Stability of Pullmonary Airways

肺气道的稳定性

• 批准号: 7877901
• 负责人: JAMES Bernard GROTBERG
• 金额: $ 37.03万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7877901
• 关键词: Adult; Adult Respiratory Distress Syndrome; Aerosols; Air; Alveolus; Antihistamines; Area; Asthma; Astronauts; Automobile Driving; Behavior; Breathing; Bronchoconstriction; Bronchodilation; Bronchodilator Agents; Caliber; Characteristics; Childhood; Childhood Asthma; Clinical; Closing Volume; Complex; Congestive Heart Failure; Couples; Critical Illness; Cystic Fibrosis; Decongestants; Dependence; Development; Disease; Doctor of Philosophy; Effectiveness; Elasticity; Elements; Event; Expectorants; Film; Gases; Health; Intervention; Laws; Lead; Life; Liquid substance; Lubrication; Lung; Mechanics; Microgravity; Modeling; Modification; Movement; Mucous body substance; Muscle Tonus; Neonatal; Outcome; Patients; Pharmaceutical Preparations; Physiology; Prevalence; Process; Property; Pulmonary Emphysema; Pulmonary function tests; Research Personnel; Respiratory physiology; Risk; Rupture; Scheme; Shapes; Smooth Muscle; Staging; Steam; Stress; Surface Tension; System; Testing; Thick; Tissues; Trees; Tube; Ventilator; Viscosity; Work; clinically relevant; flexibility; interfacial; intervention effect; lung pressure; lung volume; mathematical model; mortality; novel; patient population; physical property; planetary Atmosphere; pressure; respiratory smooth muscle; surfactant; surfactant deficiency; theories; viscoelasticity

DESCRIPTION (provided by applicant): This revised proposal to develop a mathematical model for the stability of pulmonary airways is a basic inquiry into the mechanisms that lead to airway closure of the lung in health, disease, and its modifications by therapies. Closure results from a surface tension instability that tends to pull the airway to a smaller diameter while potentially driving the liquid lining into the formation of a plug, given the right conditions. A plug blocks the lumen, stopping gas exchange and delivery of aerosol medications. It can be the terminal event in an asthmatic attack, for example. From purely the fluid mechanical perspective, the plug may or may not form depending on the liquid physical properties. Significant non-Newtonian fluid properties in disease (asthma, emphysema, cystic fibrosis) include viscoelasticity, shear-thinning viscosity, and a yield stress, all of which can alter the fluid movement. Surfactants at the air-liquid interface also influence the instability by reducing surface tension and creating surface tension gradients. The lung volume at which closure occurs is the closing volume, and it is a common pulmonary function test that is often difficult to interpret, due largely to inadequate models. This surface-tension/fluid system couples to the airway and lung elastic properties. New to this revision is the inclusion of non-linear airway elasticity, airway smooth muscle dynamics, and effects of a surrounding parenchymal tethering. This novel combination of effects will allow the development of a theory which can incorporate the simultaneous issues presented by diseases such as asthma and emphysema where bronchoconstriction, parenchymal tissue elasticity changes, and fluid property modifications (non-Newtonian fluids) acting together present a complex mechanical situation; The proposed model will provide a platform for predicting the impact of these interactions on closing volumes, as well as predict the effectiveness of therapies which may include those aimed at surfactants, or liquid material properties, or bronchoconstriction or the parenchyma. This proposal outlines a set of mathematical models, building from the simplest to the more complex, that examine the stability of a liquid-lined airway tube as it depends on (1) Newtonian vs non-Newtonian fluids, (2) rigid vs flexible tubes with parenchyma and smooth muscle tone, (3) axisymmetric vs non-axisymmetric deformations, (4) effects of surfactants, (5) effects of a forced, oscillatory core flow.

描述（由申请人提供）：这项修订的提案开发了肺气道稳定性的数学模型，这是对导致肺部在健康，疾病中及其修饰的肺闭合的机制的基本询问。闭合是由于表面张力不稳定而导致的，该张力不稳定倾向于将气道拉到较小的直径，同时有可能将液体衬里驱动到插头的形成中，鉴于正确的条件。插头将管腔阻塞，停止气体交换和气溶胶药物的输送。例如，它可以是哮喘攻击中的终端事件。从纯粹的流体机械角度来看，插头可能会根据液体物理特性而形成，也可能不会形成。疾病（哮喘，肺气肿，囊性纤维化）中明显的非牛顿液特性包括粘弹性，剪切粘稠的粘度和屈服应力，所有这些都会改变流体运动。空气界面处的表面活性剂还通过减少表面张力和产生表面张力梯度来影响不稳定。闭合的肺部体积是关闭体积，这是一种常见的肺功能测试，通常由于模型不足而难以解释。该表面张紧/流体系统将气道和肺弹性特性融合在一起。此修订的新手是包括非线性气道弹性，气道平滑肌动力学以及周围实质束缚的影响。这种新颖的效果组合将允许发展理论，该理论可以纳入诸如哮喘和肺气肿等疾病所呈现的同时问题，在该疾病中，支气管收缩，实质组织弹性变化以及流体性质修饰（非牛顿液）共同作用共同作用，呈现出复杂的机械状况；所提出的模型将提供一个平台，以预测这些相互作用对关闭体积的影响，并预测疗法的有效性，这些疗法可能包括针对表面活性剂，液体材料特性，或支气管收缩或实质性的疗法。该提议概述了一组数学模型，从最简单到更复杂的构建，这些模型检查了液体衬里的气道管的稳定性，因为它取决于（1）牛顿与非牛顿液体，（2）刚性与柔性管与细菌性和平滑肌的柔性管，（3）轴心中性vs非轴法效果（3）轴承效果（4）效果（4）效果（4）效果（4）（4）的效果（4）（4）的效果（（4）的轴承效果（（4）的临床（（4）强制振荡的核心流量。

项目成果

Steady Displacement of Long Gas Bubbles in Channels and Tubes Filled by a Bingham Fluid.

宾汉流体填充的通道和管中长气泡的稳定位移。

• DOI: 10.1103/physrevfluids.3.013302
• 发表时间: 2018
• 期刊: Physical review fluids
• 影响因子: 2.7
• 作者: Zamankhan,Parsa;Takayama,Shuichi;Grotberg,JamesB
• 通讯作者: Grotberg,JamesB

An asymptotic model of particle deposition at an airway bifurcation.

气道分叉处颗粒沉积的渐近模型。

• DOI: 10.1093/imammb/dqs002
• 发表时间: 2013
• 期刊: Mathematical medicine and biology : a journal of the IMA
• 作者: Zierenberg,JenniferR;Halpern,David;Filoche,Marcel;Sapoval,Bernard;Grotberg,JamesB
• 通讯作者: Grotberg,JamesB