Design and Control of 5-DoF Robotically Steerable Catheter for the Delivery of the Mitral Valve Implant

This paper presents the mechanism and design of a robotically steerable catheter system for percutaneous and minimally invasive treatment of mitral regurgitation. One of the main causes of mitral regurgitation is an impaired mitral valve topology, that results in severe heart-related diseases. Repair or replacement of the mitral valve through open-heart surgery such as traditional sternotomy has been conducted as a treatment. However, at least 50 % of patients with severe mitral regurgitation are not candidates for this surgery due to their age or comorbidities. Recently, minimally invasive or transcatheter approaches for mitral valve repair/replacement have been gaining attention to minimize the surgery's risk and several catheter mechanisms have been proposed in early phase clinical trials. Although dexterity and manipulability are essential functions in the transcatheter procedure, a direct torsional capability has not been implemented in the systems. We present a design of a 5-DoF robotically steerable catheter having two bending joints, two torsion joints having a direct torquing design, and a mitral implant delivery module to provide dexterous manipulation of the tip of the catheter. Designs and kinematic models of each joint module are presented and their performance is verified with experiments. Lastly, a mitral clip implanting procedure is demonstrated in a phantom heart model.