Fluoroscopic Shape and Pose Tracking of Catheters With Custom Radiopaque Markers

Safe navigation of steerable and robotic catheters in the cerebral vasculature requires awareness of the catheter's shape and pose. Currently, a significant perception burden is placed on interventionalists to mentally reconstruct and predict catheter motions from biplane fluoroscopy images. Efforts to track these catheters are limited to planar segmentation or bulky sensing instrumentation, which are incompatible with microcatheters used in neurointervention. In this work, a catheter is equipped with custom radiopaque markers arranged to enable simultaneous shape and pose estimation under biplane fluoroscopy. A design measure is proposed to guide the arrangement of these markers to minimize sensitivity to marker tracking uncertainty. This approach was deployed for microcatheters ($\leq \phi {\text{2}}\,\text {mm}$) navigating phantom vasculature with shape tracking errors <1 mm and catheter roll errors $< 40^{\circ }$. This work can enable steerable catheters to autonomously navigate under biplane imaging.