DETECTION OF BLOOD-VESSEL WALL ARTIFACTS

• US 20130324840A1
• Filed: 10/05/2011
• Published: 12/05/2013
• Est. Priority Date: 10/08/2010
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Clayton M. Young
• Inventors: Young, Clayton M., Hatib, Feras, Zhongping, Jian
• Granted Patent: US 9,492,090 B2
• Time in Patent Office: Days
• US Class Current: 600/424
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/027 using catheters
• CPC Class Codes: A61B 5/065 Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/6886 Monitoring or controlling distance between sensor and tissue
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61M 25/01 Introducing, guiding, advancing, emplacing or holding catheters A61M25/10 takes precedence

Abstract

The present application concerns detecting catheter proximity to a blood-vessel wall and blood-vessel wall artifacts associated therewith. In one embodiment, a light source, in a catheter, can be used to project light into the blood vessel. An intensity associated with at least one light wavelength that interacted with blood can be measured. Based on the measured intensity, a determination can be made regarding blood-vessel wall artifacts due to the catheter tip proximity to a blood-vessel wall. Feedback can be provided to the clinician in order to assist the clinician in adjusting the catheter to optimize signal quality and minimize artifacts due to the blood-vessel wall.

Claims

1. A method of detecting catheter proximity to a blood-vessel wall, comprising:

projecting light from a catheter into a blood vessel;

measuring an intensity of at least one wavelength associated with the projected light; and

based on the measured intensity, detecting blood-vessel wall artifacts due to catheter proximity to a blood-vessel wall.

2. The method of claim 1, wherein the detecting blood-vessel wall artifacts includes comparing the measured intensity to a predetermined threshold for the at least one wavelength, and if the intensity exceeds the predetermined threshold, outputting an indicator that signal quality is low due to the catheter placement.

3. The method of claim 1, wherein the at least one wavelength is a first wavelength and the method further includes measuring the intensity of a second wavelength and calculating a ratio of the intensity measurements of the first and second wavelengths.

4. The method of claim 1, wherein detecting blood-vessel wall artifacts includes comparing a quantity derived from the measured intensity for at least one wavelength to a predetermined threshold

5. The method of claim 1, wherein detecting blood-vessel wall artifacts includes the measured intensities for multiple wavelengths and assessment of patterns related to the measured intensities.

6. The method of claim 5 wherein the assessment of patterns related to the measured intensities includes pattern recognition, edge detection, contour analysis and analysis of spectral morphological changes.

7. The method of claim 6 wherein the edge detection includes measured intensities in the range of 400 to 700 nm

8. The method of claim 1, further including receiving the at least one wavelength and filtering the at least one wavelength to attenuate background and random noise.

9. The method of claim 1, wherein the catheter includes a transmit optical fiber and a receive optical fiber.

10. The method of claim 1, further including indicating to a clinician that the artifacts due to catheter proximity to a blood-vessel wall have exceeded a threshold.

11. The method of claim 1, wherein measuring the intensity includes receiving at least one light wavelength from a receive optical fiber and using a photodetector to capture electromagnetic energy associated therewith.

12. The method of claim 1, further including determining proximity of a catheter tip to the blood-vessel wall.

13. A computer-readable storage medium having instructions thereon to implement the method of claim 1.

14. A method of detecting catheter proximity to a blood-vessel wall, comprising:

receiving an intensity of light associated with at least one wavelength;

detecting blood-vessel wall artifacts using the received intensity; and

setting an indicator if the blood-vessel wall artifacts exceed a predetermined threshold indicating that a catheter tip is too close to a blood-vessel wall.

15. The method of claim 14, further including determining a distance of the catheter tip to the blood-vessel wall.

16. The method of claim 14, wherein setting an indicator includes outputting a visual or audio signal to a clinician.

17. The method of claim 14, further including projecting light through a transmit optical fiber in a catheter during catherization and receiving the light after it interacts with blood through a receive optical fiber.

18. The method of claim 17, wherein interaction of the light with the blood includes transmission, reflection and scattering of light waves.

19. The method of claim 14, further including using photodetectors to measure the intensity of the light.

20. The method of claim 14, the at least one wavelength is a first wavelength and the method further includes receiving the intensity of a second wavelength and calculating a ratio of the received intensities.

21. An apparatus for detection of a blood-vessel wall artifacts, comprising:

a catheter including a transmit optical fiber and a receive optical fiber;

a light source coupled to the transmit optical fiber for transmitting light into blood;

one or more photodetectors coupled to the receive optical fiber for receiving the light after it interacts with the blood; and

a controller coupled to the one or more photodetectors for receiving an intensity measurement of one or more lightwaves and for detecting a level of blood-vessel wall artifacts based on the intensity.

22. The apparatus of claim 21, wherein the light source includes one or more LEDs.

23. The apparatus of claim 21, further including an output device coupled to the controller for providing a visual or audio signal to a clinician based on the calculated proximity.

24. The apparatus of claim 21, wherein the controller dynamically and interactively modifies a visual or audio output signal as a clinician moves the catheter with a blood vessel.