The Method Research of Integrated Robot Grinding Technology for Custom Femoral Prostheses

影响非骨水泥假体长期稳定的因素是无菌松动,微动和应力遮蔽通过破坏假体近端的骨整合导致假体的无菌松动,而微动和应力遮蔽与假体的力传递相关。定制式假体的设计模型来源于病人股骨的CT数据,它建立了有限元模型与手术模型的一致性,通过有限元模型上的力传递分析,优化假体的设计和假体与髓腔的匹配,控制手术后假体上的力传递,避免假体近端大的微动和应力遮蔽而破坏假体在髓腔中的初期稳定性,促进假体近端的骨整合。针对定制式假体,发展一种新型的集成技术,形成定制式假体设计、有限元分析和制造一体化,特别是采用CAD/CAM/Robot集成技术加工定制式假体,在建立CAM软件空间各单元与机器人工作空间对应各单元一致性基础上,提高了假体的制造精度。仿真和实验结果表明,有限元分析方法可以控制假体上的力传递,机器人磨削柄体的误差小于0.9mm。The reason that affects long-term stability of cementless femoral prosthesis is aseptic loosening, micromotion and stress shielding that are related to the force transfer of prosthesis can destroy the osseointegration of proximal prosthesis and make the prosthesis to form aseptic loosening in the femur cavity. The design model of cnstomfemoral prosthesis is from the CT reconstruction of patient femur, the fit of prosthesis and femoral cavity at designperiod of the prosthesis is same the fit at surgical operation period, then the results of finite element analysis at design period can be used to control the force transfer of prosthesis at postoperative, the improper micromotion and stress shielding of proximal prosthesis that destroy the primary stability of prosthesis in femoral cavity can be avoided and the osseointegration of proximal prosthesis can form. In this paper, we develop the new technology to integrate the design, finite element analysis and manufacture of the custom prosthesis, specially, we use the CAD/CAM/robot integration method to machine custom prosthesis. On the basis of establishing consistency of each module in CAM software space and robot working space, the manufacturing precision of the prosthesis was improved. In the conclusion, the finite element analysis of the custom prosthesis can control the force transfer of prosthesis and the milling errors of custom prosthesis is less than 0.9 mm

Design, manufacture and experimental analysis of cementless hip prosthesis in torsional force transmission

背景:人体股骨髓腔具有扭转的解剖结构,如果股骨髓腔的扭转结构被复制到假体的柄体上,当假体插入髓腔并在假体上加载力时,假体将加载的力转换成股骨髓腔对柄体的扭转力并将该力传递到股骨近端。目的:优化股骨近端的力传递,避免假体近端应力遮挡。方法:利用人股骨标本的CT图片重建股骨髓腔的3D模型,将该3D模型作为柄体的设计模型。将定制式柄体模型与标准假体的近端模型拼合,形成定制式假体。采用机器人磨削技术制作定制式假体,并将定制式假体与标本股骨髓腔匹配。利用有限元仿真和实验方法分析假体上加载的力与假体近端扭转微动的关系。结果与结论:仿真和实验结果表明,股骨髓腔与柄体匹配的扭转结构,可有效地将假体上加载力以扭转力的形式传递到股骨近端,假体近端的扭转微动与柄体的微动相关,而柄体的微动可通过改变柄体与髓腔的匹配区大小得到控制。BACKGROUND: Human femur medullary cavity has torsional anatomic structure. If the femur medullary cavity's torsional structure is copied to the stem of the prosthesis, the prosthesis will transform the force loaded to torque between femur medullary cavity and prosthesis stem, and the torque is transmitted to the proximal femur when the prosthesis is inserted in the medullary cavity and load force on the prosthesis. OBJECTIVE: To optimize the force transmission of the proximal femur, and to avoid the stress shielding at the proximal end of the prosthesis. METHODS: We reconstructed a three-dimensional(3D) model of the femoral canal with the CT images of specimen femur and took the 3D model as the design model for prosthesis stem. The customized stem model and the proximal model of standard prosthesis could be put together to form customized prosthesis. We took advantage of robot grinding technology to manufacture the customized prosthesis, and matched it with specimen femur canal. Finite element analysis simulation and experimental methods were used to analyze the relationship between the loading force on the prosthesis and the micromotion of proximal end of the prosthesis. RESULTS AND CONCLUSION: The simulation and experimental results showed that the torsional structure matching by femoral canal and stem could effectively transmit the force on the prosthesis to the proximal end of the prosthesis in the form of torque. The torsional fretting of the proximal end of the prosthesis was related to the movement of the handle body. However, stem micromotion can be controlled by varying the matching size between stem and medullary cavity

