Volume spirometers need automated internal temperature sensors.
Spirometer temperature was measured automatically during all years of the Lung Health Study. Short- and long-term changes in temperature were analyzed for the 23 dry-rolling-seal volume spirometers used at the 10 clinical centers involved in the study. Within-test-session spirometer temperature increased a mean of 0.3 degrees C, and as much as 3.0 degrees C during methacholine challenge testing. The maximal change in spirometer temperature during a test day exceeded 4 degrees C more than 5% of the time. Month-to-month changes of more than 15 degrees C were not uncommon. If ambient temperature had been assumed to apply to all maneuvers and used for BTPS corrections, FEV1, and FVC measurement errors of up to 6% would have occurred. When using volume spirometers, the temperature of air inside the spirometer should be measured accurately during each breathing maneuver.
Lung Health Study Research Group, Oregon Health Sciences University, Portland.
L R
LR
Johnson
P L
PL
Enright
H T
HT
Voelker
D P
DP
Tashkin
D001985:Bronchial Provocation Tests; D005069:Evaluation Studies as Topic; D005541:Forced Expiratory Volume; D006801:Humans; D013147:Spirometry / Q000295:instrumentation* / Q000592:standards / Q000706:statistics & numerical data; D013696:Temperature; D013821:Thermometers / Q000592:standards / Q000706:statistics & numerical data; D013997:Time Factors; D014481:United States; D014797:Vital Capacity