Systems and methods for video-based monitoring of vital signs

Patent metadata

Field	Value
Publication number	US-12016674-B2
Application number	US-202217662544-A
Country	US
Kind code	B2
Filing date	May 9, 2022
Priority date	Feb 19, 2016
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

The present invention relates to the field of medical monitoring, and in particular non-contact, video-based monitoring of pulse rate, respiration rate, motion, and oxygen saturation. Systems and methods are described for capturing images of a patient, producing intensity signals from the images, filtering those signals to focus on a physiologic component, and measuring a vital sign from the filtered signals. Examples include flood fill methods and skin tone filtering methods.

First claim

What is claimed is:

1. A video-based patient monitoring system configured for measuring a patient's vital sign, comprising:
a video camera configured to transmit a video signal having a field of view;
a processor operatively connected with the video camera, the processor being programmed with computer readable instructions that, when executed, cause the processor to:
receive the video signal from the video camera;
identify a first seed point in the field of view;
flood fill in the video signal a first contiguous region from the first seed point to a boundary;
extract a first intensity signal from the first contiguous region;
measure a vital sign from the first intensity signal; and
dynamically update the contiguous region over time, including tracking the first seed point and updating the first contiguous region to create a dynamically morphing contiguous region.

2. The video-based patient monitoring system of claim 1 , further comprising:
a display operatively connected with the video camera and the processor, the display being configured to display the video signal, the contiguous region, a number derived from the measured vital sign, or any combination thereof.

3. The video-based patient monitoring system of claim 1 , wherein flood filling the contiguous region comprises identifying, adjacent the first seed point, neighboring pixels or regions that share a common characteristic with the first seed point, until the boundary is reached.

4. The video-based patient monitoring system of claim 1 , wherein identifying the first seed point comprises recognizing a facial feature and locating the first seed point relative to the recognized facial feature.

5. The video-based patient monitoring system of claim 1 , wherein extracting the intensity signal comprises extracting two time-varying color signals, and wherein measuring the vital sign comprises measuring oxygen saturation from the two time-varying color signals.

6. The video-based patient monitoring system of claim 1 , wherein identifying the first seed point comprises receiving a user input locating the first seed point.

7. The video-based patient monitoring system of claim 1 , wherein the vital sign comprises pulse rate, and wherein measuring the vital sign comprises identifying a frequency content of the intensity signal, and measuring the pulse rate from the frequency content.

8. The video-based patient monitoring system of claim 1 , wherein the first seed point comprises a dynamic seed point, and wherein dynamically updating comprises re-generating the contiguous region from the dynamic seed point at a regular time interval.

9. The video-based patient monitoring system of claim 1 , wherein the first seed point comprises a dynamic seed point, and wherein dynamically updating comprises re-generating the contiguous region as the dynamic seed point moves within the image frame.

10. The video-based patient monitoring system of claim 1 , wherein the processor is further programmed with computer readable instructions that, when executed, cause the processor to:
identify a second seed point on the patient;
flood fill a second contiguous region from the second seed point;
utilize the second contiguous region to extract a second intensity signal; and
measure a second vital sign from the second intensity signal.

11. The video-based patient monitoring system of claim 10 , wherein the first vital sign comprises pulse rate and the second vital sign comprises SpO2.

12. The video-based patient monitoring system of claim 10 , wherein the first and second vital signs are both measurements of pulse rate, and further comprising outputting the first vital sign, or the second vital sign, or a combination of both.

13. A video-based patient monitoring system configured for measuring a patient's vital sign, comprising:
a video camera configured to transmit a video signal having a field of view;
a display;
a processor operatively connected with the video camera and the display, the processor being programmed with computer readable instructions that, when executed, cause the processor to:
receive the video signal from the video camera;
identify a first seed point in the field of view;
flood fill a first contiguous region from the first seed point to a boundary;
utilize the first contiguous region to identify a target region that is fully contained within the first contiguous region, wherein the target region defines a perimeter that excludes edges of the first contiguous region;
extract a first intensity signal from the target region;
measure a vital sign from the first intensity signal;
display a number derived from the measured vital sign; and
dynamically update the contiguous region over time, including tracking the first seed point and updating the flood field to create a dynamically morphing contiguous region.

14. The video-based patient monitoring system of claim 13 , wherein flood filling the contiguous region comprises identifying, adjacent the first seed point, neighboring pixels or regions that share a common characteristic with the first seed point, until the boundary is reached.

15. The video-based patient monitoring system of claim 13 , wherein identifying the first seed point comprises recognizing a facial feature and locating the first seed point relative to the recognized facial feature or receiving a user input locating the first seed point.

16. The video-based patient monitoring system of claim 13 , wherein extracting the first intensity signal comprises extracting two time-varying color signals, and wherein measuring the vital sign comprises measuring oxygen saturation from the two time-varying color signals.

17. The video-based patient monitoring system of claim 13 , wherein utilizing the first contiguous region to identify the target region comprises determining a range of color or intensity values within the contiguous region, setting a skin tone filter with the range, and applying the skin tone filter to the video signal, and wherein the skin tone filter outputs the target region.

18. The video-based patient monitoring system of claim 13 , wherein the vital sign comprises pulse rate, and wherein measuring the vital sign comprises identifying a frequency content of the intensity signal, and measuring the pulse rate from the frequency content.

19. The video-based patient monitoring system of claim 13 , wherein the first seed point comprises a dynamic seed point, and wherein dynamically updating comprises regenerating the contiguous region from the dynamic seed point at a regular time interval.

20. The video-based patient monitoring system of claim 13 , wherein the first seed point comprises a dynamic seed point, and wherein dynamically updating comprises regenerating the contiguous region as the dynamic seed point moves within the image frame.

Assignees

• Covidien Lp

Inventors

• Jacquel Dominique
• Addison Paul Stanley
• Foo David

Classifications

• A61B5/7425

  Displaying combinations of multiple images regardless of image source, e.g. displaying a reference anatomical image with a live image · CPC title

• A61B5/7203

  for noise prevention, reduction or removal · CPC title

• A61B5/6843

  Monitoring or controlling sensor contact pressure · CPC title

• A61B5/14542

  for measuring blood gases (A61B5/14551 takes precedence) · CPC title

• A61B5/0816

  Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00) · CPC title