Medical apparatus system having optical fiber load sensing capability

• US 20070060847A1
• Filed: 05/15/2006
• Published: 03/15/2007
• Est. Priority Date: 03/04/2005
• Status: Active Grant

• Current Assignee: ST JUDE MEDICAL INTERNATIONAL HOLDING S. R.L.
• Original Assignee: Endosense SA (Abbott Laboratories Incorporated)
• Inventors: Inaudi, Daniele, Aeby, Nicolas, Leo, Giovanni
• Granted Patent: US 8,075,498 B2
• Time in Patent Office: Days
• US Class Current: 600/587
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• 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 2017/00084 Temperature
• CPC Class Codes: A61B 2034/2061 using shape-sensors, e.g. fiber shape sensors with Bragg gratings
• CPC Class Codes: A61B 2034/301 for introducing or steering flexible instruments inserted into the body, e.g. catheters or endoscopes
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 2090/397 electromagnetic other than visible, e.g. microwave
• CPC Class Codes: A61B 2562/0266 Optical strain gauges
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: A61B 90/96 using barcodes
• CPC Class Codes: A61B 90/98 using electromagnetic means, e.g. transponders

Abstract

Apparatus is provided for diagnosing or treating an organ or vessel, wherein a device having at least two optical fiber sensors disposed in a distal extremity thereof is coupled to processing logic programmed to compute a multi-dimensional force vector responsive to detected changes in the optical characteristics of the optical fiber sensors arising from deflection of the distal extremity resulting from contact with the tissue of the wall of the organ or vessel. The force vector may be used to facilitate manipulation of the catheter either directly or automatically using a robotic system.

Claims

1. Apparatus for diagnosis or treatment of a vessel or organ, the apparatus comprising:

a catheter having a distal extremity;

at least two optical fiber sensors affixed within the distal extremity; and

processing logic operatively coupled to receive an output of the optical fiber sensors, the processing logic programmed to compute at multi-dimensional force vector corresponding to a contact force between the distal extremity and a tissue wall of the organ or vessel.

2. The apparatus of claim 1, wherein the two optical fiber sensors are affixed to one another.

3. The apparatus of claim 1 further comprising a third optical fiber sensor, the third optical fiber sensor disposed within the distal extremity so that the three optical fiber sensors are not co-planar.

4. The apparatus of claim 3 wherein the processing logic is programmed to compute a three-dimensional force vector responsive to the output of the optical fiber sensors.

5. The apparatus of claim 1 wherein the optical fiber sensors are selected from the group consisting of:

Fiber Bragg Grating optical fiber strain sensors, Long Period Grating optical fiber strain sensors, Intrinsic Fabry-Perot Interferometer optical fiber strain sensors, Extrinsic Fabry-Perot Interferometer optical fiber strain sensors, Michelson interferometer optical fiber strain sensors, Brillouin scattering optical fiber strain sensors and intensity interferometer optical fiber strain sensors.

6. The apparatus of claim 1, wherein a distal part of an optical fiber of one of the optical fiber sensors extends distally beyond the other optical fiber sensor and further comprises an additional optical fiber sensor.

7. The apparatus of claim 1, wherein the optical fiber sensors are selected from the group consisting of Michelson or intensity interferometer optical fiber strain sensors and an additional optical fiber extends beyond the optical fiber sensors and includes an additional optical fiber sensor to measure temperature.

8. The apparatus of claim 1, further comprising another optical fiber sensor slidably disposed within a lumen of the catheter to measure a temperature of the distal extremity.

9. The apparatus of claim 1, wherein the catheter comprises a liquid crystal polymer.

10. The apparatus of claim 9, wherein the liquid crystal polymer includes a moisture resistant.

11. The apparatus of claim 1, wherein the distal extremity further comprises at least one electrode to measure an electric potential of the tissue of the organ or vessel.

12. The apparatus of claim 11 further comprising a processor programmed to measure the electrical potential when the contact force falls within a determined range.

13. The apparatus of claim 1, wherein the distal extremity further comprises at least one electrode for ablating tissue by depositing radiofrequency energy.

14. The apparatus of claim 12 further comprising a processor programmed to permit actuation of the electrode to ablate tissue only when the contact force falls within a determined range.

15. The apparatus of claim 1, wherein the distal extremity further comprises an irrigation channel.

16. The apparatus of claim 13, further comprising an irrigation channel that conducts radiofrequency energy to the at least one electrode.

17. The apparatus of claim 1, wherein the distal extremity further comprises a three-dimensional positioning sensor.

18. The apparatus of claim 1 further comprising a Fiber Bragg Grating Demodulator coupled to the optical fiber sensors to generate the output.

19. The apparatus of claim 18 further comprising means for articulating the distal extremity, wherein articulation of the distal extremity is determined responsive to the output.

20. The apparatus of claim 18 further comprising a robotic control system that manipulates the catheter responsive to the output.

