Non-contact heat transfer models identification: Laser hyperthermia of superficial human tissues

Abstract

Abstract Planning and predicting the processes of biological tissues heating associated with therapeutic effects involves high-precision mathematical modelling. However, the thermophysical properties of tissues can vary greatly from patient to patient. The paper presents a computational and experimental method for identifying mathematical models of heat transfer, not involving the placement of temperature sensors inside of the studied object. The experimental setup consists of a flat sample of the material, a laser setup, and a thermal imaging camera. The surface thermal response to the pulsed heat flux of the laser is an array of input data for the developed software package. The heat transfer coefficient and heat flux density are determined iteratively by minimizing the residual functional between the calculated and experimental values. The method was tested when determining the characteristics of a specimen of low-pressure polyethylene. The result was obtained in 5 iterations and under the influence of external natural convection, and without taking into account the translucency of the material, a discrepancy of calculated and experimental values of 3.5% was shown. The method can be used to plan the therapeutic process in order to ensure its maximum effectiveness.