King M, Brock G, Lundell C
J Appl Physiol (1985). 1985 Jun;58(6):1776-82. doi: 10.1152/jappl.1985.58.6.1776.
We examined the relationship between mucus rheology, depth of mucus layer, and clearance by simulated cough. A model trachea was constructed of rigid Plexiglas of rectangular cross section (1 X 2 X 35 cm). The bottom of the trachea was lined with mucus simulants, gels prepared from locust bean gum cross-linked with sodium borate. Cough was simulated by opening a solenoid valve connecting the model trachea to a pressurized tank. An upstream flow-constrictive element was used to shape the flow profile of the simulated cough to approximate the pattern seen in a normal adult. Clearance of mucus was quantitated by observing the movement of contrasting marker particles floating in the mucus layer. The median particle displacement per cough maneuver was defined as the clearance index (CI). We found that CI for any initial depth of mucus increased with the driving pressure in the tank. For a given driving pressure, CI increased linearly with increasing mucus depth. For a given driving pressure and depth, CI decreased with increasing mucus cross-link density. For mucus samples with comparable levels of dynamic viscosity, samples with higher elasticity cleared less well. Mucus clearance was associated with transient wave formation in the lining layer.
我们通过模拟咳嗽研究了黏液流变学、黏液层深度与清除率之间的关系。用横截面为矩形（1×2×35厘米）的硬质有机玻璃构建了一个模型气管。气管底部衬有黏液模拟物，即由刺槐豆胶与硼酸钠交联制备的凝胶。通过打开连接模型气管与加压罐的电磁阀来模拟咳嗽。使用上游流量收缩元件来塑造模拟咳嗽的流型，以近似正常成年人中观察到的模式。通过观察漂浮在黏液层中的对比标记颗粒的运动来定量黏液的清除率。每次咳嗽动作的中位颗粒位移被定义为清除指数（CI）。我们发现，对于任何初始黏液深度，CI都随罐内驱动压力的增加而增加。对于给定的驱动压力，CI随黏液深度的增加而线性增加。对于给定的驱动压力和深度，CI随黏液交联密度的增加而降低。对于具有相当动态粘度水平的黏液样品，弹性较高的样品清除效果较差。黏液清除与衬里层中瞬态波的形成有关。
