PID-controlled Temperature Feedback Photothermal Therapy System Based On Infrared Thermal Imager

The photothermal relationship between laser and biological tissue has always been an important research content of biomedical photonics.Photothermal therapy treats gynecological diseases and skin diseases through actinic and thermal effects,and achieves good therapeutic effects in clinical applications.In recent years,photothermal therapy has become an important way to treat tumors because of its safety and effectiveness.Temperature monitoring and temperature control are very important during the treatment.In the temperature monitoring,the temperature is usually monitored by hotspots,and the hot spot is inserted into the tissue during the monitoring process,which not only causes damage to the tissue,but also causes the transfer of the diseased cells;for certain tumor diseases,only within a certain temperature range,will play the role of treating diseases.Therefore in the process of laser heating treatment of tumor,temperature is extremely important for the treatment effect,and it is a parameter that needs to be controlled in clinical treatment.However,there is a lack of control over tissue temperature during general treatment.In order to monitor the temperature of the irradiated part in the photothermal therapy process and not damage the tissue during the monitoring process,a photothermal therapy system based on infrared thermal imager and PID control principle is designed.The system is mainly composed of three parts: temperature acquisition,data processing and heating module.The temperature acquisition module collects the temperature through the infrared thermal imager,and transmits the temperature data to the computer through the USB interface;uses the functions of calculation,analysis,storage,playback display and file management of the computer,and uses the virtual instrument control technology to process the data,and writes the data through the labview.The program virtualizes the panel of the instrument and the corresponding test function on the screen of the computer to display the temperature condition of the measured tissue in real time;finally,the control signal is output,the transmission efficiency of the laser is controlled,and the tissue temperature is controlled.In the design process of this system,the theoretical basis of system construction,the principle of photothermal therapy,infrared imaging technology and PID control principle are studied firstly.Then the hardware construction is started,and the three parts are linked through USB interface technology to connect information communication bridge;using virtual instrument technology,through the labview programming,the whole system works;through the tuning of the PID parameters,the ultimate goal of temperature control and non-destructive monitoring.The relationship between temperature and thermal damage was studied by a designed system.On the basis of the experimental equipment,the relationship between different temperatures,different distances and heating time was obtained by controlling the heating source and the edge temperature of the imager.