Contrast-Free Autonomous Navigation of Untethered Endovascular Microrobots Using Single-Plane Fluoroscopy
2026-08-31 • Robotics
Robotics
AI summaryⓘ
The authors developed a new method called VISTA that helps tiny robots move inside blood vessels while being tracked by a single X-ray camera, which usually only shows flat 2D images. VISTA creates a 3D virtual map of the vessels and uses it to figure out where the robot is and how it should move without needing extra contrast dyes. This approach was tested in lab models and live rats, showing it can make navigation faster, need fewer manual corrections, and reduce X-ray exposure. Their work could make using these small robots in medical procedures safer and more efficient.
microrobotsingle-plane fluoroscopy3D navigationdigital twinvascular anatomymagnetic actuationendovascular procedurescontrast agentnavigation milestonesradiation exposure
Authors
Husnu Halid Alabay, Tuan-Anh Le, Ping Wang, Hakan Ceylan
Abstract
Reliable three-dimensional (3D) navigation of magnetically actuated untethered microrobots remains a major barrier to clinical translation. X-ray fluoroscopy is the standard real-time imaging modality for endovascular procedures, but single-plane fluoroscopy provides only a two-dimensional (2D) projection, eliminating depth information and complicating autonomous navigation. Recovering this information through biplane imaging or repeated contrast-enhanced angiography increases procedural complexity, radiation exposure, or contrast burden. Here, we introduce VISTA (Virtual Integration for Spatial Tracking and Autonomy), a digital twin framework enabling contrast-free autonomous navigation under single-plane fluoroscopy. VISTA reconstructs vascular anatomy as a 3D digital twin, discretizes the vessel centerline into navigation milestones, and assigns the detected 2D robot position to the nearest projected milestone. Consecutive milestones define the local vessel orientation used to generate magnetic actuation commands, converting single-plane fluoroscopic observations into topology-constrained navigation states without requiring contrast injection during navigation. VISTA is demonstrated across anatomically distinct vascular phantoms under continuous flow and within the inferior vena cava of a live rat in vivo. Compared with conventional fluoroscopic human-in-the-loop control, VISTA reduced navigation time by up to 62%, corrective actuation commands by up to 98%, and radiation exposure by up to 57%. These results establish VISTA as a digital twin-guided framework for contrast-free autonomous navigation of untethered endovascular microrobots using widely available single-plane fluoroscopy.