Compliance Effect on the Flow Condition in Vascular In Vitro Experiments
Compliance Effect on the Flow Condition in Vascular In Vitro Experiments
复制标题
血管体外实验中流动条件的顺应性效应
DOI：
10.1115/imece2018-87362
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Simon Tupin and Makoto Ohta
中科院分区：
文献类型：
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作者：
Masami Matsuura;Simon Tupin and Makoto Ohta
血管内治疗已成为颅内动脉瘤治疗的标准。器械评价和临床医生培训需要包括动脉模型的体外系统。虽然硅树脂通常用于这种模型，但已知其顺应性低于血管。本研究的目的是分析模型材料的顺应性对流动性能的影响，使用硅树脂和12 [wt%]聚乙烯醇水凝胶（PVA-H）来创建两个盒形模型的显着不同的顺应性。内腔几何形状为直径4 [mm]的直管（载瘤血管）和直径10 [mm]的球体（代表动脉瘤）。用甘油、水和碘化钠的混合物制成的仿血液流体来再现血液的粘度和密度，并拟合模型的折射率。循环系统由搏动血泵和阻力阀组成。在模型内设置250±50 [ml/min]的流速和75 - 115 [mmHg]的压力。压力和流速传感器用于监测模型前后的流动状况。利用Nd：YAG固体激光系统和荧光粒子进行粒子图像测速（PIV），记录两种模型动脉瘤内的流动形态，结果显示，模型顺应性改变了动脉瘤内的流动状况。在两种模型的入口和出口之间记录流速脉冲的衰减。PVA-H模型的衰减率为51%。此外，在两个模型中记录的出口压力和出口流量曲线之间的时间滞后。PVA-H模型的时间延迟更长，因为该模型表现出更大的顺应性。PIV实验显示动脉瘤内的流动模式和速度发生了显着变化。由于其高顺应性，PVA-H模型壁在脉动条件下移动。与硅胶模型相比，在动脉瘤近端壁附近观察到血流方向改变和流速降低。这样的差异可能会修改对动脉瘤壁的应力。总之，我们的实验表明，顺应性对流动性能有显着的影响，并应考虑在体外血管模型制造。
Endovascular treatment has become the standard for intracranial aneurysm management. In vitro systems including an artery model are required for devices evaluation and clinician training. Although silicone is usually use for such model, its compliance is known to be lower than blood vessels. The purpose of this study was to analyze the influence of model material compliance on flow properties.Silicone and 12 [wt%] poly (vinyl alcohol) hydrogel (PVA-H) were used to create two box-shaped models of significantly different compliance. The inner lumen geometry was a 4 [mm] diameter straight tube (parent vessel) and a 10 [mm] diameter sphere representing the aneurysm. A blood-mimicking fluid made of a mixture of glycerin, water and sodium iodide was used to reproduce the viscosity and density of blood and fit models refractive index. The circulation system consisted of a pulsatile blood pump and resistance valve. A flow rate of 250±50 [ml/min] and pressure from 75 to 115 [mmHg] were set inside the model. Pressure and flow rate sensors were used to monitor flow conditions before and after the model. Particle image velocimetry (PIV) was performed to record the difference of flow patterns inside the aneurysm of both model using a Nd:YAG solid laser system and fluorescent particles.Results revealed a significant change of flow conditions due to model compliance. Attenuation of the flow rate pulse was recorded between the inlet and the outlet of the both model. This attenuation was 51% for PVA-H model. Moreover, a time lag between outlet pressure and outlet flow rate curves was recorded in both model. This time lag was longer with the PVA-H model, as this model exhibit a greater compliance.PIV experiments revealed significant changes of flow patterns and velocity inside the aneurysm. Because of its high compliance, PVA-H model walls moved under the pulsatile conditions. A change of flow direction and decrease of its velocity were observed near the proximal wall of the aneurysm, compared to the silicone model. Such differences might modify the stress on the wall of the aneurysm.To conclude, our experiments revealed that compliance has significant impacts on flow properties and should be taken into account for in vitro vascular model manufacturing.