|
|
||||||||
Original Articles |
The American Thoracic Society (ATS) recently adopted a new set of 26 standard flow-time waveforms for use in testing both diagnostic and monitoring devices. Some of these waveforms have a higher frequency content than present in the ATS-24 standard volume-time waveforms, which, when produced by a mechanical pump, may result in a pump flow output that is less than the desired flow due to gas compression losses within the pump. To investigate the effects of gas compression, a mechanical pump was used to generate the necessary flows to test mini-Wright and Assess peak expiratory flow (PEF) meters. Flow output from the pump was measured by two different independent methods, a pneumotachometer and a method based on piston displacement and pressure measured within the pump. Measuring output flow based on piston displacement and pressure has been validated using a pneumotachometer and mini-Wright PEF meter, and found to accurately measure pump output. This method introduces less resistance (lower back-pressure) and dead space volume than using a pneumotachometer in series with the meter under test. Pump output flow was found to be lower than the desired flow both with the mini-Wright and Assess meters (for waveform No. 26, PEFs 7.1 and 10.9% lower, respectively). To compensate for losses due to gas compression, we have developed a method of deriving new input waveforms, which, when used to drive a commercially available mechanical pump, accurately and reliably produces the 26 ATS flow-time waveforms, even those with the fastest rise-times.
This article has been cited by other articles:
![]() |
R. L. Jensen, J. G. Teeter, R. D. England, H. J. White, E. H. Pickering, and R. O. Crapo Instrument Accuracy and Reproducibility in Measurements of Pulmonary Function Chest, August 1, 2007; 132(2): 388 - 395. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. Miller, J. Hankinson, V. Brusasco, F. Burgos, R. Casaburi, A. Coates, R. Crapo, P. Enright, C. P. M. van der Grinten, P. Gustafsson, et al. Standardisation of spirometry Eur. Respir. J., August 1, 2005; 26(2): 319 - 338. [Abstract] [Full Text] [PDF] |
||||
![]() |
M R Miller, P R Atkins, and O F Pedersen Inadequate peak expiratory flow meter characteristics detected by a computerised explosive decompression device Thorax, May 1, 2003; 58(5): 411 - 416. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. MILLER, B. JONES, Y. XU, O. F. PEDERSEN, and P. H. QUANJER Peak Expiratory Flow Profiles Delivered by Pump Systems . Limitations due to Wave Action Am. J. Respir. Crit. Care Med., June 1, 2000; 161(6): 1887 - 1896. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |