Abstract: A metabolic rate analyzer is provided comprising a CO.sub.2 detector, an O.sub.2 detector, a flow resistance, a differential pressure transducer, a solenoid-actuated metering valve for producing a volumetrically-proportional sample of respired gas, a vacuum regulator for receiving the sample, a pump for drawing the sample from the vacuum regulator, and a processor for periodically sampling the differential pressure signal to provide a flow signal, to modulate power applied to the solenoid-actuated flow proportioning valve, and to provide a measure of the total volume of respired gas. The processor correlates the total volume of respired gas, O.sub.2 content and CO.sub.2 content to provide a measure of metabolic rate. Flow is recycled between the pump and the regulator valve to provide a source of mixed respired gas for analysis and digital integration of the flow signal provides a measure of the total volume of respired gas.

Abstract: The metabolic rate analyzer comprises a flow proportioning valve for producing a proportional sample of the expired gas of the subject being studied. A sample cylinder is provided for drawing a proportional sample of the expired gas of the subject being studied from the flow proportioning valve. A test chamber is provided and an O.sub.2 sensor is provided. The test chamber is provided with a selectively-permeable membrane, the selectively-permeable membrane having a selective permeability for CO.sub.2, whereby CO.sub.2 is selectively vented from the test chamber. The sample cylinder is also used for charging the test chamber with the proportional sample of the expired gas of the subject. A pressure sensor is provided for monitoring the pressure of the sample and determining the rate of pressure decay in the test chamber due to the selective venting of CO.sub.2 through the permeable membrane. An analyzing means is provided for determining CO.sub.

Abstract: The metabolic rate analyzer comprises a flow proportioning valve for producing a proportional sample of the expired gas of the subject being studied. A sample cylinder is provided for drawing a proportional sample of the expired gas of the subject being studied from the flow proportioning valve. A test chamber is provided and an O.sub.2 sensor is provided. The test chamber is provided with a selectively-permeable membrane, the selectively-permeable membrane having a selective permeability for CO.sub.2, whereby CO.sub.2 is selectively vented from the test chamber. The sample cylinder is also used for chrging the test chamber with the proportional sample of the expired gas of the subject. A pressure sensor is provided for monitoring the pressure of the sample and determining the rate of pressure decay in the test chamber due to the selective venting of CO.sub.2 through the permeable membrane. An analyzing means is provided fo determining CO.sub.