The metabolism calorimeter which uses breath gas analysis

摘要

An indirect calorimeter for measuring the metabolic rate of a subject is provided, which includes a respiratory calorimeter (10) configured to be supported in contact with the subject, passing inhaled and exhaled gases as the subject breathes. A flow pathway (22) is operable to receive and pass inhaled and exhaled gases having a first end in fluid communication with the respiratory connector (20) and a second end is in fluid communication with a source and sink for respiratory gases. A flow meter generates electrical signals as a function of the instantaneous flow volume of inhaled and exhaled gases passing through the flow pathway. A component gas concentration sensor (84) generates electrical signals as a function of the instantaneous fraction of a predetermined component gas in the exhaled gases as the gases pass through the flow pathway. As the subject breathes through the calorimeter (10), a computation unit (96) receives electrical signals from the flow meter and the component gas concentration sensor (84), calculating at least one respiratory parameter.