Measurement of the reduced scattering coefficient of turbid media using single fiber reflectance spectroscopy: fiber diameter and phase function dependence

This paper presents a relationship between the intensity collected by a single fiber reflectance device (R_SF) and the fiber diameter (d_fib) and the reduced scattering coefficient ( ${\mu }_s^{\prime }$) and phase function (p(θ)) of a turbid medium. Monte Carlo simulations are used to identify and model a relationship between R_SF and dimensionless scattering ( ${\mu }_s^{\prime }{d}_{\mathit{\text{fib}}}$). For ${\mu }_s^{\prime }{d}_{\mathit{\text{fib}}}\hspace{0.17em}>\hspace{0.17em}10$ we find that R_SF is insensitive to p(θ). A solid optical phantom is constructed with ${\mu }_s^{\prime }\hspace{0.17em}\approx \hspace{0.17em}220\hspace{0.17em}{\text{mm}}^{-1}$ and is used to convert R_SF of any turbid medium to an absolute scale. This calibrated technique provides accurate estimates of ${\mu }_s^{\prime }$ over a wide range ([0.05 – 8] mm⁻¹) for a range of d_fib ([0.2 – 1] mm).