Medical apparatus system having optical fiber load sensing

• US 20110087112A1
• Filed: 08/01/2006
• Published: 04/14/2011
• Est. Priority Date: 08/01/2005
• Status: Active Grant

• Current Assignee: ST JUDE MEDICAL INTERNATIONAL HOLDING S. R.L.
• Original Assignee: St. Jude Medical Luxembourg Holding SARL (Abbott Laboratories Incorporated)
• Inventors: Aeby, Nicoloas, Inaudi, Daniele, Leo, Giovanni
• Granted Patent: US 8,894,589 B2
• Time in Patent Office: Days
• US Class Current: 600/478
• 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 5/0084 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 5/6885 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 optical fiber contact force sensors disposed in a distal extremity thereof and a deflection mechanism configured to deflect the elongate body at a location proximal of the distal extremity. The optical fiber contact force sensors are configured to be coupled to processing logic programmed which computes a force vector responsive to detected changes in the optical characteristics of the optical fiber contact force sensors arising from deflection of the distal extremity resulting from contact with the tissue of the wall of the organ or vessel.

Claims

1. A device for introduction into a vessel or organ having a tissue wall, comprising:

an elongate body for traversing a body passageway, the elongate body having a distal extremity for contacting a tissue wall of the vessel or organ;

optical fiber contact force sensors configured for resolution of a multi-dimensional force vector responsive to a contact force between the distal extremity and tissue wall of the organ or vessel; and

a deflection mechanism disposed in the elongate body, the deflection mechanism configured to deflect the elongate body at a location proximal of the distal extremity.

2. The device of claim 1 further comprising processing logic operatively coupled to receive an output of the optical fiber contact force sensors, the processing logic programmed to compute a value of the contact force between the distal extremity and tissue wall of the organ or vessel.

3. The device of claim 1, wherein the optical fiber contact force sensors comprise at least three optical fiber contact force sensors disposed within the distal extremity so that the three optical fiber contact force sensors are not co-planar.

4. The device of claim 2 wherein the processing logic is programmed to compute a the multi-dimensional force vector from the output of the optical fiber contact force sensors.

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

7. The device 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 device of claim 1, further comprising another optical fiber sensor slidably disposed within a lumen of the elongate body to measure a temperature of the distal extremity.

9. The device of claim 1, wherein the elongate body comprises a liquid crystal polymer.

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

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

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

14. The device 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 device of claim 1, wherein the distal extremity further comprises an irrigation channel.

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

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

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

19. The device of claim 18 wherein a degree of deflection of the deflection mechanism is determined responsive to the output.

20. The device of claim 18 further comprising a robotic control system that manipulates the elongate body responsive to the output.

21. The device of claim 1 wherein the elongate body has a corresponding force-strain conversion matrix.

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

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

24. The device of claim 15 wherein the irrigation tube has 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 elongate body, the optical fiber contact force sensors affixed to the distal portion.

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

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

27. Apparatus for ablating tissue in a vessel or organ, the apparatus comprising:

an elongate body having proximal and distal ends and a distal extremity, the distal extremity comprising a deformable material and an ablator configured to ablate tissue upon contact of the ablator and introduction of radiofrequency energy to the ablator, the distal extremity further comprising an irrigation channel having a wall disposed with the distal extremity, the wall comprising a material having a coefficient of thermal expansion lower than a coefficient of thermal expansion of the deformable material; and

optical fibers comprising optical contact force sensors affixed to the distal extremity, the optical contact force sensors configured to provide an output corresponding to the value of a contact force between the distal extremity and tissue of the organ or vessel; and

a deflection mechanism disposed in the elongate body, the deflection mechanism configured to deflect the elongate body at a location proximal of the distal extremity.

28. The apparatus of claim 27 further comprising a storage device associated with the elongate 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.

29. 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.

30. The apparatus of claim 27 wherein the optical fiber contact force sensors are 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 further¹ 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 elongate body to measure a temperature of the distal extremity.

34. The apparatus of claim 27, wherein the ablator further comprises at least one electrode for measuring an electric potential of the tissue of the organ or vessel.

35. The apparatus of claim 34, wherein the console is programmed to measure the electrical potential when the contact force falls within a determined range.

36. The apparatus of claim 27, wherein the elongate body comprises a liquid crystal polymer.

37. The apparatus of claim 36, wherein the liquid crystal polymer includes a moisture resistant coating.

38. The apparatus of claim 35 wherein the ablator is configured to ablate tissue only when the contact force falls within a determined range.

39. The apparatus of claim 27, wherein the irrigation channel conducts radiofrequency energy to the ablator.

40. The apparatus of claim 39 wherein the distal portion comprises titanium.