EVALUATION OF PATENCY USING PHOTO-PLETHYSMOGRAPHY ON ENDOSCOPE IMAGES

• US 20150164592A1
• Filed: 06/20/2013
• Published: 06/18/2015
• Est. Priority Date: 06/28/2012
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Elhawary, Haytham, Popovic, Aleksandra, Verkruijsse, Willem
• Granted Patent: US 9,750,575 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 1/0005 combining images e.g. side-by-side, superimposed or tiled
• CPC Class Codes: A61B 2034/301 for introducing or steering flexible instruments inserted into the body, e.g. catheters or endoscopes
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/4851 Prosthesis assessment or monitoring
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence

Abstract

A system for evaluating patency includes a light sensor (128) positionable relative to a blood vessel to receive light from the blood vessel and convert the light into an image signal. Aphoto-plethysmography (PPG) interpretation module (115) is configured to receive the image signal and output pixel values in an image representing PPG information. An image generation module(148) is coupled to the PPG interpretation module to receive the pixel values and generate a PPG map to be output to a display for analysis.

Claims

1. A system for evaluating patency, comprising:

a light source configured to generate light for illuminating a blood vessel;

a light sensor positioned on an endoscope and positionable relative to the blood vessel, the light sensor being configured to receive light from the blood vessel responsive to the generated light and convert the light into an image signal;

a photo-plethysmography (PPG) interpretation module configured to receive the image signal and output pixel values in an image representing PPG information; and

an image generation module coupled to the PPG interpretation module and configured to receive the pixel values and generate a PPG map to be output to a display for analysis.

2. The system as recited in claim 1, wherein the light sensor includes a camera.

4. The system as recited in claim 1, further comprising a robot configured to position the light sensor relative to the blood vessel.

5. The system as recited in claim 1, wherein the light sensor is configured to be positioned at a position relative to the blood vessel at a first time to obtain a first PPG map and is further configured to be positioned in the same position at a second time to obtain a second PPG map, enabling comparison of the first and second PPG map to determine PPG changes in the blood vessel.

6. The system as recited in claim 5, further comprising a robot configured to enable repeatable positioning of the light sensor at different times.

7. The system as recited in claim 1, wherein the image generation module is further configured to generate a subtraction image of the first and second PPG maps from the first and second times.

8. The system as recited in claim 1, wherein the image generation module is further configured to overlay the subtraction image on an image from the image signal provided by the light sensor.

9. The system as recited in claim 1, wherein the image generation module is further configured to overlay the PPG map on an image from the image signal provided by the light sensor.

10. The system as recited in claim 1, wherein the image generation module is further configured to overlay the PPG map on an X-ray image.

11. The system as recited in claim 1, wherein the blood vessel includes a bypass graft and the PPG map indicates blood flow through the graft at different times.

21. The system as recited in claim 1, wherein the light source is positioned on the endoscope.

3. (canceled)

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. A method for evaluating patency, comprising:

positioning a light sensor relative to a blood vessel using an endoscope to receive light from the blood vessel illuminated by a radiation source;

converting the light received from the blood vessel into an image signal;

interpreting the image signal to determine a photo-plethysmography (PPG) signal and outputting pixel values in an image representing PPG information;

generating a PPG map to be output to a display for analysis from the pixel values; and

analyzing at least one PPG map to determine patency of the blood vessel.

17. The method as recited in claim 16, wherein the light sensor includes a camera mounted on endoscope.

18. The method as recited in claim 16, wherein positioning the light sensor includes positioning the light sensor at a same position at different times to enable determination of respective PPG signals, and comparing the PPG signals to determine PPG changes in the blood vessel, and wherein positioning the light sensor includes employing a robot to permit repeatable positioning of the light sensor at different times.

20. The method as recited in claim 16, further comprising accounting for motion in the blood vessel to register PPG maps, wherein the accounting includes providing a grid overlaid on the image signal of the blood vessel, wherein each portion of the grid includes a tracked point to follow to determine the motion of the blood vessel.

19. (canceled)