【作者】 史廷春；

【导师】 张人佶； 庄洪兴；

【作者基本信息】 清华大学 ， 材料加工工程， 2003， 博士

【摘要】 小耳畸形是与生俱来的给患者带来重大身心伤害和功能障碍的外观畸形。目前的整形修复为手工切取患者自体肋软骨或采用标准构件组装支架等进行。二者均形态不逼真，欠美观，不能做到个性化服务，且前者需对患者做两处手术。本文提出并实现了根据患者健侧外耳CT数据重构其患侧外耳数字模型，以此驱动基于离散/堆积成形原理的熔融挤压快速成形设备，选择具有优良生物相容性和生物力学性能的高分子材料，加工出可植入人体内的耳软骨支架，替代肋软骨雕刻耳软骨支架，达到修复畸形小耳重建耳廓的治疗目的。鉴于患者颅骨发育的不对称性，本文提出基于不对称颅骨的耳软骨数据的反求与设计方法，获得的患侧数据模型既保证了外耳形状的真实性，又兼顾了与健侧耳廓的协调。对超高分子量聚乙烯、高密度聚乙烯和聚氨酯等材料分别和共混制丝，进行工艺试验和材料性能实验，从最终耳软骨支架性能和加工工艺过程需求的角度对材料进行遴选，选取具有良好生物相容性、加工安全性、最终制品具有良好强度、抗疲劳性以及柔韧性的聚氨酯作为耳软骨支架材料。针对熔融挤压快速成形（MEM）设备中摩擦送料机构对柔性材料送料的困难，提出并实现了颗粒料送进机构，并通过振动分析对其设计进行完善，解决了颗粒料稳定、均匀的送进，拓宽了该工艺的选料范围，缩短了材料制备与成形工艺链，提高了工效，减少了能耗和材料性能变化与引入污染的可能性。开发了一台桌面生物材料快速成形设备。配套设计了相应电路，开发了适合于复杂不规则表面反求数据模型的快速成形数据处理接口软件系统，实现了耳软骨支架的整体成形。改进了工作台设计，提高了成形的洁净度，避免了对工作台的粘损。通过对扫描过程的控制，实现对成形制品的孔隙率与连通性的控制，从工艺角度进一步提高了植入物的结构相容性和早期愈合水平。对聚氨酯弹性体人工耳软骨支架进行了临床前试验，包括细胞毒性、组织相容性和耳廓修复动物试验，检验了材料的适用性、工艺的可行性以及成形件的可使用性，达到了预期的目标，成功研制了生物相容材料客户化快速成形人工耳软骨支架。更多还原

【Abstract】 Microtia is an inherent apparent malformation and disturbance which does serious harm to the patient’s body and mind. Presently most of the microtias are treated by manually incising the patients’ rib cartilages or with Medpor products. None of them can completely satisfy the requirement of orthopaedic operation, the former requires two operations which are more painful to the patients and the shape of the reconstructed auricle appears not lifelike, and the latter are made in standard dimensions and shapes which are not symmetrical to the normal auricles of the patients’ and not customized service.In this dissertation, the bio-manufacturing technology is adopted, designing the digital model of the abnormal ear with the CT data of the normal side is brought forward and realized to drive the rapid forming machine based on the discrete/ deposit forming principle. The biocompatible polymer of adequate mechanical performance is chosen for making the implantable auricle scaffold to replace incising the ribs for the reconstruction of microtia.In consideration of the asymmetry of skull development, the reengineering and design method of auricle cartilage based on asymmetric skull is brought forward to insure the concerted relation between both auricles.Extra high molecular weight polyethylene, high density polyethylene and polyurethane are extruded apart and together, and the materials are used in technical tests and analyzed with instruments. Polymers are studied according to the requirements of the final auricle scaffolds and the process, and the polymer of perfect biocompatibility, safety in process and nice feel is selected as material for making auricle cartilage scaffolds.In allusion to the difficulty in feeding flexible material with frictional conveying machine of MEM, directly granule feeding machine is brought forward and realized in the paper. By analyzing the vibration, the design of the machine is further improved to feed the particles steadily and equably. The realization of the feeding machine of granule greatly broadens the material scope of MEM process, shortens the processing chain of material preparation, fabricating and reduces the possibility of pollution.<WP=7>A desktop biomaterial rapid forming system is developed, also the circuits of NC, material feeding and extruding are designed systematically. A software system is developed for the rapid forming of reengineered complex anomalistic surface, the entire forming of auricle cartilage is realized. A new worktable is designed which greatly improves the cleanliness of forming, and avoids the conglutination wastage of foam table. The control of porosity and connectivity of the scaffold is realized by alternating the combination of contour, filling and control of the scanning direction which improves the structural biocompatibility of the implant and early concrescence through the technology.The auricle scaffolds made of TPU are tested for their cell toxicity, tissue compatibility and with the preclinical animal tests, also the applicability of the material and the feasibility of the technology are tested. The anticipant goal is attained for having developed the biocompatible customized auricle scaffold with rapid forming technology.更多还原