THERMOELECTRIC SYSTEM FOR EXTRACTION OF FOREIGN OBJECTS FROM HUMAN BODY

• Main Authors: O. V. Evdulov, S. G. Magomedova, I. Sh. Mispahov, N. A. Nabiyev, A. M. Nasrulaev
• Format: Article
• Language: Russian
• Published: Daghestan State Technical University 2019-07-01
• Series: Vestnik Dagestanskogo Gosudarstvennogo Tehničeskogo Universiteta: Tehničeskie Nauki
• Subjects: removal of foreign objects; freezing; thermoelectric system; modeling; thermal processes; calculation
• Online Access: https://vestnik.dgtu.ru/jour/article/view/640

Objectives. The purpose of the article is to examine the design of the thermoelectric system (TPP) for the extraction of foreign objects from the human body by the method of freezing, as well as the simulation of heat transfer processes in it.Method. A design and a physical model of the system for the extraction of foreign objects from the human body are proposed, in which the source of cold is a thermoelectric module (TEM) placed on a special mechanical device made in the form of a probe, which also provides removal of heat from the hot junctions of the module. A mathematical model of thermal power plants was developed, implemented on the basis of solving the problem of ice layer growth using the method of solving the non-stationary Fourier differential equation, presented in partial derivatives by reducing it to an equation with full derivatives based on the use of an extended version of the Lame-Clapeyron substitution, and power series, which describes the temperature distribution in the frozen ice layer and satisfies the boundary conditions of the problem.Result. Data were obtained on the change in temperature of the extracted object and the thickness of the ice layer over time at various values of the cooling capacity of TEM. It is established that the duration of the formation of an ice layer between the object to be extracted and the cold surface of the TEM, which is the executive element of the system, is within narrow limits that meet medical standards, while the speed of the ice growth process depends on its thickness (increasing the cooling capacity of the TEM from 1000 to 3000 W / m2 reduces the duration of the formation of an ice layer, 2 mm thick, by almost 40 s, while the temperature of the extracted object decreases from 269 K to 252 K). It is indicated that the selection of geometric parameters of TEM and its power supply should focus on the limitations on the operation of the device, as well as medical norms and standards in order to avoid the process of frostbite of the adjacent tissues.Conclusion. A method is proposed for increasing the efficiency of the system, according to which the preliminary cooling of the TPP by an external source of cold is used, as well as the use of forced TEM operation modes.