Kallok M J, Lai-Fook S J
J Appl Physiol Respir Environ Exerc Physiol. 1980 Mar;48(3):487-94. doi: 10.1152/jappl.1980.48.3.487.
Minimal volume (MV, gas plus tissue volume at zero transpulmonary pressure) was determined in excised dog lobes after inflation with air and with saline. MV was significantly greater in saline-filled lobes than air-filled lobes. Air inflation was performed with the lobe supported in two different ways, which were chosen to produce different deformations: 1) supported on the cephalic surface and 2) hung by strings attached to the cephalic surface. MV measured in hung lobes was significantly greater than MV measured in supported lobes. The problem of excised lobes deformed by gravity was analyzed in the two configurations using linear elasticity. The saline volume was assumed to be the stress-free state for the lobe, and the volume change was computed from the stress-free state due to the gravitational deformation. The analysis suggests that the difference between saline and air MV is due primarily to the gravitational deformation of air-filled lungs.
在用空气和盐水对切除的犬肺叶进行充气后，测定最小体积（MV，即跨肺压为零时的气体加组织体积）。充满盐水的肺叶的MV显著大于充满空气的肺叶。空气充气时，肺叶以两种不同方式支撑，选择这两种方式是为了产生不同的变形：1）支撑在头侧表面；2）通过附着在头侧表面的绳子悬挂。悬挂肺叶测得的MV显著大于支撑肺叶测得的MV。使用线性弹性理论分析了两种构型下因重力而变形的切除肺叶的问题。假定盐水体积为肺叶的无应力状态，并根据因重力变形导致的无应力状态计算体积变化。分析表明，盐水和空气MV之间的差异主要是由于充气肺的重力变形。