机器人虚拟TCP的设置及其在加工中的应用

针对机器人末端抓持工件时,无法利用生成在工件上的轮廓点进行去毛边加工的问题,对机器人末端抓持工件在工具固定的情况下去毛边加工的方法进行研究,提出在确定工件加工轮廓与机器人末端TCP的固定位姿关系之后,将固定在机器人工作空间中的工具上一点设置为虚拟TCP,以该虚拟TCP为基准,将附着于机器人末端工件上的加工轮廓点映射成机器人工作空间中的虚拟轨迹点的方法。在给出工件上轨迹点与虚拟轨迹点的映射关系,完成虚拟TCP以及机器人末端TCP设置的基础上,在Fanuc机器人仿真软件Robo Guide中对该方法进行了运动仿真验证后进行了加工,测量了其刀具进给量。实验结果表明:利用该方法对机器人夹持的工件进行去毛边加工,完全满足生产加工的精度要求。福建省重大科技专项资助项目(2016HZ0001-6

Digital design and manufacturing technology of customized hip prosthesis

针对人体的髋关节具有个性化特征以及传统假体与股骨匹配后力传递不稳定等问题,对人体髋关节假体数字化设计、有限元力传递分析、基于机器人磨削的数字化加工进行了研究,提出了在设计、仿真和加工过程中将髋关节假体模型统一的方法,实现了定制式假体数字化设计、有限元力传递的分析和机器人磨削加工的一体化,初步建立了髋关节假体的数字化设计与制造、产品生命周期的服务模型,为数字化设计与制造技术在髋关节假体等骨科植入物中的应用建立了基础。实验结果表明：采用机器人数字化磨削加工定制式假体,保持机器人软件空间与实际工作空间一致,可以有效提高假体的制造精度,实现假体与股骨髓腔的最优匹配。Aiming at the personal design of human hip joint and the stable force transmission after the matching of traditional prosthesis and femur, digital design of the human hip prosthesis , finite element analysis of force transfer and digital processing based on robot grinding were studied. The method of unifying hip prosthesis model in the process of design, simulation and processing was proposed to realize the integration of digital design of customized prosthesis, finite element analysis of force transfer and robotic grinding processing and both digital design and manufacture of hip prosthesis and service model of product life cycle were preliminary established to provide the basis for the applications of digital design and manufacturing technology in orthopaedic Implants, such as hip prosthesis. The results show that customized prosthesis produced by robotic digital grinding could effectively improve the manufacturing precision and achieve the optimal matching of prosthesis and femoral medullary cavity by keeping the robot software space consistent with the actual working space

A CAD/CAM method of individualized prosthesis base on CT reconstructing and robot grinding

