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1
Content available Modeling of photochemical and photothermal effects in soft tissue subjected to laser irradiation
Jasiński Marek, Zadoń Maria
Computer Assisted Methods in Engineering and Science
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2024
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Vol. 31, no. 1
29--50
EN
The purpose of this study is to analyze the phenomena that occur in biological tissueduring photodynamic therapy (PDT). Under the influence of the laser, triplet oxygen istransformed into singlet oxygen, which is cytotoxic to cancer tissue. The impact of thelaser on the tissue may also be accompanied by changes in the thermophysical parameters,e.g., perfusion, which can affect the supply of oxygen to the tissue and, consequently,the outcome of the therapy. The proposed model uses the optical diffusion equation,the Pennes bioheat transfer equation, and reactions equations for PDT. The connectionbetween bioheat transfer and PDT models is taken into account through the respectiverelationships between perfusion rate, capillary blood velocity, and the maximum oxygensupply rate. Furthermore, a method is proposed to model abnormal vascular patterns inthe tumor subdomain. The boundary element method and the finite difference methodwere used in the numerical implementation stage.
2
Content available Numerical analysis of thermal damage and oxygen distribution in laser irradiated tissue
Jasiński Marek
Journal of Applied Mathematics and Computational Mechanics
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2022
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Vol. 21, nr 2
51--62
EN
A numerical analysis of the thermal damage process that proceeds in biological tissue during laser irradiation is presented. Heat transfer in the tissue is assumed to be transient and two-dimensional. The internal heat source resulting from the laser irradiation based on the solution of optical diffusion equation is taken into account. Changes in tissue oxygen distribution resulting from temperature changes are analyzed using the Krogh cylinder model with Michaelis-Menten kinetics. A Hill model was used to describe the oxyhemoglobin dissociation curve. At the stage of numerical realization, the boundary element method and the finite difference method have been applied.
3
Content available Mathematical modeling of the phenomena that occur in a biological tissue containing photosensitizer
Jasiński Marek, Zadoń Maria
Journal of Applied Mathematics and Computational Mechanics
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2022
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Vol. 21, nr 4
40--51
EN
The aim of the study is to analyze photothermal and photochemical phenomena that occur during photodynamic therapy (PDT). In this type of therapy, under the influence of the laser, reactions take place related to the transformation of triplet oxygen form into its singlet form which is cytotoxic to the tissue. The increases in temperature resulting from the laser-tissue interaction during PDT are not big; however, they can lead to changes in tissue perfusion, which can affect oxygen delivery to the tissue. The proposed model uses optical diffusion equation, Pennes bioheat transfer equation, and reactions equations for PDT. The main findings of the analysis show the impact of temperature on the value of the perfusion coefficient and triplet oxygen distributions at the end of the treatment procedure.
4
Content available Modelling of biological tissue damage process with application of interval arithmetic
Korczak Anna, Jasiński Marek
Journal of Theoretical and Applied Mechanics
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2019
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Vol. 57 nr 1
249--261
EN
In the paper, the numerical analysis of thermal processes proceeding in a 2D soft biological tissue subjected to laser irradiation is presented. The transient heat transfer is described by the bioheat transfer equation in Pennes formulation. The internal heat source resulting from the laser-tissue interaction based on the solution of the diffusion equation is taken into account. Thermophysical and optical parameters of the tissue are assumed as directed intervals numbers. At the stage of numerical realization. the interval finite difference method has been applied. In the final part of the paper, the results obtained are shown.
5
Content available Modelling of thermal damage process in soft tissue subjected to laser irradiation
Jasiński M.
Journal of Applied Mathematics and Computational Mechanics
|
2018
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Vol. 17, nr 2
29--41
EN
The numerical analysis of thermal damage process proceeding in biological tissue during laser irradiation is presented. Heat transfer in the tissue is assumed to be transient and two-dimensional. The internal heat source resulting from the laser irradiation based on the solution of the diffusion equation is taken into account. The tissue is regarded as a homogeneous domain with perfusion coefficient and effective scattering coefficient treated as dependent on tissue injury. At the stage of numerical realization, the boundary element method and the finite difference method have been used. In the final part of the paper the results of computations are shown.
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