METHOD FOR DETERMINING SHEAR STRESS AND VISCOSITY DISTRIBUTION IN A BLOOD VESSEL

• US 20110275936A1
• Filed: 05/07/2010
• Published: 11/10/2011
• Est. Priority Date: 05/07/2010
• Status: Abandoned Application

• Current Assignee: Rheovector LLC
• Original Assignee: Rheovector LLC
• Inventors: Jeong, Seul Ki, Cho, Daniel J.
• Application Number:
  US12/775,983
• Publication Number:
  US 20110275936A1
• Time in Patent Office: Days
• US Class Current: 600/438
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties

Abstract

A method for computing patient specific blood viscosity and patient specific shear stress on a location of interest in the interior of a blood vessel that includes calculating shear rate of blood in the vessel, using imaging techniques and calculating the shear rate related blood viscosity.

Claims

1. A method to determine a value for patient specific blood characteristics at a locus in an interior region of a blood vessel, comprising:

obtaining an electronic image of said blood vessel at an instant, said image including said locus on said interior region of said blood vessel;

obtaining a speed value indicating speed of blood passing said locus on said interior region of said blood vessel at said instant;

measuring an interior dimension of said blood vessel at said locus based on said electronic image; and

determining a value for shear rate of said blood corresponding to said speed value and said interior dimension.

2. The method of claim 1, wherein said instant corresponds to peak systole.

3. The method of claim 1, wherein said instant corresponds to end diastole.

4. The method of claim 1, wherein said interior dimension is a diameter of said blood vessel at said locus.

5. The method of claim 1, wherein said speed value is a maximum velocity of blood.

6. The method of claim 1, wherein said electronic image is obtained by duplex ultrasonography.

7. The method of claim 1, wherein said speed value is obtained by duplex ultrasonography.

8. The method of claim 1, further comprising calculating patient specific blood viscosity at said locus based on said speed value, said dimension of said blood vessel at said locus based on said electronic image, and a measured value for viscosity of said blood.

9. The method of claim 1, further comprising calculating shear stress at said locus based on said speed value, said dimension of said blood vessel at said locus based on said electronic image, and a measured value for viscosity of said blood.

10. The method of claim 1, further comprising obtaining an electronic image of said blood vessel at another instant, said image including said locus on said interior region of said blood vessel;

obtaining another speed value indicating speed of blood passing said locus on said interior region of said blood vessel at said another instant;

measuring an interior dimension of said blood vessel at said locus based on said another electronic image;

determining a value for shear rate of said blood corresponding to said another speed value.

11. The method of claim 10, wherein said instant corresponds to peak systole and said another instant corresponds to end diastole.

12. A method wherein said steps in claim 1 are repeated for different locations along at least a portion of said vessel to obtain a wall shear stress value for all said locations, and further comprising mapping said wall shear stress values along said portion of said vessel.

13. A method wherein said steps in claim 1 are repeated for different locations along at least a portion of said vessel to obtain a blood viscosity value for all said locations, and further comprising mapping said blood viscosity values along said portion of said vessel.

14. A method according to claim 13, further comprising identifying locations that may be prone to plaque growth based on said mapped values.

15. A method according to claim 13, further comprising identifying locations that may be prone to plaque rupture.

16. The method of claim 1, wherein said electronic image is two-dimensional.

17. The method of claim 1, wherein said electronic image is three-dimensional.