Comparing MiniWright and spirometer measurements of peak expiratory flow.
The accuracy and instrument variability of the MiniWright (Clement Clarke) peak expiratory flow (PEF) meter was determined with 6 of the 24 American Thoracic Society's (ATS) standard waveforms using a mechanical pump. Both room air and air heated to 37 degrees C and saturated with water vapor were used. In addition, MiniWright-determined PEF measurements were compared with those obtained using a dry rolling-seal spirometer (Ohio No. 822; Ohio Medical Products; Madison, Wis) from 75 subjects on 2 different days. The MiniWright average coefficient of variation within a waveform was found to be 2.8%. Results using heated and humidified air (body temperature, ambient pressure, and saturated with water: body conditions) were 2.5% lower than those obtained using room air. Comparisons with mechanically simulated PEF and with spirometry-determined peak flow in 75 human subjects showed that MiniWright meters over-estimated flows at lower flow rates and slightly under-estimated flows at higher flow rates. These results suggest that the new "mechanical PEF" MiniWright scale should be used instead of the "traditional" MiniWright scale.
Hankinson
J L
JL
Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA.
Filios
M S
MS
Kinsley
K B
KB
Petsonk
E L
EL
D005069:Evaluation Studies as Topic; D006801:Humans; D006813:Humidity; D008168:Lung / Q000502:physiology; D008961:Models, Structural; D010366:Peak Expiratory Flow Rate; D012044:Regression Analysis; D012129:Respiratory Function Tests / Q000295:instrumentation* / Q000706:statistics & numerical data; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013147:Spirometry / Q000295:instrumentation* / Q000706:statistics & numerical data; D013696:Temperature