A Study on Active Catheter System (1st Report, Structure, Experimental Results and Characteristic Evaluation of Multiunits Using SMA Active Catheter with Multi D. O. F.)

In this paper, we propose a new protoype model of the active microcatheter of which its bending has two degrees of freedom. The design and fabrication methods of this active microcatheter are described. It is 4Fr, 5Fr, 6Fr (1Fr = 0.333 mm) in diameter and consists of 3 active units with SMA wires in its lumina as the servo actuator. The bending motion, bending directions and bending angle of the active catheter have been measured by application of electricity in air and in physiological saline solution. We also modeled this active microcatheter. Experimental results show that the model of the active catheter is reasonable for practical applications. By using simulators (conditions similar to those of a body cavity), we also carried out simulation experiments in vitro and in vivo. The experimental results indicate that the proposed active catheter is applicable to intracavity operations.