Numerical experiment for Ultrasonic-Measurement-Integrated simulation of three-dimensional unsteady blood flow
Numerical experiment for Ultrasonic-Measurement-Integrated simulation of three-dimensional unsteady blood flow
复制标题
DOI：
10.1007/s10439-008-9519-7
复制
发表时间：
2008-08-01
影响因子：
3.8
通讯作者：
Yambe, Tomoyuki
中科院分区：
文献类型：
--
作者：
Funamoto, Kenichi;Hayase, Toshiyuki;Yambe, Tomoyuki
超声测量和数值模拟的结合是突破现有方法获取完整血流动力学信息的局限性的可能途径。在此，我们提出了超声-测量-积分(UMI)仿真，在该仿真中，将基于反馈点处测量和计算的多普勒速度确定的速度矢量中的误差的最优估计的反馈信号添加到控制方程中。着眼于实际测量数据的UMI模拟的实用化，通过处理动脉瘤内复杂血流的数值实验，研究了其对三维非定常血流分析的效率和处理超声测量的低时间分辨率的方法。即使应用简化的边界条件，UMI模拟也将覆盖动脉瘤的反馈域中的速度和压力误差分别降低到31%和53%。估计了局部最大壁面剪应力，给出了合适的位置和数值，偏差为1%。仅在获得测量数据时应用的适当设计的间歇反馈与在每个计算时间步长应用的反馈具有相同的计算精度。因此，这种反馈方法是克服超声测量时间分辨率不足的一种可能的解决方案。
Integration of ultrasonic measurement and numerical simulation is a possible way to break through limitations of existing methods for obtaining complete information on hemodynamics. We herein propose Ultrasonic-Measurement-Integrated (UMI) simulation, in which feedback signals based on the optimal estimation of errors in the velocity vector determined by measured and computed Doppler velocities at feedback points are added to the governing equations. With an eye towards practical implementation of UMI simulation with real measurement data, its efficiency for three-dimensional unsteady blood flow analysis and a method for treating low time resolution of ultrasonic measurement were investigated by a numerical experiment dealing with complicated blood flow in an aneurysm. Even when simplified boundary conditions were applied, the UMI simulation reduced the errors of velocity and pressure to 31% and 53% in the feedback domain which covered the aneurysm, respectively. Local maximum wall shear stress was estimated, showing both the proper position and the value with 1% deviance. A properly designed intermittent feedback applied only at the time when measurement data were obtained had the same computational accuracy as feedback applied at every computational time step. Hence, this feedback method is a possible solution to overcome the insufficient time resolution of ultrasonic measurement.