Brand P, Selzer T, Tuch T, Schulz A, Heyder J
GSF, Forschungszentrum für Umwelt und Gesundheit, Neuherberg, Germany.
Exp Lung Res. 1994 May-Jun;20(3):185-205. doi: 10.3109/01902149409064382.
Aerosol-derived airway morphometry (ADAM) uses sedimentational deposition of monodisperse aerosol particles during breathhold to estimate intrapulmonary air-space dimensions. To determine the accuracy and resolution power of this technique a simple physical lung model comprised of uniform glass beads was investigated. Using the chordlength model, aerosol recovery from this porous medium was calculated by computer simulation of the geometrical structure of air-spaces between glass beads. The results of this calculation were then compared with experimental data: Calculated and measured air-space dimensions differ less than 2% for particles with diameters above about 1 micron. The measured air-space dimension can be described geometrically by the mean chordlength of the porous medium. To estimate the resolution power of ADAM, a defined change in air-space dimensions represented by a horizontal air slit was introduced into the porous medium. This air slit induces a marked increase of measured air-space dimensions. The volumetric width of this increase is the higher the deeper the slit is situated within the medium. Intercomparison of these data with the results of aerosol bolus dispersion measurements suggests that the resolution power of ADAM is decreased by the same mechanisms that increase dispersion of aerosol boluses, demonstrating the close relationship between both methods.
气溶胶衍生气道形态测量法（ADAM）利用屏气期间单分散气溶胶颗粒的沉降沉积来估计肺内气腔尺寸。为了确定该技术的准确性和分辨率，研究了一个由均匀玻璃珠组成的简单物理肺模型。使用弦长模型，通过对玻璃珠之间气腔几何结构的计算机模拟，计算了从这种多孔介质中回收的气溶胶。然后将该计算结果与实验数据进行比较：对于直径约1微米以上的颗粒，计算得到的气腔尺寸与测量值的差异小于2%。测量得到的气腔尺寸可以通过多孔介质的平均弦长进行几何描述。为了估计ADAM的分辨率，在多孔介质中引入了由水平气隙表示的气腔尺寸的定义变化。该气隙会导致测量得到的气腔尺寸显著增加。气隙在介质中位置越深，这种增加的体积宽度就越大。将这些数据与气溶胶团块扩散测量结果进行相互比较表明，ADAM的分辨率因增加气溶胶团块扩散的相同机制而降低，这表明两种方法之间存在密切关系。
