A heat transfer model of skin tissue for the detection of lesions: sensitivity analysis

In this paper, we study the transient thermal response of skin layers to determine to which extent the surface temperature distribution reflects the properties of subsurface structures, such as benign or malignant lesions. Specifically, we conduct a detailed sensitivity analysis to interpret the changes in the surface temperature distribution as a function of variations in thermophysical properties, blood perfusion rate, metabolic heat generation and thicknesses of skin layers, using a multilayer computational model. These properties can vary from individual to individual or depend on location, external and internal influences, and in certain situations accurate property data are not available in the literature. Therefore, the uncertainties in these data could potentially affect the accuracy of the interpretation/diagnosis of a lesion in a clinical setting. In this study, relevant parameters were varied within characteristic physiological ranges, and differences in the surface temperature response were quantified. It was observed that variations in these parameters have a small influence on the surface temperature distribution. Analysis using this multilayer model was further conducted to determine the sensitivity of transient thermal response to different lesion sizes. This work validates the idea of examining the transient thermal response obtained using a thermal imaging system with the objective of lesion identification. The modeling effort and the sensitivity analysis reported in this paper comprise a portion of a comprehensive research effort involving experimentation on a skin phantom model as well as measurements on patients in a clinical setting, that are currently underway. One of the preliminary results from the ongoing clinical trial is also included to demonstrate the feasibility of the proposed approach.