PULMONARY MASS AND HEAT TRANSPORT

肺传质和传热

• 批准号: 6182330
• 负责人: JAMES Bernard GROTBERG
• 金额: $ 20.07万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6182330
• 关键词: biological fluid transport; computer simulation; fluid flow; laboratory rat; mathematical model; model design /development; nonblood rheology; pulmonary surfactants; respiratory airflow measurement; respiratory airway clearance; respiratory airway pressure; respiratory airway volume; respiratory gas transport; video microscopy; biological fluid transport; computer simulation; fluid flow; laboratory rat; mathematical model; model design /development; nonblood rheology; pulmonary surfactants; respiratory airflow measurement; respiratory airway clearance; respiratory airway pressure; respiratory airway volume; respiratory gas transport; video microscopy

This proposal intends to study two aspects of pulmonary transport, one in the gas phase and one in the airway liquid phase, which are involved in respiratory therapeutic modalities. The distribution of transported material (gas, surfactant, drugs) in both depends upon the interaction of diffusive and convective processes as well as boundary conditions determined by common local lung structure and composition, while techniques to investigate both involve tracking the dispersion of an imposed gas or surfactant bolus or microbolus. Our major objective is to identify the important determinants of contaminant transport within the airstream (on the scale of the entire airway tree), and within the airway liquid lining/tissue (on the scale of spreading surfactant). Two important and different studies of transport are proposed which share many similarities both in detail and in approach. In the first project pulmonary gas transport during intra-tracheal insufflation (ITI), with or without external chest vibrations, will be studied to investigate ITI as a means of enhancing C02 removal and ventilatory efficiency in models of chronic ventilatory failure (e.g. spinal cord injury, neuromuscular disorders). The experimental technique underlying this transport study will be to follow the dispersion of a localized bolus of tracer-gas by intra-lumenal gas sampling, in animal and hardware models of ITI. This new technique will allow us to interpret a local D-eff from the concentration data measured at the point of injection, giving us the unique ability to examine regional and local differences in transport. Predictive models of this transport will be developed in tandem with the experimentation to provide a framework for interpreting data and guiding experimental parameter ranges. In the second project pulmonary liquid transport following the delivery of exogenous surfactants, either in aerosol droplets or large scale slugs which feed a surfactant monolayer, will be studied. This situation is found in surfactant replacement therapy for surfactant-deficient neonates or intra-airway drug delivery. The aim is to understand how far and how fast the surfactant (plus any dissolved species) is transported from where it impacts on the lining to its destination. The technique underlying this investigation will be the introduction of a localized surfactant bolus (microdroplet or slug) onto the air-liquid interface in animal and hardware models, while video-microscopy and laser interferometric methods will be used to track its dispersion along the interface and to investigate film rupture phenomena. In addition to measuring the spreading rates, use of our theoretical modelling will allow us to infer physical properties of the liquid lining (thickness, viscosity, surface tension) in airways and in alveoli. Theoretical modelling will provide a basis for interpreting the data and suggesting how to control the delivery.

该提案打算研究肺运输的两个方面， 一个在气相，一个在气道液相中，一个是 参与呼吸治疗方式。 分布 两者中的运输材料（气体，表面活性剂，药物）的 扩散和对流过程的相互作用 作为通过常见局部肺结构确定的边界条件 和组成，而研究两者都涉及 跟踪施加的气体或表面活性剂推注或 微生物。 我们的主要目标是确定重要的 气流内污染物运输的决定因素（在 整个气道树的比例）和气道液体内 衬里/组织（根据扩散表面活性剂的规模）。 二 提出了重要和不同的运输研究 在详细和方法上分享许多相似之处。 在 通行器内的第一个项目肺气传输 不外加（ITI），有或没有外部胸部振动，将 研究以研究ITI作为增强C02去除的一种手段 和慢性通气衰竭模型的通气效率 （例如，脊髓损伤，神经肌肉疾病）。 这 这项运输研究的实验技术将是 遵循通过 ITI的动物和硬件模型中的浅叶内气体采样。 这种新技术将使我们能够从 在注射点测量的浓度数据，给出 我们可以检查区域和地方差异的独特能力 运输。 将开发该运输的预测模型 与实验一起提供了一个框架 解释数据和指导实验参数范围。 在 第二个项目之后的肺液体传输 在气溶胶液滴或 喂食表面活性剂单层的大型sl弹将是 研究。 这种情况在表面活性剂替代疗法中发现 用于表面活性剂缺陷型新生儿或机内药物输送。 目的是了解表面活性剂的距离和多快（加上 任何溶解的物种）都从影响到对 衬里到达目的地。 这是基础的技术 调查将是引入局部表面活性剂 推注（微圆或sl）到空气中的空气界面 动物和硬件模型，而视频微观和激光 干涉方法将用于跟踪其分散体 界面并研究膜破裂现象。 在 除了测量传播率，使用我们的理论 建模将使我们推断液体的物理特性 衬里（厚度，粘度，表面张力）在气道和 肺泡。 理论建模将为 解释数据并建议如何控制交付。