VARIABILITY OF THE CONFIGURATION OF MAXIMUM EXPIRATORY FLOW-VOLUME CURVES
VARIABILITY OF THE CONFIGURATION OF MAXIMUM EXPIRATORY FLOW-VOLUME CURVES
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DOI:
10.1152/jappl.1979.46.3.565
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发表时间:
1979-01-01
影响因子:
3.3
通讯作者:
MEAD, J
中科院分区:
文献类型:
--
作者:
TIEN, YK;ELLIOTT, EA;MEAD, J
With a computer technique variability of the configuration of maximum expiratory flow-volume (MEFV) curves was studied in terms of slope ratio, SR. (SR = d.ovrhdot.V/dV .div. .ovrhdot.V/V, where .ovrhdot.V is the instantaneous flow and V is the volume increment above residual volume.) Approximately 4 SR-V curves, each based on 3-5 smoothed and averaged MEFV curves, were derived for each of 20 normal subjects (aged 23-55 yr) on a single occasion, and again at least 1 wk later. Individual curves were largely reproducible, the maximum difference in SR at most volumes being 0.3-1 U[units], but frequently showed substantial yet reproducible fluctuations with volume. These corresponded to hitherto unrecognized irregularities of maximum expiratory flow that may reflect sudden changes in the location of flow limitation.