Correction of an adding-doubling inversion algorithm for the measurement of the optical parameters of turbid media.

Paul Lemaillet,Dirk Grosenick,Jeeseong Hwang,Heidrun Wabnitz,David W Allen,Catherine C Cooksey,Lin Yang

doi:10.1364/boe.9.000055

Abstract

We present broadband measurements of the optical properties of tissue-mimicking solid phantoms using a single integrating sphere to measure the hemispherical reflectance and transmittance under a direct illumination at the normal incident angle. These measurements are traceable to reflectance and transmittance scales. An inversion routine using the output of the adding-doubling algorithm restricted to the reflectance and transmittance under a direct illumination was developed to produce the optical parameters of the sample along with an uncertainty budget at each wavelength. The results for two types of phantoms are compared to measurements by time-resolved approaches. The results between our method and these independent measurements agree within the estimated measurement uncertainties.

Highlights

Well-characterized tissue-mimicking phantoms are essential to validate the performance and to calibrate measurement results in the development and clinical applications of biomedical instruments from the bench and to the bedside
INO does not provide an estimation of the uncertainties of their results so we used the uncertainty values computed for different samples at λ = 660 nm as presented in their reference paper (Ref. [3])
We present the broadband measurements of the optical parameters of two types of tissuemimicking solid phantoms, one polyurethane-based from INO and the other made at National Institute of Standards and Technology (NIST) using

Summary

Introduction

Well-characterized tissue-mimicking phantoms are essential to validate the performance and to calibrate measurement results in the development and clinical applications of biomedical instruments from the bench and to the bedside. A variety of measurement techniques with the aids of physics-based photon-transport models have been developed to measure these parameters. Measurements of the optical properties of turbid media in the time domain are based on the estimation of the temporal spreading of a light pulse subjected to scattering and absorption events as it travels through the sample. Analysis using the diffusion approximation of the radiative transfer equation (RTE) or Monte Carlo (MC)based model were used to obtain μa and μs = μs(1 − g) (reduced scattering coefficient) of liquid [1,2] and solid phantoms [3]. In the scope of the diffusion approximation, frequency domain measurements techniques were used to measure the optical properties of turbid liquids [4,5,6]

Methods

Results

Conclusion