scholarly journals PARAMETRIC STUDY OF TISSUE OPTICAL CLEARING BY LOCALIZED MECHANICAL COMPRESSION USING COMBINED FINITE ELEMENT AND MONTE CARLO SIMULATION

2010 ◽  
Vol 03 (03) ◽  
pp. 203-211 ◽  
Author(s):  
WILLIAM C. VOGT ◽  
HAIOU SHEN ◽  
GE WANG ◽  
CHRISTOPHER G. RYLANDER
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Optical Properties ◽  
Light Transmission ◽  
Compressive Strain ◽  
Monte Carlo Model ◽  
Biological Tissues ◽  
Optical Clearing ◽  
Tissue Optical Properties ◽  
Tissue Optical Clearing

Tissue Optical Clearing Devices (TOCDs) have been shown to increase light transmission through mechanically compressed regions of naturally turbid biological tissues. We hypothesize that zones of high compressive strain induced by TOCD pins produce localized water displacement and reversible changes in tissue optical properties. In this paper, we demonstrate a novel combined mechanical finite element model and optical Monte Carlo model which simulates TOCD pin compression of an ex vivo porcine skin sample and modified spatial photon fluence distributions within the tissue. Results of this simulation qualitatively suggest that light transmission through the skin can be significantly affected by changes in compressed tissue geometry as well as concurrent changes in tissue optical properties. The development of a comprehensive multi-domain model of TOCD application to tissues such as skin could ultimately be used as a framework for optimizing future design of TOCDs.

QUANTITATIVE CONTROL OF OPTICAL CLEARING EFFECTS STUDIED WITH TISSUE-LIKE PHANTOM

2010 ◽  
Vol 03 (03) ◽  
pp. 195-202 ◽  
Author(s):  
JINGYING JIANG ◽  
WEI CHEN ◽  
QILIANG GONG ◽  
KEXIN XU
Keyword(s):  
Optical Properties ◽  
Biological Tissues ◽  
Porcine Skin ◽  
Tissue Samples ◽  
Optical Clearing ◽  
Tissue Optical Properties ◽  
Application Potential ◽  
The Difference ◽  
Tissue Optical Clearing

Tissue optical clearing by use of optical clearing agents (OCAs) has been proven to have potential to reduce the highly scattering effect of biological tissues in optical techniques. However, the difference in tissue samples could lead to unreliable results, making it difficult to quantitatively control the dose of OCAs during the course of tissue optical clearing. In this work, in order to study the effects of optical clearing, we customized tissue-like phantoms with optical properties of some biological tissue. Diffuse reflectance and total transmittance of tissue-like phantoms with different OCAs (DMSO or glycerol) and porcine skin tissues were measured. Then optical property parameters were calculated by inverse adding-doubling (IAD) algorithm. Results showed that OCAs could lead to a reduction in scattering of tissue-like phantoms as it did to porcine skin tissue in vitro. Furthermore, a series of relational expressions could be fit to quantitatively describe the relationship between the doses of OCAs and the reduction of scattering effects. Therefore, proper tissue-like phantom could facilitate optical clearing to be used in quantitative control of tissue optical properties, and further promote the application potential of optical clearing to light-based noninvasive diagnostic and therapeutic techniques.

scholarly journals Measurement of tissue optical properties in the context of tissue optical clearing

2018 ◽  
Vol 23 (09) ◽  
pp. 1 ◽  
Author(s):  
Alexey N. Bashkatov ◽  
Kirill V. Berezin ◽  
Konstantin N. Dvoretskiy ◽  
Maria L. Chernavina ◽  
Elina A. Genina ◽  
...  
Keyword(s):  
Optical Properties ◽  
Optical Clearing ◽  
Tissue Optical Properties ◽  
Tissue Optical Clearing

scholarly journals Machine learning estimation of tissue optical properties

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brett H. Hokr ◽  
Joel N. Bixler
Keyword(s):  
Neural Network ◽  
Optical Properties ◽  
Biological Tissues ◽  
Homogeneous Layer ◽  
In Vivo Measurement ◽  
Tissue Optical Properties ◽  
The Neural Network ◽  
Spatio Temporal ◽  
Fully Connected

AbstractDynamic, in vivo measurement of the optical properties of biological tissues is still an elusive and critically important problem. Here we develop a technique for inverting a Monte Carlo simulation to extract tissue optical properties from the statistical moments of the spatio-temporal response of the tissue by training a 5-layer fully connected neural network. We demonstrate the accuracy of the method across a very wide parameter space on a single homogeneous layer tissue model and demonstrate that the method is insensitive to parameter selection of the neural network model itself. Finally, we propose an experimental setup capable of measuring the required information in real time in an in vivo environment and demonstrate proof-of-concept level experimental results.

