【作者】 高俊杰；

【导师】 陈焱； 王炳强；

【作者基本信息】 天津大学 ， 机械工程， 2018， 硕士

【摘要】 微创医疗机器人的出现和发展,使得微创手术较传统手术具有出血少、创伤小、并发症少、术后恢复快等优点并正在被越来越多的医生和患者所接受和采纳。现有的微创手术钳包含传统刚性手术钳、柔顺机构微创手术钳、多功能微创手术钳,它们具有摩擦大、机械效益低、零部件装配过程复杂、变形大的缺点,为解决此类问题,本文采用折纸艺术的理念,设计了一种具有双稳态性能并采用柔性铰链的微创手术钳。本文的主要工作内容如下:首先,以提高手术钳的机械效益、采用柔性铰链一体设计为目的,依据厚板折纸理论,初步提出了一种可单自由度驱动的厚板手术钳机构,并对其进行了模型设计。但是由于厚板手术钳铰链数目多、结构复杂以及受微创手术钳直径要求限制,手术钳的制作加工较为困难,同时,由于采用曲线折痕的一体折纸结构具有实现双稳态的可能,因此考虑将该结构引入微创手术钳的设计。其次,依据双稳态结构原理,分析可展曲面设计双稳态结构的可行性。通过激光切割方法,设计了平面PET材料上的曲线折痕,并采用高温加热方法,使平面PET材料塑性变形,从而产生曲面结构。为了找到使曲面结构上的曲线折痕抗弯曲次数增多的条件,对PET材料在不同加热温度与加热时间下进行试验,最终选择加热时间为12分钟、加热温度为110℃,并在此种情况下,实验测试了其力学性能。最后,通过对曲面结构在铰链处厚度和弹性模量的一系列参数化仿真,找到与实验结果相匹配的铰链厚度和弹性模量值。在此基础上,以优化双稳态性能为目标,利用数值分析方法仿真了各参数对双稳态性能的影响,包括厚度、横梁结构、孔结构、斜切圆柱的平面角度、曲率、宽度六个参量。依据各参数对双稳态性能的影响结果,重新优化设计了曲面结构、微创手术钳驱动丝路径以及支架结构,完成具有双稳态性能且可以采用柔性铰链一体设计的手术钳,并进行了手术钳双稳态性能的验证实验。为实验比较传统手术钳与双稳态手术钳的机械效益,我们设计了最大外径为15mm的小型双稳态手术钳,实验结果表明其机械效益相比传统手术钳提高了40.9%。更多还原

【Abstract】 The emergence and development of minimally invasive surgical(MIS)robots make the open surgery less bleeding,small trauma,few complications and quick recovery after operation,and the MIS has being accepted and adopted by more and more doctors and patients.The existing MIS forceps,such as the traditional rigid surgical forceps,the flexible MIS forceps and the multifunctional MIS forceps,have the disadvantages of large friction,low mechanical efficiency,complicated assembly process of components and large deformation.In order to solve these problems,we design origami-inspired MIS forceps with bi-stable performance and flexible hinge in this thesis.The main work of this thesis is as follows:First of all,in order to improve the mechanical benefits of surgical forceps and to obtain integrated MIS forceps with flexible hinges,according to the theory of thick panel origami,a kind of surgical forceps mechanism driven by single degree of freedom is proposed and the model is designed.However,the surgical forceps with thick panel origami patterns are difficult to manufacture because they have large number hinges and complex structure,and their diameter is difficult to meet the requirements of MIS forceps.At the same time,due to the possibility of achieving a bi-stable performance of the monolithic folding structure using curved creases,it is considered to introduce this structure into the MIS forcepsSecondly,based on the principle of bi-stable structure,it is proved to be feasible to design a bi-stable structure with developable surface.By means of laser cutting,the curved creases on the plane PET material are designed,and the plane PET material is plastically deformed by using the high temperature heating method to generate the curved surface structure.In order to find out the condition of increasing the number of curved creases bending resistance,the PET material is tested under different heating temperature and heating time,the proper heating time is 12 minutes,the heating temperature is 110 ℃,and in this case its mechanical properties is tested.Finally,a series of parametric simulations of the thickness and elastic modulus of the curved structure at the hinge are carried out to find the thickness and elastic modulus of the hinge that matched the experimental results.On this basis,the bi-stable performance of each parameter is simulated by numerical analysis with the purpose of optimizing the bi-stable performance,including the thickness,cross-beam structure,hole structure,plane angle,curvature and width.According to the influence of each parameters on bi-stable performance,the surface structure,the path of the MIS forceps drive wire and the stent structure are re-optimized,and the integrated surgical forceps with bi-stable performance and flexible hinges are accomplished,and its bi-stable performance is verified.To compare the mechanical benefits of conventional surgical forceps with bi-stable surgical forceps,we design a miniature bi-stable surgical forceps with a maximum outer diameter of 15 mm.The experimental results show that the mechanical benefits are 40.9% greater than the traditional surgical forceps.更多还原