FLOW DYNAMICS & RESISTANCES IN THE UPPER AIRWAYS

这项拟议的研究旨在了解气流和 鼻腔呼吸道的阻力。为此，实验将是 在比例鼻道模型、鼻型、动物和 人类受试者。流体力学知识和技术 将采用系统识别的方法来设计 实验，分析数据，并解释结果。主要是 但不只是回答“什么”和“如何”的问题，而是 除了“为什么”，这项研究包括三个部分，每个部分都有 三个具体目标。 第1部分介绍机头内的流动动力学。理想化鼻腔 3：1比例的呼吸道模型将由透明亚克力制成 还将制作鼻子的塑料和透明模型。这个 在模型中获得的流动可视化结果将作为 用激光在透明模型中设计流动可视化的指南 纸张扫描。模型中的详细速度测量将 使用激光多普勒测速仪进行测量。压力-流量 将获得演员阵容中的关系和因素 对其主要特点进行了考察。 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。一种非侵入性强制 振动法是基于鼻部和下部的 呼吸道为空气从口中进入形成平行的通道。一个 第二种方法是让受试者戴着一个 口罩。这些技术将产生鼻阻抗，由此 抗药性是可以识别的。两者都将在正常情况下进行测试 无论是受试者还是病人。 第三部分由动物实验组成，旨在理解三个 鼻部生理学方面。关于以下方面的三个工作假设 本实验使用的是机头内的流动和阻力：(1) 高频辅助鼻窦排气更容易。 振荡气流比稳定的气流流经鼻腔 (2)限流的波速理论适用于 最大鼻腔吸气流量；(3)鼻腔严重增加 阻力导致肺阻力增加，主要原因是 肺组织阻力的增加。

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.