Schreck S, Sullivan K J, Ho C M, Chang H K
Department of Biomedical Engineering, University of Southern California, Los Angeles 90089-1451.
J Appl Physiol (1985). 1993 Oct;75(4):1767-75. doi: 10.1152/jappl.1993.75.4.1767.
The relationship between the pressure losses within the nasal airways and nasal geometry were studied in a 3:1 scale model. The geometry of the model was based on magnetic resonance images of the skull of a healthy male subject. Pressure measurements, flow visualization, and hot-wire anemometry studies were performed at flow rates that, in vivo, corresponded to flows of between 0.05 and 1.50 l/s. The influence of nasal congestion and the collapse of the external nares were examined by using modeling clay to simulate local constrictions in the cross section. A dimensionless analysis of the pressure losses within three sections of the airway revealed the influence of various anatomic dimensions on nasal resistance. The region of the exterior nose behaves as a contraction-expansion nozzle in which the pressure losses are a function of the smallest cross-sectional area. Losses in the interior nose resemble those associated with channel flow. The nasopharynx is modeled as a sharp bend in a circular duct. Good correspondence was found between the predicted and actual pressure losses in the model under conditions that stimulated local obstructions and congestion.
在一个3:1比例的模型中研究了鼻气道内压力损失与鼻腔几何形状之间的关系。该模型的几何形状基于一名健康男性受试者颅骨的磁共振图像。在流速对应于体内0.05至1.50升/秒之间的流量下进行了压力测量、流动可视化和热线风速测量研究。通过使用造型黏土模拟横截面中的局部收缩来研究鼻充血和外鼻孔塌陷的影响。对气道三个部分内的压力损失进行无量纲分析，揭示了各种解剖学尺寸对鼻阻力的影响。外鼻区域的作用类似于收缩-扩张喷嘴，其中压力损失是最小横截面积的函数。鼻内部的损失类似于与通道流相关的损失。鼻咽被建模为圆形管道中的急转弯。在模拟局部阻塞和充血的条件下，模型中预测的压力损失与实际压力损失之间发现了良好的对应关系。
