Narrow Results

Several studies have been conducted on the applicability of hyperthermia radiofrequency in the treatment of liver tumors. Many theoretical studies have reported the relevance of various physical parameters in terms of their efficacy in combating tumors and have analyzed the impact of these physical parameters on the temperature profile in the diseased tissue. Parameters such as thermal and electrical conductivities have been investigated during simulations of thermal ablation. Such parameters play an important role in the process of heat transfer in tissues. The purpose of this study is to predict the lesion volume, considering the inclusion of temperature dependence of thermal-electrical properties. This paper introduces a three-dimensional computational model that includes different comparative combinations of tissue thermal-electrical parameters as a mapping of temperature (such as thermal and electrical conductivities and specific heat). The finite-element method is employed for simulating hepatic radiofrequency ablation through the numerical solutions of the bioheat, Laplace, and Navier–Stokes equations. The results suggest that different combinations of tissue temperature-dependent parameters can significantly affect the computed lesion volume and that the temperature dependence of electrical conductivity has a major impact on the computed lesion volume and temperature distribution.

In recent days, the number of cancer cases is escalating promptly around the world. In general, conventional ablation methods, encompassing comprehensive drawbacks, are employed to cure cancer. At present, photo thermal therapy (PTT) is showing great promise to the treatment of cancer. However, the effective implementation of this technology is utmost challenging as several parameters affect the tumor surroundings. In this work, the effects of different parameters on the performance of PTT have been thoroughly investigated by considering a realistic model of human tissue underneath the skin using a finite element solver, COMSOL Multiphysics. Two different conditions, with and without considering gold nanoparticles at tumor site, are investigated where a laser beam is used as a source of energy. Fluence rate, temperature distribution, and thermal damage are highlighted in this work. It is observed that by utilizing a miniature needle with integrated waveguide and gold nanoparticles, a tumor can be effectively eradicated along with assuaging the conventional drawbacks of PTT. This study would also be useful for designing operative PTT for different parts of human tissue.

Biothermomechanics of skin tissue is highly interdisciplinary, involving bioheat transfer, burn damage, biomechanics and physiology. Characterization of the thermomechanical behavior of skin tissue is of great importance and can contribute to a variety of medical applications. However, few studies have attempted to address the influence of heat induced thermal damage on the mechanical properties of skin tissue. This paper presents the compressive behavior of pigskin at different thermal damage levels and discusses the possible mechanisms of thermal damage–dependent compressive behavior of skin. The results demonstrate that skin stiffness decreases with increasing thermal damage degree and there exists strain rate sensitivity at different damage levels, caused mainly by hydration changes.

Skin thermal damage is the most common thermal trauma in civilian and military communities. Besides, advances in laser, microwave, and similar technologies have led to recent developments of thermal treatments for diseases involving skin tissue aiming at inducing damage precisely within targeted tissue structures without affecting the surrounding healthy tissue. Pain sensation accompanying thermal damage is also a serious problem for burn patients. Therefore, it is of great importance to quantify the thermal damage in skin tissue. In this review, we detail the progress of the state-of-the-art mathematical models and experimental methods for the quantification of thermal damage (both heat damage and cold damage) and the general development of thermal treatments in tissue engineering. This could enable better understanding of the underlying mechanisms of skin thermal damage and the optimization of clinical thermal therapies.

This paper deals with the study of fractional bioheat equation for hyperthermia treatment in cancer therapy with external electromagnetic (EM) heating. Time fractional derivative is considered as Caputo fractional derivative of order α ∈ (0, 1]. Numerical solution is obtained by implicit finite difference method. The effect of anomalous diffusion in tissue has been studied. The temperature profile and thermal damage over the entire affected region are obtained for different values of α.

As a starting point for developing analytical models of predicting skin temperature and damage extent into multi-layer ones, a double-layer model consisting of two distinguished and attached layers is considered: a tissue layer containing blood vessels and a tissue layer containing no blood vessels. The Pennes model is applied for the tissue containing blood vessels. Applying the Laplace transform, then the inversion theorem for Laplace transforms and the Cauchy residue theorem, the desired skin temperature function is obtained. Applying the temperature function in a damage model, the severity and degree of damage can be determined. Validating this model against previous analytical, numerical and experimental data, the error rate is determined.

A semi-analytical solution of bio-heat conduction on the three-layer skin is presented. The performance of the typical heat treatment (heating by laser and cooling by fluid at skin surface) is studied. The transient temperature field and thermal damage of skin are investigated. Effects of several parameters on temperature variation and thermal damage are discussed. The results of the paper will be useful for heat therapy in clinics. In addition, the presented result is very consistent to that by the finite element method. The semi-analytical method can be easily applied for solving the general problem of heat conduction in any multilayer structure.

This paper deals with the study of heat transfer and thermal damage in triple layer skin tissue using fractional bioheat model. Here, we consider three types of heating viz. sinusoidal heat flux, constant temperature and constant heat flux heating on skin surface. An implicit finite difference scheme is obtained by approximating fractional time derivative by quadrature formula and space derivative by central difference formula. The temperature profiles and thermal damage in the skin tissue are obtained to study the effect of fractional parameter $\alpha$ on diffusion process for constant temperature and heat flux boundary heating on skin surface. A parametric study for sinusoidal heat flux at skin surface has also been made.