OPTICAL FIBER SHAPE SENSING SYSTEMS

• US 20080285909A1
• Filed: 04/18/2008
• Published: 11/20/2008
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Hansen Medical Incorporated (Johnson & Johnson)
• Inventors: Tanner, Neal A., Ramamurthy, Bhaskar S., Younge, Robert G., Schlesinger, Randall L., Udd, Eric
• Granted Patent: US 8,050,523 B2
• Time in Patent Office: Days
• US Class Current: 385/13
• CPC Class Codes: A61B 1/009 with bending or curvature detection of the insertion part
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2017/00053 Mapping
• CPC Class Codes: A61B 2034/2061 using shape-sensors, e.g. fiber shape sensors with Bragg gratings
• CPC Class Codes: A61B 2090/067 for measuring angles
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: G02B 6/022 using mechanical stress, e.g. tuning by compression or elongation, special geometrical shapes such as "dog-bone" or taper G02B6/02204 takes precedence; optical modulation using photo-elastic effect G02F1/0131

Abstract

A medical instrument system includes an elongate flexible instrument body with an optical fiber substantially encapsulated in a wall of the instrument body, the optical fiber including one or more fiber gratings. A detector is operatively coupled to the optical fiber and configured to detect respective light signals reflected by the one or more fiber gratings. A controller is operatively coupled to the detector, and configured to determine a twist of at least a portion of the instrument body based on detected reflected light signals. The instrument may be a guide catheter and may be robotically or manually controlled.

Claims

1. A medical instrument system, comprising:

an elongate flexible instrument body;

an optical fiber substantially encapsulated in a wall of the instrument body, the optical fiber including one or more Bragg gratings;

a detector operatively coupled to the optical fiber and configured to detect respective light signals reflected by the one or more Bragg gratings; and

a controller operatively coupled to the detector and configured to determine a twist of at least a portion of the instrument body based on an analysis of detected reflected light signals.

2. The system of claim 1, wherein the instrument is robotically controlled.

3. The system of claim 1, wherein the instrument is manually controlled.

4. The system of claim 1, wherein the instrument is a guide catheter.

5. The system of claim 1, wherein a portion of the optical fiber having the one or more Bragg gratings forms one or more rosettes, each of the one or more rosettes comprising at least three, non-parallel sides, each side having a respective Bragg grating.

6. The system of claim 5, wherein the one or more rosettes are each triangular in shape.

7. The system of claim 1, wherein the optical fiber comprises multiple fiber cores, each core including one or more Bragg gratings.

8. The system of claim 1, the optical fiber comprising a plurality of spaced-apart Bragg gratings.

9. The system of claim 8, wherein the Bragg gratings are spaced approximately equidistantly along the optical fiber.

10. The system of claim 8, wherein the Bragg gratings are more densely spaced along a distal portion of the optical fiber than along a proximal portion.

11. The system of claim 1, wherein the controller determines the twist of at least a portion of the instrument body based on a change in polarization of the detected reflected light signals.

12. The system of claim 11, wherein the one or more Bragg gratings are polarization dependent.

13. The system of claim 11, wherein the one or more Bragg gratings are polarization independent.

14. The system of claim 11, the optical fiber comprising at least first and second Bragg gratings, and wherein the controller determines the twist of at least a portion of the instrument body based at least in part on a change in polarization of detected portions of the light signals reflected from the first Bragg grating and detected portions of the light signals reflected from the second Bragg grating.

15. The system of claim 1, wherein the controller is operatively coupled to the detector via a wireless communication link.

32. The system of claim 1, wherein the elongate body has a longitudinal axis, and wherein a portion of the optical fiber having the one or more Bragg gratings is coupled to the elongate body at an angle to the longitudinal axis.

33. The system of claim 32, wherein the portion of the optical fiber having the one or more Bragg gratings is coupled to the elongate body substantially orthogonal to the longitudinal axis.

34. The system of claim 33, wherein the portion of the optical fiber having the one or more Bragg gratings is wound around the elongate body.

35. The system of claim 34, wherein the portion of the optical fiber having the one or more Bragg gratings is spirally wound around the elongate body.

16. A medical instrument system, comprising:

A flexible elongate instrument body;

a plurality of optical fibers substantially encapsulated in a wall of the instrument body, each optical fiber including one or more Bragg gratings;

a detector operatively coupled to the respective optical fibers and configured to detect light signals reflected by the respective Bragg gratings; and

a controller operatively coupled to the detector and configured to determine a twist of at least a portion of the instrument body based upon an analysis of detected light signals.

17. The system of claim 16, wherein respective portions of the optical fibers collectively form one or more rosettes, each of the one or more rosettes comprising at least three, non-parallel sides, each side having a respective Bragg grating.

