Blood pressure measuring method and system

Patent metadata

Field	Value
Publication number	US-9922420-B2
Application number	US-201515100480-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Jun 26, 2015
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A blood pressure measuring method and system. The method includes: obtaining at least one video that captures a first body area and a second body area of a testee; extracting multiple gray scale values for corresponding images that capture the first body area and multiple gray scale values for corresponding images that capture the second body area; drawing a pulse-wave waveform of the first body area based on the multiple gray scale values of the first body area, and drawing a pulse-wave waveform of the second body area based on the multiple gray scale values of the second body area; determining a pulse-wave propagation time based on the pulse-wave waveform of the first body area and the pulse-wave waveform of the second body area; and obtaining a blood pressure value of the testee based on a corresponding relation between the pulse-wave propagation time and blood pressure.

First claim

What is claimed is:

1. A blood pressure measuring method, comprising:
obtaining at least one video that captures a first body area and a second body area of a testee, wherein each video from the at least one video includes a plurality of frames;
extracting, from the frames of the at least one video, a plurality of gray scale values for corresponding images that capture the first body area and a plurality of gray scale values for corresponding images that capture the second body area;
drawing a pulse-wave waveform of the first body area based on the plurality of gray scale values for the corresponding images of the first body area, and drawing a pulse-wave waveform of the second body area based on the plurality of gray scale values for the corresponding images of the second body area;
determining a pulse-wave propagation time based on the pulse-wave waveform of the first body area and the pulse-wave waveform of the second body area; and
obtaining a blood pressure value of the testee based on a corresponding relation between the pulse-wave propagation time and blood pressure,
wherein extracting, from the frames of the at least one video, the plurality of gray scale values for corresponding images that capture the first body area and the plurality of gray scale values for corresponding images that capture the second body area, includes:
identifying the corresponding images of the first body area and the corresponding images of the second body area from frames of the at least one video; and
extracting a plurality of gray scale values of a red channel signal in the corresponding images of the first body a plurality of gray scale values of the red channel signal in the corresponding images of the second body area from the frames of the at least one video.

2. The blood pressure measuring method according to claim 1 , wherein:
the at least one video includes one video; and
obtaining at least one video that captures the first body area and the second body area of the testee includes: filming areas including face and a hand of the testee using an imaging device to generate the video.

3. The blood pressure measuring method according to claim 1 , wherein:
the at least one video includes a first video and a second video; and
obtaining at least one video that captures the first body area and the second body area of the testee includes: filming the first body area of the testee using an imaging device to generate the first video, and simultaneously filming the second body area of the testee using another imaging device to generate the second video.

4. The blood pressure measuring method according to claim 2 , wherein the imaging device is a high-speed camera with an imaging frequency greater than or equal to 100 frames per second.

5. The blood pressure measuring method according to claim 1 , wherein:
the at least one video includes one video; and
extracting, from the frames of the at least one video, the plurality of gray scale values for corresponding images that capture the first body area and the plurality of gray scale values for corresponding images that capture the second body area, further includes:
identifying a corresponding image of the first body area and a corresponding image of the second body area from each frame of the video; and
extracting a gray scale value of the red channel signal in the corresponding image of the first body area and a gray scale value of the red channel signal in the corresponding image of the second body area from each frame of the video.

6. The blood pressure measuring method according to claim 5 , wherein:
each gray scale value of the corresponding image of the first body area is a gray scale value of any test point in the corresponding image of the first body area in one corresponding frame of the video, or a mean value of gray scale values of at least two test points in the corresponding image of the first body area; and
each gray scale value of the corresponding image of the second body area is a gray scale value of any test point in the corresponding image of the second body area in one corresponding frame of the video, or a mean value of gray scale values of at least two test points in the corresponding image of the second body area.

7. The blood pressure measuring method according to claim 1 , wherein:
the at least one video includes a first video and a second video; and
extracting, from the frames of the at least one video, the plurality of gray scale values for corresponding images that capture the first body area and the plurality of gray scale values for corresponding images that capture the second body area, further includes:
identifying a corresponding image of the first body area in each frame of the first video and a corresponding image of the second body area in each frame of the second video; and
extracting a gray scale value of the red channel signal in the corresponding image of the first body area from each frame of the first video and a gray scale value of the red channel signal in the corresponding mage of the second body area from each frame of the second video.

8. The blood pressure measuring method according to claim 7 , wherein:
each gray scale value of the corresponding image of the first body area is a gray scale value of any test point in the corresponding image of the first body area in one corresponding frame of the first video, or a mean value of gray scale values of at least two test points in the corresponding image of the first body area; and
each gray scale value of the corresponding image of the second body area is a gray scale value of any test point in the corresponding image of the second body area in one corresponding frame of the second video, or a mean value of gray scale values of at least two test points in the corresponding image of the second body area.

9. The blood pressure measuring method according to claim 1 , wherein determining the pulse-wave propagation time based on the pulse-wave waveform of the first body area and the pulse-wave waveform of the second body area, includes:
selecting a wave crest in the pulse-wave waveform of the first body area, and selecting another wave crest, which has a shortest time interval to the wave crest, in the pulse-wave waveform of the second body area;
obtaining the time interval between the wave crest and the other wave crest;
obtaining a plurality of time intervals by repeating the above operations for a plurality of times, wherein wave crests in a plurality of successive cycles in the pulse-wave waveform of the first body area are selected in sequence in the repeating process; and
calculating a mean value of the plurality of time intervals as the pulse-wave propagation time.

10. The blood pressure measuring method according to claim 1 , wherein the relation between the pulse-wave propagation time and the blood pressure is as follows:

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Assignees

• Boe Technology Group Co Ltd

Inventors

• Wang Xin
• Han Xuelin
• Jin Xiaoli

Classifications

• G06T7/0016

  involving temporal comparison · CPC title

• G06T7/0012 Primary

  Biomedical image inspection · CPC title

• G06T2207/10016

  Video; Image sequence · CPC title

• G06T2207/30076

  Plethysmography · CPC title

• A61B5/02125

  of pulse wave propagation time · CPC title