The effects of curvature on fluid flow fields in pulmonary artery models: flow visualization studies.
The effects of curvature on fluid flow fields in pulmonary artery models: flow visualization studies.
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曲率对肺动脉模型中流体流场的影响：流动可视化研究。
DOI：
10.1115/1.2895476
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Yoganathan,AP
中科院分区：
文献类型：
--
作者：
Lynch,PG;Saylor,A;Ha,B;Lucas,C;Henry,GW;Ferreiro,JI;Yoganathan,AP
在体外进行脉动流可视化研究，以评估右心室流出道（RVOT）和主肺动脉（MPA）的不同曲率半径对一个月的羔羊肺动脉模型的主，右，左肺动脉中的流场的影响。研究了三个玻璃流通模型;一个没有曲率，一个具有正确的解剖曲率，一个在RVOT和MPA上具有过度强调的曲率。所有其他几何参数保持不变。在9种血流条件下进行脉动流可视化研究;心率为70、100和140 bpm，心输出量为1.5、2.5和3.5 l/min，相应的平均肺动脉压为10、20和30 mmHg。随着流出道曲率、心率和平均肺动脉压的变化，观察到肺血流场的变化。血管曲率的增加导致流场的整体径向性质以及形成更快、起源于更下游且占据更多血管面积的流动分离区域的增加。在较高的心率下，分离区的最大尺寸减小，而血流分离区在心动周期中出现得更早，生长得更快。心率也影响血流逆转的开始;在较低心率时，血流逆转发生在心动周期后期。心率和平均肺动脉压均影响肺动脉流场的稳定性和相干结构的出现。此外，平均肺动脉压的增加增加了反向流动的幅度。这些流动可视化观察指导了更多的定量研究，如脉冲多普勒超声和激光多普勒风速测量。
In vitro pulsatile flow visualization studies were conducted to assess the effects of varying radii of curvature of the right ventricular outflow tract (RVOT) and main pulmonary artery (MPA) on the flow fields in the main, right, and left pulmonary arteries of a one month lamb pulmonary artery model. Three glass flow-through models were studied; one with no curvature, one with the correct anatomic curvature, and one with an overaccentuated curvature on the RVOT and MPA. All other geometric parameters were held constant. Pulsatile flow visualization studies were conducted at nine flow conditions; heart rates of 70, 100, and 140 bpm, and cardiac outputs of 1.5, 2.5 and 3.5 l/min with corresponding mean pulmonary pressures of 10, 20, and 30 mmHg. Changes were observed in the pulmonary flow fields as the curvature of the outflow tract, heart rate and mean pulmonary pressure were varied. An increase in vessel curvature led to an increase in the overall radial nature of the flow field as well as flow separation regions which formed faster, originated further downstream, and occupied more of the vessel area. At higher heart rates, the maximum size of the separation regions decreased, while flow separation regions appeared earlier in the cardiac cycle and grew more quickly. Heart rate also affected the initiation of flow reversal; flow reversal occurred later in the cardiac cycle at lower heart rates. Both heart rate and mean pulmonary pressure influenced the stability of the pulmonary flow field and the appearance of coherent structures. In addition, an increase in mean pulmonary pressure increased the magnitude of reverse flow. These flow visualization observations have directed more quantitative studies such as pulsed Doppler ultrasound and laser Doppler anemometry velocity measurements.