Analytical and experimental solution for heat source located under skin: chest tumor detection via IR camera

Infrared (IR) imaging could be used as both noninvasive and nonionizing technology. Utilizing IR camera, it is possible to measure skin temperature with the aim of finding any superficial tumors. Since tumors are highly vascular and usually have a higher temperature than the rest of the body, using thermograms, it is possible to assess various tumor parameters, such as depth, intensity, and radius. In this study, we have developed an analytical method to detect tumor parameters in both spherical and cubical tissues to represent female breast and male chest tissue. This includes development of analytical solution for solving inverse bio-heat problem as well as laboratory set up for further validation of the analytical achievements. The models were developed by solving Penne’s Bioheat equation for each tissue under certain conditions and two main assumptions: 1. The tumor was assumed as separate heat source; 2. The developed model does not change with time (steady state condition). Finally, the analytical findings were validated by utilizing a laboratory test set-up containing an IR camera, 1% Agar solution (tissue phantom), and a heater of variable powers. The models were set to test by adjusting the heater (0.9W) in various depth and imaging the tissue phantom. Comparing the analytically obtained results with the experimental results, it can be concluded that the method is able to detect superficial tumors of small size only by measuring the body surface temperature and ambient temperature.