Systems and methods for measuring tissue oxygenation

1. A method for determining tissue oxygenation comprising:

at a system comprising a processor and memory, the memory including instructions for:

obtaining a data set comprising a plurality of images of a tissue of interest, each respective image in the plurality of images resolved at a different spectral band, in a predetermined set of eight to twelve spectral bands, and comprising an array of pixel values;

registering, using the processor, the plurality of images on a pixel-by-pixel basis, to form a plurality of registered images of the tissue; and

performing spectral analysis at a plurality of points in a two-dimensional area of the plurality of registered images of the tissue, the spectral analysis including determining approximate values of oxyhemoglobin levels and deoxyhemoglobin levels at each respective point in the plurality of points,

wherein the predetermined set of eight to twelve spectral bands includes spectral bands having central wavelengths of:

(i) 510±3 nm, 530±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 620±3 nm, and 660±3 nm,

(ii) 520±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 610±3 nm, 620±3 nm, and 640±3 nm, or

(iii) 500±3 nm, 530±3 nm, 545±3 nm, 570±3 nm, 585±3 nm, 600±3 nm, 615±3 nm, and 640±3 nm; and

wherein each respective spectral band in the eight to twelve spectral bands has a full width at half maximum of less than 15 nm.

2. The method of claim 1 , wherein obtaining the data set comprises:

at the system:

capturing the plurality of images of the tissue of interest.

3. The method of claim 2 , wherein all of the plurality of images are captured concurrently.

4. The method of claim 2 , wherein a first subset of the plurality of images is captured concurrently at a first time point and a second subset of the plurality of images is captured concurrently at a second time point, other than the first time point.

5. The method of claim 2 , wherein the system is an imaging system and the spectral analysis is performed at the imaging system.

6. The method of claim 1 , wherein performing the spectral analysis comprises:

resolving absorption signals at each respective point in the plurality of points;

accounting for a melanin contribution and loss of signal from diffuse scattering at each respective point in the plurality of points, thereby forming a plurality of corrected absorption signals; and

determining approximate values of oxyhemoglobin levels and deoxyhemoglobin levels from the corrected absorption signals at each respective point in the plurality of points.

7. The method of claim 6 , wherein the contribution provided by melanin and the losses provided by diffuse scattering to the plurality of tissue oxygenation measurements are collectively modeled as a second order polynomial.

8. The method of claim 1 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, wherein the set of eight spectral bands have central wavelengths of:

(i) 510±3 nm, 530±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 620±3 nm, and 660±3 nm;

(ii) 520±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 610±3 nm, 620±3 nm, and 640±3 nm; or

(iii) 500±3 nm, 530±3 nm, 545±3 nm, 570±3 nm, 585±3 nm, 600±3 nm, 615±3 nm, and 640±3 nm.

9. The method of claim 1 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, wherein the set of eight spectral bands have having central wavelengths of:

(i) 510±2 nm, 530±2 nm, 540±2 nm, 560±2 nm, 580±2 nm, 590±2 nm, 620±2 nm, and 660±2 nm;

(ii) 520±2 nm, 540±2 nm, 560±2 nm, 580±2 nm, 590±2 nm, 610±2 nm, 620±2 nm, and 640±2 nm; or

(iii) 500±2 nm, 530±2 nm, 545±2 nm, 570±2 nm, 585±2 nm, 600±2 nm, 615±2 nm, and 640±2 nm.

10. The method of claim 1 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, wherein the set of eight spectral bands have central wavelengths of:

(i) 510±1 nm, 530±1 nm, 540±1 nm, 560±1 nm, 580±1 nm, 590±1 nm, 620±1 nm, and 660±1 nm;

(ii) 520±1 nm, 540±1 nm, 560±1 nm, 580±1 nm, 590±1 nm, 610±1 nm, 620±1 nm, and 640±1 nm; or

(iii) 500±1 nm, 530±1 nm, 545±1 nm, 570±1 nm, 585±1 nm, 600±1 nm, 615±1 nm, and 640±1 nm.

