An evaluation of the P.K. Morgan pocket spirometer.
The P. K. Morgan pocket spirometer, which has recently become available in the United States, is small, portable, relatively inexpensive, and measures forced vital capacity (FVC) and the forced exhaled volume in 1 second (FEV1). We conducted this study to evaluate the accuracy of the FVC and FEV1 measurements by the P.K. Morgan spirometer.


METHODS
The flow signal used to evaluate the Morgan spirometer was produced by a Vent-Aid TTL Training Test Lung. The flow of air from the test lung was directed in series through the Morgan's volume transducer and into the bell of a 9-L Collins water-sealed spirometer.


RESULTS
The difference between Collins mean FVC and Morgan mean FVC was not significant (P = 0.17). The correlation coefficient for the relationship between Collins FVC and Morgan FVC was 0.996. American Thoracic Society (ATS) standards for accuracy were met by 56% of the FVC volumes measured by the Morgan. The difference between Collins mean FEV1 and Morgan mean FEV1 was clinically small but statistically significant (P = 0.01). The correlation coefficient for the relationship between Collins FEV1 and Morgan FEV1 was 0.999. ATS standards for accuracy were met by 87% of the FEV1 volumes measured by the Morgan.


CONCLUSIONS
The overall accuracy of the Morgan spirometer is adequate for bedside screening, but its accuracy is not sufficient to allow it to be used for diagnostic spirometry in place of more accurate pulmonary function equipment.
D004865:Equipment and Supplies, Hospital / Q000592:standards*; D005069:Evaluation Studies as Topic; D013147:Spirometry / Q000295:instrumentation*