| 摘要 |
An indirect calorimeter for calculating the metabolic rate of a subject by measuring the oxygen consumption during respiration over a period of time includes a gas flow meter providing output electric signals to a microprocessor which drives a display and printer. A carbon dioxide scrubber is connected to the flow meter and a mouthpiece so that inhaled gas passes first through the scrubber and then through the flow meter before being provided to the subject's respiratory system through the mouthpiece. The exhaled gas passes through the scrubber and then through the flow meter. The difference in volume between the inhaled gas and the exhaled gas is proportional to the oxygen consumption of the subject and the microprocessor integrates that signal over the time of the test, and multiplies it by a constant to provide a metabolic rate display. By passing both the inhaled and exhaled gases through the scrubber before their volume is measured, their temperature and humidity are modified to a state of equal temperature and humidity.
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