Thermo-vibrational analyses of skin tissue subjected to laser heating source in thermal therapy

Rayleigh waves in thermally affected skin tissues based on age, gender and morphology

The present work studies the variation in the nature of Rayleigh waves due to change in age, gender and morphological region of human skin tissue in the context of three-phase-lag (TPL) nonlocal thermoelastic theory. The secular equations are derived using the stress free, thermally insulated or isothermal boundary conditions. These secular equations are solved numerically and two significant modes of Rayleigh wave are noted to propagate simultaneously. The phase speeds, attenuation coefficients and path of the particle motion for both modes are presented graphically. These results are compared for different age, gender and morphological region of the source skin tissue. We have observed that the phase speeds increase with the increases of stiffness of the skin and vice versa. Certain specific angular frequencies and phase speeds are obtained which can be used for the detection and thermal therapy of skin disorders. Some published results are recovered as special cases to validate the current results.

Mathematical Modelling with the Exact Solution of Three Different Bioheat Conduction Models of a Skin Tissue Shocked by Thermoelectrical Effect

This research deals with the temperature increment and responsiveness of skin tissue to a continuous flow of surface heat induced by a constant-voltage electrical current. The exact analytical solution for the dual-phase-lag (DPL) of bioheat transfer has been obtained. It is used to confine the variables to a limited domain to solve the governing equations. The transition temperature reactions have been measured and investigated. The figures provide a comparison of the Pennes, Tzou models, and Vernotte-Cattaneo models. The numerical results demonstrate the values of the voltage, resistance, electric shock time, and dual-phase-lag time parameters which have significant influences on the distributions of the dynamic and conductive temperature rise through the skin tissue.

Refined Lord-Shulman Theory for 1D Response of Skin Tissue under Ramp-Type Heat

In this article, we present a mathematical model of thermoelastic skin tissue based on a refined Lord-Shulman heat conduction theory. A small thickness of skin tissue is considered to be one-dimensional with mechanical clamped surfaces. In addition, the skin tissue's outer surface is subjected to ramp-type heating while its inner surface is adiabatic. A simple Lord-Shulman theory, as well as the classical coupled thermoelasticity, are also applied in this article. Laplace transform techniques and their inversions are calculated to return to the time domain. Numerical outcomes are represented graphically to discuss the significant impacts on the temperature, dilatation, displacement, and stress distributions. Such results provide a more comprehensive and better insight for understanding the behavior of skin tissue during the temperature distribution of a specific boundary condition.