3D打印指骨骨折弹性固定器的研究

发布时间：2018-04-27 11:33

本文选题：指骨骨折 + 生物力学　；参考：《杭州电子科技大学》2017年硕士论文

【摘要】：在指骨骨折外固定领域中,为了避免石膏固定透气性差、高分子绷带固定不牢靠、夹板固定压迫边缘皮肤的各自缺陷,本文旨在研究一种符合人体手部生物力学的个性化、不等刚度的弹性外固定器。该外固定器不仅匹配患者手指的形状,而且匹配患者骨折部位,可实现指骨骨折部位的可靠精确固定。本文以拇指远节指骨骨折患者为研究对象,主要研究内容如下:1.拇指模型的三维重建及外固定器模型的设计。需要重建的拇指模型包含拇指骨骼和整个拇指两种三维模型。利用指骨骨折患者的手部CT数据,研究Mimics软件阈值分割方法,快速重建手部骨骼三维模型和整个手的三维模型。为简化计算量,需切割出拇指的骨骼三维模型和整个拇指三维模型。依据整个手的三维模型,在3DMax中设计出个性化、不等刚度、透气的外固定器。2.有限元分析模型的建立。建立三种用于有限元分析的实体模型:拇指骨骼、拇指软组织、外固定器。其中拇指软组织模型是通过实体化之后的拇指骨骼模型和整个拇指模型在有限元软件中做布尔减运算获得。在建模中,手动规划各个模型的NURBS曲面,并且采用六面体主导划分法划分网格。3.有限元分析。探索不同外力冲击外固定器表面所对骨折部位的应力和形变影响。当49N的外力作用在外固定器1cm2的面上时,尽管骨折部位受到最大值为2.0435Mpa的应力,但其发生的形变很小,可以忽略不计。4.用于成型外固定器的材料及3D打印技术的研究。通过对比TPU、PLA、光敏树脂这三种材料3D打印所成型的外固定器,确定TPU材料选取的正确性。再对比颗粒状和线状TPU所快速成型的外固定器以及所使用的打印机设备,确定线状TPU更佳。最终确定Ultimaker2+型号3D打印机打印线状TPU材料所成型的外固定器最适合于指骨骨折外固定。本研究的外固定器历经从无到有的整个过程,最终快速成型的外固定器实现了透气、可靠固定、穿戴舒适的目标。另外,该外固定器具有确切的生物力学性能指标,即固定器1cm2的面上可承受49N的外力冲击而不会再次对骨折部位造成伤害。
[Abstract]:In the field of external fixation of phalanx fracture, in order to avoid the defects of immobilization of plaster, immobilization of polymer bandage and immobilization of splint on the edge of the skin, the purpose of this paper is to study a kind of individualized biomechanics which accords with the biomechanics of human hand. Elastic external fixator with unequal stiffness. The external fixator not only matches the shape of the patient's finger, but also matches the fracture site of the patient, which can achieve reliable and accurate fixation of the fracture site of the phalangeal bone. Patients with distal phalangeal fractures of the thumb were studied in this paper. The main contents of the study were as follows: 1. Three-dimensional reconstruction of thumb model and design of external fixator model. The thumb model to be reconstructed consists of two three-dimensional models: the thumb skeleton and the whole thumb. Based on the CT data of patients with phalangeal fracture, the threshold segmentation method of Mimics software was studied to reconstruct the 3D model of hand bone and the 3D model of the whole hand. In order to simplify the calculation, the three-dimensional model of thumb bone and the whole three-dimensional model of thumb should be cut out. According to the 3D model of the whole hand, a personalized, unequal stiffness, breathable external fixator. 2. 2 was designed in 3DMax. The establishment of finite element analysis model. Three kinds of solid models for finite element analysis were established: thumb bone, thumb soft tissue and external fixator. The soft tissue model of thumb is obtained by Boolean subtraction in finite element software. In the modeling, the NURBS surface of each model is planned manually, and the hexahedron dominating method is used to divide the mesh. 3. Finite element analysis. To explore the effect of different external forces on the stress and deformation of the external fixator. When the external force of 49N acts on the surface of the external fixator 1cm2, although the fracture site is subjected to the maximum stress of 2.0435Mpa, the deformation is very small and can be ignored. Research on material and 3D printing technology for forming external fixator. By comparing the external fixators of TPU PLA and Guang Min resin, the selection of TPU materials was confirmed. Compared with the rapid prototyping of granular and linear TPU external fixators and the printer equipment used to determine that linear TPU is better. Finally, it is determined that the external fixator formed by Ultimaker2 3D printer printed linear TPU material is the most suitable for external fixation of phalangeal fracture. The external fixator in this study has experienced the whole process from nothing to existence, and finally the rapid prototyping external fixator has achieved the goal of breathable, reliable fixation and comfortable wearing. In addition, the external fixator has certain biomechanical properties, that is, the surface of the 1cm2 can withstand an external force shock of 49N without causing injury to the fracture site again.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R687.3;TP391.73

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