Investigation of memory influences on bio-heat responses of skin tissue due to various thermal conditions.

Advancement of new technologies such as laser, focused ultrasound, microwave and radio frequency for thermal therapy of skin tissue has increased numerous challenging situations in medical treatment. In this article, a new meticulous bio-heat transfer model based on memory-dependent derivative with dual-phase-lag has been developed under different thermal conditions such as thermal shock and harmonic-type heating. Laplace transform method is acquired to perceive the analytical consequences. Quantitative results are evaluated for displacement, strain and temperature along with stress distributions in time domain by adopting the technique of inverse Laplace transform. Impacts of the constituents of memory-dependent derivatives-kernel functions along with time-delay parameter are analysed on the studied fields (temperature, displacement, strain and stress) for both thermal conditions separately using computational results. It has been found that the insertion of the memory effect proves itself a unified model, and therefore, this model can better predict temperature field data for thermal treatment processes.

Nonlocal heat conduction approach in a bi-layer tissue during magnetic fluid hyperthermia with dual phase lag model.

In this work, a nonlocal dual-phase-lag (NL DPL) model is introduced to accommodate the effects of thermomass and size-dependent thermophysical properties at nanoscale heat transport. Heat transfer at nanoscale is essentially nonlocal and quite different from that at the micro- or macro scale. To illustrate the nonlocal effect, a bi-layered structure is considered during magnetic fluid hyperthermia (MFH) treatment which is used successfully in prostate, liver, and breast tumors and the effect of size-dependent characteristic lengths is discussed in tumor and normal region of tissue. The problem is solved by using the finite difference scheme in space coordinate and Legendre wavelet Galerkin approach in time coordinate with the Dirichlet, Neumann and Robin boundary conditions. The effect of boundary conditions, characteristic lengths, phase lag parameters and nanomaterial parameters is discussed in tumor and healthy tissue domain and the results are presented graphically. This study is expected to be helpful for modeling of bioheat transfer equation at nano-scale, and may be beneficial to design nano-sized and multi-layered devices for heat transfer.