摘要
针对肝脏穿刺仿真系统的计算效率、实时性与真实性问题,本文提出了一种基于改进的振子弹簧模型的实时肝脏面模型,通过贪心策略以及形变域约束来实时构建肝脏面模型,可提高仿真系统的效率和实时性。本文首先根据振子弹簧模型建立运动学和力学方程,然后利用欧拉显式积分法求解约束形变域内的振子运动学方程,减少了运算量,并通过设置较小的时间步长提高了模拟精确度。实验结果表明,本文提出的方法较好地模拟了肝脏穿刺仿真系统的穿刺形变过程,满足肝脏穿刺仿真系统的实际需求。
Aiming at developing an efficient liver puncture simulation system,this paper presents a liver model based on an improved mass-spring model that can simulate the deformation of the liver accuratelyin real time. It can greatly improve the efficiency of the simulation system by using a greedy strategy and applying a deformation domain constraints in real time. In this paper,the kinematics and mechanical equations are established according to the traditional mass-spring model,then the kinematic equations of the mass in the constrained deformation domain are solved by the Eulerian explicit integral method. It can reduce computational complexity and improves simulation accuracy by setting a small time step. The results show that the proposed method can simulate deformation of liver accurately and meet the requirement of liver puncture simulation system.
引文
[1] Weil J. The synthesis of cloth objects[J]. Conference on Computer Graphics and Interactive Techniques,1986,20(4):49-54.
[2]劳尔.工程中的有限元法[M].傅子智,译.北京:科学出版社,1991.Raul. Finite Element Method in Engineering[M]. Fu Zizhi. Beijing:Science Press,1991
[3]James D L,Pai D K. Accurate real timedeformable objects[C]//Proceedings of SIGGRAPH'99 Conference. Los Angeles:CA Press,1999,65-72.
[4]Provot X. Deformation constraints in a mass-spring model to describe rigid cloth behavior[J]. Proceedings of Graphics Interface,1995,141-155.
[5]Breen D E,House D H,Wozny M J. Predicting the drape of woven cloth using interacting particles[C]//Breen D E.Proceedings of the 21st Annual Conference on Computer Graphics and Interactive Techniques. New York:ACM Press,1999,365-372.
[6] Zhu L,Ye X,et al. A real-time deformation modeling scheme of soft tissue for virtual surgical[C]//Proceedings of IEEE International Conference on Information and Automation. Harbin:IEEE,2010,771-775.
[7]闫雒恒.基于改进弹簧振子模型的软组织形变仿真[J].计算机仿真,2012,29(7):330-333.Yan Luoheng. Simulation of soft tissue deformation based on improved spring oscillator model[J]. Computer Simulation,2012,29(7):330-333.
[8]Chang Y H,Chen Y T,Chang C W,et al. Development scheme of haptic-based system for interactive deformable simulation[J]. Computer-Aided Design,2010,42(5):414-424.
[9]Zhong Y,Shirinzadeh B,Smith J,et al. An electromechanical based deformable model for soft tissue simulation[J].Artificial Intelligence in Medicine,2009,47(3):275-288.
[10]U. V9llinger,H. Stier,J. Priesnitz,et al. Evolutionary optimization of mass-spring models[J]. Cirp Journal of Manufacturing Science&Technology,2009,1(3):137-141.
[11] Liu P X,Zheng W,Chebbi B. Surgical simulation with high-fidelity haptic feedback[J]. International Journal of Robotics&Automation,2007,22(1):59-68.
[12]Terzopoulos D,Waters K. Physically-based facial modeling,analysis and animation[J]. Journal of Visualization&Computer Animation,1990,1(2):73-80.
[13]闫世春,周建钊,朱会杰,等.基于虚拟维修系统的碰撞检测算法综述[J].机械制造与自动化,2012,41(1):98-101.Yan Shichun,Zhou Jianzhao,Zhu Huijie. Overview of collision detection algorithms based on virtual maintenance system[J]. Mechanical Manufacturing and Automation,2012,41(1):98-101.
[14]吴涓,宋爱国,李建清.图像的力触觉表达技术研究综述[J].计算机应用研究,2007,24(5):1-3.Wu Juan,Song Aiguo,Li Jianqing. Overview of research on haptic expression technology of images[J]. Computer Application Research,2007,24(5):1-3.
[15]刘凌霞,宋强.基于简化的质点-弹簧模型织物变形仿真研究[J].计算机仿真,2011,28(5):406-409.Liu Lingxia,Song Qiang. Simulation of fabric deformation based on simplified particle spring model[J]. Computer Simulation,2011,28(5):406-409.
[16]胡江帆,严佩敏,周俊玮,等.基于改进质点弹簧模型下的布料实时仿真[J].计算机仿真,2008,25(7):184-187.Hu Jiangfan,Yan Peimin,Zhou Junwei. Real time cloth simulation based on improved particle spring model[J].Computer Simulation,2008,25(7):184-187.
[17]李祐国,熊岳山,谭珂,等.基于改进弹簧振子模型的实时肌腱模拟[J].计算机工程,2009,35(15):253-255.Li Youguo, Xiong Yueshan, Tan Ke,et al. Real time tendon simulation based on improved spring oscillator model[J]. Computer Engineering,2009,35(15):253-255.
[18]张爱军,蒋高明,李欣欣,等.应用弹簧-质点模型的双贾卡提花织物形变仿真[J].纺织学报,2017,38(1):146-151.Zhang Aijun, Jiang Gaoming, Li Xinxin, et al.Deformation simulation of double jacquard fabric using mass-spring model[J]. Journal of Textile Research,2017,38(1):146-151.
[19]丁龙辉.虚拟针刺手术软组织形变建模与力反馈算法研究[D].天津工业大学,2018.Ding Longhui. Research of Virtual Surgery Soft Tissue Deformation Model and Force Feedback Algorithm[D].Tianjin Polytechnic University,2018.