Assessment of blood volume flow in slightly curved arteries from a single velocity profile
Assessment of blood volume flow in slightly curved arteries from a single velocity profile
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DOI：
10.1016/j.jbiomech.2009.04.032
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发表时间：
2009-08-07
影响因子：
2.4
通讯作者：
van de Vosse, F. N.
中科院分区：
文献类型：
--
作者：
Leguy, C. A. D.;Bosboom, E. M. H.;van de Vosse, F. N.
动脉血流量的无创估计已成为心血管风险评估的核心问题。Poiquilille和Womersley方法通常用于从中心线速度评估BVF，但这两种方法都忽略了曲率的影响。基于弯曲管道中的速度作为给定径向位置的圆周位置的函数可以用余弦近似的假设，BVF也可以通过平均径向相对位置处的速度来估计，称为余弦θ模型（CTM）。计算流体动力学模拟用于计算曲率对速度分布的影响。然后，利用CTM和基于Poietville、Womersley的方法，利用中心流速度和最大速度处的速度波形，从模拟结果中估算出BVF，并与给定的BVF进行比较。对于Poiesville和Womersley，曲率半径为50 mm和100 mm时，时间平均BVF分别被低估了最大10.4%和7.8%。CTM的估计误差较低，曲率半径为50 mm和100 mm时的估计误差分别为4.2%和1.2%，由此可知，与Womersley方法相结合的中心流速度波形相比，应选择最大值位置处的速度波形。如果体内速度分布可用，CTM改进了当前的估计技术。(c)2009爱思唯尔有限公司版权所有。
Non-invasive estimation of arterial blood volume flow (BVF) has become a central issue in assessment of cardiovascular risk. Poiseuille and Womersley approaches are commonly used to assess the BVF from centerline velocity, but both methods neglect the influence of curvature. Based on the assumption that the velocity in curved tubes as function of the circumferential position for a given radial position can be approximated by a cosine, the BVF can also be estimated by averaging velocities at opposite radial positions, referred to as the cosine theta model (CTM).This study investigates the accuracy of BVF estimation in slightly curved arteries for BVF waveforms obtained in the brachial artery of 6 volunteers. Computational fluid dynamics simulations were used to compute the influence of curvature on velocity profiles. The BVF was then estimated from the simulation results with the CTM and methods based on Poiseuille, Womersley and using the center stream velocity and the velocity waveform at the position where the maximum velocity is observed, and compared to the prescribed BVF.The simulations show that the influence of curvature is strongest when the flow decelerates. For Poiseuille and Womersley, the time average BVF was underestimated by maximally 10.4% and 7.8% for a radius of curvature of 50 and 100 mm, respectively. The estimation error is lower for the CTM and equals 4.2% and 1.2% for a radius of curvature of 50 and 100 mm, respectively.From this study, we can conclude that the velocity waveform at the position of the maximum rather than the center stream velocity waveform combined with the Womersley method should be chosen. The CTM improves current estimation techniques if in-vivo velocity distributions are available. (c) 2009 Elsevier Ltd. All rights reserved.