Numerical Simulation Of Tumor Thermal Partition Therapy Base On Fe-based Amorphous Soft Magnetic Alloy

In this thesis,the thermal partition numerical model of irregular tumor penetrated by venous vessels was reasonably established.The finite element method was used to couple the flow field,temperature field and magnetic field in the numerical simulation of magnetic induction hyperthermia.The in vitro biological tissue experiment was also performed to further verify the effectiveness of the simulation results.Meanwhile,the Fe-based amorphous soft magnetic material used in the research of magnetic induction hyperthermia was rarely known in the previous studies,and the results in this thesis can pave the way for the application of new materials in magnetic induction hyperthermia for tumors.In this thesis,a numerical model of tumor tissue penetrated by venous blood vessels was established.By analyzing the power density of cylinder Fe-based amorphous soft magnetic alloy in an alternating magnetic field and reasonably setting the model conditions,the multiphysical field coupling of flow field,temperature field and magnetic field was achieved.The alternating magnetic field generating device was explored,and the field strength and uniformity of two different magnetic circuit models and the air gap between magnetic cores were analyzed.After comprehensive comparison,the C-type electromagnet of model I was finally selected as the magnetic circuit part of the alternating magnetic field generating device.This thesis analyzed the distribution of multiple physical fields under different magnetic fields.In the aspect of magnetic field,the magnetic flux density of Fe-based amorphous soft magnetic alloy is much larger than that of tumor tissue and muscle tissue,and the farther away from alloy,the greater the magnetic field intensity.In terms of temperature field,the overall temperature of region Ⅰ is lower,while the temperature of region Ⅱ is generally lower than that of region Ⅲ,but is generally closer to region Ⅳ.Based on the equivalent thermal dose theory of Sapareto and Dewey,the thermal damage of human tissues with and without Fe-based amorphous soft magnetic alloy implantation were analyzed.The results showed that when the magnetic field strength was in the range of 7-11 kA/m and the frequency was in the range of 90-150 kHz,the increase in the temperature of the biological tissue caused by the magnetic field was negligible.When cylinder Fe-based amorphous soft magnetic alloy were implanted for treatment,the overall thermal damage can be achieved in less than 60min when the magnetic field strength is in the range of 9-11 kA/m and the frequency is in the range of 90-150 kHz.The in vitro tissue experiments of cylindrical Fe-based amorphous soft magnetic medium were carried out at last,and the optimization model of experimental coil was reasonably established.The in vitro tissue experiments of cylindrical Fe-based amorphous soft magnetic medium were simulated and verified,and the temperature rise curves of each temperature measurement point in biological tissue were obtained,which verified the effectiveness of multiphysical field coupling for magnetic induction thermal therapy.The results showed that the temperature rise rate of the temperature measuring point is fast at first and then slow,and finally tends to a steady state;Under different current conditions,the error between the numerical simulation temperature and the experimental temperature of each temperature measurement point is 5.6%at maximum and 2.9%at minimum,and the difference between the numerical simulation temperature and the experimental temperature of each temperature measurement point is about 2℃ at maximum and about 1℃ at minimum.