增强VAR/EBR尼丁醇的疲劳性能用于跨导管心脏门应用:材料特性和设计影响
Maximilien E Launey1, Trey Bobo2, Behnood Miri2
1G.RAU Inc., Scotts Valley, California, USA.
概括
超清洁的真空弧复合/电子束复合 (VAR/EBR) 尼醇为跨导管中枢置换器件提供优越的耐疲劳性. 这一进步提高了安全边缘,满足了严格的III类监管耐久性要求.
科学领域:
- 生物材料工程 生物材料工程
- 材料科学 材料科学 材料科学
- 心血管设备技术的技术
背景情况:
- 透导管心血管器械,特别是等级III器械,如关节更换器械,需要具有异常耐疲劳的材料.
- 尼丁醇是关键的合金,但传统的变种在满足严格的耐用性标准方面面临限制,因为含有含有.
- 超清洁的真空弧复合/电子束复合 (VAR/EBR) 尼醇可以更好地控制材料缺陷.
研究的目的:
- 描述超清洁VAR/EBR尼丁醇在适用于跨导管中枢置换 (TMVR) 的条件下的疲劳行为.
- 为了评估VAR/EBR尼丁醇在HighLife中枢替换系统中的性能.
- 评估超清洁对疲劳失效机制和安全边际的影响.
主要方法:
- 来自VAR/EBR尼丁醇管道的钻石形疲劳样本被测试到4x10^8周期.
- 测试涉及不同的平均菌株 (1.5%-9%) 和菌株幅度 (0.50%-2.50%),模拟TMVR环境.
- 进行了断层分析,以确定裂开始地点和故障模式.
主要成果:
- 与传统的VAR Nitinol相比,VAR/EBR Nitinol在4x10^8周期的疲劳应变极限 (FSL) 中改善了130%.
- 疲劳行为表现出两种不同的应变模式,与压力诱导的马氏体转变有关.
- 断层分析证实了从包含启动到微观结构缺陷独立的疲劳失败的转变.
结论:
- 超清洁的VAR/EBR尼丁醇显著提高了疲劳性能,这对于III类心血管设备至关重要.
- 材料改善的疲劳行为将故障机制从缺陷主导转变为压力主导.
- 在复杂的操作条件下,这种金进步为TMVR设备 (如HighLife系统) 提供了更大的安全边缘.
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