Subhash N N, Rajeev Adathala, Sujesh Sreedharan, Muraleedharan C V
Department of Medical Devices Engineering, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
Proc Inst Mech Eng H. 2017 Aug;231(8):758-765. doi: 10.1177/0954411917703676. Epub 2017 Apr 11.
Average age group of heart valve replacement in India and most of the Third World countries is below 30 years. Hence, the valve for such patients need to be designed to have a service life of 50 years or more which corresponds to 2000 million cycles of operation. The purpose of this study was to assess the structural performance of the TTK Chitra tilting disc heart valve model TC2 and thereby address its durability. The TC2 model tilting disc heart valves were assessed to evaluate the risks connected with potential structural failure modes. To be more specific, the studies covered the finite element analysis-based fatigue life prediction and accelerated durability testing of the tilting disc heart valves for nine different valve sizes. First, finite element analysis-based fatigue life prediction showed that all nine valve sizes were in the infinite life region. Second, accelerated durability test showed that all nine valve sizes remained functional for 400 million cycles under experimental conditions. The study ensures the continued function of TC2 model tilting disc heart valves over duration in excess of 50 years. The results imply that the TC2 model valve designs are structurally safe, reliable and durable.
在印度和大多数第三世界国家,心脏瓣膜置换的平均年龄组低于30岁。因此,需要为这类患者设计使用寿命达50年或更长时间的瓣膜,这相当于20亿次的操作循环。本研究的目的是评估TTK Chitra倾斜盘式心脏瓣膜模型TC2的结构性能,从而解决其耐久性问题。对TC2模型倾斜盘式心脏瓣膜进行评估,以评估与潜在结构失效模式相关的风险。更具体地说,研究涵盖了基于有限元分析的疲劳寿命预测以及对九种不同瓣膜尺寸的倾斜盘式心脏瓣膜进行加速耐久性测试。首先,基于有限元分析的疲劳寿命预测表明,所有九种瓣膜尺寸都处于无限寿命区域。其次,加速耐久性测试表明,在实验条件下,所有九种瓣膜尺寸在4亿次循环后仍能正常工作。该研究确保了TC2模型倾斜盘式心脏瓣膜在超过50年的时间内持续发挥功能。结果表明,TC2模型瓣膜设计在结构上是安全、可靠和耐用的。