Evaluating commercially available spirometers.

This study was designed to: (1) determine the performance characteristics of available spirometers; (2) assess the practically and applicability of the American Thoracic Society's (ATS) Snowbird Workshop recommendations on Standardization of Spirometry; and (3) determine whether spirometer testing could be done with room air. Nineteen spirometers were tested with 16 different forced vital capacity waveforms. Fourteen spirometers met the ATS forced vital capacity requirements. Three of these 14 spirometers had difficulties in determining the end of expiration. Fourteen of the devices tested met the requirements for forced expiratory volume in one second. Ten of 13 devices tested for maximal voluntary ventilation were satisfactory. The standards recommended by ATS were believed to be applicable and practical. The testing methods recommended by ATS need to be expanded to include more patient waveforms. Testing with room air is easier and simpler and, for most devices, just as effective as heated and humidified air. We conclude that most available spirometers can faithfully record forced spirograms and that if a spirometer meets the ATS requirements, it makes no difference on which device the spirogram is recorded.