An electronic peak flowmeter with optional coded display

Abstract

A portable electronic spirometer giving peak expiratory flow rate was developed and used successfully in studies of asthma [human]. A turbine flow transducer produces a pulsed output whose frequency is proportional to flow. The output was coded to keep the results blind to the patient. The code is suitable for use on other electronic instruments employing a similar display. It has been successfully used to investigate patients'' perception of their asthma.