Method and apparatus for fractional flow reserve measurements

• US 9,615,755 B2
• Filed: 04/13/2016
• Issued: 04/11/2017
• Est. Priority Date: 06/27/2011
• Status: Active Grant

• Current Assignee: Bayer Healthcare LLC (Bayer AG)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Riley, Michael A., Spohn, Michael A., Callan, Gerald W.
• Primary Examiner(s): Peng, Bo J
• Application Number:
  US15/097,846
• Publication Number:
  US 20160220126A1
• Time in Patent Office: 363 Days
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02158 provided with two or more sensor elements
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: A61M 2025/0002 with a pressure sensor at the distal end
• CPC Class Codes: A61M 2025/0183 Rapid exchange or monorail catheters
• CPC Class Codes: A61M 25/00 Catheters; Hollow probes dilators A61M29/00; peritoneal catheters A61M1/285; tracheal tubes A61M16/04; for drainage A61M27/00; for uterus, vagina or rectum A61M31/00 ; for measuring or testing A61B; materials for catheters A61L29/00
• CPC Class Codes: A61M 5/007 for contrast media

Abstract

A method of determining fractional flow reserve (FFR) in a blood vessel having stenosis includes injecting fluid into the blood vessel upstream of the stenosis using a power fluid injector, measuring pressure drop across the stenosis, and calculating FFR from measured pressure drop. The injected fluid may comprise a contrast medium. Further action may include placing a pressure sensor proximal of the stenosis, injecting fluid into the blood vessel upstream of the stenosis using the power fluid injector, and measuring pressure in the blood vessel proximal of the stenosis. The pressure sensor may then be repositioned to a position distal of the stenosis, fluid may be reinjected into the blood vessel upstream of the stenosis using the power fluid injector, and pressure may be measured in the blood vessel distal of the stenosis.

Claims

1. A method of determining fractional flow reserve (FFR) in a blood vessel having a stenosis, the method comprising:

injecting a fluid with a fluid delivery system into the blood vessel upstream of the stenosis using a power fluid injector;

measuring a pressure drop across the stenosis with the fluid delivery system during injection of the fluid with the power fluid injector;

reducing or discontinuing injecting the fluid when retrograde flow is present in the blood vessel; and

calculating FFR from the measured pressure drop.

2. The method of claim 1, wherein the injected fluid comprises a contrast medium.

3. The method of claim 1, wherein measuring the pressure drop comprises placing a pressure sensor proximal of the stenosis.

4. The method of claim 3, wherein measuring the pressure drop further comprises:

repositioning the pressure sensor to a position distal of the stenosis;

repeating the injecting the fluid into the blood vessel upstream of the stenosis using the power fluid injector; and

measuring a pressure in the blood vessel distal of the stenosis.

5. The method of claim 4, wherein repeating the injecting the fluid into the blood vessel is reduced or discontinued when retrograde flow is present in the blood vessel.

6. The method of claim 4, wherein repeating the injecting the fluid into the blood vessel is reduced or discontinued after a preset period of time.

7. The method of claim 4, wherein measuring the pressure drop across the stenosis comprises calculating a ratio of a distal pressure to a proximal pressure in the blood vessel.

8. The method of claim 1, wherein injecting the fluid into the blood vessel is reduced or discontinued after a preset period of time.

9. The method of claim 1, further comprising displaying the FFR on a user interface display associated with the power fluid injector.

10. The method of claim 1, further comprising measuring a pressure in the blood vessel upstream of the stenosis during injection of the fluid with the power fluid injector.

11. The method of claim 1, further comprising measuring the pressure drop across the stenosis with the fluid delivery system based on the flow rate during injection of the fluid with the power fluid injector.

12. The method of claim 1, wherein measuring the pressure drop comprises placing a first pressure sensor proximal of the stenosis and a second pressure sensor distal of the stenosis.

13. The method of claim 12, further comprising taking pressure readings simultaneously using the first pressure sensor and the second pressure sensor.

14. The method of claim 1, further comprising measuring a size of the stenosis with an optical sensor.

15. A method of determining fractional flow reserve (FFR) in a blood vessel having a stenosis, the method comprising:

inserting a multi-lumen catheter into the blood vessel;

injecting a fluid with a fluid delivery system into the blood vessel upstream of the stenosis using a power fluid injector;

measuring a pressure drop across the stenosis with the fluid delivery system during injection of the fluid with the power fluid injector;

reducing or discontinuing injecting the fluid when retrograde flow is present in the blood vessel; and

calculating FFR from the measured pressure drop.

16. The method of claim 15, wherein the injected fluid comprises a contrast medium.

17. The method of claim 15, wherein measuring the pressure drop comprises placing a pressure sensor proximal of the stenosis.

18. The method of claim 17, wherein injecting the fluid into the blood vessel is reduced or discontinued after a preset period of time.

19. The method of claim 17, further comprising measuring a proximal pressure in the blood vessel proximal of the stenosis, wherein measuring the proximal pressure comprises substantially simultaneously measuring pressure using the pressure sensor and a hemodynamic monitoring port on the multi-lumen catheter.

20. The method of claim 17, wherein measuring the pressure drop further comprises:

repositioning the pressure sensor to a position distal of the stenosis;

repeating the injecting the fluid into the blood vessel upstream of the stenosis using the power fluid injector; and

substantially simultaneously measuring a pressure in the blood vessel distal of the stenosis using the pressure sensor and proximal of the stenosis via a hemodynamic monitoring port on the multi-lumen catheter.

21. The method of claim 20, wherein repeating the injecting the fluid into the blood vessel is reduced or discontinued when retrograde flow is present in the blood vessel or after a preset period of time.

22. The method of claim 20, further comprising:

further repositioning the pressure sensor to a position proximal of the stenosis;

repeating the injecting the fluid into the blood vessel upstream of the stenosis using the power fluid injector; and

substantially simultaneously measuring the pressure in the blood vessel proximal of the stenosis using the pressure sensor and the hemodynamic monitoring port on the multi-lumen catheter.

23. The method of claim 15, wherein the multi-lumen catheter comprises at least a fluid injecting lumen and a hemodynamic monitoring lumen.

24. The method of claim 15, wherein measuring the pressure drop comprises placing a first pressure sensor proximal of the stenosis and a second pressure sensor distal of the stenosis.

25. The method of claim 24, further comprising taking pressure readings simultaneously using the first pressure sensor and the second pressure sensor.

26. The method of claim 15, further comprising measuring a size of the stenosis with an optical sensor.