Dual phase lag behavior of living biological tissues in laser hyperthermia
Abstract
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] A Generalized dual phase lag behavior for living biological tissues are investigated for blood and tissues and also developed a generalized dual phase model for artery, vein and tissues in this thesis. There are two parts of this thesis: a) A Generalized dual phase lag (DPL) bioheat model based on the non equilibrium heat transfer in living biological tissues is applied to investigate thermal damage induced by laser irradiation. Comparisons of the temperature responses and thermal damages between the generalized and classical DPL bioheat model, derived from the constitutive DPL model and Pennes bioheat equation, and as well as Fourier heat conduction model are carried out. It is shown that the generalized DPL model could predict significantly different temperature and thermal damage from the classical DPL model and Fourier heat conduction model. The generalized DPL equation can reduce to the classical Pennes heat conduction equation only when the phase lag times of temperature gradient ( T) and heat flux vector ( q) are both zero. The effects of laser parameters such as laser exposure time, laser irradiance, and coupling factor on the thermal damage are also studied. b) Arterial, venous blood and solid tissue are the three energy carriers that contribute to heat transfer in the living biological tissues. A generalized dual-phase lag mode for living biological tissues based on nonequilibrium heat transfer between tissue, artery and venous bloods is presented in this thesis. The phase lag times for heat flux and temperature gradient only depend on properties of artery, vein and tissue, blood perfusion rate and convective heat transfer rate and are estimated using the available properties from the literature. It is found that the phase lag times for heat flux and temperature gradient are the identical for the case that the tissue and blood have the same properties. However, the phase lag times are different for the case that the properties of tissue and bloods are different. The phase lag times for brain and muscles are also discussed.
Degree
M.S.
Thesis Department
Rights
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