Physical Performance Monitoring and Monitors

• US 20090024013A1
• Filed: 07/14/2008
• Published: 01/22/2009
• Est. Priority Date: 07/13/2007
• Status: Active Grant

• Current Assignee: University Of Massachusetts
• Original Assignee: University Of Massachusetts
• Inventors: Soller, Babs R.
• Granted Patent: US 8,818,477 B2
• Time in Patent Office: Days
• US Class Current: 600/324
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/4866 Evaluating metabolism A61B5/083 takes precedence

Abstract

Methods and systems are disclosed for determining an anaerobic threshold and/or an oxygen consumption rate in a human or animal subject. The methods include exposing a tissue of the subject to illumination radiation, collecting emitted radiation from the tissue, the emitted radiation including a portion of the illumination radiation reflected or transmitted from the tissue, processing the emitted radiation to form a spectrum of the tissue, and determining, based on the spectrum of the tissue, the anaerobic threshold and/or the oxygen consumption rate of the subject.

Claims

1. A method of determining an anaerobic threshold of a human or animal subject, the method comprising:

exposing a tissue of the subject to illumination radiation;

collecting emitted radiation from the tissue, the emitted radiation comprising a portion of the illumination radiation reflected or transmitted from the tissue;

processing the emitted radiation to form a spectrum of the tissue; and

determining, based on the spectrum of the tissue, an anaerobic threshold of the subject.

2. The method of claim 1, further comprising determining the anaerobic threshold based on a plurality of concentration values of an analyte in the tissue.

3. The method of claim 1, further comprising determining the anaerobic threshold based on a plurality of pH values of the tissue, wherein each of the plurality of pH values is obtained by measuring a spectrum of the tissue and determining a pH value from the spectrum.

4. The method of claim 3, wherein determining the anaerobic threshold based on the plurality of pH values comprises:

fitting more than one of the plurality of pH values to a mathematical equation to determine parameters of the equation; and

determining the anaerobic threshold from the mathematical equation.

5. The method of claim 3, wherein determining the anaerobic threshold based on the plurality of pH values comprises:

determining a plurality of hydrogen ion concentration values of the tissue from the plurality of pH values;

fitting more than one of the plurality of hydrogen ion concentration values to a mathematical equation to determine parameters of the equation; and

determining the anaerobic threshold from the mathematical equation.

6. The method of claim 5, wherein the mathematical equation is of the form

7. The method of claim 6, wherein the measure of exercise intensity is a rate of oxygen consumption in the tissue.

8. The method of claim 3, wherein determining the anaerobic threshold comprises:

determining a plurality of hydrogen ion concentration values of the tissue from the plurality of pH values;

fitting more than one of the plurality of hydrogen ion concentration values to a mathematical equation to determine parameters of the equation; and

determining a measure of exercise intensity at which a first derivative of the mathematical equation changes.

9. The method of claim 8, wherein the measure of exercise intensity is an oxygen consumption rate.

10. The method of claim 1, wherein determining the anaerobic threshold comprises determining a pH value or a hydrogen ion concentration value of the tissue that corresponds to the anaerobic threshold, the method further comprising monitoring a pH value or a hydrogen ion concentration value in the subject during a period of physical exercise.

11. The method of claim 1, wherein determining the anaerobic threshold comprises determining a pH value or a hydrogen ion concentration value of the tissue that corresponds to the anaerobic threshold, the method further comprising determining a first pH value or a first hydrogen ion concentration value in the subject prior to a period of physical exercise, and determining a second pH value or a second hydrogen ion concentration value in the subject following the period of physical exercise.

12. The method of claim 1, further comprising determining a pH value or a hydrogen ion concentration value of the tissue that corresponds to the anaerobic threshold, and further determining pH values or hydrogen ion concentration values in the subject at least twice during a period of physical exercise to assess whether the subject'"'"'s anaerobic threshold has been reached, wherein the pH values or the hydrogen ion concentration values are determined at a frequency of 0.1 Hz or more.

13. The method of claim 1, further comprising assessing one or both of a physical condition of the subject and an effectiveness of an exercise regimen performed by the subject based on the anaerobic threshold.

