[Elementary precautions necessary for the validity of ventilatory function measurements with electronic spirometers].
The increase of morbidity rate of chronic bronchitis demonstrates the interest of an early check-up, in the free symptom phase of illness, because obstruction of small bronchii may be reversible, as it has been pointed out by previous longitudinal studies. These finding involve the use of simple devices, easy to manage and rebrabld. The three apparatus have been tested : Ohio 842 spirograph, Oude Delft expirometer and Chemetron Corporation P.F.I., in 165 patients. All of them have been compared to Jaeger spirometer. No good agreement has been found between expirometer, P.F.I. and Jaeger spirometer. But Ohio 842 spirograph values were quiet close to those observed with Jaeger spirometer. Electronic spirometers present a digital display without graphic recording or calibration. It has been difficult to detect errors at a first glance. Mostly they came from non linearity of response of thermistance, irregular expiratory flow, insufficient cooperation of patients.
D001991:Bronchitis / Q000175:diagnosis*; D002000:Bronchospirometry / Q000295:instrumentation*; D005541:Forced Expiratory Volume; D006801:Humans; D008450:Maximal Midexpiratory Flow Rate
Contraintes élémentaires nécessaires a la validité des mesures de la fonction ventilatoire enregistrée par des "spiromètres secs".