【摘要】：經(jīng)皮左心耳封堵術(shù)是存在抗凝禁忌房顫患者有效物理治療手段,在應(yīng)用中具有安全有效,創(chuàng)傷微小,藥物適應(yīng)性強(qiáng),操作靈活性強(qiáng)等優(yōu)點,成為目前研究熱點之一。在NiTi左心耳封堵器設(shè)計與制備過程中,優(yōu)異的表面質(zhì)量能有效提高封堵器的生物相容性和耐腐蝕性能。因此,本論文以NiTi合金左心耳封堵器作為研究對象,采用無水硫酸甲醇體系對NiTi合金進(jìn)行電化學(xué)拋光,再對其熱處理定型和化學(xué)鈍化處理,研究了表面處理工藝對NiTi合金左心耳封堵器表面顯微組織,親水性能,耐腐蝕性能和生物相容性的影響。論文主要研究內(nèi)容和研究成果如下:(1)對NiTi合金左心耳封堵器表面處理工藝進(jìn)行研究。在電化學(xué)拋光工藝中,影響表面平整度的主要因素為拋光電壓,而拋光電壓和拋光時間的交互作用對重量損失產(chǎn)生重要影響。最佳電化學(xué)拋光工藝參數(shù)為21V±2V的拋光電壓,-20℃的拋光溫度。最佳熱處理工藝為在500℃對合金退火10min,Af點溫度有效控制在21℃±3℃范圍內(nèi)。最佳化學(xué)鈍化工藝為在40℃的濃硝酸溶液中鈍化處理30min,經(jīng)過該表面處理工藝,能解決Ni Ti合金左心耳封堵器形狀復(fù)雜引起的電化學(xué)拋光過程中局部過腐蝕問題。(2)對表面處理合金的表面顯微組織、親水性和耐蝕性能進(jìn)行研究。結(jié)果表明,在經(jīng)過電化學(xué)拋光處理(EP)后NiTi合金表面會形成一層非常薄的TiO2氧化層,主要為吸附氧結(jié)構(gòu),表面光滑。在經(jīng)過電化學(xué)拋光+熱處理+化學(xué)鈍化處理(HCP)后,NiTi合金表面TiO2氧化層增厚,主要為晶格氧結(jié)構(gòu),表面光滑。對NiTi合金表面性能進(jìn)行表征,結(jié)果表明該表面處理工藝改善了NiTi合金表面親水性能,同時表現(xiàn)出優(yōu)異的耐腐蝕性能,擊穿電壓達(dá)到到1500mv以上。(3)對NiTi合金左心耳封堵器生物相容性進(jìn)行動物活體移植實驗評估。動物實驗期間,從影像學(xué)及病理解剖學(xué)評估心臟左心耳封堵系統(tǒng)在活體實驗動物的血管腔及心房內(nèi)輸送、定位、釋放、回撤過程均順利。1例手術(shù)后即刻出現(xiàn)心耳穿孔,大量心包填塞而死亡,其余9例實驗,沒有發(fā)現(xiàn)實驗動物在28天、180天隨訪期內(nèi)出現(xiàn)不良癥狀及死亡,但2例180d后造影出現(xiàn)輕度殘余分流。實驗期間左心耳封堵器在觀察期內(nèi)未出現(xiàn)腐蝕及結(jié)構(gòu)破壞,同時組織相容性良好,內(nèi)皮細(xì)胞可緊密結(jié)合生長在器械表面。
[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 鹵2 V polishing voltage and 20 鈩，

本文編號：2125637