title: Microprocessor exercise physiology systems vs a nonautomated system. A comparison of data output.
abstract: Several microprocessor exercise physiology systems have been introduced recently. Comparison of the data output between these systems and more traditional nonautomated systems has not been reported extensively. Twelve normal adult men were exercised in random sequence on different days on a Sensormedics MMC Horizon system, the Medical Graphics Corporation System 2000, and a nonautomated system. heart rate, minute ventilation, tidal volume, respiratory frequency, oxygen consumption, and carbon dioxide production were compared at each level of work during a maximal incremental test and during a constant work load test. The overall data output between the three systems was comparable. However, minute ventilation was consistently higher on the Medical Graphics system, oxygen consumption was consistently lower on the Horizon system, and a technical error was discovered in the Medical Graphics system which resulted in a systematic overestimation of carbon dioxide production. Different methods of analyzing the data from the same test (60-s average, 15-s average, breath-by-breath, and 8-breath average) resulted in differences of up to 20 percent in the maximal values. This was greater than the differences between the three systems. Despite the comparability of the data output, important differences did exist which can be potentially significant when data output from one system are compared to predicted normal values obtained under different conditions.
mesh_terms: D000328:Adult; D003196:Computer Graphics; D006321:Heart / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D008491:Medical Informatics Applications; D008838:Microcomputers; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D005082:Physical Exertion; D011897:Random Allocation