Tissue oxygen saturation detection and related apparatus and methods
A wearable optical device is described for optically detecting parameters of interest within muscle, such as during physical activity or when at rest. The parameters of interest include oxygenation level and/or hemoglobin concentrations in some situations. The detected parameters, such as oxygenation level, may be used to assess physical performance, such as the extent to which the muscle is utilizing aerobic or anaerobic processes. Methods for determining the parameters of interest, such as oxygenation level, from the detected optical signals are also described, and feedback may be provided to a user.
1. A wearable narrow-band optical monitor for determining muscle oxygenation level, comprising:
an item of clothing;
an optical detector module embedded in the item of clothing, the optical detector module comprising:
an optical source array including a plurality of narrow-band optical sources;
a plurality of optical detectors including at least three optical detectors arranged substantially in a linear arrangement on a same side of the optical source array, wherein the at least three optical detectors include a first optical detector of a first size disposed a first distance from the optical source array, a second optical detector of a second size larger than the first size disposed a second distance greater than the first distance from the optical source array, and a third optical detector disposed a third distance greater than the second distance from the optical source array,
wherein the first optical detector, the second optical detector, and the third optical detector are configured to detect an optical signal emitted from the optical source array; and
a control module coupled to the optical detector module and configured to receive output signals from the optical detectors of the optical detector module in response to an optical signal emitted by the optical source array, and to determine the muscle oxygenation level based on the output signals.
2. The wearable narrow-band optical monitor of claim 1 , wherein the optical detector module comprises a flexible substrate on which the optical detectors are disposed, wherein the flexible substrate is configured to conform to the item of clothing.
3. The wearable narrow-band optical monitor of claim 1 , wherein the optical detector module comprises a rigid substrate on which the optical detectors are disposed.
4. The wearable narrow-band optical monitor of claim 2 , wherein the control module is coupled to a user wearing the item of clothing.
5. The wearable narrow-band optical monitor of claim 4 , wherein the control module is affixed to the item of clothing.
6. The wearable narrow-band optical monitor of claim 4 , wherein the control module is removable from the item of clothing.
7. The wearable narrow-band optical monitor of claim 1 , wherein item of clothing comprises a flexible material configured to provide compression tension to securely attach the optical detector module to a body portion of a user wearing the item of clothing.
8. The wearable narrow-band optical monitor of claim 7 , wherein the item of clothing comprises an adjustable strap to which the optical detector module is affixed.
9. The wearable narrow-band optical monitor of claim 1 , further comprising a housing, wherein the optical detector module is disposed in the housing.
10. The wearable narrow-band optical monitor of claim 9 , wherein the plurality of narrow-band optical sources occupy a single position within the housing.
11. The wearable narrow-band optical monitor of claim 9 , wherein the control module is disposed in the housing.
12. The wearable narrow-band optical monitor of claim 9 , wherein the housing includes a recess in which the optical source array is disposed such that the optical source array lies beneath a surface of the housing.
13. The wearable narrow-band optical monitor of claim 9 , wherein the housing includes respective recesses in which the plurality of narrow-band optical sources are disposed such that the plurality of narrow-band optical sources lie beneath a surface of the housing.
14. The wearable narrow-band optical monitor of claim 9 , wherein the housing includes respective recesses in which the plurality of optical detectors are disposed such that the plurality of optical detectors lie beneath a surface of the housing.
15. The wearable narrow-band optical monitor of claim 1 , wherein the control module is coupled to the optical detector module by a wireless connection.
16. The wearable narrow-band optical monitor of claim 1 , wherein the plurality of narrow-band optical sources are arranged substantially in a linear arrangement with respect to each other, and wherein the linear arrangement of the plurality of narrow-band optical sources is substantially perpendicular to the linear arrangement of the at least three optical detectors.
17. The wearable narrow-band optical monitor of claim 1 , wherein the third optical detector is larger than the second optical detector.
18. The wearable narrow-band optical monitor of claim 1 , wherein the third optical detector is configured to detect an optical signal emitted only from narrow-band optical sources that are disposed on the same side of the optical source array.
19. The wearable narrow-band optical monitor of claim 1 , wherein the optical detector module is a first optical detector module, and
the wearable narrow-band optical monitor further comprises a second optical detector module embedded in the item of clothing.
20. The wearable narrow-band optical monitor of claim 1 , further comprising wireless communication circuitry configured to wirelessly transmit data indicative of signals produced by the plurality of optical detectors.