Cheng S.F.,National Chung Hsing University |
Su W.C.,National Chung Hsing University |
Lin S.C.,Shin Ming Reviving Clinic |
Chen M.H.,Shin Ming Reviving Clinic
Digest Journal of Nanomaterials and Biostructures | Year: 2014
In this research, we aim to study the boundary heating problem of organisms and to develop a novel methodology for future applications in bioheat transfer and cosmetic laser surgery problems. For biological tissues, the characteristic time needed for accumulating the thermal energy required for propagative transfer to the nearest element within nonhomogeneous inner structures is very large. If the boundary heat source is relatively weak, the Pennes equation is appropriate for describing the heat transfer mechanism. However, for very strong heat source such as laser irradiation, which requires an extremely short time and its heat flux is tremendously high, the thermal wave effect becomes evident during the heat transfer process. In this case, the governing equation is a hyperbolic thermal wave equation. We propose a sampled-data strategy for boundary control of this heat conduction problem modeled by either the Pennes equation or the thermal wave equation. With zero-order-hold, the boundary control law becomes a piecewise constant signal, in which a step change of value occurs at each sampling instant. Through this discretization technique, the governing partial differential equation is dissected into a sequence of constant input problems, to be solved individually for a sampled-data formulation. With this sampled-data formulation, the boundary control problem can be solved and implemented digitally. © 2014, Inst Materials Physics. All rights reserved.