基于绳牵引并联机构的微创手术器械研究

发布时间：2018-05-21 10:36

本文选题：微创手术 + 并联机构　；参考：《上海工程技术大学》2015年硕士论文

【摘要】：微创外科是临床医学界的前沿发展方向,微创外科手术具有手术创伤小、疼痛轻、恢复快等特点,在越来越多的传统手术领域获得了革命性的成功,逐渐成为全球外科手术发展的主旋律。微创手术器械的机械结构、传动方式等方面的合理设计,将直接影响其灵活性、操作性、控制精确性等性能乃至手术效果。由于微创手术工作空间较小,而传统微创手术器械灵活性差,因此,为提高微创手术器械灵活性和操作柔性,弥补手术切口造成器械自由度的损失,本文根据腹腔手术及微创手术器械结构特点,设计一种绳牵引多自由度手持式微创手术器械。研究内容主要包括以下几个方面:(1)通过对微创手术过程、传统微创手术器械、手术操作力以及手术器械操作环境进行详细分析,确定新型多自由度手术器械的期望要求;根据器械所需完成目标任务映射其设计要求,得出手术器械最小自由度数为4;提出基于组合并联机构单元实现腕部关节俯仰、偏转运动方案,并采用钢丝绳、柔性杆以及软轴组合传动方式,设计4自由度手持式微创手术器械。(2)利用方位特征集理论对腕部关节组合并联机构单元进行机构综合,确定4SPS-1U为并联机构单元构型;基于手术器械尺寸设计要求以及并联机构单元结构,确定并联机构单元合理尺度参数,并分析并联机构单元转动角度和转动半径的范围;根据腕部关节所需实现工作空间范围,为腕部关节配置不同数目的并联机构单元。(3)基于尺度相容性条件,运用D-H矩阵构建4SPS-1U并联机构运动学方程,以牛顿迭代法求解位置正解;通过对运动学方程求导,获得速度、加速度雅克比矩阵,并建立速度、加速度运动学方程;利用ADAMS软件对该并联机构单元运动学和动力学进行仿真分析,求解并联机构单元动力学;构建末端腕部关节实验模型进行实验分析,以验证末端腕部关节机构设计的合理性以及钢丝绳牵引力的正确性。(4)针对钢丝绳传动进行受力分析,建立钢丝绳受力平衡方程,并对钢丝绳拉伸及弯曲状态进行应力分析,得出传动过程中钢丝绳危险点分布情况;利用Solid Works Simulation进行有限元仿真分析,求得钢丝绳传动过程中最大应力,并将有限元仿真结果与数学模型计算结果进行对比,以验证钢丝绳受力模型的正确性;通过对传动过程中钢丝绳摩擦磨损以及疲劳寿命进行分析,得出所选用钢丝绳对手术器械使用寿命影响极小。本文所设计的4自由度手持式微创手术器械,为进一步研制高性能微创手术器械提供理论基础。
[Abstract]:Minimally invasive surgery is the frontier development direction of clinical medicine. Minimally invasive surgery has the characteristics of less trauma, less pain and faster recovery. It has achieved revolutionary success in more and more traditional surgical fields. Gradually become the main theme of the development of surgery around the world. The reasonable design of the mechanical structure and transmission mode of minimally invasive surgical instruments will directly affect its flexibility, maneuverability, control accuracy and even surgical effect. In order to improve the flexibility and operation flexibility of minimally invasive surgical instruments and make up for the loss of the degree of freedom caused by the surgical incision, the minimally invasive operation space is small and the traditional minimally invasive surgical instruments are less flexible. According to the structure characteristics of celiac surgery and minimally invasive surgical instruments, a multi-freedom hand-held minimally invasive surgical instrument with rope traction was designed in this paper. The main contents of this study are as follows: (1) by analyzing the process of minimally invasive surgery, the traditional minimally invasive instruments, the operating force and the operating environment of the surgical instruments in detail, the expectation requirements of the new type of multi-degree-of-freedom surgical instruments are determined. According to the design requirements of the target task mapping, the minimum degree of freedom of the surgical instrument is 4, and the scheme of wrist joint pitch and deflection based on the combined parallel mechanism unit is proposed, and the wire rope is used. Flexible rod and flexible shaft combination drive mode, design 4 degrees of freedom hand-held minimally invasive surgical instrument. 2) utilize azimuth characteristic set theory to synthesize the mechanism of wrist joint combined parallel mechanism, and determine 4SPS-1U as the configuration of parallel mechanism unit. Based on the size design requirements of surgical instruments and the unit structure of parallel mechanism, the reasonable scale parameters of parallel mechanism unit are determined, and the range of rotation angle and radius of parallel mechanism unit is analyzed, and the workspace range of wrist joint is realized according to the need of wrist joint. Based on the criterion of scale compatibility, the kinematics equation of 4SPS-1U parallel mechanism is constructed by using D-H matrix, and the position positive solution is solved by Newton iteration method, and the velocity is obtained by derivation of kinematics equation. The acceleration Jacobian matrix and the velocity and acceleration kinematics equations are established, and the kinematics and dynamics of the parallel mechanism are simulated and analyzed by ADAMS software to solve the dynamics of the parallel mechanism. In order to verify the rationality of the design of the end wrist joint mechanism and the correctness of the wire rope traction force, the experimental model of the end wrist joint is constructed to analyze the force on the wire rope transmission, and to establish the balance equation of the wire rope force. The distribution of the dangerous point in the transmission process is obtained by the stress analysis of the tension and bending state of the wire rope, and the maximum stress in the transmission process is obtained by the finite element simulation analysis with Solid Works Simulation. The finite element simulation results are compared with the results of mathematical model to verify the correctness of the steel wire rope force model, the friction and wear of the wire rope and the fatigue life of the wire rope during transmission are analyzed. It is concluded that the selection of wire rope has minimal influence on the service life of surgical instruments. The 4-DOF hand-held minimally invasive surgical instrument designed in this paper provides a theoretical basis for the further development of high-performance minimally invasive surgical instruments.
【学位授予单位】：上海工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R608;TH112

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