRI-Guided Magnetically Actuated Steerable Catheter System

“…Liu et al [3, 21] developed a method combining a finite differences approach with beam theory and rotation groups to model the proposed MRI-actuated catheter’s three dimensional deflection motion, including bending and torsion. There are some earlier studies where Cosserat rod theory is applied to model continuum robots (e.g., [17, 48]).…”

“…There are some earlier studies where Cosserat rod theory is applied to model continuum robots (e.g., [17, 48]). The main advantage of the employed formulation [3, 21] is that it is easy to incorporate external forces and torques on the tip or along the catheter body, which is essential for calculating deflections under multi-coil actuation. In this paper, a Jacobian-based inverse kinematics method for control of the steerable catheter based on the proposed model [3, 21] is developed.…”

“…In the kinematic model presented in [3, 21], the catheter is approximated to be composed of a set of finite segments 1 (shown in Fig. 2).…”

“…For the proposed catheter system, the Jacobian matrix, which relates changes of the currents through the coils (system input) to changes of the tip position (system output), is derived from a three dimensional model proposed by Liu et al [3, 21]. The inverse kinematics method is implemented using the damped least squares method [22–24] which avoids stability problems in the neighborhood of singularities that exist in the Jacobian matrix.…”

Achieving Commutation Control of an MRI-Powered Robot Actuator

“…For example, endoscopes actuated by permanent magnets have been proposed for imaging the GI tract [2] and the stomach [3]. Catheters with embedded current-carrying microcoils have been actuated by the forces generated by the magnetic field of the magnetic resonance imaging (MRI) scanner [4]. Custom electromagnetic control systems have been employed for intravascular [5], intraocular [6], and intracochlear [7] Fig.…”