FLOW DYNAMICS & RESISTANCES IN THE UPPER AIRWAYS

这项拟议中的研究旨在了解气流， 鼻气道阻力。 为此，实验将 在缩放的鼻气道模型、鼻模型、动物和 人类实验对象 具备流体力学知识和技术 的系统识别将被用来设计 实验，分析数据，解释结果。 主要 但不只是回答“是什么”和“如何”的问题， 除了“为什么”，本研究由三个部分组成，每个部分都有 三个具体目标。 第1部分涉及鼻子中的流动动力学。 理想化鼻音 3：1比例的气道模型将由透明丙烯酸制成 并会制作塑胶及透明的鼻模。 的 在铸型中获得的流动显示结果将作为 用激光在透明模型中进行流动显示的设计指南 纸张扫描 模型中的详细速度测量将 使用激光多普勒风速仪。 压力流量 将获得铸件中的关系， 管理其主要特征调查。 研究的第二部分试图建立两种新的方法， 测量鼻腔气流阻力。 一种非侵入性的强制 振荡方法是基于这样一个事实，即鼻和下 气道形成空气从口腔进入的平行路径。 一 第二种方法是由戴着口罩的受试者闻几下， 面罩。 这些技术将产生鼻阻抗， 可以识别阻力。 两者都将在正常情况下进行测试 受试者和患者。 第3部分包括动物实验，旨在了解三个 鼻生理学方面。 三个工作假设 实验中使用了机头内的流动和阻力：（1） 高频电刺激更容易刺激鼻窦， 振荡气流比通过鼻腔的稳定气流 （2）流速限制理论适用于 最大鼻吸气流量;和（3）严重增加的鼻 阻力引起肺阻力增加，主要是由于 肺组织抵抗力的增强。

This proposed research is aimed at understanding airflow and resistance in the nasal airways. To this end, experiments will be conducted in scaled nasal airway models, nose casts, animals and human subjects. Knowledge of fluid mechanics as well as techniques of system identification will be employed to design the experiments, analyze the data, and interpret the results. Mainly but not exclusively to answer questions of "What" and "how" rather than "why", this research consists of three parts, each having three specific aims. Part 1 deals with flow dynamics in the nose. Idealized nasal airway models of 3:1 scale will be constructed out of clear acrylic plastic and transparent casts of the nose will also be made. The flow visualization results obtained in the casts will serve as a guide to design flow visualization in the clear models by laser sheet scanning. Detailed velocity measurement in the models will be made using Laser Doppler Anemometry. Pressure-flow relationships in the casts will be obtained and the factors governing their main features investigated. Part 2 of the research seeks to establish two new methods of measuring nasal airflow resistance. A non-invasive forced oscillation method is based on the fact that the nasal and lower airways form parallel paths for air entering from the mouth. A second method consists of a few sniffs by the subject wearing a face mask. These techniques will yield nasal impedance from which resistance can be identified. Both will be tested in normal subjects as well as patients. Part 3 consists of animal experiments designed to understand three aspects of nasal physiology. Three working hypotheses regarding flow and resistance in the nose are used for this experiment: (1) it is easier to ventilate a paranasal sinus by high-frequency oscillating air current than by steady flow through the nasal chamber; (2) the wave-speed theory of flow limitation applies to maximal nasal inspiratory flow; and (3) severely increased nasal resistance causes an increase in pulmonary resistance, due mainly to an augmentation of lung tissue resistance.