Peak flow whistle: preliminary report.

A peak flow (PF) measuring device, the Peak Flow Whistle (PFW), has recently been designed. The principle of a threshold activated reed is utilized to register PF, which differs significantly from the spring distortion mechanism utilized in currently marketed devices. Prototypes of the PFW were tested in the laboratory and in clinical settings as part of our preliminary studies. When compared with a pneumotachograph in the laboratory, the values correlated significantly (p less than .0001). In field studies both in asthmatic and non-asthmatic children, the PFW values correlated significantly (p less than .0001) with those of the Wright Peak Flow Meter and performance was found to be satisfactory.