Design and Calibration of a Robot-Driven Catheter Actuation System

Abstract

Flexible steerable tendon-driven systems are crucial in medical interventions, due to their ease of access to narrow spaces and safe operation [1]. Two examples of these systems are ablation and intra-cardiac echocardiog- raphy (ICE) catheters, used for non-invasive ultrasound imaging and ablation in cardiac procedures inside the heart. However, precise positioning of these devices to obtain optimal anatomical views is challenging for the cardiologist and requires specialized training [2]. Custom-made tendon-driven robots have been developed and modeled using Cosserat rod theory [3], [4]. How- ever, most of these efforts have been directed towards creating new flexible robots with known parameters rather than adapting pre-existing tendon-driven systems, such as conventional ICE or ablation catheters. In [5] a 4-DoF robot was developed to manipulate and con- trol a 4-tendon ICE catheter by actuating the knobs on the catheter handle. Nevertheless, the dynamics of the catheter’s knob introduce friction and dead zones in the system. In our study, we developed a novel robot for catheter control and experimentally determined the parameters of a 2-DoFs quasi-static model of the ICE catheter. Our design eliminates the complexity of catheter knob dynamics by employing direct tendon actuation, distinguishing it from existing literature. The proposed robot will later be used in a visual-servoing mode to autonomously follow an ablation catheter.