Patent ID: 6899684

Claim:
A method of determining a respiratory parameter for a subject using an indirect calorimeter, comprising: initializing the indirect calorimeter, wherein the indirect calorimeter includes a respiratory connector for passing inhaled and exhaled gases as the subject breathes, a flow pathway operable to receive and pass the inhaled and exhaled gases and having a flow tube within the flow pathway through which the inhaled and exhaled gases pass, a flow meter, a component gas concentration sensor, and a computation unit having a processor and a memory; passing the inhaled and exhaled gases through the respiratory connector, if the indirect calorimeter is initialized; sensing a flow volume of the inhaled and exhaled gases passing through the flow pathway, using the flow meter, and transmitting a signal representing the sensed flow volume to the computation unit; sensing a concentration of a predetermined component gas in at least one of the inhaled and exhaled gases passing through the flow pathway, using the component gas concentration sensor, and transmitting a signal representing the sensed concentration to the computation unit; determining if the subject's breathing has reached steady state; calculating at least one respiratory parameter for the subject at steady state using the sensed flow volume and the sensed concentration; and providing the at least one respiratory parameter to the subject.