21. The apparatus of claim 1 wherein the catheter has a corresponding force-strain conversion matrix.

22. The apparatus of claim 21 wherein the force-strain conversion matrix is stored in a memory chip, bar code or RFID tag provided with the catheter.

23. The apparatus of claim 21 wherein the force-strain conversion matrix is provided to the processing logic prior to use of the catheter.

24. The apparatus of claim 15 wherein the irrigation tube having a proximal portion and a distal portion disposed in the distal extremity, the distal portion comprising a material having a coefficient of thermal expansion substantially less than the coefficient of thermal expansion of the catheter, the at least two optical fiber sensors affixed to the distal portion.

25. The apparatus of claim 24 wherein the distal portion comprises titanium.

26. The apparatus of claim 24 further comprising a polymeric housing disposed in the distal extremity to surround the distal portion.

27. Apparatus for diagnosis or treatment of a vessel or organ, the apparatus comprising:

an elongated body having proximal and distal ends and a distal extremity, the distal extremity comprising a deformable material;

three optical fibers extending through the elongated body and affixed within the distal extremity so that the optical fibers are not co-planar;

at least one optical strain sensor disposed within the distal extremity and coupled to each one of the three optical fibers; and

a storage device associated with the elongated body, the storage device containing a force-strain conversion matrix that enables computation of a three-dimensional force vector corresponding to a contact force between the distal extremity and a tissue wall of the organ or vessel.

28. The apparatus of claim 27 further comprising a console having a laser diode, a photodetector and processing logic, wherein the processing logic is programmed to receive an output from the optical strain sensor and to compute the three-dimensional force vector using the force-strain conversion matrix.

29. The apparatus of claim 27, wherein the three optical fibers are affixed to one another to form a sub-assembly.

30. The apparatus of claim 27 wherein the optical fiber strain sensor is selected from the group consisting of:

a Fiber Bragg Grating optical fiber strain sensor, a Long Period Grating optical fiber strain sensor, an Intrinsic Fabry-Perot Interferometer optical fiber strain sensor, an Extrinsic Fabry-Perot Interferometer optical fiber strain sensor, a Michelson interferometer optical fiber strain sensor, a Brillouin scattering optical fiber strain sensor and an intensity interferometer optical fiber strain sensor.

31. The apparatus of claim 27, wherein a distal part of one of the optical fibers extends distally beyond the other optical fibers and further comprises an additional optical fiber sensor for use in determining temperature.

32. The apparatus of claim 27, wherein the three optical fibers comprise arms of a Michelson or intensity interferometer optical fiber strain sensor and an additional optical fiber extends through the elongate body and distally beyond the other optical fibers and includes an additional optical fiber sensor to measure temperature.

33. The apparatus of claim 27, further comprising a fourth optical fiber having an optical fiber sensor slidably disposed within a lumen of the elongated body to measure a temperature of the distal extremity.

34. The apparatus of claim 28, wherein the distal extremity further comprises an end effector to perform a diagnosis or treatment of the organ or vessel.

35. The apparatus of claim 34, wherein the end effector comprises at least one electrode for measuring an electric potential of the tissue of the organ or vessel.

36. The apparatus of claim 35, wherein the console is programmed to measure the electrical potential when the contact force falls within a determined range.

37. The apparatus of claim 34, wherein the end effector comprises at least one electrode for ablating tissue by depositing radiofrequency energy.

38. The apparatus of claim 27, wherein the elongated body comprises a liquid crystal polymer.

39. The apparatus of claim 38, wherein the liquid crystal polymer includes a moisture resistant.

40. The apparatus of claim 37 wherein the console is programmed to permit actuation of the electrode to ablate tissue only when the contact force falls within a determined range.

41. The apparatus of claim 37, wherein the distal extremity further comprises an irrigation channel.

42. The apparatus of claim 41, wherein the irrigation channel conducts radiofrequency energy to the at least one electrode.

43. The apparatus of claim 41 wherein the irrigation channel comprises a tube having proximal and distal portions, the distal portion disposed within the distal extremity and comprising a material having a coefficient of thermal expansion substantially less than the coefficient of thermal expansion of the deformable material, the at least two optical fiber sensors affixed to the distal portion.

44. The apparatus of claim 43 wherein the distal portion comprises titanium.

45. The apparatus of claim 43 further comprising a polymeric housing disposed in the distal extremity to at least partially surround the distal portion.

46. The apparatus of claim 27, wherein the distal extremity further comprises a three-dimensional positioning sensor.

47. The apparatus of claim 28 further comprising means for articulating the distal extremity, the means for articulating responsive to an output of the processing logic.

48. The apparatus of claim 28 further comprising a robotic control system that manipulates the elongated body responsive to the output.

49. The apparatus of claim 27 wherein the storage device comprises a memory chip, bar code or RFID tag associated with the catheter.

50. The apparatus of claim 28 wherein the force-strain conversion matrix is input to the processing logic prior to use of the catheter.