Real-time intravascular shear stress in the rabbit abdominal aorta.
Real-time intravascular shear stress in the rabbit abdominal aorta.
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DOI：
10.1109/tbme.2009.2013455
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发表时间：
2009-06
期刊：
影响因子：
--
通讯作者：
Hsiai TK
中科院分区：
文献类型：
--
作者：
Ai L;Yu H;Dai W;Hale SL;Kloner RA;Hsiai TK
流体剪应力与血管细胞的生物活性密切相关。研制了一种柔性微电子机械系统(MEMS)传感器，用于检测成年新西兰白兔腹主动脉血管内切应力(ISS)的时空变化分量。通过与计算流体力学(CFD)模拟壁面剪应力(WSS)的比较，对实时ISS(ISSReal-time)进行了分析。用GAMBIT软件建立腹主动脉的三维几何模型和网格模型。用FLUENT软件建立动脉血流分布的仿真模型。对于非牛顿流体流动，求解了N-S方程。基于同轴导线的MEMS传感器通过股动脉切断术被植入兔的腹动脉。根据CFD分析，传感器在同轴线(直径0.4 mm)上的入射长度小于10 mm。三维透视和对比染料可以显示传感器的位置和血管与同轴钢丝直径的比率。多普勒超声为CFD边界条件提供了速度分布。如果同轴导线放置在血管中心，CFD分析的平均ISS值为31.1DYN·cm−2，收缩峰值为102.8 dyn·cm−2，平均WSS为10.1dyn·cm−2，收缩峰值为33.2dyn·cm−2，同轴导线的引入使平均WSS增加5.4dyn·cm−2，收缩峰值增加18.0dyn·cm−2。平均ISS值为11.9dyn·cm−2，收缩峰值位于47.0dyn·cm−2。实验ISS值与CFD液的波形相似，平均差值为30.2%，峰值收缩切应力差值为8.9%。尽管CD和实验结果不同，但基于柔性同轴导线的MEMS传感器提供了实时评估NZW兔腹主动脉ISS的可能性。
Fluid shear stress is intimately linked with the biological activities of vascular cells. A flexible microelectromechanical system (MEMS) sensor was developed to assess spatial- and temporal-varying components of intravascular shear stress (ISS) in the abdominal aorta of adult New Zealand white (NZW) rabbits. Real-time ISS (ISSreal-time) was analyzed in comparison with computational fluid dynamics (CFD) simulations for wall shear stress (WSS). Three-dimensional abdominal arterial geometry and mesh were created using the GAMBIT software. Simulation of arterial flow profiles was established by FLUENT. The Navier–Stokes equations were solved for non-Newtonian blood flow. The coaxial-wire-based MEMS sensor was deployed into the abdominal arteries of rabbits via a femoral artery cutdown. Based on the CFD analysis, the entrance length of the sensor on the coaxial wire (0.4 mm in diameter) was less than 10 mm. Three-dimensional fluoroscope and contrast dye allowed for visualization of the positions of the sensor and ratios of vessel to coaxial wire diameters. Doppler ultrasound provided the velocity profiles for the CFD boundary conditions. If the coaxial wire were positioned at the center of vessel, the CFD analysis revealed a mean ISS value of 31.1 with a systolic peak at 102.8 dyn · cm−2. The mean WSS was computed to be 10.1 dyn · cm−2 with a systolic peak at 33.2 dyn · cm−2, and the introduction of coaxial wire increased the mean WSS by 5.4 dyn · cm−2 and systolic peak by 18.0 dyn · cm−2. Experimentally, the mean ISS was 11.9 dyn · cm−2 with a systolic peak at 47.0 dyn · cm−2. The waveform of experimental ISS was similar to that of CFD solution with a 30.2% difference in mean and 8.9% in peak systolic shear stress. Despite the difference between CD and experimental results, the flexible coaxial-wire-based MEMS sensors provided a possibility to assess real-time ISS in the abdominal aorta of NZW rabbits.