Hankinson J L, Das M K
Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA.
Am J Respir Crit Care Med. 1995 Aug;152(2):702-6. doi: 10.1164/ajrccm.152.2.7633729.
Peak expiratory flow (PEF) is a dynamic parameter and therefore requires a measuring device with a high-frequency response. This study evaluated the frequency-response characteristics of eight commercially available PEF meters, using simulated forced-expiratory maneuvers with a computer-controlled mechanical pump. Three different PEF levels were used (200, 400, and 600 L/min) at six levels of harmonic-frequency content similar to those observed in human subjects. For waveforms with higher frequency content (at the high end or above the physiologic range), the Assess, Vitalograph, Pocket Peak, and Spir-O-Flow PEF meters all overread PEF (greater than 15% difference from target values) at all three PEF levels. These results suggest that the frequency response of PEF meters is an important consideration in the selection of such meters and should be included in device requirements. The current practice of using various levels of American Thoracic Society (ATS) waveform 24 with its low-frequency content may not adequately evaluate the frequency characteristics of PEF meters. An upper range (5% of the fundamental frequency) of 12 Hz, within the range observed in normal subjects, appears to be more practical than an upper limit of 20 Hz.
呼气峰值流速（PEF）是一个动态参数，因此需要一个具有高频响应的测量装置。本研究使用计算机控制的机械泵进行模拟用力呼气动作，评估了八种市售PEF测量仪的频率响应特性。在与人类受试者中观察到的类似的六个谐波频率含量水平下，使用了三种不同的PEF水平（200、400和600升/分钟）。对于具有较高频率含量的波形（在高端或高于生理范围），Assess、Vitalograph、Pocket Peak和Spir-O-Flow PEF测量仪在所有三个PEF水平下均高估了PEF（与目标值的差异大于15%）。这些结果表明，PEF测量仪的频率响应是选择此类测量仪时的一个重要考虑因素，应纳入设备要求中。目前使用具有低频含量的美国胸科学会（ATS）24号波形不同水平的做法可能无法充分评估PEF测量仪的频率特性。在正常受试者中观察到的范围内，12赫兹的上限（基频的5%）似乎比20赫兹的上限更实用。