scholarly journals Simulation of Light Distribution in Gamma Irradiated UHMWPE Using Monte Carlo Model for Light (MCML) Transport in Turbid Media: Analysis for Industrial Scale Biomaterial Modifications

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3039
Author(s):  
Ali Rizwan ◽  
Muhammad Saleem ◽  
Suhail H. Serbaya ◽  
Hemaid Alsulami ◽  
Aqsa Ghazal ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Optical Properties ◽  
Monte Carlo Model ◽  
Media Analysis ◽  
Light Distribution ◽  
Light Transport ◽  
Photon Absorption ◽  
Industrial Scale ◽  
Scattering Coefficients ◽  
Gamma Irradiated

(1) Background: This study investigated the miscibility of carbon-based fillers within industrial scale polymers for the preparation of superior quality polymer composites. It focuses on finding the light distribution in gamma irradiated ultra-high molecular weight polyethylene (UHMWPE). (2) Methods: The Kubleka–Munk model (KMM) was used to extract the optical properties, i.e., absorption coefficients (μa) and scattering coefficients (μs). Samples amounting to 30 kGy and 100 kGy of irradiated (in the open air) UHMWPE from 630 nm to 800 nm were used for this purpose. Moreover, theoretical validation of experimental results was performed while using extracted optical properties as inputs for the Monte Carlo model of light transport (MCML) code. (3) Conclusions: The investigations revealed that there was a significant decrease in absorption and scattering coefficient (μa & μs) values with irradiation, and 30 kGy irradiated samples suffered more compared to 100 kGy irradiated samples. Furthermore, the simulation of light transport for 800 nm showed an increase in penetration depth for UHMWPE after gamma irradiation. The decrease in dimensionless transport albedo  μs(μa+μs) from 0.95 to 0.93 was considered responsible for this increase in photon absorption per unit area with irradiation. The report results are of particular importance when considering the light radiation (from 600 nm to 899 nm) for polyethylene modification and/or stabilization via enhancing the polyethylene chain mobility.

scholarly journals Energy transport in conjugated polymers: electronic structure and kinetic Monte Carlo simulations

2020 ◽  
Author(s):  
Laura Simonassi Raso de Paiva ◽  
Leonardo Evaristo de Sousa ◽  
Pedro Henrique de Oliveira Neto
Keyword(s):  
Monte Carlo ◽  
Optical Properties ◽  
Conjugated Polymers ◽  
Energy Transport ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Model ◽  
Active Materials ◽  
Exciton Diffusion ◽  
Polymeric Chains ◽  
Kinetic Monte Carlo Simulations

Conjugated polymers are materials that have attracted much attention from the research community because of their charge and energy transport properties. In this sense, it is necessary to understand the mechanism behind exciton transfer in this particular class of systems. However, direct application of procedures done for different organic compounds is not straightforward for long polymeric chains, because such procedures would be computationally impracticable. In that matter, alternative treatments are required. In this work, we perform spectrum simulations for poly-thiophene (PTH) and poly(p-phenylene vinylene) (PPV) chains by analyzing the evolution of electronic properties with oligomer sizes and its effects on exciton diffusion. Furthermore, employing a kinetic Monte Carlo model, we also investigate the efficiency of intrachain exciton diffusion. Our results show a reliable description of the optical properties for long polymeric chains, and a comparison is made between the different approaches in describing the optical properties of such polymers. This study may be useful in the development of more sophisticated optoelectronic devices that use conjugated polymers as its active materials.

Tissue Optical Clearing Devices: Effects of Water Content on the Hyperelastic Mechanical Properties of Ex Vivo Porcine Skin

2010 ◽  
Author(s):  
William Vogt ◽  
Alondra Izquierdo-Roman ◽  
Christopher G. Rylander
Keyword(s):  
Near Infrared ◽  
Light Transmission ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Complex Structure ◽  
Heterogeneous Material ◽  
Index Of Refraction ◽  
Water Displacement ◽  
Optical Clearing ◽  
Tissue Optical Clearing

Skin is a highly anisotropic and heterogeneous material composed of water, proteins, and various cells arranged in several different layers. Because of this complex structure, there is a large mismatch in index of refraction between the tissue constituents, creating a highly scattering medium for near-infrared and visible light. “Tissue optical clearing” methods can improve light transmission through tissues, potentially improving optical imaging techniques and photoirradiative treatments [1]. Dehydration has been suggested as a possible mechanism of optical clearing [2], and previous work has demonstrated mechanical loading as a method of creating reversible localized water displacement in skin using novel tissue optical clearing devices (TOCDs) [3–4]. These TOCDs were hypothesized to increase light transmission by displacing water locally in the tissue, causing local dehydration. A model of the mechanical behavior of skin will enable improvement of current TOCDs that utilize local mechanical compression.

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