PULMONARY MASS AND HEAT TRANSPORT

肺传质和传热

• 批准号: 3358635
• 负责人: JAMES Bernard GROTBERG
• 金额: $ 15.63万
• 依托单位: NORTHWESTERN UNIVERSITY
• 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 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3358635
• 关键词: aerosols; computer simulation; disease /disorder model; dogs; environmental contamination; environmental toxicology; heterodyning; high frequency ventilation; interferometry; laboratory rat; mathematical model; microscopy; model design /development; nonblood rheology; phantom model; pulmonary surfactants; respirators; respiratory airflow disorder; respiratory airflow measurement; respiratory airway pressure; respiratory airway volume; respiratory gas transport; respiratory insufficiency /failure; surfactant; video recording system

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.

这项建议打算研究肺运输的两个方面， 一个在气相中，一个在气液相中，它们是 参与呼吸系统治疗。分布情况 运输材料(气体、表面活性剂、药物)在这两者中的含量取决于 关于扩散过程和对流过程的相互作用 作为由常见的局部肺结构确定的边界条件 和构图，而研究两者的技术都涉及到 跟踪施加的气体或表面活性剂团剂的扩散或 微丸。我们的主要目标是找出重要的 污染物在气流中传输的决定因素(关于 整个呼吸道树的比例)，以及在呼吸道液体内 衬里/纸巾(涂抹表面活性剂的规模)。二 提出了对运输的重要和不同的研究 在细节和方法上都有许多相似之处。在 首个项目气管内的肺气体输送 无论有没有胸外震动，雾化(ITI)都会 研究ITI作为促进二氧化碳脱除的方法 慢性呼吸衰竭模型的通气性和通气性 (例如脊髓损伤、神经肌肉疾病)。这个 这项交通研究的实验技术将是 跟随局部示踪气体团团的分散 ITI的动物和硬件模型的腔内气体采样。 这项新技术将允许我们解释来自 在注射点测量的浓度数据，给出 美国独一无二的能力，可以检查地区和地方差异 运输。将开发这种运输的预测模型 与实验相结合，提供一个框架 对实验数据进行解释，指导实验参数范围。在……里面 第二个项目是肺液输送 外源表面活性剂的输送，无论是气雾剂液滴还是 供给表面活性剂单分子层的大规模段塞将是 学习。这种情况出现在表面活性物质替代疗法中。 适用于表面活性物质缺乏的新生儿或呼吸道内给药。 其目的是了解表面活性剂(加上 任何溶解的物种)被从它影响到 排成一排直达目的地。这背后的技术 调查将引入一种本地化的表面活性剂 气液界面上的团状物(微滴或段塞) 动物和硬件模型，而视频显微镜和激光 干涉测量方法将被用来跟踪它的散布 并对薄膜破裂现象进行研究。在……里面 除了测量传播率，使用我们的理论 建模将使我们能够推断出液体的物理性质 呼吸道内衬(厚度、粘度、表面张力) 肺泡。理论模型将提供一个基础 解读数据并提出如何控制交付的建议。