NiTi合金左心耳封堵器表面改性及组织与性能表征
发布时间：2018-07-15 22:52
【摘要】：经皮左心耳封堵术是存在抗凝禁忌房颤患者有效物理治疗手段,在应用中具有安全有效,创伤微小,药物适应性强,操作灵活性强等优点,成为目前研究热点之一。在NiTi左心耳封堵器设计与制备过程中,优异的表面质量能有效提高封堵器的生物相容性和耐腐蚀性能。因此,本论文以NiTi合金左心耳封堵器作为研究对象,采用无水硫酸甲醇体系对NiTi合金进行电化学抛光,再对其热处理定型和化学钝化处理,研究了表面处理工艺对NiTi合金左心耳封堵器表面显微组织,亲水性能,耐腐蚀性能和生物相容性的影响。论文主要研究内容和研究成果如下:(1)对NiTi合金左心耳封堵器表面处理工艺进行研究。在电化学抛光工艺中,影响表面平整度的主要因素为抛光电压,而抛光电压和抛光时间的交互作用对重量损失产生重要影响。最佳电化学抛光工艺参数为21V±2V的抛光电压,-20℃的抛光温度。最佳热处理工艺为在500℃对合金退火10min,Af点温度有效控制在21℃±3℃范围内。最佳化学钝化工艺为在40℃的浓硝酸溶液中钝化处理30min,经过该表面处理工艺,能解决Ni Ti合金左心耳封堵器形状复杂引起的电化学抛光过程中局部过腐蚀问题。(2)对表面处理合金的表面显微组织、亲水性和耐蚀性能进行研究。结果表明,在经过电化学抛光处理(EP)后NiTi合金表面会形成一层非常薄的TiO2氧化层,主要为吸附氧结构,表面光滑。在经过电化学抛光+热处理+化学钝化处理(HCP)后,NiTi合金表面TiO2氧化层增厚,主要为晶格氧结构,表面光滑。对NiTi合金表面性能进行表征,结果表明该表面处理工艺改善了NiTi合金表面亲水性能,同时表现出优异的耐腐蚀性能,击穿电压达到到1500mv以上。(3)对NiTi合金左心耳封堵器生物相容性进行动物活体移植实验评估。动物实验期间,从影像学及病理解剖学评估心脏左心耳封堵系统在活体实验动物的血管腔及心房内输送、定位、释放、回撤过程均顺利。1例手术后即刻出现心耳穿孔,大量心包填塞而死亡,其余9例实验,没有发现实验动物在28天、180天随访期内出现不良症状及死亡,但2例180d后造影出现轻度残余分流。实验期间左心耳封堵器在观察期内未出现腐蚀及结构破坏,同时组织相容性良好,内皮细胞可紧密结合生长在器械表面。
[Abstract]:Percutaneous left atrial appendage closure is an effective physical therapy for patients with anticoagulant contraindication atrial fibrillation. It has the advantages of safety and effectiveness, minimal trauma, strong drug adaptability and strong operational flexibility, which has become one of the research hotspots at present. In the process of design and fabrication of Niti left atrial appendage occluder, the excellent surface quality can effectively improve the biocompatibility and corrosion resistance of the occluder. Therefore, in this paper, the Niti alloy left atrial ear occluder was used as the research object, the anhydrous methanol sulphate system was used for electrochemical polishing of the Niti alloy, and then the heat treatment and chemical passivation were performed on the Niti alloy. The effects of surface treatment technology on the surface microstructure, hydrophilicity, corrosion resistance and biocompatibility of Niti alloy left atrial ear occluder were studied. The main contents and results are as follows: (1) the surface treatment technology of Niti alloy left atrial appendage occluder is studied. In the electrochemical polishing process, the main factor affecting the surface smoothness is the polishing voltage, and the interaction between the polishing voltage and the polishing time has an important effect on the weight loss. The optimum process parameters of electrochemical polishing are 21 V 卤2 V polishing voltage and 20 鈩，
本文编号：2125637
[Abstract]:Percutaneous left atrial appendage closure is an effective physical therapy for patients with anticoagulant contraindication atrial fibrillation. It has the advantages of safety and effectiveness, minimal trauma, strong drug adaptability and strong operational flexibility, which has become one of the research hotspots at present. In the process of design and fabrication of Niti left atrial appendage occluder, the excellent surface quality can effectively improve the biocompatibility and corrosion resistance of the occluder. Therefore, in this paper, the Niti alloy left atrial ear occluder was used as the research object, the anhydrous methanol sulphate system was used for electrochemical polishing of the Niti alloy, and then the heat treatment and chemical passivation were performed on the Niti alloy. The effects of surface treatment technology on the surface microstructure, hydrophilicity, corrosion resistance and biocompatibility of Niti alloy left atrial ear occluder were studied. The main contents and results are as follows: (1) the surface treatment technology of Niti alloy left atrial appendage occluder is studied. In the electrochemical polishing process, the main factor affecting the surface smoothness is the polishing voltage, and the interaction between the polishing voltage and the polishing time has an important effect on the weight loss. The optimum process parameters of electrochemical polishing are 21 V 卤2 V polishing voltage and 20 鈩，
本文编号：2125637
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