Simultaneous estimation of controllable parameters in a living tissue during thermal therapy

• Controllable parameters in hyperthermia are estimated simultaneously.
• The investigation was done for one dimensional skin tissue.
• The Pennes bioheat equation was solved by the finite volume method.
• Conjugate gradient method is utilized as an inverse method.
• The effect of measurement errors was considered.

During hyperthermia, controlling the temperature distribution along the tissue can cause remedial advantages. This can be obtained by proper manipulation of effective parameters in hyperthermia such as the external heat source and the heat transfer coefficient at the skin surface. In this study, these parameters are estimated simultaneously for an arbitrary temperature distribution in a skin tissue. The direct problem is solved by the fully implicit finite volume method to obtain the temperature data. This data is used as additional information to estimate the external heat source and the heat transfer coefficient at the skin surface simultaneously. Both of these parameters are considered as functions of time, and since no information exists about their functional form, the problem is classified as the function estimation approach. Conjugate gradient method is applied as an inverse method. Two test cases are considered and the effect of measurement errors is evaluated. The comparison of estimated results with measurements confirms the accuracy of this method.