Bégin P, Peslin R
Am Rev Respir Dis. 1984 Jul;130(1):121-3. doi: 10.1164/arrd.1984.130.1.121.
Frequency dependence of thoracic gas volume (Vtg) and phase angles between volume and mouth pressure signals were evaluated in 10 normal subjects and in 31 patients with bronchitis, who panted sequentially at 0.8 Hz and 2.5 Hz during the same occlusion. A slight negative frequency dependence of Vtg (-1.2 +/- 0.9%/Hz, -m +/- SD), accompanied by a very small phase lag of volume with respect to pressure variations (-1.5 +/- 0.9 degrees at 2.5 Hz) was found in normal subjects. In contrast, patients with bronchitis exhibited a mild positive frequency dependence of Vtg (+ 0.5 +/- 1.7%/Hz and + 0.8 +/- 2.3%/Hz in subjects with normal and increased airway resistance, respectively), whereas the volume signal slightly led the pressure signal at 2.5 Hz. Both the frequency dependence and the phase difference increased when the subjects with the largest airway resistance did not support their cheeks during the panting maneuvers. The data confirm previous indirect evidence that Vtg is, in most instances, accurately measured by Boyle's law in mild and moderate chronic airway obstruction.
在10名正常受试者和31名支气管炎患者中评估了胸内气体容积（Vtg）的频率依赖性以及容积与口腔压力信号之间的相位角，这些受试者在相同的阻塞期间以0.8Hz和2.5Hz的频率依次进行急促呼吸。在正常受试者中发现Vtg有轻微的负频率依赖性（-1.2±0.9%/Hz，-m±SD），同时容积相对于压力变化存在非常小的相位滞后（在2.5Hz时为-1.5±0.9度）。相比之下，支气管炎患者表现出Vtg有轻度的正频率依赖性（气道阻力正常和增加的受试者分别为+0.5±1.7%/Hz和+0.8±2.3%/Hz），而在2.5Hz时容积信号略微超前于压力信号。当气道阻力最大的受试者在急促呼吸动作中不托住脸颊时，频率依赖性和相位差都会增加。这些数据证实了先前的间接证据，即在大多数情况下，在轻度和中度慢性气道阻塞中，Vtg可通过波义耳定律准确测量。
