A validation study of the Q-Plex I cardiopulmonary exercise system

[摘要] A total of 27 Ss from the University of Wisconsin-La Crosse, ages 19-34yrs, volunteered to participate in the validation study of the Q-Plex ICardiopulmonary Exercise System developed by the Quinton InstrumentCompany. Each S performed a constant speed, grade incremented treadmilltest to volitional exhaustion. Simultaneous measurements of expired airware performed with the Q-Plex and a meteorological balloon gascollection system to determine the validity of the Q-lex. Respiratoryand metabolic assessments were made during at least 3 different levelsof exercise; low steady state, medium steady state, and at maximalexertion. A total of 93 gas samples were collected and analyzed by the2 methods. The means for FeO2 and FeCO2 were significantly (p0.85)different. However, the absolute mean differences were only 0.5% for FeO2and 0.3% for FeCO2 which are within the accuracy of the reported error forthe analyzers. These results indicated that the Q-Plex gas analyzersare as accurate as the micro-Scholander technique. Correlationcoefficients between the 2 systems were .9735 for FeO2 and .9729 forFeCO2. After all the validation data were collected a final comparisonwas mule between a series of volumes obtained with the Parkinson-Cowan meter and the Tissot spirometer. These results indicated there was amuch larger discrepancy in volumes obtained between these methods thanthose initially reported. These differences were of sufficientmanitude to question the accuracy of using this meter to validate thevolumes obtained with the Q-Plex. Since it was impossible to determinethe cause of this error, or at what point in the study it occurred, theVE volumes of the Q-Plex could not be legitimately validated using theParkinson-Cowan meter. Unfortunately, since the accuracy of measuringVO2 and VCO2 is dependent upon VE volumes, neither of these volumescould be compared. Within the limitations of the present study, it wasconcluded that the gas analyzers in the Q-Plex demonstrate accuracycomparable to that of the micro-Scholander technique.

[发布机构] University of Wisconsin

[效力级别] Treadmill exercise tests - Validity

[关键词] Pulmonary function tests - Validity;Treadmill exercise tests - Validity;Pulmonary gas exchange;Q-Plex I Cardiopulmonary Exercise System