集成机器人磨削的定制式假体制作方法研究

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.