Systems, devices, and/or methods for measuring metabolic energy expenditure
AssigneeBarron Associates, Inc.
InventorsB. Eugene Parker, Jr., Kevin M. Ehlmann, William T. Gressick
Life of this patent
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Abstract
Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, composition of matter, and/or user interface adapted for and/or resulting from, and/or a method and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise and/or relate to, facilitating determination of the oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure of a mammal.
Claims27
A flowmeter-free indirect calorimetry system configured to facilitate determination of the oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure of a mammal, the system comprising:
- a mixing tank configured to contain a mixture comprising at least a portion of each of a group of samples of exhaled gases provided by the mammal during a predetermined time period, the tank configured to promote homogeneous mixing of the samples;
- a flow tube configured to route each of the group of samples toward the mixing tank;
- a conduit configured to convey the exhaled gases from the flow tube toward the mixing tank and configured to reduce a water vapor pressure of the exhaled gases within the conduit to approximately a water vapor pressure in air outside the flow tube;
- a plurality of sensors comprising:
- an oxygen sensor configured to measure a volumetric oxygen fraction of the mixture in the mixing tank;
- a self-calibrating carbon dioxide sensor configured to measure a volumetric carbon dioxide fraction of the mixture in the mixing tank;
- and
- a wireless transceiver configured to convey sensor measurement data;
- and
- a processor;
- wherein:
- the processor is configured to determine the oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure based on the volumetric oxygen fraction and the volumetric carbon dioxide fraction of the mixture in the mixing tank;
- and
- the determined oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure is independent of a time constant of the oxygen sensor and a time constant of the carbon dioxide sensor.
A flowmeter-free indirect calorimetry method that is configured to facilitate determination of the oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure of a mammal, the method comprising activities comprising:
- sampling, via a flow tube, at least a portion of each of a group of samples of exhaled gases provided by the mammal during a predetermined time period, the flow tube configured to direct each of the group of samples toward a mixing tank;
- conveying the samples through a conduit, from the flow tube toward the mixing tank, the conduit configured to reduce a water vapor pressure of the exhaled gases within the conduit to approximately a water vapor pressure in air outside the flow tube;
- in the mixing tank, mixing the samples to form a mixture;
- via an oxygen sensor, measuring a volumetric oxygen fraction of the mixture in the mixing tank;
- via a self-calibrating carbon dioxide sensor, measuring a volumetric carbon dioxide fraction of the mixture in the mixing tank;
- wirelessly transmitting sensor measurement data for determination of the oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure based on the volumetric oxygen fraction and the volumetric carbon dioxide fraction;
- and
- determining the oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure based on the volumetric oxygen fraction and the volumetric carbon dioxide fraction;
- wherein the determined oxygen consumption, carbon dioxide production, respiratory exchange ratio, and/or energy expenditure is independent of a time constant of the oxygen sensor and a time constant of the carbon dioxide sensor.
Dependencies are inferred from the claim text.