生物力学影响的靶区位姿精度保持方法研究  

Ensuring target positioning accuracy under biomechanical effects

作　　者：李瑞星 张来喜 陈惠贤[1] 宋明涛[2] 雷武乐 张鹏[1] LI Ruixing;ZHANG Laixi;CHEN Huixian;SONG Mingtao;LEI Wule;ZHANG Peng(School of Mechanical and Electrical Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]兰州理工大学机电工程学院,甘肃兰州730050 [2]中国科学院近代物理研究所,甘肃兰州730000

出　　处：《中国医学物理学杂志》2021年第3期375-381,共7页Chinese Journal of Medical Physics

基　　金：国家自然科学基金(51765031)。

摘　　要：目的:分析二次摆位中靶区位姿在生物力学影响下的器官肿瘤变形规律,控制机械臂位置来补偿此误差。方法:利用解剖学和生物力学相关知识,通过Mimics v17.0软件建立包含肿瘤的肺组织有限元模型,将建立的有限元模型导入ANSYS15.0,利用前人总结的生物力学特性参数仿真分析肺和肿瘤的变形误差。结果:得到在二次摆位中肺组织最大变形为21.24 mm,肿瘤最大变形为3.17 mm,并利用二次多项式拟合给出了误差模型,摆位验证后其误差变形均在此范围内,其中头脚方向变形最大。结论:基于自主设计的六自由度摆位医用机械臂提出一种通过前馈修正的位置控制方法,该方法在二次摆位过程中可以预先补偿肿瘤的位移误差,提高放疗精度和效率,减少对治疗靶区周围正常组织的损伤。Objective To analyze the deformation rules of the organ and tumor under the effects of biomechanics on target position in the second positioning,and to compensate for the error by controlling the position of mechanical arm.Methods According to anatomy and biomechanics,a finite element model of the lung and tumor was established by Mimics v17.0 software,and then the established finite element model was imported intoANSYS15.0.Finally,the deformation errors of the lung and tumor were analyzed using the biomechanical parameters summarized by predecessors.Results In the second positioning,the maximum deformations of the lung and tumor were 21.24 mm and 3.17 mm,respectively,and an error model was obtained by a quadratic polynomial fitting.After position verification,the error deformations were within the range,of which the deformation in the head and foot direction was the largest.Conclusion Based on the self-designed 6-degree-of-freedom positioning mechanical arm,a method for position control through feed-forward correction is proposed.The proposed method can compensate the displacement error of tumor in advance during the second positioning,thereby improving the accuracy and efficiency of radiotherapy,and reducing the damages to the normal tissues around the treatment target.

关 键 词：靶区位姿 生物力学 变形误差 前馈修正 

分 类 号：R318[医药卫生—生物医学工程] R811.1[医药卫生—基础医学]