Normalized Fabrication And Bending Loss Compensation Of Optical X-ray Sensor

Radiotherapy is one of the main methods for the treatment of cancer at present.In China,about 50%-70%of cancer patients need radiotherapy in the treatment process.In order to improve the effect of radiotherapy,precision radiotherapy is developed rapidly,aiming to enhance the radiation dose of tumor area and reduce the radiation dose received by surrounding tissues and organs,so higher requirements are put forward for radiation detection.Compared with the traditional radiation detection equipment,the optical fiber X-ray sensor has become a new type of radiation detection equipment because of its small size,flexibility and real-time response.The research on the performance of the inorganic scintillator optical fiber X-ray sensor is also increasing at home and abroad,but the difficulties in its manufacture and application still need to be solved in the final clinical application.In order to meet the needs of clinical application and obtain accurate real-time measurement data in vivo,the optical fiber X-ray sensor needs good uniformity,durability and long-term stability.However,the difficulties in the fabrication of plastic X-ray optical fiber sensor are precisely drilling a tine hole in the end face of the fiber core and uniformly filling in the inorganic scintillator powder.In order to overcome these problems,a new fabrication method of inorganic scintillator X-ray optical fiber sensors is proposed.In terms of fiber processing,a set of equipment is made to drill accurately at the end face of the fiber.In terms of scintillator filling,a scintillator filling technology mixed with a UV glue is used to ensure the stable amount of scintillator in each sensor.In terms of sensor sealing,a method of adding fiber cap is used to improve the packaging effect of the sensor.It is confirmed by experiments that these new processes enhance the homogeneity and stability of the optical fiber sensor.The optical fiber X-ray sensor is a kind of optical fiber sensors with intensity modulation.In the actual applications,the optical fiber sensor could be bended or twisted according to the requests of patients.The bending and twisting will cause the attenuation of signal light intensity and affect the measurement results.A compensation structure is proposed to solve the problem.Based on the response of inorganic scintillator materials to UV lights,a UV LED is coupled with the optical fiber to excite the scintillator.The fluorescence returns to the detector.Comparing with the fluorescence intensity without fiber bending or twisting,it can be determined whether there is bending loss in the transmission fiber.Based on the fluorescence loss in the compensation process,the bending loss can be calculated by a compensation algorithm,and the detected radiation dose can be compensated to get a more accurate radiation dose.Compared with other compensation methods of other intensity modulated optical fiber sensors,this set of intensity self-compensation device has a simple structure,which can achieve the intensity self-compensation without increasing the volume of the optical fiber sensor.It is convenient to place the sensor in the patient's body for radiation detection.