Optical central venous pressure measurement

Patent metadata

Field	Value
Publication number	US-10080528-B2
Application number	US-201514715793-A
Country	US
Kind code	B2
Filing date	May 19, 2015
Priority date	May 19, 2015
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

This document describes optical central venous pressure measurement. To determine the central venous pressure (CVP) of a person optically, video of a right side of the person's neck is captured. By way of example, a medical professional records a video of the right side of the person's neck using a smartphone. The right side of the person's neck is captured because it is where the person's external and internal jugular veins are located and pulsatile motions that are usable to measure CVP occur in those veins. The video is then processed according to video motion amplification techniques to generate a reconstructed video of the right side of the person's neck. In the reconstructed video, the pulsatile motion of the person's venous system that occurs at the right side of their neck is visually amplified. Using the reconstructed video, measurements are made of a distance between a peak of the visually-amplified pulsatile motion and an anatomical feature of the person. The measured distance between the peak of the visually-amplified pulsatile motion and the anatomical feature is used to determine CVP of the person. These techniques enable CVP to be determined without relying on estimates made by medical professionals.

First claim

What is claimed is:

1. A method for outputting a central venous pressure (CVP) of a person computed by at least one computing device, the method comprising:
generating, by the at least one computing device and using a camera associated with the at least one computing device, a video of the person raising their hands;
generating, by the at least one computing device, a reconstructed video in which motion that results from at least one of veins collapsing in the person's arms or a change in pulse is amplified based on detection of the collapsing of veins in the person's arms or the change in the person's pulse at different spatial frequency bands by processing the video according to one or more video motion amplification techniques;
measuring, by the at least one computing device, an angle and height of the raised hands, relative to the person's heart, in the reconstructed video at a time that corresponds to the collapsing of the veins or the change in pulse;
computing, by the at least one computing device, the CVP of the person based on the measured angle and height of the raised hands; and
outputting, by the at least one computing device, digital content indicative of the computed CVP.

2. The method as described in claim 1 , wherein:
the motion that results from the at least one of the collapsing of veins in the person's arms or the change in pulse in the video of the person raising their hands is visually imperceptible to an unaided human eye; and
the motion that results from the at least one of the collapsing of veins in the person's arms or the change in pulse in the reconstructed video is visually perceptible by the unaided human eye.

3. The method as described in claim 1 , wherein processing the video according to one or more video motion amplification techniques to generate the reconstructed video includes, by the at least one computing device:
spatially decomposing the captured video into different spatial frequency bands;
applying temporal filters to filter for the pulsatile motion at the different spatial frequency bands; and
visually amplifying the motion that results from the at least one of the collapsing of veins in the person's arms or the change in pulse based in part on the different spatial frequency bands in which the motion is observed.

4. The method as described in claim 1 , further comprising generating a user interface to present the digital content indicative of the computed CVP on a display device.

5. The method as described in claim 1 , further comprising:
comparing the CVP to one or more previously computed CVPs, the one or more previously computed CVPs having each been determined by performing the generating, the measuring, and the computing for a respective previously generated video; and
determining a trend in cardiovascular health of the person based on results of comparing the CVP to the one or more previously-determined CVPs.

6. The method as described in claim 1 , further comprising:
generating, by the at least one computing device and using the camera associated with the at least one computing device, another video that includes the person's neck;
generating, by the at least one computing device, another reconstructed video in which pulsatile motion of the person's venous system that occurs in the person's neck is amplified based on detection of the pulsatile motion at different spatial frequency bands by processing the other video according to the one or more video motion amplification techniques;
calculating, by the at least one computing device, a distance between a detected peak of the amplified pulsatile motion and a selected anatomical feature of the person; and
computing, by the at least one computing device, another CVP of the person based on the calculated distance for the amplified pulsatile motion.

7. The method as described in claim 6 , wherein the selected anatomical feature corresponds to a mandibular angle of the person or an ear lobe of the person.

8. The method as described in claim 6 , further comprising determining the selected anatomical feature relative to which to measure the distance based in part on the person's anatomical features that remain visible in the reconstructed video when the distance is calculated.

9. The method as described in claim 6 , further comprising:
analyzing the reconstructed video by the at least one computing device to determine a breathing rate of the person; and
performing the calculating during respiratory pauses of the determined breathing rate.

10. A device comprising:
a video camera to capture video of a person raising their hands;
a display device to display a reconstructed video of the person raising their hands; and
a processing system to implement a central venous pressure (CVP) measurement manager configured to:
generate the reconstructed video in which motion that results from at least one of veins collapsing in the person's arms or a change in pulse is amplified based on detection of the collapsing of veins in the person's arms or the change in the person's pulse at different spatial frequency bands by processing the video according to one or more video motion amplification techniques;
measure an angle and height of the raised hands, relative to the person's heart, in the reconstructed video at a time that corresponds to the collapsing of veins or the change in pulse;
compute CVP measurements for the person based on the measured angle and height of the raised hands; and
present digital content indicative of the CVP measurements.

11. The device as described in claim 10 , further comprising storage media configured to store CVP measurements that are determined at different times for access by the CVP-measurement manager to determine a trend in cardiovascular health of the person based on a comparison of the stored CVP measurements.

12. The device as described in claim 10 , wherein:
the device is configured as a smartphone; and
an application embodied on the smartphone enables a user to initiate the CVP-measurement manager to determine the CVP measurements of the person.

13. The device as described in claim 10 , further comprising one or more hyperspectral cameras, the CVP-measurement manager being further configured to locate the collapsing veins of the person using at least one of images or videos captured with the one or more hyperspectral cameras, and process the captured video by applying the one or more video motion amplification techniques to the portions of the video that correspond to the located veins.

14. The device as described in claim 10 , wherein:
the motion that results from the at least one of the collapsing of veins in the person's arms or the change in pulse is visually imperceptible to an unaided human eye; and
the motion that results from the at least one of the collapsing of veins in the person's arms or the change in pulse is visually perceptible by the unaided human eye in the reconstructed video.

15. The device as described in claim 14 , further comprising at least one of:
one or more lasers employed by the CVP-measurement manager to detect the motions that result from the at least one of the collapsing of veins in the person's arms or the change in pulse; or
one or more light emitting devices that emit structured light and are employed by the CVP-measurement manager to detect the motions that result from the at least one of the collapsing of veins in the person's arms or the change in pulse.

16. The device as described in claim 10 , wherein
the video camera captures another video that includes the person's neck; and
the CVP-measurement m

Assignees

• Google Inc
• Google Llc

Inventors

• Debusschere Brian Derek
• Reid James Moad
• Rogers Jeffrey L

Classifications

• A61B5/02125

  of pulse wave propagation time · CPC title

• A61B5/0205

  Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition · CPC title

• A61B5/0059 Primary

  using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455) · CPC title

• A61B5/1072

  measuring distances on the body, e.g. measuring length, height or thickness (A61B5/1076 takes precedence) · CPC title

• A61B5/0077 Primary

  Devices for viewing the surface of the body, e.g. camera, magnifying lens · CPC title