Abstract: A system for real time, breath by breath sampling of a patient receiving up to 100 percent oxygen to determine nutritional requirements of the patient through indirect calorimetry includes a pneumotach member for measuring the volume rate of flow of inspired and expired gas flow at the patient/endotracheal tube/ventilator connection. A sample line extends from the pneumotach to a gas analyzer which measures the percent concentration of constituent respiratory gases in the expired gas flow. A flowmeter is coupled to the gas analyzer for determining the volume flow rate of the expiratory gas flow through the sample line. A microprocessor control samples the analog electrical signals from the gas analyzer, the flow meter and the pneumotach in a predetermined sequence, dynamically compensating for variations in gas flow rate.

Abstract: A single-use, disposable, elastomeric patient valve has a pair of one-way check valves disposed in the cross-piece portion thereof to create a barrier against patient infection. The check valves prevent contamination by a first patient of the reusable demand valve portion as he or she exhales into the patient valve and prevents the inhalation of possibly infected materials into the lungs, via the sampling chamber and associated tubing coupling same to the patient valve.

Abstract: A method for optimizing either fat utilization or cardiovascular performance during an exercise regimen includes the steps of using a cardiovascular exercise system to measure a subject's respiratory exchange ratio on a breath-by-breath basis and also locating the subject's anaerobic threshold. By locating a fat burning point as the point where the RER is a minimum less than 0.90 at a time when oxygen uptake is less than 55 percent of the peak oxygen uptake and then correlating that fat burning point with the existing heart rate, a fat burning zone can be established by taking that heart rate and adding and subtracting 10 percent from it. The work rate at the target heart rate can also be used to determine the zone. For enhanced cardiovascular performance training, the heart rate existing at the subject's anaerobic threshold is determined and it is set as the lower boundary for a zone whose upper boundary is that value plus 20 percent.