Self-Steering Catheters for Neuroendovascular Interventions.

The size limitations and tortuosity of the neurovasculature currently exceed the capabilities of existing robotic systems. Furthermore, safety considerations require a fail-safe design whereby some passive compliance is used for an added layer of safety and for sensing the lateral load on the steerable portion of the catheter. To address these needs, we propose a novel multi-articulated robotic catheter technology that aims to increase technical precision, reduce procedural time and radiation exposure, and enable the semi-automation of catheters during neuroendovascular procedures. This catheter uses joint-level sensing and fluoroscopic imaging to actively bend in two separate planes. Its design also uses series-elastic actuation for increased safety and active compliance (self-steering). We present the design, kinematic modeling, and calibration of this system. A multi-mode real-time control architecture of the system was implemented and experimentally validated. We demonstrate the use of the robotic catheter for branch selection, insertion in an unknown channel under active compliance, and autonomous deployment within a 2D vasculature model. Furthermore, we developed algorithms for intra-operative catheter tracking and pose filtering. Methods presented in this paper make significant strides towards the future goal of enabling semi-autonomous navigation for neuroendovascular procedures.