Evaluation of a hand-held spirometer, the Respiradyne, for the measurement of forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR)

A hand-held spirometer, the Respiradyne (R), was evaluated for the measurement of forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) by comparing it with a Vitalograph spirometer (V) and a Wright's peak flow meter (W) in 70 subjects (normals and patients). The results showed close agreement for FEV1; r=0.99, R=0.961V+0.03×10−5 and FVC; r=0.99, R-1.003V−0.044. Results for PEFR using the Respiradyne were generally higher than with the peak flow meter; r=0.98, R=1.151W−17.576. The Respiradyne is portable and simple to operate and may be suited to use in a variety of non-laboratory situations.