Feedback-controlled Technique Of Photothermal Therapy For Tumor

The photothermal effect of tissues is an important research content of biomedical photonics,and it has important theoretical and practical significance for the phototherapy of tumors and other diseases in medicine.In this thesis,some key issues such as the light transmission and heat transfer of tumor photothermal therapy and the influence of blood vessels on temperature were studied.A photothermal and dynamic coupling model of biological tissues was established.The heat damage zone and temperature field distribution of tissue photothermal therapy was simulated and calculated.We analyze the influence of various physical parameters on the temperature distribution and thermal damage,and provide reference for the development of photothermal therapy for tumors.However,due to the complexity of the geometrical and physical properties(including optical and thermal properties)of the tissue which change with temperature,it is difficult to accurately determine the characteristics of temperature and tissue damage at each location according to the photothermal and dynamic coupling model.A dual-channel PID feedback-controlled system based on finite element simulation is designed in this thesis to control the heating area autonomously.One of the channels controls the temperature in the vicinity of the light source,avoiding the temperature of the center leading to vaporization and carbonization of the tissue,and the other controls the degree of damage in the heating range to reduce thermal damage to the surrounding tissues.This model can adjust and control the power of the laser in real time,so that the temperature and degree of damage can meet the expected temperature and degree of damage,and provide a technical solution for accurate photothermal therapy of complex tumors.