Cohen B S, Sussman R G, Lippmann M
Institute of Environmental Medicine, New York University Medical Center, New York.
Respir Physiol. 1993 Sep;93(3):261-78. doi: 10.1016/0034-5687(93)90073-j.
Air velocity was measured at end airways of hollow replicate casts of the human tracheobronchial tree in order to determine the flow distribution within casts extending to 3 mm diameter airways. Measurements were made by hot-wire anemometry for constant inspiratory flow rates of 7.5, 15, 30 and 60 L.min-1. Average flow distribution among the lung lobes was as follows: right upper, 18.5%; right middle, 9.2%; right lower, 32.3%; left upper, 15.7%; and left lower, 24.3%. An empirical model derived from the experimental flow distribution data demonstrated the effect of various morphometric parameters of the hollow cast on the distribution of airflow. Airway cross-sectional area, branching angle and total path-length were found to have the greatest influence. As the tracheal flow rate decreased from 60 to 7.5 L.min-1, the influence of branching angle was reduced, while total path-length became more influential. These results provide evidence for the transition of flow regimes within the TB tree within normal physiological flow ranges.
为了确定延伸至直径3毫米气道的铸型内的气流分布，在人体气管支气管树的空心复制铸型的终末气道处测量了风速。通过热线风速仪对7.5、15、30和60升·分钟⁻¹的恒定吸气流量进行了测量。肺叶之间的平均流量分布如下：右上叶，18.5%；右中叶，9.2%；右下叶，32.3%；左上叶，15.7%；左下叶，24.3%。从实验流量分布数据推导的经验模型表明了空心铸型的各种形态测量参数对气流分布的影响。发现气道横截面积、分支角度和总路径长度的影响最大。随着气管流速从60降至7.5升·分钟⁻¹，分支角度的影响减小，而总路径长度的影响变得更大。这些结果为正常生理流量范围内气管支气管树内流动状态的转变提供了证据。
