Active Catheters for Neuroradiology

Abstract

Surgeons performing endovascular interventions have high expectations with regard to the improvement of their operating tools and, more specifically, of their catheters. Active catheters, in which the tip moves actively using Shape Memory Alloy (SMA) actuators, constitute a promising approach. In this article, we review existing SMA-based active catheters present in the literature. We analyze their performances regarding the requirements imparted to neuroradiology. Then, we propose a new analytical model for predicting the thermo-mechanical behavior of steerable catheters actuated through SMA wires. Particularly, we give an expression for the maximal achievable bending angle of the catheter tip. These results are finally applied to the design of single-use small-diameter active catheters especially devoted to neuroradiology. In particular, we present a 3.3-Fr catheter suited for navigating into the Willis’ polygon and for accurate positioning into aneurysmal cavities.