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PULMONARY MASS AND HEAT TRANSPORT

肺传质和传热

基本信息

批准号：
6536934
负责人：
JAMES Bernard GROTBERG
金额：
$ 20.26万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-08-01 至 2004-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6536934
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

项目摘要

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.

本建议旨在研究肺转运的两个方面，一种在气相中，一种在气道液相中，参与呼吸治疗模式。分布运输材料（气体，表面活性剂，药物）在这两个依赖也取决于扩散和对流过程的相互作用作为由共同的局部肺结构确定的边界条件和组成，而调查这两种情况的技术都涉及跟踪施加的气体或表面活性剂团的分散，或微团。我们的主要目标是确定重要的空气流中污染物传输的决定因素（在整个气道树的比例），并且在气道液体内衬里/组织（在铺展表面活性剂的规模上）。两提出了重要的和不同的运输研究，在细节和方法上都有许多相似之处。在气管内第一计划肺气体输送吹气（ITI），有或没有外部胸部振动，将研究ITI作为增强CO2去除的手段在慢性排泄衰竭模型中的排泄效率 (e.g.脊髓损伤、神经肌肉疾病）。的这项运输研究的实验技术将是在示踪气体的局部团块的分散之后，在ITI的动物和硬件模型中进行腔内气体采样。这种新技术将使我们能够从在注射点测得的浓度数据，我们独特的能力，研究区域和地方差异，运输将开发这种运输的预测模型在实验的同时，提供一个框架，解释数据和指导实验参数范围。在第二个项目肺液体运输后，外源性表面活性剂的递送，或者在气溶胶液滴中，或者供给表面活性剂单层的大规模段塞将被研究了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乏的新生儿或气道内药物递送。目的是了解表面活性剂（加上任何溶解的物种）从它影响的地方被转移到排队到达目的地这背后的技术研究将是引入局部表面活性剂团（微滴或小块）到空气-液体界面上，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其分散沿着界面和研究膜破裂现象。在除了测量扩散率，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衬里（厚度、粘度、表面张力）肺泡理论模型将为以下方面提供基础：解释数据并建议如何控制交付。