Thermal Radiation of the Human Body and Its Medical Application

This chapter is devoted to the study of the peculiarities of thermal (temperature) radiation by objects of living (organic) and non-living (inorganic) nature. Thermal electromagnetic radiation is a manifestation of the presence of internal energy, which is associated with the thermal movement of atoms and molecules of all heated bodies. In Section 5A, the basic laws of thermal radiation, as well as the peculiarities of thermal radiationThermal radiation of the human body, will be considered at the popular level. Thermal radiation is the most powerful channel of radiation of the physical fields of the human body. It turns out that the average power of thermal radiation from the entire surface area of the human body in the infrared range of electromagnetic radiation is equal to a fairly significant value, which is approximately 100 W. The same section contains the results of our experimental studies of the process of temperature relaxation of thermal radiation, which will allow us to further determine the numerical values of the parameters of this process for the human body. It will be proven that the time dependence of the temperature of thermal radiation does not obey an exponential law, as for objects of an inorganic nature, but occurs in the form of dаmped temperature оsсіllations over time under the influence of thermoreceptors, which create a sensory system located in various parts and organs of the human body. Section 5B will provide the theoretical basis for the basic laws of thermal radiation obtained by using reliable mathematical methods and consistent approaches of theoretical physics and carrying out precise physical experiments. The theoretical processing of the obtained experimental results for the thermal radiation of the human skin made it possible to determine the following parameters of the temperature relaxation process: the period of decaying temperature оsсіllations, the decay coefficient and the relaxation time of the temperature оsсіllations of the thermal radiation of the human skin, as well as the frequency of the decaying and natural temperature оsсіllations. In addition to finding the specified parameters, one of the important theoretical results was the finding of an explicit form of the second-order differential equation, which describes the change in the temperature of thermal radiation of human skin. The use of thermal radiation of the human body as a diagnostic method of thermography has a unique value and a certain fundamental advantage in comparison with other diagnostic methodsUniqueness of thermography as a non-invasive diagnostic method, such as X-ray computer tomography, magnetic resonance tomography, positron emission tomography, ultrasound studies. The main difference is explained by the fact that thermographyBasic laws of thermography uses the human body’s own (and therefore non-invasive) thermal radiationExperimental data for thermal radiation of human skin, and not external (and therefore to a certain extent invasive) radiation, which can cause, under sоme conditions, quite significant dose loads on organs and tissues human body.