| 摘要 |
A calorimeter for generating signals representative of the oxygen consumption of a subject over a test period includes a bidirectional volume flow sensor and a carbon dioxide scrubber connected to a mouthpiece. Interconnections are such that the air inhaled by the subject passes through the flow meter and the exhaled breath passes first through the carbon dioxide scrubber and then through the flow meter. The electrical output signals from the flow meter are provided to a microprocessor-based computer which integrates the volume differences between the inhaled gas, and the exhaled gas after the carbon dioxide has been removed from it, over the period of the test. Since the exhaled carbon dioxide essentially replaces the oxygen used by the subject during the test, this integral difference is a function of the patient's oxygen consumption. The use of a bidirectional flow meter results in a simple instrument that may be disposed after a single use to avoid the need for sterilization.
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