Title: Design, Modeling, Imaging, and Control of a Robotically Steerable Transcatheter Delivery System

Date: Wednesday, July 10th, 2024

Time: 12:30 PM - 2:30 PM EST

Location: UAW 3115 - McIntire Conference Room

Virtual Link: https://gatech.zoom.us/j/8412722722?pwd=cDR3d1RhL0tlR1Zpd1haNXcwVndSQT09&omn=97092383201

    Meeting ID: 841 272 2722

    Passcode: 102332

Namrata Unnikrishnan Nayar

Robotics Ph.D. Student

School of Mechanical Engineering

Georgia Institute of Technology

Committee:

Dr. Jaydev P. Desai (Advisor) - Department of Biomedical Engineering, Georgia Institute of Technology

Dr. Brooks Lindsey - Department of Biomedical Engineering, Georgia Institute of Technology

Dr. Yue Chen - Department of Biomedical Engineering, Georgia Institute of Technology

Dr. Levi Wood - School of Mechanical Engineering, Georgia Institute of Technology

Dr. Jun Ueda - School of Mechanical Engineering, Georgia Institute of Technology

Abstract: 

Mitral regurgitation affects 1.7% of the general population and 10% of those over 75, representing the most prevalent valvular heart disease. Transcatheter mitral valve repair (TMVr), increasingly preferred for nearly half of MR patients who are non-surgical candidates, currently utilizes manually operated devices that expose clinical staff to increased radiation, require experienced operators to facilitate intuitive compensations of the joints, and offer limited precision compared to potential robotic systems. This work introduces a robotically steerable transcatheter delivery system for treating mitral regurgitation, demonstrating effective positioning and orientation of the implant with respect to the mitral valve leaflets and extensive testing to validate its clinical relevance. Over five generations of the robotic transcatheter system, the steerable end tip design is optimized for effective implant deployment and the actuation system is refined for adequacy and compactness. 

Relevant clinical features are incorporated to enable intravascular surgery, intuitive control is demonstrated via joystick, and precise implant delivery is validated using existing TMVr procedure imaging modalities. The kinematics of the steerable end are derived, and a control system is presented. Since pure kinematics does not capture all the physical phenomena of a long catheter system, research has focused on characterizing tendon elongation, tendon sheath friction, and the influence of catheter configuration and tendon pre-tension. Furthermore, stiffness optimization of the bending joint with super elastic reinforcements minimizes deflection in pulsatile flow while ensuring compliant manipulation by the steerable outer sheath. Moreover, the study demonstrates the integration of a new real-time pose estimation technique utilizing ultrasound imaging for joint space control, and accurate positioning in conjunction with fluoroscopic imaging along with automatic trajectory generation. This is aimed at reducing trauma to the heart tissue during implant deployment. Extensive feasibility testing across phantom benchtop experiments, ex vivo heart models, and in vivo studies confirms the system’s efficacy, highlighting its readiness for clinical adoption and significant advancement in robotic catheter technology.