Single-fiber Forward-viewing A-scan Optical Coherence Tomography Allows Robot-assisted Blood Vessel Detection and Hemodynamic Monitoring in Complex Luminal Anatomies: A Phantom Study

Minimally invasive robotic surgery requires precise information about the subsurface vasculature within complex luminal anatomies, including the position, diameter, and number of blood vessels. Additionally, the blood flow rate in vessels is also crucial for intraoperative decision-making. While endoscopic radial-scanning optical coherence tomography (OCT) catheters face challenges from motion artifacts and luminal adhesion, single-fiber forward-viewing A-scan OCT integrated with robotics offers a promising alternative to detect vasculature in tortuous or stenotic environments. In this study, we designed a vascular phantom experiment to verify the blood vessel detection ability of single-fiber forward-viewing A-scan OCT. Based on imaging the vascular phantom in M-mode (repeated A-scans at the same position) and a decorrelation-based OCT motion contrast algorithm, our system can not only quantitatively measure the location and diameter of the vascular channel, but also provide stable monitoring of qualitative hemodynamic change. These results demonstrate that by combining robotic stabilization and motion contrast OCT analysis, the single-fiber forward-viewing A-scan OCT can provide potential for real-time vascular detection during guided interventions. © 2025 The Authors.