Rafferty G F, Evans J, Gardner W N
Department of Physiology, King's College London, United Kingdom.
J Appl Physiol (1985). 1995 May;78(5):1910-20. doi: 10.1152/jappl.1995.78.5.1910.
Combinations of 17 normal awake humans breathed mildly hyperoxic and hypercapnic gas mixtures via a pneumotachograph into an open circuit. Respiratory pattern was measured for each breath in real time by computer. Use of computer-controlled auditory feedback at a constant end-tidal PCO2 (PETCO2) allowed prolonged changes of 1) inspiratory time (TI) at constant inspired tidal volume (VTI), 2) VTI up and down in repeated steps at constant TI, and 3) expiratory time (TE) at constant VTI. The remaining variables were free to be determined by the subjects' automatic respiratory control mechanisms. We showed that TE changed in parallel with the change in TI despite constant VTI, TE did not change in response to step changes in VTI at constant TI, and large changes in TE had no influence on the subsequent TI, but VTI increased slightly as TE lengthened despite clamping. Time for expiratory flow (TE--end-expiratory pause) changed in parallel with TE in all protocols. Thus, in conscious humans, inspiratory timing has a direct influence on expiratory timing, independent of volume change and chemical drive, but expiratory timing has no influence on the inspiratory timing of the subsequent breath but has a small influence on volume.
17名正常清醒的受试者通过呼吸速度描记器向开路中呼吸轻度高氧和高碳酸气体混合物。计算机实时测量每次呼吸的呼吸模式。在恒定的呼气末二氧化碳分压（PETCO2）下使用计算机控制的听觉反馈，可以实现以下长期变化：1）在恒定吸气潮气量（VTI）下的吸气时间（TI）；2）在恒定TI下，VTI以重复步骤上下变化；3）在恒定VTI下的呼气时间（TE）。其余变量可由受试者的自动呼吸控制机制自由决定。我们发现，尽管VTI恒定，但TE与TI的变化平行，在恒定TI下，TE不随VTI的阶跃变化而改变，TE的大幅变化对随后的TI没有影响，但尽管进行了钳制，随着TE延长，VTI仍略有增加。在所有方案中，呼气流量时间（TE - 呼气末暂停）与TE平行变化。因此，在清醒的人类中，吸气时间对呼气时间有直接影响，与容积变化和化学驱动无关，但呼气时间对随后呼吸的吸气时间没有影响，但对容积有微小影响。
