Abstract
In a conventional ICG fluorescence observation system, the flow of ICG is observed using an IR camera and displayed on a monitor. However, it can be difficult to clearly understand the correspondence between the area of fluorescence on the body and that displayed on the monitor. We therefore propose a novel system that projects the area of ICG fluorescence directly onto the body surface. The system is composed of a commercially available IR camera, a laser projector, and an IR LED. The system excites the ICG by irradiation from the IR LED and detects the area of fluorescence by subtracting a non-excited image from an excited image and applying threshold processing. The subtracted image is transformed to correct distortion using a space-coding method and projected onto the body. The results of accuracy evaluation showed that the average transformation error was less than 0.5 mm. ICG fluorescence in a biological phantom could be observed to a depth of about 12 mm. The feasibility of employing this system in clinical applications was also assessed by conducting animal experiments.
