Modeling Non-Linear Effects in a 4-DoF Robotic Transcatheter Delivery System

Transcatheter mitral valve repair (TMVr), a minimally invasive approach, is becoming increasingly popular for treating mitral regurgitation (MR) since nearly half of the MR patients are non-surgical candidates. However, current TMVr devices are operated manually, increasing radiation exposure to the clinical staff and making telesurgery infeasible. A robotically steerable transcatheter delivery system can alleviate these issues while also enhancing consistency, improving precision, and mitigating human fatigue during the procedure. Moreover, precise manipulation of a surgical robotic system requires effective system modeling. Therefore, in this work, we model a full-scale robotically steerable transcatheter delivery system, accounting for the hysteresis, friction, tendon elongation, and catheter configuration. We also account for the coupling between the joints of the robotic steerable end and the effect of the catheter configuration on the joints. Experiments were conducted in free air to validate the proposed model while subjecting the robotic transcatheter delivery system to similar tortuosity as encountered during a TMVr procedure.