Computational Analysis of Beveled-Tip Fiber Probes for Selective Detection of Subsurface Fluorophores in Turbid Media

摘要

Optimization of illumination-collection parameters may lead to an improvement in the efficacy of fluorescence spectroscopy devices for minimally invasive disease detection. While device-tissue interface geometry has been shown to have a strong influence on the origin of detected fluorescence, prior studies have tended to focus on systems which deliver and collect light at approximately normal incidence to the tissue surface. Optical fibers with beveled surfaces enable the delivery and/or collection of light at a range of angles. This feature may make it possible to interrogate subsurface tissue regions with a greater degree of spatial selectivity. In this study, simulations were performed using a Monte Carlo model of fluorescent light propagation in order to estimate the behavior and potential limitations of this approach. The effect of tissue optical properties, illumination angle, collection angle and illumination-collection fiber separation distance were investigated. Results indicated that beveled fiber probes may significantly improve the ability of fiberoptic probes to selectively interrogate specific tissue regions or layers, however, the advantage over flat fibers is reduced as tissue attenuation increases.