Modeling of Aerosol Transport in Alveolated Airways

肺泡气道中气溶胶传输的建模

• 批准号: 6914718
• 负责人: CHANTAL DARQUENNE
• 金额: $ 25.69万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6914718
• 关键词: acinar cell; aerosols; air pollution; disease /disorder model; environmental exposure; lung; model design /development; particle; pulmonary respiration; sedimentation velocity; suspensions

DESCRIPTION (provided by applicant): The long-term objective of this study is to better understand the fate of inhaled particulate matter (PM) in the human lung. This is important whether PM exposure results from atmospheric pollution, biological warfare, and occupational factors or inhaled drug therapy. More and more evidence links the presence of fine PM in the air with cardiopulmonary diseases. This PM is of great concern because it can penetrate deep into the acinus. To date, the most realistic model of the human acinus consists of a multi-bifurcation structure of two-dimensional alveolated ducts (AD). In the present study we will develop three-dimensional acinar models of children and adult lung with a high degree of anatomical realism. A first type of model will consist of a single bifurcation of AD with rigid walls. A second type of model will address the effects of alveolar wall motions during breathing and will form a realistic structure of up to four successive bifurcations. This will be the most comprehensive acinar models yet developed. PM transport and deposition (DE) will be simulated for particle diameters (dp) ranging 0.005-5 (m and for flow rates ranging from quiet breathing to moderate exercise. For 0.5<dp<5 (m, DE is mainly due to gravitational sedimentation and is mainly affected by the structure orientation with respect to the gravity vector. For dp < 0.5 (m, DE is mainly due to Brownian diffusion and is affected by the alveolar surface available to PM to deposit. The contribution of velocity profiles, rhythmical motions of the alveolar walls and PM intrinsic motions to overall convective mixing will be determined. Convective mixing causes inhaled PM to be irreversibly transferred to the resident air. As a result, some PM remains in suspension in the distal airways at the end of a normal expiration and penetrates deeper in the lung during the next breath where it eventually deposits. The process of stretch and fold where, because of non-reversibility of flow in the lung, air streamlines become folded back on themselves, will also be simulated to determine whether it is responsible for additional mixing in the acinus, and consequently for higher DE than that previously predicted. Finally the numerical predictions will be compared to experimental data obtained in human subjects and in simple physical models. The results of this study will provide a link to the mechanisms by which even seemingly modest PM exposure can cause or exacerbate lung disease and will also help to better design spatial targeting of inhaled drugs.

描述（由申请人提供）：这项研究的长期目标是更好地了解人肺中吸入的颗粒物（PM）的命运。无论是由大气污染，生物战和职业因素还是吸入药物治疗引起的PM暴露是重要的。越来越多的证据与心肺疾病中的空气中存在细PM的存在有关。这个PM引起了极大的关注，因为它可以深入刺激。迄今为止，人类刺激的最现实模型是由二维肺泡管（AD）的多分泌结构组成。在本研究中，我们将开发具有高度解剖现实主义的儿童和成人肺的三维腺泡模型。第一类模型将由AD的单个分叉和刚性壁组成。第二种模型将解决呼吸过程中肺泡壁运动的影响，并将形成多达四个连续分叉的现实结构。这将是迄今为止开发的最全面的痤疮模型。将模拟PM传输和沉积（DE）的颗粒直径（DP），范围为0.005-5（M和从安静的呼吸到中度运动范围的流量。对于0.5 <dp <5（m，DE）主要是由于引力沉积物而引起的，主要是由于dp <0.5（M，M，MISTIENTIENIAN）的影响。肺泡表面可用于沉积速度的贡献。沉积物。由于肺部流动的不可逆性，空气流线被折叠在自己身上，还将模拟它是否负责毒素中的额外混合，因此对于更高的DE，也将模拟空气流。最后，将将数值预测与在人类受试者和简单物理模型中获得的实验数据进行比较。这项研究的结果将提供与即使看似适中的PM暴露也会引起或加剧肺部疾病的机制的联系，还将有助于更好地设计吸入药物的空间靶向。