BLUE RIBBON POSTER IMAGING: A Portable Time-Gated Fluorescence Imaging System for Quantitative Perfusion Assessment during Open Orthopedic Surgeries
Abstract
Purpose
Accurate intraoperative assessment of tissue perfusion is critical for guiding debridement in traumatic and orthopedic injuries. However, existing fluorescence imaging systems are often unsuitable for resource-limited or high-ambient-light environments. This study developed and validated a compact, portable fluorescence imaging system for tissue perfusion imaging using indocyanine green (ICG), designed to enable quantitative perfusion assessment during open orthopedic surgeries in austere surgical settings.
Methods
The imaging system utilized battery-powered time-gated acquisition synchronized with pulsed near-infrared LED excitation to suppress ambient light interference during fluorescence imaging. A curved LED array was engineered to improve excitation uniformity across the large field of view. System performance was evaluated through simulations and phantom studies. A comprehensive comparison with a commercial fluorescence imaging system was conducted, assessing excitation uniformity, sensitivity, dynamic range, noise floor, spatial resolution, and total system weight. In vivo validation was performed in a rat model under skin-on, skin-off, and fractured bone conditions following intravenous ICG administration.
Results
The complete system weighed 5.9 lbs, representing an 87% reduction compared to the commercial system. The curved LED array design significantly improved excitation homogeneity, increasing the area receiving ≥70% of peak intensity from 37.3% to 65.8%. Phantom studies demonstrated higher ICG detection sensitivity and a substantially broader dynamic range under high ambient lighting. In vivo studies showed improved contrast between poorly perfused bone and surrounding soft tissue, reduced noise, and clearer differentiation of dynamic perfusion patterns.
Conclusion
The compact portable fluorescence imaging system delivers quantitative perfusion imaging with performance comparable to or exceeding that of commercial systems while offering greatly enhanced portability and resistance to ambient light. These advantages support its potential deployment in field hospitals, disaster response, and other resource-constrained surgical environments.