11. The method of claim 1 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, where the set of eight spectral bands have central wavelengths of:

(i) 510 nm, 530 nm, 540 nm, 560 nm, 580 nm, 590 nm, 620 nm, and 660 nm;

(ii) 520 nm, 540 nm, 560 nm, 580 nm, 590 nm, 610 nm, 620 nm, and 640 nm; or

(iii) 500 nm, 530 nm, 545 nm, 570 nm, 585 nm, 600 nm, 615 nm, and 640 nm.

12. The method of claim 1 , wherein each respective spectral band in the eight to ten spectral bands has a full width at half maximum of less than 5 nm.

13. An electronic device, comprising:

one or more processors;

memory;

one or more programs, the one or more programs stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for:

obtaining a data set comprising a plurality of images of a tissue of interest, each respective image in the plurality of images resolved at a different spectral band in a predetermined set of eight to twelve spectral bands, and comprising an array of pixel values;

registering, using the processor, the plurality of images on a pixel-by-pixel basis, to form a plurality of registered images of the tissue; and

performing spectral analysis at a plurality of points in a two-dimensional area of the plurality of registered images of the tissue, the spectral analysis including determining approximate values of oxyhemoglobin levels and deoxyhemoglobin levels at each respective point in the plurality of points,

wherein the predetermined set of eight to twelve spectral bands includes spectral bands having central wavelengths of:

(i) 510±3 nm, 530±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 620±3 nm, and 660±3 nm;

(ii) 520±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 610±3 nm, 620±3 nm, and 640±3 nm; or

(iii) 500±3 nm, 530±3 nm, 545±3 nm, 570±3 nm, 585±3 nm, 600±3 nm, 615±3 nm, and 640±3 nm; and

wherein each respective spectral band in the eight to twelve spectral bands has a full width at half maximum of less than 15 nm.

14. The electronic device of claim 13 , wherein the electronic device is an imaging system further comprising:

one or more photo-sensors, the one or more photo-sensors in electronic communication with the one or more processors and configured to resolve light of the predetermined set of eight to twelve spectral bands, and

wherein the instructions for obtaining the data set include instructions for capturing the plurality of images of the tissue of interest using the one or more photo-sensors.

15. The electronic device of claim 14 , wherein the plurality of images is captured concurrently.

16. The electronic device of claim 14 , wherein a first subset of the plurality of images is captured concurrently at a first time point and a second subset of the plurality of images is captured concurrently at a second time point, other than the first time point.

17. The electronic device of claim 13 , wherein the instructions for performing the spectral analysis includes instructions for:

resolving absorption signals at each respective point in the plurality of points;

accounting for a melanin contribution and loss of signal from diffuse scattering at each respective point in the plurality of points, thereby forming a plurality of corrected absorption signals; and

determining approximate values of oxyhemoglobin levels and deoxyhemoglobin levels from the corrected absorption signals at each respective point in the plurality of points.

18. The electronic device of claim 17 , wherein the contribution provided by melanin and the losses provided by diffuse scattering to the plurality of tissue oxygenation measurements are collectively modeled as a second order polynomial.

19. The electronic device of claim 13 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, wherein the set of eight spectral bands have central wavelengths of:

(i) 510±3 nm, 530±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 620±3 nm, and 660±3 nm;

(ii) 520±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 610±3 nm, 620±3 nm, and 640±3 nm; or

(iii) 500±3 nm, 530±3 nm, 545±3 nm, 570±3 nm, 585±3 nm, 600±3 nm, 615±3 nm, and 640±3 nm.

20. The electronic device of claim 13 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, wherein the set of eight spectral bands have central wavelengths of:

(i) 510 nm, 530 nm, 540 nm, 560 nm, 580 nm, 590 nm, 620 nm, and 660 nm;

(ii) 520 nm, 540 nm, 560 nm, 580 nm, 590 nm, 610 nm, 620 nm, and 640 nm; or

(iii) 500 nm, 530 nm, 545 nm, 570 nm, 585 nm, 600 nm, 615 nm, and 640 nm.

