重离子治癌点扫描动态电流实时反馈系统设计  

Design of real-time feedback system of dynamic current for spot scanning in medical heavy-ion facility

作　　者：姜浩宇 赵江[1,2] 周忠祖 王德志[1] 高大庆 JIANG Haoyu;ZHAO Jiang;ZHOU Zhongzu;WANG Dezhi;GAO Daqing(The Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;School of Nuclear Science and Technology,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院近代物理研究所,兰州730000 [2]中国科学院大学核科学与技术学院,北京100049

出　　处：《核技术》2021年第4期21-26,共6页Nuclear Techniques

基　　金：中国科学院重点部署项目,医用重离子加速器产业化(No.Y700050)。

摘　　要：重离子治癌中的点扫描治疗是一种精确的放疗方法,点扫描治疗的过程就是扫描电源快速实时改变电流的过程。点扫描束流位置控制的精度取决于扫描电源的重复性和模型参数的稳定性,但点扫描中位置电流的变化快、幅值小,且容易被噪声淹没,使得治疗终端远程精确获取这种扫描动态电流存在一定的难度。为快速分析和优化点扫描位置电流的精度和重复性,基于Xilinx公司的新一代可扩展处理系统Zynq-7000 SoCx平台,结合高速光纤通信与PCI-E(Peripheral Component Interface Express)串行总线技术设计并实现了一种点扫描动态电流的实时反馈系统。经过兰州重离子治疗装置现场测试,该系统能实时获取点扫描的位置电流点阵并进行偏差计算,实测位置电流偏差为0.1068 A,满足小于0.17 A的设计要求。为点扫描位置电流的精度控制及优化提供了一种有效的技术手段。[Background]Spot scanning therapy is an accurate radiotherapy method in medical heavy-ion facilities.The process of spot scanning therapy is that the current of scanning power supply changes rapidly in real-time.The accuracy control of beam position depends on the repeatability of the scanning power supplies and the stability of the model parameters during spot scanning therapy.However,the amplitude of position current is small and changes rapidly,it is easy to be submerged by noise,which makes it difficult for the treatment terminal to obtain accurate scanning dynamic current remotely.[Purpose]This study aims to design and implement a real time feedback system of point scan position current for quick analysis and optimization of the accuracy and repetition of the point scanning position current for medical heavy-ion facility.[Methods]The Xilinx's new scalable processing platform Zynq-7000 SoC(System on Chip)was employed to implement this system by combining high speed Fiber-optic communication with PCIE(Peripheral Component Interface Express)serial bus technology.Both the waveform data acquisition of Direct Coupled Current Transformer(DCCT)and feedback calculation of the remote power supply output current were achieved in the platform.The position current feedback system was tested in field of Lanzhou heavy ion therapy facility.[Results]The field test results show that the system can obtain the position current data of spot scanning in real time,and the measured position current deviation is 0.1068 A,satisyfying the design requirement of less than 0.17 A.[Conclusions]The study provides an effective technical means for the precision control and optimization of spot scanning position current.

关 键 词：点扫描 SOC 光纤传输 PCIE 

分 类 号：R730.5[医药卫生—肿瘤] TP212[医药卫生—临床医学]