Swanson G D, Bellville J W
J Appl Physiol. 1975 Sep;39(3):377-85. doi: 10.1152/jappl.1975.39.3.377.
A dynamic end-tidal forcing technique for producing step changes in end-tidal CO2 with end-tidal O2 held constant independent of the ventilation response or the mixed venous return is introduced for characterizing the human ventilation response to end-tidal CO2 step changes for both normoxic (PAO2 = 125 Torr) and hypoxic (PAO2 = 60 Torr) conditions. The ventilation response approaches a steady state within 5 min. In normoxia, the on-transient is faster than the off-transient, presumably reflecting the action of cerebral blood flow. The hypoxic step response is faster than the normoxic response presumably reflecting the increased contribution from the carotid body. The delay in the ventilation response after the change in end-tidal CO2 is less in hypoxia than in normoxia and reflects the action of a transport delay and that of a virtual delay. These delays are interpreted with respect to the high-frequency phase shift data for the same subject, generated using sinusoidal end-tidal forcing. The methods of others for experiments utilizing step changes in inspired CO2 are considered with respect to our methods.
介绍了一种动态呼气末强制技术，用于在呼气末O2保持恒定的情况下产生呼气末CO2的阶跃变化，该技术与通气反应或混合静脉回流无关，用于表征在常氧（PAO2 = 125 Torr）和低氧（PAO2 = 60 Torr）条件下人体对呼气末CO2阶跃变化的通气反应。通气反应在5分钟内接近稳态。在常氧状态下，上升瞬态比下降瞬态快，这可能反映了脑血流的作用。低氧阶跃反应比常氧反应快，这可能反映了颈动脉体贡献的增加。呼气末CO2变化后通气反应的延迟在低氧状态下比在常氧状态下小，这反映了传输延迟和虚拟延迟的作用。这些延迟是根据使用正弦呼气末强制产生的同一受试者的高频相移数据来解释的。相对于我们的方法，考虑了其他人在使用吸入CO2阶跃变化进行实验时的方法。
