User's Manual

Chapter 13 - Appendix - 145
ATS 94 recommendations
Reference: “Standardization of Spirometry: 1994 Update” “American J. Respiratory
Critical Care Medicine”, Vol. 152, 1107-1136; 1995.
ATS recommendations
Volume range: 8l (BTPS)
Flow range: ±14 l/sec
Volume accuracy: ±3% or < 50ml
Flow accuracy: ±5% or < 200ml/sec
Flowmeter resistance: <1.5 cmH2O da 0 a 14 l/sec
Reproducibility: the 2 largest of 3 acceptable FEV1 and FVC values should be within
5% or 150 ml.
The end of test: no change in volume for 1 second with at least 6 seconds of collected
volume.
Accumulation time: the maximum time allowed for volume accumulation during the
VC manoeuvre should be at least 30 seconds and at least 15 seconds during the FVC.
The spirometer should be store at least 8 FVC maneuvres.
FEV1 should be calculated by using the “back extrapolation” method to detect the start
of the test, extrapolated volume must not be higher then 5% FVC or 150ml.
The graphic resolution of the printed report must be as in the following:
Volume: 10 mm/l
Flow: 5 mm/l/sec
Time: 20 mm/sec
F/V ratio: 2:1
The total number of error (FVC e FEV1 >±3.5%, FEF25-75% >5.5%) during the
measurement of the 24 standard waveforms must be lower than 4.