多孔仿生骨单元植入物三维打印成型系统开发及实验研究

发布时间：2019-01-09 13:16

【摘要】：理想的人工骨植入物,不仅要求外形与患者的骨缺损部位相符合,还应具有良好的力学性能及合适的生物仿生结构。采用传统加工方法制备人工骨植入物存在耗时长、内部孔隙结构加工困难、无法满足患者个性化需求等问题。利用3D打印技术制备人工骨植入物,不仅有利于实现复杂结构的人工骨植入物快速成型,同时能够精确控制孔隙结构、尺寸及分布,有利于促进骨细胞生长,加快骨修复过程。本课题针对目前骨修复过程中,存在修复植入体结构单一、多孔仿生结构难以加工等问题,通过对多孔结构进行力学仿真分析以及对三维印刷(Three Dimensional Printing, 3DP)打印工艺的研究,提出一种改进的生物陶瓷多孔骨单元三维打印成型系统,主要研究内容如下:选取兔骨小梁缺损部位为研究对象,对其进行图像分割、特征提取,建立骨小梁缺损部位的三维模型。在获取骨小梁缺损部位外轮廓的基础上,通过对植入环境中骨单元的生物力学性能要求进行分析,构建包括“疏松”型、“密质”型、“双层”型和“三层”型在内的四种多孔骨单元内部三维空间构架。再利用布尔运算,建立多孔骨植入物的三维模型。最后,利用有限元分析软件,研究上述多孔骨单元结构特征对其生物力学性能的影响规律。有限元分析结果表明“三层”型结构不仅构造与人体骨骼更为相似,力学性能也更加优越。其次,研究了一种改进的基于3DP工艺的多孔生物陶瓷快速成型方法,并搭建面向骨修复的3DP快速成型实验平台,完成机械结构、运动控制系统及软件设计等。在此基础上,完成多孔骨单元植入物制备并通过相应性能测试,探讨骨单元植入物成型过程中系统参量、模型结构以及烧结工艺对成型骨单元微观外貌和力学性能的影响规律。此研究内容可以为基于3DP工艺的高质量仿生骨骼打印制造的实现提供理论依据,对人工骨骼临床修复有重要的理论和实验意义。
[Abstract]:The ideal artificial bone implants should not only match the shape of bone defect, but also have good mechanical properties and bionic structure. The traditional method of manufacturing artificial bone implants has some problems such as long time consuming, difficult to process internal pore structure, and unable to meet the individual needs of patients. Using 3D printing technology to fabricate artificial bone implants is not only conducive to the rapid prototyping of artificial bone implants with complex structures, but also can accurately control the pore structure, size and distribution, promote the growth of bone cells and speed up the process of bone repair. In order to solve the problems of single implant structure and difficult machining of porous bionic structure in the process of bone repair at present, the mechanical simulation analysis of porous structure and the printing process of 3D printing (Three Dimensional Printing, 3DP are carried out. An improved three dimensional printing system for bioceramic porous bone unit is proposed. The main research contents are as follows: the rabbit trabecular defect is selected as the object of study, and the image segmentation and feature extraction are carried out. A three-dimensional model of bone trabecular defect was established. On the basis of obtaining the external contour of the bone trabecular defect, the biomechanical properties of the bone unit in the implanted environment were analyzed, and the types of "loose" and "dense" were constructed. Four types of porous bone units, including double-layer and three-layer, have three-dimensional structures. Then the three-dimensional model of porous bone implants was established by Boolean operation. Finally, the effects of the structural characteristics of the porous bone elements on the biomechanical properties of the porous bone units are studied by using the finite element analysis software. The results of finite element analysis show that the "three-layer" structure is not only more similar to the human skeleton, but also more superior in mechanical properties. Secondly, an improved rapid prototyping method of porous bioceramics based on 3DP process is studied, and the experimental platform of 3DP rapid prototyping for bone repair is built to complete the mechanical structure, motion control system and software design. On this basis, the porous bone unit implants were prepared and their properties were tested. The effects of system parameters, model structure and sintering process on the microstructure and mechanical properties of bone unit implants were discussed. This research can provide theoretical basis for the realization of high quality bionic bone printing based on 3DP process, and has important theoretical and experimental significance for the clinical restoration of artificial bone.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08;TP391.73

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