18. The system of claim 17, wherein the one or more rosettes are each triangular in shape.

19. A medical instrument system, comprising:

a flexible elongate instrument body;

a plurality of optical fibers attached to or substantially encapsulated within a wall of the instrument body, each optical fiber including one or more Bragg gratings;

a detector operatively coupled to the respective optical fibers and configured to detect light signals reflected by the respective Bragg gratings; and

a controller operatively coupled to the detector and configured to determine a twist of at least a portion of the instrument body based on detected light signal reflections from Bragg gratings located in the respective optical fibers, and further based on known physical relationships of the optical fibers and instrument body.

20. An instrument system, comprising:

a first elongate body defining an interior lumen and having a distal opening in communication with the lumen;

a second elongate body having a bendable distal end portion, the second elongate body at least partially positioned in the lumen of, and movable relative to, the first elongate body;

an optical fiber including a plurality of spaced apart Bragg gratings, the optical fiber coupled to the second elongate body such that at least one of the Bragg gratings is located in the bendable distal end portion thereof;

a detector operatively coupled to the optical fiber and configured to detect respective light signals reflected by the respective Bragg gratings; and

a controller operatively coupled to the detector and configured to determine a length of the distal end portion of the second elongate body extending out of the distal opening of the first elongate body based on detected reflected light signals.

21. The system of claim 20, wherein the optical fiber comprises multiple fiber cores, each core including a respective plurality of spaced-apart Bragg gratings.

22. The system of claim 21, wherein the first elongate body is a sheath instrument, and the second elongate body is a guide catheter instrument.

23. The system of claim 22, wherein the fiber cores are substantially encapsulated in a wall of the guide catheter instrument.

36. The system of claim 20, wherein the plurality of Bragg gratings comprises continuous or substantially continuous Bragg gratings written on a fiber core of the optical fiber.

37. The system of claim 21, wherein one or more of the respective fiber cores each comprise continuous or substantially continuous Bragg gratings.

24. A medical instrument system, comprising:

an elongate flexible instrument body;

an optical fiber substantially encapsulated in a wall of the instrument body, the optical fiber including a plurality of Bragg gratings unevenly spaced along the optical fiber;

a detector operatively coupled to the optical fiber and configured to detect respective light signals reflected by the Bragg gratings; and

a controller operatively coupled to the detector and configured to determine one or both of a bending and a twist of at least a portion of the instrument body based upon an analysis of detected reflected light signals from the unevenly spaced gratings.

25. An instrument system, comprising:

an elongate body;

an optical fiber coupled to the elongate body, the optical fiber including one or more Bragg gratings;

a localization sensor coupled to the elongate body;

a detector operatively coupled to the optical fiber and configured to detect respective light signals reflected by the one or more Bragg gratings; and

a controller operatively coupled to the detector and configured to determine a bending, a twist, or both, of at least a portion of the elongate body based on detected reflected light signals and on a relative position of the localization sensor.

26. The system of claim 25, wherein the elongate body is a flexible medical guide instrument.

27. The system of claim 26, wherein the optical fiber is substantially encapsulated in a wall of the guide instrument.

28. The system of claim 25, wherein the localization sensor is of a type selected from the group comprising electromagnetic sensors, potential difference sensors, and ultrasound sensors.

29. An instrument system, comprising:

an elongate body having a longitudinal axis;

an optical fiber coupled to the elongate body, the optical fiber including one or more Bragg gratings;

a detector operatively coupled to the optical fiber and configured to detect light signals reflected by the respective Bragg gratings; and

a controller operatively coupled to the detector and configured to determine a bending of at least a portion of the elongate body based on detected reflected light signals,

wherein the optical fiber is coupled to the elongate body in a manner such that twisting of the elongate body about its longitudinal axis does not cause a corresponding twisting of the optical fiber.

30. The system of claim 29, wherein the elongate body is a flexible medical guide instrument.

31. The system of claim 30, wherein the optical fiber is substantially encapsulated in a wall of the guide instrument.

38. A method of measuring twist of an elongate flexible medical instrument, the instrument having an optical fiber grating sensor coupled thereto such that a longitudinal axis of at least a portion of the optical fiber is substantially orthogonal to a longitudinal axis of the instrument, the method comprising:

detecting, with a detector operatively coupled to the optical fiber grating sensor, light signals reflected by respective fiber gratings in the portion of the optical fiber that is substantially orthogonal to the longitudinal axis of the instrument; and

analyzing the light signals to determine a twist of at least a portion of the instrument body.

39. The method of claim 38, wherein at least a portion of the optical fiber is wound around the instrument.

40. The method of claim 38, wherein at least a portion of the optical fiber is helically wound around the instrument.