Broadband spectroscopy for characterization of tissue-like phantom optical properties

Abstract

Optical phantoms are widely used for evaluating the performance of biomedical optical modalities, and hence, absorbing and scattering materials are required for the construction of optical phantoms. Towards that aim, new readily available and inexpensive black Ink (Parker) as a simulating absorber as well as Intralipid 20% as a simulating scatterer are thoroughly investigated. Broadband Transmittance and Diffuse reflectance spectroscopic measurements were performed in the visible range 400 -700 nm. Optical properties of the phantom materials are determined. Analytical expressions for absorption and scattering coefficient related to the concentrations and wavelength of the Parker ink and Intralipid are also presented and discussed. The results show nonlinear trend in the absorption coefficient of Parker ink over the examined visible spectral range. Furthermore, Intralipid scattering coefficient variation across the mentioned spectral range shows a tissue-like scattering trend. The findings demonstrate the capability of the broadband transmission and diffuse reflectance for characterizing tissue-like phantom materials in the examined spectral range.

Optical characterization of tissue-simulating phantom components at 405nm

“…Therefore, the pure ink extinction coefficient turned out to be 148.4 mm −1 , absorption coefficient was 132.9 mm −1 , scattering coefficient was 15.5 mm −1 and albedo was 0.1044. In the best of our knowledge, Parker ink has not been studied previously at 405 nm [4][5][6][7]15]. Furthermore, the present findings have shown a small scattering of ink in comparison to the absorption coefficient at 405 nm but this value has not been neglected in many cases.…”

Polystyrene Microsphere Optical Properties by Kubelka–Munk and Diffusion Approximation with a Single Integrating Sphere System: A Comparative Study

“…Spectrophotometric transmission spectroscopy was used to measure the collimated transmittance of a 1 μm polystyrene utilized to estimate the extinction coefficient, Figure 2. From Figure 2 and equation (9), the power correlation of the extinction coefficient and wavelength over a studied range were obvious. Based on diffuse transmittance and reflectance that were measured by a single integrating sphere system and collimated transmittance, the scattering coefficient of 1 μm polystyrene sphere could be predicted using Kubelka-Munk and diffusion approximation methods, Figures 4(a) and 4(b), respectively.…”

“…e sample was illuminated with a collimated white light beam. us, the transmission intensity may be approximated by the Beer-Lambert Law [8,9]:…”

“…where μ t (λ) is the extinction coefficient, I z (λ) is the intensity of light passed through the studied sample, I 0 (λ) is the reference intensity, z is the optical path length (thickness of cuvette), c is the concentration, and T c is the collimated transmittance [8,9].…”

“…e present method has been investigated with a single integrating sphere system over visible and N-IR wavelength range on biological tissues and optical phantoms [7,8]. On the other hand, diffusion approximation has been considered as an approximate solution of the radiative transfer equation for semi-infinite and high diffusive medium for collimated incident light [9,10].…”