Numerical study of bioheat transfer in biological tissues using the finite volume method (FVM)

The analysis of heat transfer and temperature in biological systems is important. It is of high significance to have a clear view of temperature distribution in the skin and tissues due to various amounts and types of the applied thermal power during laser therapy to achieve the treatment goals while not hurting the patient. In this study, the transient Pennes equation, with the source term depending on time and space, is analyzed numerically in one dimension on the skin surface by implementing the finite volume method, during various modes of low-power laser therapy. Three different laser types are studied, including a constant one, a time-dependent cosine form, as well as one with exponential form. The limits of burn injury are considered to select the duration of laser therapy. Results show that forced convection with a higher coefficient, along with a cooler ambient surrounding the skin surface, increases the heat transfer, and consequently, blood perfusion and reduces the tissue temperature. The results also indicate that the cosine power function is better than the exponential and constant powers.