IP Library › Granted Patent US 12,622,613
Granted Patent B2
US 12,622,613 · App. 18/547,198 · Granted May 12, 2026

Remote monitoring of oxygenation status and blood pulsation within skin tissue

Inventors: Ruikang K. Wang (Seattle, WA); Qinghau He (Seattle, WA)
Assignee: University of Washington
A61B5/14551A61B5/02427A61B5/6898A61B5/7225A61B5/742G06T7/0012G06T7/70G06T7/90G06T2207/10016G06T2207/10024G06T2207/30088
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Quick Facts
Patent No.
US 12,622,613
App. No.
18/547,198
Granted
May 12, 2026
Kind
B2
Abstract

A method of measuring blood oxygenation including acquiring one or more images of a portion of a body with an RGB camera, converting RGB colors in the one or more images into a multispectral data imaging cube, wherein the multispectral date imaging cube comprises a red channel, a blue channel, and a green channel, decoupling an oxygenated blood information and a deoxygenated blood information from the multispectral data imaging cube based on a first reflectance of the green channel and a second reflectance of the red channel, and determining a blood measurement based on the oxygenated blood information and the deoxygenated blood information.

Claims (158)

1 . A method of measuring blood oxygenation comprising:

acquiring one or more images of a portion of a body with an RGB camera;

converting RGB colors in the one or more images into a multispectral data imaging cube, wherein the multispectral data imaging cube comprises a red channel, a blue channel, and a green channel;

decoupling an oxygenated blood information and a deoxygenated blood information from the multispectral data imaging cube based on a first reflectance of the green channel and a second reflectance of the red channel, wherein decoupling the oxygenated blood information and the deoxygenated blood information comprises:

recording the first reflectance at the green channel and the second reflectance the red channel;

calculating a ratio of ratios from the first reflectance of the green channel and the second reflectance of the red channel, wherein the ratio of ratios is determined as:

R

=

ε

Hb

(

λ

1

)

+

[

ε

HbO

2

(

λ

1

)

-

ε

Hb

(

λ

1

)

]

⁢

SO

2

ε

Hb

(

λ

2

)

+

[

ε

HbO

2

(

λ

2

)

-

ε

Hb

(

λ

2

)

]

⁢

SO

2

where ε Hb is an extinction coefficient of the deoxygenated blood,

ε HbO 2 , is an extinction coefficient of the oxygenated blood,

λ 1 is a first wavelength;

λ 2 is a second wavelength, and

SO 2 is an oxygen saturation; and

measuring an average gray value of the red channel, green channel, and blue channel, wherein the average gray value is the sum of the gray values of all the pixels in the image divided by the number of pixels; and

determining a blood measurement based on the oxygenated blood information and the deoxygenated blood information.

2 . The method of claim 1 , wherein the multispectral data imaging cube represents spectral information at wavelengths of 450, 500, 550, 600, 650 and 700 nm.

3 . The method of claim 1 , wherein determining the blood measurement comprises applying a multiple linear regression algorithm to the oxygenated blood information and the deoxygenated blood information based on the calculated ratio of ratios and the averaged gray values of the red channel, green channel, and blue channel.

4 . The method of claim 1 , wherein the blood measurement is a set of blood pulsation amplitudes, a set of blood pulsation phases, or both.

5 . The method of claim 4 , wherein obtaining the set of blood pulsation amplitudes further comprises applying a window-based lock-in amplification to the oxygenated blood information and the deoxygenated blood information.

6 . The method of claim 1 , wherein the RGB camera is on a communication device.

7 . The method of claim 6 , wherein the communication device is a smartphone.

8 . The method of claim 7 , wherein the method further comprises displaying the blood measurement on a second communication device.

9 . The method of claim 1 , wherein the method further includes illuminating the portion of the body with a light source while acquiring the one or more images of the portion of the body.

10 . The method of claim 9 , wherein the light source is on communication device.

11 . The method of claim 1 , wherein the method further comprises calibrating the RGB camera with a Weiner estimation method and a color-checker.

12 . The method of claim 1 , wherein the method further comprises taking the oxygenated blood information and the deoxygenated blood information from a first region of a body and a second region of a body in an image.

13 . The method of claim 1 , wherein the one or more images comprise a video.

14 . A method of measuring blood oxygenation comprising:

acquiring one or more images of a portion of a body with an RGB camera;

converting RGB colors in the one or more images into a multispectral data imaging cube, wherein the multispectral data imaging cube comprises a red channel, a blue channel, and a green channel;

decoupling an oxygenated blood information and a deoxygenated blood information from the multispectral data imaging cube based on a first reflectance of the green channel and a second reflectance of the red channel, and

performing bilateral asymmetry analysis on the oxygenated blood information and the deoxygenated blood information of both the first region of the body and the second region of the body, wherein performing bilateral asymmetry analysis comprises:

generating a phase map and an amplitude map; and

regionally extracting a first pulse signal from the first region of the body, and a second pulse signal from the second region of the body.

15 . The method of claim 14 , wherein generating the phase map and the amplitude map comprises:

filtering the first pulse signal and the second pulse signal with one or more heartbeat frequencies to generate a filtered signal; and

using the filtered signal as a reference function to extract and amplify the first pulse signal and the second pulse signal with the same frequency as the filtered signal at each voxel of the image.

16 . The method of claim 14 , wherein the first region of the body comprises bilateral carotid regions of a neck and the second region of the body comprises bilateral jugular regions of a neck.

17 . The method of claim 16 , wherein the first pulse signal comprises a carotid pulse, and the second pulse signal comprises a jugular vein pulse.

18 . A computer-implemented method comprising:

acquiring one or more images of a portion of a body with an RGB camera;

converting RGB colors in the one or more images into a multispectral data imaging cube, wherein the multispectral date imaging cube comprises a red channel, a blue channel, and a green channel;

decoupling an oxygenated blood information and a deoxygenated blood information from the multispectral data imaging cube based on a first reflectance of the green channel and a second reflectance of the red channel, wherein decoupling the oxygenated blood information and the deoxygenated blood information comprises:

recording the first reflectance at the green channel and the second reflectance the red channel;

calculating a ratio of ratios from the first reflectance of the green channel and the second reflectance of the red channel, wherein the ratio of ratios is determined as:

R

=

ε

Hb

(

λ

1

)

+

[

ε

HbO

2

(

λ

1

)

-

ε

Hb

(

λ

1

)

]

⁢

SO

2

ε

Hb

(

λ

2

)

+

[

ε

HbO

2

(

λ

2

)

-

ε

Hb

(

λ

2

)

]

⁢

SO

2

where ε Hb is an extinction coefficient of the deoxygenated blood,

ε HbO 2 is an extinction coefficient of the oxygenated blood,

λ 1 is a first wavelength;

μ 2 is a second wavelength, and

SO 2 is an oxygen saturation; and

measuring an average gray value of the red channel, green channel, and blue channel, wherein the average gray value is the sum of the gray values of all the pixels in the image divided by the number of pixels; and

determining a blood measurement based on the oxygenated blood information and the deoxygenated blood information.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 21, 2023
From: WANG, RUIKANG K.; HE, QINGHAU
To: UNIVERSITY OF WASHINGTON
Reel/Frame 064647/0885 →
Continuity (2)
Provisional Application 63154100 · Feb 26, 2021
Related Publication 20240148289A1 · May 9, 2024
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