21. The electronic device of claim 13 , wherein each respective spectral band in the eight to twelve spectral bands has a full width at half maximum of less than 5 nm.

22. A nontransitory computer-readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by an electronic device comprising a processor and memory, cause the electronic device to:

obtain a data set comprising a plurality of images of a tissue of interest, each respective image in the plurality of images resolved at a different spectral band, in a predetermined set of eight to twelve spectral bands, and comprising an array of pixel values;

register, using the processor, the plurality of images on a pixel-by-pixel basis, to form a plurality of registered images of the tissue; and

perform spectral analysis at a plurality of points in a two-dimensional area of the plurality of registered images of the tissue, the spectral analysis including determining approximate values of oxyhemoglobin levels and deoxyhemoglobin levels at each respective point in the plurality of points,

wherein the predetermined set of eight to twelve spectral bands includes spectral bands having central wavelengths of:

(i) 510±3 nm, 530±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 620±3 nm, and 660±3 nm;

(ii) 520±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 610±3 nm, 620±3 nm, and 640±3 nm; or

(iii) 500±3 nm, 530±3 nm, 545±3 nm, 570±3 nm, 585±3 nm, 600±3 nm, 615±3 nm, and 640±3 nm; and

wherein each respective spectral band in the eight to ten spectral bands has a full width at half maximum of less than 10 nm.

23. The nontransitory computer-readable storage medium of claim 22 , wherein the instructions, when executed by an imaging system further comprising one or more photo-sensors configured to resolve light of the predetermined set of eight to twelve spectral bands, further cause the imaging system to:

capture the plurality of images of the tissue of interest, each respective image in the plurality of images resolved at a different spectral band in the predetermined set of eight to twelve spectral bands, thereby obtaining the plurality of images of the tissue of interest.

24. The computer-readable storage medium of claim 23 , wherein the instructions cause the imaging system to capture the plurality of images concurrently.

25. The computer-readable storage medium of claim 23 , wherein the instructions cause the imaging system to capture a first subset of the plurality of images concurrently at a first time point and to capture a second subset of the plurality images concurrently at a second time point, other than the first time point.

26. The computer-readable storage medium according to claim 22 , wherein the instructions for performing the spectral analysis cause the electronic device to:

resolve absorption signals at each respective point in the plurality of points;

account for a melanin contribution and loss of signal from diffuse scattering at each respective point in the plurality of points, to form a plurality of corrected absorption signals; and

determine approximate values of oxyhemoglobin levels and deoxyhemoglobin levels from the corrected absorption signals at each respective point in the plurality of points.

27. The computer-readable storage medium of claim 26 , wherein the contribution provided by melanin and the losses provided by diffuse scattering to the plurality of tissue oxygenation measurements are collectively modeled as a second order polynomial.

28. The computer-readable storage medium according to claim 22 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, wherein the set of eight spectral bands have central wavelengths of:

(i) 510±3 nm, 530±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 620±3 nm, and 660±3 nm;

(ii) 520±3 nm, 540±3 nm, 560±3 nm, 580±3 nm, 590±3 nm, 610±3 nm, 620±3 nm, and 640±3 nm; or

(iii) 500±3 nm, 530±3 nm, 545±3 nm, 570±3 nm, 585±3 nm, 600±3 nm, 615±3 nm, and 640±3 nm.

29. The computer-readable storage medium according to claim 22 , wherein the predetermined set of eight to twelve spectral bands consists of a set of eight spectral bands, wherein the set of eight spectral bands have central wavelengths of:

(i) 510 nm, 530 nm, 540 nm, 560 nm, 580 nm, 590 nm, 620 nm, and 660 nm;

(ii) 520 nm, 540 nm, 560 nm, 580 nm, 590 nm, 610 nm, 620 nm, and 640 nm; or

(iii) 500 nm, 530 nm, 545 nm, 570 nm, 585 nm, 600 nm, 615 nm, and 640 nm.

30. The computer-readable storage medium according to claim 22 , wherein each respective spectral band in the eight to twelve spectral bands has a full width at half maximum of less than 5 nm.