Kraman S S, Wang P M
VA Medical Center, Lexington, KY 40511.
Chest. 1990 Feb;97(2):461-6. doi: 10.1378/chest.97.2.461.
We examined the distribution of airflow-generated sound within a flexible model of canine airways. Sounds were picked up by a microphone adapted to a glass conical probe which was introduced through puncture holes in the wall of the model. We acquired 341 measurements in 31 airways between 2.0 and 19.0 mm in diameter at airflow rates from 0 to 2.5 L/s in the inspiratory and expiratory directions. We found that in the expiratory direction, the sound amplitude was approximately linearly related to airway cross-sectional area, with the greatest amplitude occurring in the largest airway. In the inspiratory direction the greatest amplitude occurred in airways of 5 to 8 mm in diameter. At all levels within the model, sound amplitude was approximately linearly related to the square of the airflow. Our findings suggest that in canine airways, the predominant vesicular lung sound-producing locations are the large airways for the expiratory component and the medium-sized airways for the inspiratory component.
我们在犬类气道的柔性模型中研究了气流产生声音的分布情况。声音由一个适配于玻璃锥形探头的麦克风采集，该探头通过模型壁上的穿刺孔插入。我们在直径为2.0至19.0毫米的31条气道中，以0至2.5升/秒的气流速度在吸气和呼气方向上进行了341次测量。我们发现，在呼气方向上，声音幅度与气道横截面积大致呈线性关系，最大幅度出现在最大的气道中。在吸气方向上，最大幅度出现在直径为5至8毫米的气道中。在模型内的所有水平上，声音幅度与气流平方大致呈线性关系。我们的研究结果表明，在犬类气道中，产生主要肺泡呼吸音的位置，呼气成分是大气道，吸气成分是中等大小的气道。
