THE MECHANISM OF MUCUS CLEARANCE IN COUGH
THE MECHANISM OF MUCUS CLEARANCE IN COUGH
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DOI：
10.1115/1.3168381
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发表时间：
1989-11-01
影响因子：
1.7
通讯作者：
GRIFFITH, P
中科院分区：
文献类型：
--
作者：
BASSER, PJ;MCMAHON, TA;GRIFFITH, P
一种类似雪崩的不稳定性被认为是咳嗽时粘液从呼吸道排出的机制。在模型气道中模拟咳嗽事件。在这些实验中，空气被迫通过一个通道，该通道的壁衬有一种流变学上类似于气管粘液的非牛顿材料。从高速电影照片帧显示一个不稳定的事件，开始作为一个波动的自由表面，并发展到一个灾难性的清除渠道。纵向压力梯度的测量支持这样的假设，即当施加到粘液类似物的总应力超过其有限屈服应力时，清除事件开始。连续模型预测，屈服发生在粘液类似物的底层内。基于气管几何形状和气流估计值的计算表明，此处研究的清除事件预计发生在咳嗽期间，而不是正常呼吸期间。实验还表明，在通道壁和粘液层之间引入的润滑剂可以降低沉淀间隙所需的空气流速。
An instability resembling an avalanche is proposed as the mechanism by which mucus is expelled from the respiratory tract during cough. The cough event was simulated in a model airway. In these experiments, air was forced through a channel whose walls were lined with a non-Newtonian material rheologically similar to tracheal mucus. Frames from high-speed cine photographs showed an unstable event which began as an undulation of the free surface and progressed to a catastrophic clearance of the channel. Measurements of the longitudinal pressure gradient support the hypothesis that the clearance event is initiated when the total stress applied to the mucus analog exceeds its finite yield stress. A continuum model predicts that yielding occurs within the bottom layers of the mucus analog. Calculations based upon estimates of tracheal geometry and air flow show that the clearance event studied here would be expected to occur during a cough but not during normal breathing. Experiments also show that a lubricant introduced between the channel walls and the mucus blanket can reduce the air flow rate required to precipitate the clearance.