Real-time robotically assisted optical coherence tomography with low-latency surface tracking for large-area skin imaging

Abstract

Optical coherence tomography (OCT) is an imaging modality for depth-resolved visualization of tissue with microscopic resolution but is typically limited to small imaging areas of ~10×10 mm ² . To address this, we previously developed a large-area robotically assisted OCT (LARA-OCT) system combining MHz-rate swept-source OCT with robotic scanning for imaging of extended and nonplanar surfaces, particularly for in vivo skin imaging. However, earlier implementations were constrained by data-transfer-induced dead times, resulting in discontinuous acquisition. In this work, we present a real-time extension of LARA-OCT that improves temporal performance and control. Real-time volumetric OCT processing enables direct estimation of sample surface height and orientation and low-latency feedback for closed-loop probeto- surface alignment. This increases the control loop frequency from a few Hertz to the OCT volume rate of 20- 200 Hz, enabling faster probe positioning and synchronized robot motion with minimal dead time. Proof-of-concept experiments demonstrate high-throughput imaging with improvements of approximately 3× in physical area acquisition rate and 3.7× in volume acquisition rate. This represents a key step towards continuous large-area imaging and enables fast, automatic, and reproducible large-area acquisition for clinical applications.