FRACTIONAL FLOW RESERVE (FFR) INDEX WITH ADAPTIVE BOUNDARY CONDITION PARAMETERS

• US 20150112191A1
• Filed: 10/22/2013
• Published: 04/23/2015
• Est. Priority Date: 10/22/2013
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: GILBOA, Guy, LAMASH, Yechiel, GOSHEN, Liran
• Granted Patent: US 10,595,806 B2
• Time in Patent Office: Days
• US Class Current: 600/425
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 6/03 Computed tomography [CT] echo-tomography A61B8/14
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/5217 extracting a diagnostic or physiological parameter from medical diagnostic data
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

A method includes obtaining a boundary condition estimate. The boundary condition estimate includes at least an estimated outlet resistance of a vessel with a stenosis. The method further includes correcting the boundary condition estimate based on a severity of the stenosis, thereby creating a corrected boundary condition. The method further includes determining an FFR index based on the corrected boundary condition. The method further includes displaying the FFR index. A computing system includes a computer readable storage medium with instructions that iteratively determine at least an FFR index based on a severity of a stenosis of a vessel. The computing system further includes a computer processor that processes the instructions and generates the FFR index based on the severity of the stenosis of the vessel.

Claims

1. A method, comprising:

obtaining a boundary condition estimate, wherein the boundary condition estimate includes at least an estimated outlet resistance of a vessel with a stenosis;

correcting the boundary condition estimate based on a severity of the stenosis, thereby creating a corrected boundary condition;

determining an FFR index based on the corrected boundary condition; and

displaying the FFR index.

2. The method of claim 1, further comprising:

correcting the boundary condition estimate using an iterative correction.

3. The method of claim 2, the correcting, comprising:

generating a first corrected boundary condition based on the boundary condition estimate and a correction factor, wherein the correction factor is a function of an FFR of a previous iteration;

performing a first CFD simulation using the first corrected boundary condition; and

generating a first FFR index based a result of the first CFD simulation.

4. The method of claim 3, wherein the correction factor is one of a function or a look up table.

5. The method of claim 3, wherein the correction factor is defined for all 0<

FFR<

=1.

6. The method of claim 3, wherein the correction factor monotonically decreases.

7. The method of claim 3, wherein, for a first iteration, the FFR of the previous iteration is a predetermined initial condition with a value of 1.

8. The method of claim 7, further comprising:

comparing the first FFR index with the value of 1;

performing a second iteration in response to a difference between the first FFR index and the value of 1 is greater than a predetermined threshold value.

9. The method of claim 3, wherein, for a subsequent iteration, the FFR of the previous iteration is the FFR for the immediately preceding iteration.

10. The method of claim 9, further comprising:

comparing the first FFR index with the FFR for the immediately preceding iteration;

performing a second iteration in response to a first difference between the first FFR index and the FFR for the immediately preceding iteration is greater than a predetermined threshold value.

11. The method of claim 10, further comprising:

generating a second corrected boundary condition based on the first corrected boundary condition and the correction factor;

performing a second CFD simulation using the second corrected boundary condition; and

generating a second FFR index based a result of the second CFD simulation.

12. The method of claim 11, further comprising:

comparing the second FFR index with the first FFR;

performing a third iteration in response to a second difference between the second FFR index and the first FFR being greater than the predetermined threshold value.

13. The method of claim 11, further comprising:

setting the FFR index equal to the first FFR index in response to the difference between the first FFR index and the FFR for the immediately preceding iteration satisfying the predetermined threshold value.

14. The method of claim 1, further comprising:

estimating the boundary condition estimate based on a geometry of the vessel and flow parameter of the vessel.

15. A computing system, comprising:

a computer readable storage medium with instructions that iteratively determine at least an FFR index based on a severity of a stenosis of a vessel; and

a computer processor that processes the instructions and generates the FFR index based on the severity of the stenosis of the vessel.

16. The computing system of claim 15, wherein the computer processor estimates a boundary condition estimate that includes an estimated outlet resistance of the vessel with the stenosis, corrects the boundary condition estimate based on the severity of the stenosis, and determines the FFR index based on the corrected boundary condition.

17. The computing system of claim 16, wherein the computer processor corrects the boundary condition estimate based on previously determined FFR index.

18. The computing system of claim 17, wherein, for a first iteration, the previously determined FFR index is a predetermined initial condition.

19. The computing system of claim 18, wherein the predetermined initial condition assumes the vessel is healthy and does not include the stenosis.

20. The computing system of claim 17, wherein, for a second or subsequent iteration, the previously determined FFR index is a FFR index determined in the immediately preceding iteration.

21. The computing system of claim 17, wherein the previously determined FFR index indicates the severity of the stenosis of the vessel.

22. The computing system of claim 17, wherein the processor generates a first corrected boundary condition based on the boundary condition and a correction factor, performs a first CFD simulation using the first corrected boundary condition;

and generates a first FFR index based a result of the first CFD simulation.

23. The computing system of claim 22, wherein the processor generates a second corrected boundary condition based on the first corrected boundary condition and the correction factor, performs a second CFD simulation using the second corrected boundary condition;

and generates a second FFR index based a result of the second CFD simulation.

24. The computing system of claim 22, wherein the correction factor is a function of the previously determined FFR index.

25. A computer readable storage medium encoded with computer readable instructions, which, when executed by a processor of a computing system, causes the processor to:

estimate an outlet resistance boundary condition estimate for a vessel with a stenosis based on a geometry of the vessel and a flow parameter of the vessel;

iteratively correct the boundary condition estimate based on a severity of the stenosis; and

determine an FFR index based on the corrected boundary condition.