Middle Tube Rotation of the COAST Guidewire Robot: Design and Modeling

Endovascular interventions aimed at treating conditions such as peripheral arterial disease (PAD) or atherosclerosis often necessitate the use of guidewires to navigate catheters and other medical devices through complex vasculatures. The tortuosity of blood vessels poses challenges for interventionists while maneuvering guidewires. To address these challenges, robotic guidewires have been investigated to improve steerability within a vasculature. Traditional mechanically-actuated continuum robots for minimally invasive surgery predominantly fall into two categories: tendon-driven mechanisms (TDMs) and concentric tube mechanisms (CTMs). In this work, we introduce a modified actuation system for the COaxially Aligned STeerable (COAST) guidewire robot, seamlessly incorporating the principles of CTMs and TDMs by enabling the rotation of the middle tube of the tendon-driven guidewire system. We present the kinematic and mechanical modeling of the combined tube assembly for variable middle tube orientations, validated through imaging, with a RMSE of 4.48m
^-1
and 2.77 m
^-1
for the
$x$
and
$y$
directions, respectively. Furthermore, through navigation experiments in a custom phantom, we validate the dexterity and effectiveness of the guidewire robot. The proposed middle tube rotation mechanism for the COAST guidewire demonstrates potential in achieving precise and versatile navigation through complex vasculature, which could be steps toward a transformative impact on navigation for endovascular interventions.