Conclusion : mitral and aortic valves were vulnerable to calcification which was the major change of heart valve in patients with crf on maintenance hemodialysis , the degree of calcification was closely related to hyperphosphoremia , secondary hyperparathyroidism and a longer period of hemodialysis 结论:慢性肾功能衰竭维持性血液透析患者心脏瓣膜病变均以钙化为主,尤以二尖瓣、主动脉瓣易发,且钙化程度与钙磷乘积、继发性甲状旁腺机能亢进和血液透析年限密切相关。
Diamond - like carbon gradient film on ti6a14v alloy substrate have been prepared by means of plasma source ion implanted - ion beam enhanced deposition ( psii - ibed ) . for potential applications as artificial joint materials and artificial cardiac valve materials , its trobological performance and hemocompatibility has also been evaluated in the present ph . d . thesis 本研究采用等离子源离子注入?离子束增强沉积技术( psii - ibed )制备了钛合金基类金刚石梯度薄膜材料，对类金刚石梯度薄膜这一新型人工关节材料和人工心脏瓣膜材料的生物摩擦学性能和血液相容性进行了研究和评价，研究了摩擦磨损对材料血液相容性的影响。
In consideration of time and budget factor , the first step is to manufacture 8 - type ( groove axle structure ) and circle bore type mechanical heart valve . here , the concentration is on the structure design , process and process equipment design , and manufacture of valve on a trial basis 考虑到时间进程和经费因素，初步选定进行8字型凹槽枢轴结构平面瓣型及圆柱孔枢轴圆孔型心瓣进行试制加工，本论文工作的重点是人工心脏瓣膜的结构设计，工艺和工艺装备设计，以及人工心脏瓣膜试制。
This study is based on the analyses of a series of different types of artificial heart valve in home and abroad . to overcome the shortcoming of existed artificial heart valve , several forms of bileaflet mechanical heart valve are developed . after a thorough comparison and analysis of the characters of these forms , some ideal structures are selected to be manufactured 本文的研究工作是对国内外诸多瓣膜产品进行深入分析研究的基础上开展的，为了克服人工心脏瓣膜存在的各种弊端，本文提出了三种结构形式的双叶瓣，并就各种结构形式的特点进行分析比较。
