| 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 (42) providing output electric signals to a microprocessor (20) which drives a display and printer. The output of the flow meter (42) is connected to a mouthpiece (12), The exhaled gas passes through a CO2 scrubber (30) and then through the flow meter (42). The difference in volume be- tween the inhaled gas and the exhaled gas is proportional to the oxygen consumption of the subject and the micropro- cessor (20) integrates that sig- nal over the time of the test, and multiples it by a constant to provide a metabolic rate display. The temperature and water vapor content of the in- haled air are adjusted to that of the exhaled air either by passing both the inhaled and exhaled gases through the scrubber (30) before their volume is measured, or by preheating the inhaled air and employing a water absorbent member to add moisture to the inhaled air and remove it from the exhaled air.
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