A simple office spirometer for the pediatrician.

A comparative study of a new, simple, pneumatic, direct-recording office spirometer versus a long-accepted, water-sealed, water-filled spirometer was performed on 103 patients ranging from four to 20 years of age. Good correlation between the two spirometers was seen through a wide range of values for forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced expiratory flow during 25% to 75% of forced vital capacity and FEV1/FVC.