Calorimetry systems and methods

A system for measuring a metabolic rate of an individual, comprising:

• a calorimeter including:
• an inlet configured to receive expiratory respiration from the individual;
• a respiratory flow sensor in communication with said inlet;
• a mixing chamber in communication with said inlet to receive at least one expiratory breath from the individual;
• and
• a gas sensor in communication with said mixing chamber;
• a flow meter in communication with said respiratory flow sensor;
• a gas meter in communication with said gas sensor;
• a cardiac rate monitor;
• a processor in communication with said flow meter, said gas meter, and said cardiac rate monitor;
• and
• a portable calorimeter configured to communicate with said processor so as to receive data therefrom.

A method for measuring a metabolic rate of an individual, comprising:

• evaluating expiratory respiration of the individual to determine an oxygen consumption of the individual;
• measuring a cardiac rate of the individual substantially concurrently with said evaluating;
• transmitting data representative of said oxygen consumption and said cardiac rate to a portable calorimeter;
• measuring a cardiac rate of the individual following said transmitting;
• and
• calculating the metabolic rate of the individual based on said transmitted data and said cardiac rate measured by said portable calorimeter.

A portable calorimeter configured to be worn by an individual, comprising:

• a processor;
• a cardiac rate monitor in communication with said processor, said cardiac rate monitor being configured to communicate signals representative of a cardiac rate of the individual to said processor, said processor being configured to determine a metabolic rate of the individual based on previously obtained respiratory or metabolic rate data of the individual;
• and
• an output element in communication with said processor and being configured to communicate information representative of at least the metabolic rate of the individual.

A calorimeter, comprising:

• a flow path in communication with an airway of an individual;
• a respiratory gas measurement component positioned along said flow path so as to receive gases exhaled by the individual without use of a valve or pump;
• and
• a calibrator in communication with said flow path and configured to cause at least one calibration gas to flow through said flow path in an opposite direction from that in which gases exhaled by the individual flow so as to expose said respiratory gas measurement component to said at least one calibration gas.