Design of a pulsatile flow facility to evaluate thrombogenic potential of implantable cardiac devices.
Design of a pulsatile flow facility to evaluate thrombogenic potential of implantable cardiac devices.
复制标题
设计脉动流设施以评估植入式心脏装置的血栓形成潜力。
DOI：
10.1115/1.4029579
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Yoganathan,AjitP
中科院分区：
文献类型：
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作者：
Arjunon,Sivakkumar;Ardana,PabloHidalgo;Saikrishnan,Neelakantan;Madhani,Shalv;Foster,Brent;Glezer,Ari;Yoganathan,AjitP
由于临床试验的昂贵性质，植入式心脏装置应该首先在体外进行广泛的表征。人工心脏瓣膜(PHV)是这类装置中的一类，已被证明与血栓栓塞性并发症有关。虽然已经设计了各种体外系统来量化这些PHV中由非生理性血流动力学剪应力引起的血细胞损伤和血小板激活，但很少有系统试图在同一测试系统中同时表征PHV的血液损伤和流体动力学方面的特征。各种数值建模方法也在不断发展，以模拟这些设备的结构力学、流体力学和血液损伤方面。本文介绍了一种完全血液相容性的小体积测试平台，可用于血栓形成研究和实验流体力学表征。使用可编程的活塞泵将新鲜提取的人体血液驱动到圆柱体中，该系统可以模拟测试PHV时的各种生理和病理生理条件。该系统包括一个模块化的设备安装室，在本案例中，使用了一个23 mm的圣裘德医疗(SJM)Regents®机械心脏瓣膜(MHV)作为测试设备。该系统通过测量测试仪本身造成的血液损伤(使用新鲜提取的全人类血液)来量化血液损伤的能力得到了验证。血液损伤程度是通过对人体血液的临床相关分析来确定的，而流体动力学则是使用模拟血液的液体使用时间分辨粒子图像测速仪(PIV)来表征的。通过凝血酶-抗凝血酶(TAT)、凝血酶原因子1.2(PF1.2)和溶血(Drabkins试验)评估，测试仪本身引起的血液损伤在临床可接受的水平内。该测试仪的水动力性能显示出一致的、可重复的生理压力和流动条件。此外，该系统还包含接近感应器，可准确捕捉整个心脏周期中的叶运动。PIV结果显示，由于两个小叶的不对称闭合，导致泄漏射流的偏斜。所有这些结果对于表征SJM Regents®MHV的血液损伤和流体动力学特性至关重要，证明了该测试仪作为评估各种PHV的血流动力学和血栓形成能力的精确系统的实用性。
Due to expensive nature of clinical trials, implantable cardiac devices should first be extensively characterized in vitro. Prosthetic heart valves (PHVs), an important class of these devices, have been shown to be associated with thromboembolic complications. Although various in vitro systems have been designed to quantify blood-cell damage and platelet activation caused by nonphysiological hemodynamic shear stresses in these PHVs, very few systems attempt to characterize both blood damage and fluid dynamics aspects of PHVs in the same test system. Various numerical modeling methodologies are also evolving to simulate the structural mechanics, fluid mechanics, and blood damage aspects of these devices. This article presents a completely hemocompatible small-volume test-platform that can be used for thrombogenicity studies and experimental fluid mechanics characterization. Using a programmable piston pump to drive freshly drawn human blood inside a cylindrical column, the presented system can simulate various physiological and pathophysiological conditions in testing PHVs. The system includes a modular device-mounting chamber, and in this presented case, a 23 mm St. Jude Medical (SJM) Regents®mechanical heart valve (MHV) in aortic position was used as the test device. The system was validated for its capability to quantify blood damage by measuring blood damage induced by the tester itself (using freshly drawn whole human blood). Blood damage levels were ascertained through clinically relevant assays on human blood while fluid dynamics were characterized using time-resolved particle image velocimetry (PIV) using a blood-mimicking fluid. Blood damage induced by the tester itself, assessed through Thrombin-anti-Thrombin (TAT), Prothrombin factor 1.2 (PF1.2), and hemolysis (Drabkins assay), was within clinically accepted levels. The hydrodynamic performance of the tester showed consistent, repeatable physiological pressure and flow conditions. In addition, the system contains proximity sensors to accurately capture leaflet motion during the entire cardiac cycle. The PIV results showed skewing of the leakage jet, caused by the asymmetric closing of the two leaflets. All these results are critical to characterizing the blood damage and fluid dynamics characteristics of the SJM Regents®MHV, proving the utility of this tester as a precise system for assessing the hemodynamics and thrombogenicity for various PHVs.