Systems, devices, and/or methods for measuring metabolic energy expenditure

• US 10,271,766 B1
• Filed: 03/21/2016
• Issued: 04/30/2019
• Est. Priority Date: 03/20/2015
• Status: Active Grant

• Current Assignee: Barron Associates Inc
• Original Assignee: Barron Associates Inc
• Inventors: Parker, Jr., B. Eugene, Ehlmann, Kevin M., Gressick, William T.
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): Portillo, Jairo H
• Application Number:
  US15/076,237
• Time in Patent Office: 1,135 Days
• Field of Search: None
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/0271 Thermal or temperature sensors
• CPC Class Codes: A61B 5/0015 characterised by features of the telemetry system
• CPC Class Codes: A61B 5/0833 Measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses

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.

Claims

1. 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;

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 the water vapor pressure of the exhaled gases within the conduit to approximately a water vapor pressure in air outside the conduit;

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;

a relative humidity sensor configured to measure a relative humidity of the mixture in the mixing tank;

a temperature sensor configured to measure a temperature of the mixture in the mixing tank; and

a barometric pressure sensor configured to measure a barometric pressure of the mixture in the mixing tank;

a one-way inlet valve configured to prevent the mixture from escaping from the tank via the conduit;

a wireless transceiver configured to convey sensor measurement data; and

a battery configured to power the sensors and/or the wireless transceiver;

wherein;

the tank is formed from a non-conductive plastic;

the tank comprises a removable lid and a gasket configured to form a gas-tight seal between the tank and the lid;

the tank is configured to promote homogeneous mixing of the samples;

the tank comprises an inlet port and an outlet port, an entrance to the inlet port aligned perpendicularly to an entrance to the outlet port;

the battery is located on a bottom of the tank;

the barometric pressure sensor is integrated with the oxygen sensor;

the temperature sensor is integrated with the carbon dioxide sensor; and

the relative humidity sensor is integrated with the carbon dioxide sensor.

3. The system of claim 1, further comprising:

a vacuum pump configured to induce flow of the exhaled gases to the tank via the flow tube.

2. 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 at least a portion of each of a group of samples of exhaled gases provided by the mammal during a predetermined time period, the sampler 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 the water vapor pressure of the exhaled gases within the conduit to approximately a water vapor pressure in air outside the conduit;

in the mixing tank, mix 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;

measuring a relative humidity of the mixture in the mixing tank;

measuring a temperature of the mixture in the mixing tank;

measuring a barometric pressure of the mixture in the mixing tank;

prior to the mixing tank containing the mixture, and via the oxygen sensor, measuring a volumetric oxygen fraction of a gaseous content of the tank;

prior to the mixing tank containing the mixture, and via the carbon dioxide sensor, measuring a volumetric carbon dioxide fraction of the gaseous content of the 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;

wirelessly transmitting the volumetric oxygen fraction;

wirelessly transmitting the volumetric carbon dioxide fraction;

wirelessly transmitting the relative humidity;

wirelessly transmitting the temperature;

wirelessly transmitting the barometric pressure;

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 substantially independent of a time constant of the oxygen sensor and a time constant of the carbon dioxide sensor;

a pressure in the tank remains at substantially atmospheric pressure throughout said measuring activities.

4. The method of claim 2, further comprising:

inducing flow of the samples to the tank via a vacuum pump.