An investigation into patient-specific 3D printed titanium stents and the use of etching to overcome Selective Laser Melting design constraints
An investigation into patient-specific 3D printed titanium stents and the use of etching to overcome Selective Laser Melting design constraints
复制标题
对患者特异性 3D 打印钛支架的研究以及使用蚀刻来克服选择性激光熔化设计限制
DOI：
10.1016/j.jmbbm.2022.105388
复制
发表时间：
2022
影响因子：
3.9
通讯作者：
McGee O
中科院分区：
文献类型：
--
作者：
McGee O
由于用于治疗主动脉缩窄的可用儿科支架的局限性，成人支架通常在标签外使用，导致结局不佳。CT和/或MR成像在术前评估中的日益广泛的使用，以及3D打印等增材制造工艺的出现，可以使定制设备的生产效率和成本效益更高。然而，3D打印的金属支架需要自支撑，这导致其设计的局限性。在这项研究中，我们研究了使用蚀刻来克服这些设计限制并改善支架表面光洁度。此外，使用实验台测试和有限元（FE）方法相结合，我们研究了蚀刻如何影响支架性能。然后使用逆有限元方法校准和比较打印和蚀刻支架的材料特性。我们发现，在没有蚀刻钛支架的情况下，与蚀刻支架设计的平均76.84 GPa相比，逆FE方法低估了完工支架的刚度（E = 33.89 GPa）。最后，使用患者特定的有限元模型，不同的支架的性能进行了测试，以评估患者的结果和管腔增益和血管应力被发现受到支架设计和后处理的强烈影响。在这项研究中，蚀刻被确认为一种手段，以创建开孔支架设计，同时仍然符合增材制造的“规则”，并伴随着改善支架表面光洁度。此外，还证明了使用体内成像-产品开发管道的可行性，该管道可针对不同解剖结构生产患者特定支架，以实现最佳器械性能。
Due to limitations in available paediatric stents for treatment of aortic coarctation, adult stents are often used off-label resulting in less than optimal outcomes. The increasingly widespread use of CT and/or MR imaging for pre-surgical assessment, and the emergence of additive manufacturing processes such as 3D printing, could enable bespoke devices to be produced efficiently and cost-effectively. However, 3D printed metallic stents need to be self-supporting leading to limitations in their design.In this study, we investigate the use of etching to overcome these design constraints and improve stent surface finish. Furthermore, using a combination of experimental bench testing and finite element (FE) methods we investigate how etching influences stent performance. Then using an inverse finite element approach the material properties of the printed and etched stents were calibrated and compared. We show that without etching the titanium stents, the inverse FE approach underestimates the stiffness of the as-built stent (E = 33.89 GPa) when compared to an average of 76.84 GPa for the etched stent designs. Finally, using patient-specific finite element models the different stents’ performance were tested to assess patient outcomes and lumen gain and vessel stresses were found to be strongly influenced by the stent design and postprocessing.Within this study, etching is confirmed as a means to create open-cell stent designs whilst still conforming to additive manufacturing ‘rules’ and concomitantly improving stent surface finish. Additionally, the feasibility of using an in-vivo imaging-to-product development pipeline is demonstrated that enables patient-specific stents to be produced for varying anatomies to achieve optimum device performance.