Performance limitations in feedback control systems with application to radiotherapy

反馈控制系统在放射治疗中的性能限制

• 批准号: 238743-2006
• 负责人: Davison, Daniel
• 金额: $ 2.04万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=362087
• 关键词: Performance; limitations; feedback; control; systems

External radiotherapy is a cancer treatment process where external high-energy x-ray beams are used to eradicate tumor cells.  Recently, the applicant and other researchers have introduced feedback control into the radiotherapy process so that the x-ray beam tracks the position of the tumor as it moves; movement is caused by a number of processes, including breathing, heart beat, and changes in the gastrointestinal tract.  Advantages of the feedback scheme include a reduction in side effects, more accurate radiation dose delivery to the tumor, and a reduction in treatment time.  The radiotherapy research has revealed deficiencies in current control engineering knowledge, and has inspired research in several directions, including the direction of the proposed research.  The basic question that the proposed research seeks to answer is:  are there any limitations on what can be done using feedback control?  Understanding the existence and nature of such performance limitations is important because the knowledge helps engineers avoid trying to solve impossible problems, and aids engineers in modifying problems to overcome performance limitations that otherwise cannot be overcome.  The proposed research will focus on several aspects of controller performance.  First, the issue of "tracking" is addressed:  is there a limit to how well the x-ray beam can track the tumor?  Second, the issue of "disturbance rejection" is dealt with:  if the patient moves on the treatment table, is there any fundamental reason why the tumor tracking system should not be able to accommodate the movement?  Finally, the issue of "robustness" is studied:  how much knowledge about the patient's tumor dynamics must be known for treatment to be effective?   Several potential causes for the existence of performance limitations will be considered, including time delays, instabilities in the system, and controller structure.  Although motivated by and applied specifically to radiotherapy, the theoretical work in the proposed research is general; indeed, almost any system that uses feedback control (airplanes, automobiles, nuclear reactors, distillation columns, rockets, etc.) can potentially benefit from the work.

外部放射疗法是其他研究人员的癌症信任过程，将反馈控制引入了放射疗法过程中，因此X射线梁跟踪该运动的后期是由许多过程，心跳和胃肠道的变化引起的方案包括副作用的修订，更准确的辐射剂量向肿瘤递送，放疗研究揭示了当前控制工程的缺陷，并且在严重方向上启发了H。寻求回答：是否有任何可以使用反馈控制的限制？ 。肿瘤是否可以处理“干扰拒绝”的问题：如果患者在那里移动的任何基本原因为什么肿瘤跟踪系统无法进行移动t。对于患者的肿瘤动力学的知识必须是有效的，这是在系统中的有效原因，系统中的Instab iNivility和控制器结构确实是一般的。汽车，核反应堆，蒸馏柱，火箭等）可以从工作中受益。