Research On Structure Design And Control System Of High Dose Rate Afterloader For Radiotherapy

At present,afterloading brachytherapy is one of the important methods in clinical radiotherapy,which is a hot research direction of tumor treatment.In this paper,under the support of the Tianjin Science and Technology Support Plan Key Project,we have designed and developed the high-dose afterloader machine.Eventually,we finished the completion of the medical instrument prototype,applicator and control system.In addition,the position accuracy experiment of radiation source is completed.The research has achieved the following results:Firstly,based on the specific clinical requirements,the functional analysis and research are completed.According to the demand of channel selection and source cable driving system,the scheme comparison and detailed design of the mechanism are carried out.Besides,the three dimensional modeling and assembly of afterloader mechanical structure are built in the SolidWorks environment.We also have carried on the corresponding simulation analysis to the machine.In view of the specific functional requirements of different parts,the selection of suitable materials and auxiliary mechanism and processing methods are decided.Secondly,according to the characteristic of the mechanical structure and function parameters,the selection of electronic components and standard parts involved in this mechanism are carried out.The construction of control system is based on PLC and HMI system.Combined with the mechanical structure of the mechanical structure of afterloader and touch screen control,the prototype assembly is finally completed.Thirdly,this paper analyzes configuration of applicator in magnetic resonance imaging.Combined with the existing applicator structure characteristics of afterloader,we use photosensitive resin material to make applicator by 3D printing.In view of the appearance characteristics of medical robot,this research designs the shell of afterloader and assembles with the machine.Finally,we use the grating ruler and optical fiber sensor to innovate experiment of source position accuracy.Based on PID neural network,we can greatly improve the position accuracy of the source,and the accuracy of the results is much higher than clinical needs.