Dynamics of respiratory response to sinusoidal work load in humans.
Dynamics of respiratory response to sinusoidal work load in humans.
复制标题
人类对正弦工作负荷的呼吸反应动态。
DOI：
10.1055/s-2007-972631
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发表时间：
1997
影响因子：
2.5
通讯作者：
H. Ikegami
中科院分区：
文献类型：
--
作者：
Y. Fukuoka;M. Shigematsu;Y. Fukuba;S. Koga;H. Ikegami
本研究旨在探讨呼吸变量（包括O2摄取量（VO 2），CO2输出量（VCO 2）和通气量（VE））对正弦工作负荷的响应可能出现的失真，并找出传统的传输模型是否适用于分析这些变量的动态。六名健康受试者进行运动32分钟的自行车功率计与电磁制动。工作负荷正弦变化之间的30 W和60%的最大O2摄取量（VO 2 max）在1至16分钟期间。呼吸变量进行了测量呼吸的基础上与质谱仪和计算机系统。VO_2、VCO_2和VE对正弦工作负荷的反应在4-16 min期间不完全呈正弦形式，但有些扭曲，形成锯齿波，斜率较陡，但在1 min或2 min期间未观察到这种扭曲。然而，该结果可以近似地由一阶模型描述，没有或有时间延迟。无时间延迟的一阶模型的时间常数分别为VO 2 46秒、VCO 2 62秒和VE 73秒。我们还发现VO 2和VCO 2的时间常数与VO 2 max之间有密切的关系。这些结果表明，指数函数可以被应用，并预计将产生有效的结果，在评估身体素质，虽然控制运动中的排气和气体交换显示出非线性特征。
The present study was undertaken to investigate possible distortion in responses of respiratory variables including O2 uptake (VO2), CO2 output (VCO2), and ventilation (VE) to sinusoidal work load, and to find out whether the conventional transfer models were applicable to analyze the dynamics of these variables. Six healthy subjects performed exercise for 32 min on a bicycle ergometer with electro-magnetic braking. The work load was varied sinusoidally between 30 W and 60% of maximum O2 uptake (VO2max) during periods from 1 to 16 min. The respiratory variables were measured on a breath-by-breath basis with a mass spectrometer and a computer system. The responses of VO2, VCO2, and VE to sinusoidal work load were not completely sinusoidal in form but were somewhat distorted, forming saw-tooth waves with steeper down-slopes during periods of 4-16 min, but this distortion was not observed at 1 min or 2 min periods. However, the results could be approximately described by a first-order model without or with time delay. Time constants of the first-order model without time delay were 46 sec for VO2, 62 sec for VCO2, and 73 sec for VE, respectively. We also found a close relationship between the time constants of VO2 and VCO2 and VO2max. These results suggested that exponential functions may be applied and are expected to yield valid results in assessing physical fitness, although the control of ventilatory and gas exchange in exercise does show non-linear characteristics.