14. A method of determining an oxygen consumption rate of a human or animal subject, the method comprising:

exposing a tissue of the subject to illumination radiation;

collecting emitted radiation from the tissue, the emitted radiation comprising a portion of the illumination radiation reflected or transmitted from the tissue;

processing the emitted radiation to form a spectrum of the tissue; and

determining, based on the spectrum of the tissue, an oxygen consumption rate of the subject.

15. The method of claim 14, wherein determining the rate of oxygen consumption comprises determining a difference between arterial oxygen saturation and tissue oxygen saturation in the tissue.

16. The method of claim 15, wherein determining the rate of oxygen consumption further comprises determining a stroke volume of the subject based on a heart rate of the subject.

17. The method of claim 15, wherein determining the rate of oxygen consumption further comprises determining a hemoglobin concentration in the tissue.

18. The method of claim 17, wherein determining the hemoglobin concentration in the tissue comprises:

determining a hematocrit level in the tissue based on the spectrum of the tissue; and

determining a hemoglobin concentration in the tissue based on the hematocrit level.

19. The method of claim 14, wherein the rate of oxygen consumption in the tissue is determined according to

{dot over (V)}O₂=SV·

HR·

C_(a-b)O₂

where {dot over (V)}O₂ is the rate of oxygen consumption in the tissue, SV is a stroke volume of the subject, HR is a heart rate of the subject, and C_(a-b)O₂ is a difference between arterial and venous oxygen content in the tissue.

20. The method of claim 19, wherein the difference between arterial and venous oxygen content, C_(a-b)O₂, is calculated based on values of arterial and venous oxygen saturation in the tissue and a hemoglobin concentration in the tissue.

21. The method of claim 14, further comprising determining, based on the spectrum of the tissue, an anaerobic threshold of the subject.

22. An apparatus, comprising:

a spectrometer configured to detect light emitted from a tissue of a human or animal subject, and to determine a spectrum of the tissue from the detected light; and

an electronic processor coupled to the spectrometer and configured to determine, based on the spectrum of the tissue, at least one of an oxygen consumption rate and an anaerobic threshold of the subject.

23. The apparatus of claim 22, wherein the electronic processor is configured to:

determine a plurality of spectra of the tissue;

determine a plurality of pH values of the tissue, wherein each one of the plurality of pH values is obtained from one of the plurality of spectra; and

determine the anaerobic threshold based on the plurality of pH values.

24. The apparatus of claim 22, wherein the spectrometer comprises:

at least one light source;

one or more incident light ports configured to transmit light from the at least one light source to the tissue; and

one or more light receiving ports configured to transmit light from the tissue to a detector,

wherein the one or more incident light ports and the one or more light receiving ports are enclosed in a housing that comprises an attachment mechanism for attaching the housing to a portion of a subject'"'"'s body.

25. The apparatus of claim 24, wherein the at least one light source comprises a plurality of light emitting diodes.

26. The apparatus of claim 24, wherein:

the one or more light receiving ports comprise one light receiving port;

the one or more incident light ports comprise a first light port positioned at a first distance from the light receiving port and a second light port positioned at a second distance, shorter than the first distance, from the light receiving port; and

the electronic processor is configured to correct spectral data derived from light from the first light port with spectral data derived from light from the second light port.

27. The apparatus of claim 22, further comprising a communication interface in electrical communication with the electronic processor, the communication interface being configured to transmit signals from the electronic processor to a device over at least one of a communication link and a network.

28. The apparatus of claim 27, wherein the device is at least one of a computer, a handheld computing device, a mobile telephone, and a display device.

29. The apparatus of claim 27, wherein the signals comprise information about the subject, and the device is a computing device configured to monitor the information about the subject.

30. A system, comprising:

an electronic device connected to a data transmission network; and

a plurality of monitoring devices, each monitoring device corresponding to the apparatus of claim 22,

wherein each monitoring device is configured to transmit information about one of multiple human or animal subjects to the electronic device over the data transmission network, the information comprising at least one of the oxygen consumption rate and the anaerobic threshold of the subject.