Probe design for implantable fluorescence-based sensors

Fluorescent chemical sensors ate being developed for in vivo use in quantification of important physiological species. Design of an optical probe for delivery of excitation radiation and collection of light emitted from subcutaneous fluorescent sensors is a critical step in developing reliable measurement methods. This paper outlines the use of Monte Carlo simulations of light propagation in estimating the radial distribution of light emitted from the sensor as well as tissue fluorescence. A discussion of how the results of such models can be used to optimize probe geometry for maximum signal-to-noise is presented. Sensitivity of the simulation to layer thickness, tissue optical properties, and sensor composition are detailed. Simulation output is also compared with experimental results and progress in development of one potential sensor system is presented.