目的 传统的脊柱侧弯矫形器普遍存在制作周期过长、材料消耗高和生物力学矫治效果不明确等缺点,针对这些问题,本研究拟采用有限元分析,对计算机辅助设计的3D打印脊柱侧弯矫形器进行生物力学镂空优化设计,从而使其实现具有良好的力学强度和模型轻量化等优点。方法 利用手持式三维扫描仪对志愿者躯干体廓进行扫描,构建志愿者体表模型；根据三点力原理、牵引及免荷原理,对志愿者的体表模型进行修型,设计出压力区和释放区,初步设计出脊柱侧弯矫形器模型；然后采用正交试验方法对32种不同尺寸的镂空组合进行局部优化对比研究,根据优化结果,对脊柱侧弯矫形器模型进行镂空处理和生物力学分析,对比镂空设计的3D打印脊柱侧弯矫形器的应力分布,验证矫形器模型的优化效果。结果 对目前3D打印脊柱侧弯矫形器,采用半径为9mm的圆孔,间距23mm的局部镂空优化设计(局部减重约40%),可得到重量更轻、透气性更好和足够强度的3D打印脊柱侧弯矫形器。结论 基于有限元生物力学分析,采用非压力区域的局部圆孔镂空优化设计,可以实现3D打印脊柱侧弯矫形器的打印材料减少,透气性增加等优点,最终可提高患者的穿戴舒适度和依从性。
Objective Traditional scoliosis orthosis has some disadvantages, such as long manufacturing cycle, high material consumption and unclear biomechanical effect. In order to solve these problems, this study intends to use finite element analysis to optimize the design of 3D printing scoliosis orthosis with computer-aided design, so as to achieve good mechanical strength and lightweight model. Method A hand-held three-dimensional scanner was used to scan the body contour of volunteers, and then the body surface model was imported into the three-dimensional modeling software for modeling processing. The CT data and X-ray film of volunteers were analyzed. According to the three-point force principle, traction and load-free principle, the body surface model was modified, and the pressure area and release area were designed. The model of scoliosis orthosis was designed preliminarily. Then, the local optimization of 32 different sizes of hollow combination is studied. According to the optimization results, the model of scoliosis orthosis was hollowed out and analysed biomechanically. The stress distribution of the 3D printing scoliosis orthosis designed by hollowing out was compared to verify the optimization effect of the orthosis model. Results For the current 3D printing scoliosis orthosis, a 3D printing scoliosis orthosis with lighter weight, better air permeability and sufficient strength can be obtained by suing optimal design of local hollowing out with 9mm radius and 23mm spacing round holes (local weight loss of about 40%). Conclusion Based on the finite element biomechanical analysis, with hollowing out optimization design, 3D printing scoliosis orthosis can achieve the advantages of less printing materials and increased air permeability, and ultimately improve the wearing comfort and compliance of patients.