Jakobsson Jonas, Wollmer Per, Löndahl Jakob
Department of Ergonomics and Aerosol Technology, Lund University, Lund, Sweden.
Department of Translational Medicine, Lund University, Malmö, Sweden.
J Appl Physiol (1985). 2018 Dec 1;125(6):1832-1840. doi: 10.1152/japplphysiol.00410.2018. Epub 2018 Sep 6.
Airspace Dimension Assessment (AiDA) is a technique to assess lung morphology by measuring lung deposition of inhaled nanoparticles. Nanoparticles deposit in the lungs predominately by diffusion, and average diffusion distances, corresponding to effective airspace radii (), can be inferred from measurements of particle recovery after varied breath holds. Also, particle recovery after a 0-s breath hold () may hold information about the small conducting airways. This study investigates at different volumetric sample depths in the lungs of healthy subjects. Measurements were performed with 50-nm polystyrene nanospheres on 19 healthy subjects aged 17-67 yr. Volumetric sample depths ranged from 200 to 5,000 ml and breath-hold times from 5 to 20 s. At the examined volumetric sample depths, values ranged from ~200-600 μm, which correspond to dimensions of the bronchiolar and the gas-exchanging regions of the lungs. decreased with volumetric sample depth and showed more intersubject variation than . Correlations were found between the AiDA parameters, anthropometry, and lung function tests, but not between and . For repeated measurements on 3 subjects over an 18-mo period, varied on average within ± 7 μm (± 2.4%). The results indicate that AiDA has potential as an efficient new in vivo technique to assess individual lung properties. The information obtained by such measurements may be of value for lung diagnostics, especially for the distal lungs, which are challenging to examine directly by other means. This is the first study to measure effective airspace radii () at volumetric sample depths 200-5,000 ml in healthy subjects by Airspace Dimension Assessment (AiDA). Observed were 200-600 μm, which corresponds to airspaces for the bronchiolar and the gas-exchanging regions around airway generation 14-17. correlated with lung function tests and anthropometry. Measurements of on 3 subjects over 11-18 mo were within ± 7 μm.
空域尺寸评估（AiDA）是一种通过测量吸入纳米颗粒在肺部的沉积来评估肺部形态的技术。纳米颗粒主要通过扩散沉积在肺部，对应于有效空域半径（）的平均扩散距离可以从不同屏气时间后颗粒回收率的测量中推断出来。此外，屏气0秒后的颗粒回收率（）可能包含有关小传导气道的信息。本研究在健康受试者肺部的不同体积样本深度下研究。对19名年龄在17 - 67岁的健康受试者使用50纳米的聚苯乙烯纳米球进行测量。体积样本深度范围为200至5000毫升，屏气时间为5至20秒。在所检查的体积样本深度下，值范围约为200 - 600微米，这对应于细支气管和肺部气体交换区域的尺寸。随体积样本深度减小，且受试者间差异比更大。在AiDA参数、人体测量学和肺功能测试之间发现了相关性，但和之间未发现相关性。在18个月期间对3名受试者进行重复测量，平均变化在±7微米（±2.4%）以内。结果表明，AiDA作为一种有效的新型体内技术具有评估个体肺部特性的潜力。通过此类测量获得的信息可能对肺部诊断有价值，特别是对于难以通过其他方法直接检查的远端肺部。这是第一项通过空域尺寸评估（AiDA）在健康受试者200 - 5000毫升的体积样本深度下测量有效空域半径（）的研究。观察到的值为200 - 600微米，这对应于气道第14 - 17级周围细支气管和气体交换区域的空域。与肺功能测试和人体测量学相关。对3名受试者在11 - 18个月内的测量在±7微米以内。
