Computational Modeling of Device-tissue Interface Geometries for Time-resolved Fluorescence in Layered Tissue

摘要

Temporal measurements of fluorescence emitted from biological tissue provide information on biochemistry and morphology which may be useful in identifying neoplasia onset. Depth-selective detection of time-resolved fluorescence may enable enhanced discrimination of signals originating from individual tissue layers and thus improve device efficacy. In this study, we investigate how illumination-collection design parameters influence a device's ability to measure fluorophore lifetime and changes in superficial layer thickness. A two-layer, time-resolved Monte Carlo model of fluorescence light propagation in colonic polyps was used to simulate temporal decay curves. Several normal- and oblique-incidence geometries were investigated. Also, the efficacy of a convolution-based, bi-exponential lifetime calculation is compared to a full-width-half-max decay curve metric. Results indicate that interface design has a significant effect on the accuracy of fluorophore lifetime estimates and the ability to discrimnate changes in tissue morphology. This is due to changes in the relative contribution of each tissue layer to the total detected signal.