人体髋关节髓腔具有个性化的S型形状,现有标准型的直柄股骨假体与病人髓腔形成三点接触,降低了股骨假体与病人髓腔的匹配度。利用猪腿骨的CT数据重建其; 髓腔的三维模型,将该三维模型作为假体设计模型导入机器人仿真软件进行编程和磨削仿真,并生成机器人磨削程序,利用机器人磨削程序将该假体模型复制到铜棒; 上。将加工好的假体与猪腿骨髓腔匹配,通过X射线图检测两者匹配情况,利用截取的骨断面测量假体与髓腔断面间的尺寸误差,验证个性化假体设计方法以及机器; 人磨削个性化假体的可行性。实验结果表明,假体与髓腔完成匹配后,90.84%匹配区域的假体与髓腔的间隙小于1mm。Human hip joint has a S-shaped canal , the existing standard straight; hip prosthesis matching with the femur cavity of the patient , will form; a three-point contact and reduce the fit precision between hip; prosthesis and femur cavity. The pig shank CT data is applied to; reconstruct the three-dimensional model of femur cavity to as a design; model of the prothesis, which is imported into robot simulation software; for programming and simulation of grinding , then,the prosthesis model; is copied on the copper bar by using robotic grinding technology. After; the prosthesis matched with femur cavity, the matching case is detected; by X-ray image , and the size error between the prosthesis and femur; cavity on the cross-sectional is measured to verify the method of; individualized prosthesis design and the feasibility of robot grinding; prosthesis. The experimental results show that 90.84% of the matching; area is less than 1mm when the femur cavity is matched with prosthesis

Study and Experiment on Rehabilitation Methods to Improve Total Hip Arthroplasty

最大限度恢复并维持患者的行动能力和活动强度，延长髋关节置换寿命，减少返修率，一直是全髋关节置换追求的主要目标。就全髋关节置换手术而言，手术操作技术已经成熟。全髋关节置换手术最终的成功与否与术后近端骨整合形成的质量密切相关，近端骨整合是手术成功的基础，而远端高匹配度是手术成功的必要条件。手术康复期，近端骨整合取决于力的传导。当假体上的力无法传导到股骨近端时，股骨近端将产生骨溶解，无法使假体与股骨形成良好的整合，假体在髓腔中的稳定性不足，易于引起假体的无菌松动。在长期稳定阶段，当假体上加载的力过大时，力向股骨近端的过度传导破坏假体近端的骨整合区，影响假体在髓腔中的长期稳定。因此，如何精确控制力传导...The main goal of total hip arthroplasty is to maximally restore the patient's mobility and activity, extend the hip replacement life and reduce the rate of repairing. In terms of total hip arthroplasty, surgical techniques are already mature. The final success of total hip arthroplasty is closely related to the quality of postoperative proximal osseointegration. Proximal osseointegration is the ba...学位：工学硕士院系专业：航空航天学院_精密仪器及机械学号：1992014115288

The Method and Experiment Research of Milling Die-casting by Robot

将机器人用于压铸件产品加工,需要解决软件自动生成加工轨迹,建立一致性的虚拟模型空间与实际模型空间等技术.采用机器人及其末端的标定工具,获得机器人; 与工作台、机器人与刀架之间的变换矩阵,从而建立虚拟模型空间和实际模型空间的一致性.利用CAM软件生成加工工件的刀具轨迹,通过后处理方法将刀具轨迹; 转换成机器人加工轨迹.对生成的轨迹点进行转换,形成工件绕刀具平动的虚拟加工轨迹.实验结果表明,与理论加工轨迹相比,实际加工轨迹形成了2; mm左右的系统误差,该误差由机器人零位误差和本体几何误差产生.通过缩放工件模型来产生轨迹,可以有效消除系统误差.消除系统误差后的加工精度可以达到; 0.1 mm,满足压铸件去除毛边的加工要求.The robot is used in die casting.lt is necessary to solve the problem,; in which the machining path is generated by software, and establishment; of spatial consistency between virtual model space and real model, and; so on.In this paper, transformation matrix between the robot and the; workbench,as well as between the robot and the tool holder are obtained; by using the robot and its calibration tool,and the consistency between; virtual model space and real model is achieved.Then,the tool path of the; workpiece is generated by using the universal CAM software,and the tool; path is transformed into the machining path.Finally,the generated; trajectory point conversion leads to the virtual machining locus of; workpiece around tool motion.Experimental results show that,compared; with the theory of machining trajectory,the actual machined path yields; an approximately 2 mm system error,which is generated by the robot-body; zero error and geometric error.The zoom-workpiece model generated; trajectory can effectively eliminate the system error.Eliminating the; system error after the processing precision,we are capable of reaching; 0.1 mm,and meet the processing pressure casting burr removing; requirements.福建省科技重大专