Gouinaud Laure, Katz Ira, Martin Andrew, Hazebroucq Jean, Texereau Joëlle, Caillibotte Georges
a Medical Gases Group, Air Liquide Santé International, Centre de Recherche Claude Delorme , 1 Chemin de la Porte des Loges, B.P. 126, Les Loges-en-Josas 78354 , France.
Comput Methods Biomech Biomed Engin. 2015;18(12):1358-66. doi: 10.1080/10255842.2014.903932. Epub 2014 Apr 4.
A numerical pressure loss model previously used for adult human airways has been modified to simulate the inhalation pressure distribution in a healthy 9-month-old infant lung morphology model. Pressure distributions are calculated for air as well as helium and xenon mixtures with oxygen to investigate the effects of gas density and viscosity variations for this age group. The results indicate that there are significant pressure losses in infant extrathoracic airways due to inertial effects leading to much higher pressures to drive nominal flows in the infant airway model than for an adult airway model. For example, the pressure drop through the nasopharynx model of the infant is much greater than that for the nasopharynx model of the adult; that is, for the adult-versus-child the pressure differences are 0.08 cm H2O versus 0.4 cm H2O, 0.16 cm H2O versus 1.9 cm H2O and 0.4 cm H2O versus 7.7 cm H2O, breathing helium-oxygen (78/22%), nitrogen-oxygen (78/22%) and xenon-oxygen (60/40%), respectively. Within the healthy lung, viscous losses are of the same order for the three gas mixtures, so the differences in pressure distribution are relatively small.
先前用于成人人气道的数值压力损失模型已被修改，以模拟健康9个月大婴儿肺形态模型中的吸气压力分布。计算了空气以及氦气和氙气与氧气混合物的压力分布，以研究该年龄组气体密度和粘度变化的影响。结果表明，婴儿胸外气道中存在显著的压力损失，这是由于惯性效应导致在婴儿气道模型中驱动标称流量所需的压力远高于成人气道模型。例如，婴儿鼻咽模型的压降远大于成人鼻咽模型；也就是说，成人与儿童相比，分别呼吸氦氧（78/22%）、氮氧（78/22%）和氙氧（60/40%）时，压力差分别为0.08 cm H₂O对0.4 cm H₂O、0.16 cm H₂O对1.9 cm H₂O和0.4 cm H₂O对7.7 cm H₂O。在健康肺内，三种气体混合物的粘性损失量级相同，因此压力分布差异相对较小。
