Development of a Shape Memory Alloy Actuated Catheter for Cardiovascular Procedures

Abstract

This research highlights the design, fabrication and experimental validation of a Shape Memory Alloy (SMA) actuated robotic catheter. The prototype consists of four SMA tendons that actuate a central tubular substructure in two orthogonal directions. The experimental shape memory characteristics are used to optimize the design. Joule heating is used to generate tip deflections and the experimental bending characteristics are obtained using a dual camera imaging system. These measurements reveal important nonlinearities and hysteretic characteristics of the system. A dynamic model of the system is developed to describe the SMA-effected bending mechanics, and simulation results are compared to experimental measurements for model validation. The applicability of this technology to cardiovascular procedures, like atrial ablation, is demonstrated through precise tracking of trajectories using PID control.