Laboratory of Hemodynamics and Cardiovascular Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Am J Physiol Heart Circ Physiol. 2011 Sep;301(3):H1173-82. doi: 10.1152/ajpheart.00821.2010. Epub 2011 May 27.
The aim of this study is to develop and validate a patient-specific distributed model of the systemic arterial tree. This model is built using geometric and hemodynamic data measured on a specific person and validated with noninvasive measurements of flow and pressure on the same person, providing thus a patient-specific model and validation. The systemic arterial tree geometry was obtained from MR angiographic measurements. A nonlinear viscoelastic constitutive law for the arterial wall is considered. Arterial wall distensibility is based on literature data and adapted to match the wave propagation velocity of the main arteries of the specific subject, which were estimated by pressure waves traveling time. The intimal shear stress is modeled using the Witzig-Womersley theory. Blood pressure is measured using applanation tonometry and flow rate using transcranial ultrasound and phase-contrast-MRI. The model predicts pressure and flow waveforms in good qualitative and quantitative agreement with the in vivo measurements, in terms of wave shape and specific wave features. Comparison with a generic one-dimensional model shows that the patient-specific model better predicts pressure and flow at specific arterial sites. These results obtained let us conclude that a patient-specific one-dimensional model of the arterial tree is able to predict well pressure and flow waveforms in the main systemic circulation, whereas this is not always the case for a generic one-dimensional model.
本研究旨在开发和验证一种特定于患者的全身动脉树的分布式模型。该模型是使用特定个体的几何和血流动力学数据构建的，并使用同一个体的非侵入性流量和压力测量进行验证，从而提供了特定于患者的模型和验证。全身动脉树的几何形状是从磁共振血管造影测量中获得的。考虑了动脉壁的非线性粘弹性本构定律。动脉壁可扩展性基于文献数据，并进行了调整以匹配特定对象的主要动脉的波传播速度，该速度是通过压力波传播时间估计的。内膜切应力使用 Witzig-Womersley 理论进行建模。血压通过平板眼压测量，流量通过经颅超声和相位对比-MRI 测量。该模型在定性和定量方面都很好地预测了体内测量的压力和流量波形，包括波的形状和特定的波特征。与通用的一维模型相比，结果表明，特定于患者的动脉树的一维模型能够更好地预测特定动脉部位的压力和流量。这些结果表明，特定于患者的动脉树的一维模型能够很好地预测主要全身循环中的压力和流量波形，而通用的一维模型则并非总是如此。
