Optical properties of PlatSil SiliGlass tissue-mimicking phantoms

Abstract

In this work, we revise the preparation procedure and conduct an in depth characterization of optical properties for the recently proposed silicone-based tissue-mimicking optical phantoms in the spectral range from 475 to 925 nm. The optical properties are characterized in terms of refractive index and its temperature dependence, absorption and reduced scattering coefficients and scattering phase function related quantifiers. The scattering phase function and related quantifiers of the optical phantoms are first assessed within the framework of the Mie theory by using the measured refractive index of SiliGlass and size distribution of the hollow silica spherical particles that serve as scatterers. A set of purely absorbing optical phantoms in cuvettes is used to evaluate the linearity of the absorption coefficient with respect to the concentration of black pigment that serves as the absorber. Finally, the optical properties in terms of the absorption and reduced scattering coefficients and the subdiffusive scattering phase function quantifier γ are estimated for a subset of phantoms from spatially resolved reflectance using deep learning aided inverse models. To this end, an optical fiber probe with six linearly arranged optical fibers is used to collect the backscattered light at small and large distances from the source fiber. The underlying light propagation modeling is based on the stochastic Monte Carlo method that accounts for all the details of the optical fiber probe.

Brain-inspired optical imaging: a neuromorphic computing approach for image reconstruction of dynamic targets obscured by dense turbid media

“…Our experimental setup (Figure 1), designed for both transmission and reflection/backscattering geometries, employed a continuous wave near-infrared laser (850 nm, 15 mW). The laser illuminated silicone-based phantoms, simulating turbid media with microscale SiO2 particles [7], characterized by a scattering coefficient (µs = 6 mm-1) and anisotropy factor (g = 0.9) [8]. For dynamic target simulation, an electronic ink (E-ink) display [9] was used, positioned behind the phantom to display (flash) various MNIST dataset characters and images.…”

Effect of curvature correction on parameters extracted from hyperspectral images

“…The tissue phantoms were prepared from SiliGlass according to a slightly modified recipe of Sekar et al. 19 , 20 The substrate is platinum-cured silicon rubber (PlatSil ® SiliGlass), which is polymerized from two liquid parts, namely part A and part B. Therefore, it can reap the benefits of liquid phantoms such as easy customization of each optical layer by adding small quantities of absorber or scatterer.…”

“…An interested reader can find more information in Refs. 19 and 20 . First, the absorber and part A were mixed in a disposable plastic cup for 10 min using a magnetic stirrer and a glass rod.…”

Open-source protocol for preparation of turbid phantoms with microsphere suspensions

“…The accuracy of the required parameters directly influences the accuracy of the calculated optical properties. Recently, we have proposed a simple approach to measure the refractive index of polystyrene microspheres 8 . We have found that the most appropriate value for the microspheres is provided by Nikolov et al 6 , although a significant number of publications dealing with turbid phantoms refer to the refractive index of Ma et al 7 .…”