Division of Physics and Biophysics, Department of Materials Research and Physics, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria;
J Thorac Dis. 2011 Sep;3(3):156-70. doi: 10.3978/j.issn.2072-1439.2011.04.03.
The structure of extrathoracic passages, variability of tracheobronchial (TB) airways and alveolar dimensions and individual variations of breathing pattern exhibit significant intersubject variations, which affect extrathoracic deposition and, in further consequence, the fraction of inhaled particles actually reaching the thoracic region. The present study was conducted to quantify the intersubject variability of lung deposition fractions caused by the fluctuations in these three major sources of intersubject variability.
To quantify intersubject variability of extrathoracic, thoracic and total deposition fractions (TDF), different combinations of the three sources of variability were simulated to identify the most important factors. Deposition fractions of inhaled particles were computed by the stochastic airway generation model IDEAL. The dimensions of the respiratory airways were scaled in proportion to age and height of the subject to calculate TDFs.
The variability of deposition fractions increased with the stepwise addition of influencing factors and the resulting standard deviations ranged up to 30%. While some combinations enhanced the effects of individual factors on deposition by up to 40%, others seemed to compensate each other with only a minor effect on deposition.
The present study attempts to quantify experimentally observed intersubject variability of regional deposition fractions caused by individual variations of nasal and oral geometry, lung airway dimensions and breathing patterns in healthy lungs, serving as a baseline for subsequent calculations for diseased lungs, e.g. asthma, COPD, and emphysema, which may further increase intersubject variabilities of medically relevant depositions.
胸外通道的结构、气管支气管 (TB) 气道的可变性和肺泡尺寸以及呼吸模式的个体差异表现出显著的个体间差异，这会影响胸外沉积，进而影响吸入颗粒中实际到达胸部区域的部分。本研究旨在量化这三个主要个体差异源波动引起的肺沉积分数的个体间变异性。
为了量化胸外、胸内和总沉积分数 (TDF) 的个体间变异性，模拟了这三个来源的变异性的不同组合，以确定最重要的因素。吸入颗粒的沉积分数通过随机气道生成模型 IDEAL 计算。呼吸气道的尺寸按受试者的年龄和身高成比例缩放，以计算 TDF。
沉积分数的变异性随着影响因素的逐步增加而增加，所得标准偏差高达 30%。虽然某些组合通过高达 40%的方式增强了个体因素对沉积的影响，但其他组合似乎通过仅对沉积产生较小影响来相互补偿。
本研究试图量化健康肺部中个体差异的鼻口几何形状、肺气道尺寸和呼吸模式对区域性沉积分数的个体间变异性，作为随后对疾病肺部（例如哮喘、COPD 和肺气肿）进行计算的基线，这些疾病可能会进一步增加与医学相关的沉积的个体间变异性。
