【作者】 张峰峰；

【导师】 孙立宁；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2009， 博士

【摘要】 近几年来,骨科手术机器人技术已经成为国际研究热点之一,然而,由于其操作对象是复杂的人体,对医生与手术机器人的交互技术提出了更高的要求,这是目前制约骨科手术机器人研究和发展的瓶颈问题。随着虚拟现实和虚拟增强技术的提高,机器人辅助骨科虚拟手术技术成为解决这一难题的有效途径之一。论文结合国家863计划项目和国家自然科学基金项目,针对机器人辅助骨科手术中的人机交互问题,通过虚拟现实技术、遥操作技术和现代医学图像理论,对机器人辅助骨科虚拟手术仿真中的虚拟环境图形建模、人体腿部三维形态学建模、人体腿部生物力学模型和软组织变形等关键技术进行研究,建立了机器人辅助骨科虚拟手术系统。在虚拟环境图形建模方面,首先研究了几何模型的表示方法,并针对课题实际情况和应用需求,研究了建模方案,选择了基于Pro/E建模和Java3D编程的机器人交互式图形仿真方法,建立了机器人三维几何模型和交互式虚拟场景。对导航机器人、C型臂及复位机器人分别进行了运动学建模研究。进行了碰撞检测分析研究,采用词法分析器原理,提取模型表面的近似多面体信息,用球模型表达实体,并对各种碰撞检测算法进行分析,结合八叉树算法和模型的球表达法,建立了虚拟环境下的图形碰撞检测模块。在人体腿部的三维形态学建模方面,详细讨论了基于医学CT图像的人体腿部生物组织三维几何重建问题。对CT图像进行了预处理研究,应用改进的MC重建算法、渐进网格简化算法,完成了获取医学体数据、抽取等值面、简化网格等几个方面的工作,实现了基于CT图像的人体股骨、胫骨、腿部肌肉、皮肤等组织的集合建模和共组。在人体腿部的生物力学建模方面,在给出线性弹性模型、非线性弹性模型描述生物组织变形特性理论模型的基础上,提出了建立多结构、多层次、多种材料并存的物理建模方法,完成了人体腿部各生物组织的有限元模型的建模。基于骨骼、肌肉、皮肤等组织的生物力学特性,在对外力做功、重力做功、生物组织边界条件分析的基础上,建立了生物组织运动的静态平衡方程和动态平衡方程,为生物组织变形的计算提供了理论方法。针对肌肉解剖形体复杂,难以精确建模的问题,提出了一种基于形态解剖学的新型肌肉建模方法,既考虑了肌腱的生物力学特性,又体现了肌纤维的微观解剖结构。对建立的人体腿部有限元模型进行了仿真验证,将计算后的有限元仿真数据与通过人体标本实验获得的力位数据相比较,二者的吻合性证明了建立的人体腿部有限元模型的可信性。最后,以腿部生物力学建模仿真的实现为应用实例,阐述了虚拟手术开发环境、控制界面及手术系统几种操作模式,并对虚拟系统根据功能进行了模块化分,对系统的机器人性能进行了测试研究。为了提高虚拟手术仿真系统进行实际作业的能力,提出了以BP神经网络模型来代替有限元模型,实现实时的生物力学响应。结合已有的机器人辅助接骨系统,构建了虚拟手术主从控制系统实验平台,利用并联主手输入运动信息,提供力反馈,而虚拟手术平台则负责提供视觉和计算对抗牵引力的大小,最后分别进行了力反馈实验和虚拟骨折复位手术实验。实验结果证明了基于生物信息的虚拟手术仿真系统的有效性和可用性。更多还原

【Abstract】 In recent years, orthopaedics surgical robot technology has become one hot topic. However, operational objectives are human beings, so it raises the request about the interactive technique between the doctor and surgical robot. It’s a key problem that prevents the research and development of the orthopaedics surgical robot. With the improvement of virtual reality and virtual reinforcement technology, robot-assisted orthopaedics surgical robot technology becomes a available way to solve the problem.This paper, combined with the China 863 Program as well as the National Natural Science Foundation projects, aimed at the human-computer interaction issues in the robot-assisted orthopaedics surgery, using virtual reality technology, tele-operate technology and modern medicinal image theory, researches virtual environment image modeling, human leg three-dimensional geometric model and soft tissue deformation in the robot-assisted orthopaedics surgical simulation. And a robot-assisted orthopaedics surgical simulation system has been built.In terms of Graphical modeling of virtual environment, we introduced the representation method of geometric model, combined with the actual situation in the subject, the paper proposed a novel method using Java3D and the Pro/E to establish a virtual environment modeling and robotics program, get the model of virtual environment bone surgery and robot, and kinematic analysis of navigation robot, C-arm and recovery robot, then researched on the corresponding collision detection. Used the creative lexical analyzer principle to extracte the approximated polyhedron information of the model’s surface, expressed the entities with the sphere model. And analysed a variety of collision detection algorithm, combined with octree algorithm and the expression of sphere model, established the graphic collision detection module in the virtual environment.In terms of three-dimensional morphology of human legs, this paper discusses how to reconstruct three-dimensional geometric model of human legs based on medical CT images in detail. Using MC arithmetic, Gradient Mesh simplified arithmetic, arithmetic of cube model etc, some works have been finished, including obtaining medical cube data, taking out contour surface, simplifying mesh, constructing cube model and so on. Finally, assembly modeling together about human thighbone, cannon, leg skin based on CT images has been realized.In terms of biomechanical modeling of human legs, based on giving linear elastic model and nonlinear elastic model, this article discusses how to build multi-structure, multilayer and multi-material physical modeling and constructs finite element model of biological tissue of human leg. Base on biomechanical character of human tissue such as skeleton, muscle and skin, analyzing work of external force, boundary condition of biological tissue, this paper establishes static balance function and dynamic balance function of biological tissue, and supplies a theoretical method for calculation about deformation of biological tissue. Aimed at the problem of complexity of muscle dissection and difficulty of establishing model accurately, we raise a new modeling way based on morphology anatomy. This method considers biomechanical character of muscle tendon as well as microcosmic anatomy structure of muscle fibre. We process finite element simulation validation of human leg and then compare data of finite element simulation after calculating with data of forth location obtaining from body exemplar experiment, and inosculation of the data proves creditability of finite element model simulation of human leg.In the end, taking biomechanical modeling simulation of leg for example, it expounds some manipulation mode about development environment, control interface and surgical system of virtual surgery. To raise capacity that virtual surgical simulation system deals with real work, this article introduces BP NN model instead of finite element model, and realizes real-time biomechanical response. Then combining robot Assisted bone-knitting system, virtual surgical master-slave control test platform has been established. Using shunt-wound maser hand, manipulator inputs locomotion information and gets force feedback information. Virtual environment provides vision, calculates opposed tractive force and carries out force feedback experiments and virtual bone-knitting surgery experiments. The result of experiments testifies validity and usability of virtual surgical simulation system based on biology information.更多还原