Tena Ana F, Fernández Joaquín, Álvarez Eduardo, Casan Pere, Walters D Keith
University of Oviedo. Hospital Universitario Central de Asturias (HUCA), Avda de Roma s/n, 33011, Oviedo, Spain.
University of Oviedo, Department of Energy, Campus de Barredo, 33600, Mieres, Spain.
Int J Numer Method Biomed Eng. 2017 Jun;33(6). doi: 10.1002/cnm.2830. Epub 2016 Oct 7.
The need for a better understanding of pulmonary diseases has led to increased interest in the development of realistic computational models of the human lung.
To minimize computational cost, a reduced geometry model is used for a model lung airway geometry up to generation 16. Truncated airway branches require physiologically realistic boundary conditions to accurately represent the effect of the removed airway sections. A user-defined function has been developed, which applies velocities mapped from similar locations in fully resolved airway sections. The methodology can be applied in any general purpose computational fluid dynamics code, with the only limitation that the lung model must be symmetrical in each truncated branch.
Unsteady simulations have been performed to verify the operation of the model. The test case simulates a spirometry because the lung is obliged to rapidly perform both inspiration and expiration. Once the simulation was completed, the obtained pressure in the lower level of the lung was used as a boundary condition. The output velocity, which is a numerical spirometry, was compared with the experimental spirometry for validation purposes.
This model can be applied for a wide range of patient-specific resolution levels. If the upper airway generations have been constructed from a computed tomography scan, it would be possible to quickly obtain a complete reconstruction of the lung specific to a specific person, which would allow individualized therapies.
对肺部疾病有更深入了解的需求促使人们对开发逼真的人体肺部计算模型的兴趣日益增加。
为了将计算成本降至最低，对于直至第16代的模型肺气道几何结构，使用了简化几何模型。截断的气道分支需要符合生理实际的边界条件，以准确表示被切除气道部分的影响。已开发出一个用户定义函数，该函数应用从完全解析的气道部分中相似位置映射的速度。该方法可应用于任何通用计算流体动力学代码，唯一的限制是肺模型在每个截断分支中必须对称。
已进行非稳态模拟以验证模型的运行情况。测试案例模拟肺活量测定，因为肺部必须快速进行吸气和呼气。模拟完成后，将在肺下部获得的压力用作边界条件。将作为数值肺活量测定的输出速度与实验性肺活量测定进行比较以进行验证。
该模型可应用于广泛的患者特定分辨率水平。如果从计算机断层扫描构建了上呼吸道代，那么有可能快速获得特定于某个人的肺部完整重建，这将允许进行个性化治疗。
