Inadequate peak expiratory flow meter characteristics detected by a computerised explosive decompression device

摘要: Methods: The dynamic response of mini-Wright (MW), Vitalograph (V), TruZone (TZ), MultiSpiro (MS) and pneumotachograph (PT) flow meters was tested by delivering two differently shaped flow-time profiles from a computer controlled explosive decompression device fitted with fast solenoid valve. These matched population 5th 95th centiles for rise time 10% to 90% PEF dwell above PEF. Profiles were delivered five times identical chamber pressure aperture at Any difference in recorded the indicates poor response. Results: absolute (% mean) differences l/min V, MW, PT 25 (4.7), 20 (3.9), 2 (0.3), respectively, ≈500 l/min, (10.5), (8.7) 6 (3.0) ≈200 l/min. For TZ MS 228 (36.1) 257 (39.2), they 51 (23.9) 1 (0.5). All met ATS accuracy requirements when their waveforms. Conclusions: An improved method testing detects marked overshoot (underdamping) responses not identified 26 This error could cause patient misclassification using such asthma guidelines.