Non-Fourier transient thermal analysis of biological tissue phantoms subjected to high intensity focused ultrasound

The present study is concerned with the numerical analysis of the non-Fourier heat transfer phenomena in biological tissue samples subjected to high intensity focused ultrasound (HIFU). Due to the inherent non-homogeneous nature of biological samples, the well-known Pennes bioheat equation (PBHTE) is not strictly suitable for correctly predicting the temperature distribution in the tissue medium subjected to HIFU. In this respect, thermal wave model of bioheat transfer (TWMBT), which takes into account the finite propagation speed of thermal front, plays an important role in describing the observed wave-like behavior of heat transfer in biological tissue medium. The temperature profiles obtained from TWMBT show the presence of oscillations during the process of diffusion of thermal wave after reaching its maximum peak, depending upon the corresponding relaxation time. Results show that the thermal dosage with finite value of relaxation time gives lesser heat-affected area compared to the dosage calculated by considering the infinite propagation of thermal front as in the case of the conventional Fourier model. These observations make the present study important as otherwise, the target area is prone to remain under insufficiently heated conditions. (C) 2019 Elsevier Ltd. All rights reserved.