METHOD OF SENSING FORCES ON A WORKING INSTRUMENT

• US 20070197939A1
• Filed: 02/22/2007
• Published: 08/23/2007
• Est. Priority Date: 02/22/2006
• Status: Active Grant

• Current Assignee: Auris Health, Inc. (Johnson & Johnson)
• Original Assignee: Hansen Medical Incorporated (Johnson & Johnson)
• Inventors: Goldenberg, Alex, Camarillo, David, Stahler, Gregory, Clopp, Mathew, Reis, Gene, Younge, Robert, Wallace, Daniel, King, Toby
• Granted Patent: US 8,052,621 B2
• Time in Patent Office: Days
• US Class Current: 600/587
• CPC Class Codes: A61B 17/3403 Needle locating or guiding means guides for suture needles A61B17/0482; guiding or tracking by nuclear magnetic resonance G01R33/285
• CPC Class Codes: A61B 17/3476 Powered trocars, e.g. electrosurgical cutting, lasers, powered knives
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• 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 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61M 25/01 Introducing, guiding, advancing, emplacing or holding catheters A61M25/10 takes precedence

Abstract

A method for estimating the force on a distal end of a working catheter includes positioning a portion of a robotically controlled guide catheter and working catheter into a body lumen wherein a distal end of the working catheter projects distally from a distal end of the guide catheter. The working catheter and guide catheter are dithered with respect to one another using a dithering device operatively connected to a proximal portion of the working catheter. The coupling may occur directly to the working catheter or via a seal such as a Touhy seal. The force experienced by the working catheter at a proximal region is measured through at least one dithering cycle. The force at the distal end of the working catheter is then estimated based on the measured force at the proximal region. The estimated force may be displayed to a physician on, for example, a monitor.

Claims

1. A method of estimating the force on a distal end of a working catheter passing through a robotically controlled guide catheter adapted for insertion into a body lumen comprising:

positioning a portion of the robotically controlled guide catheter and working catheter into the body lumen, wherein the distal end of the working catheter projects distally from a distal end of the guide catheter;

dithering one of the working catheter and the guide catheter with respect to one another using a dithering device operatively connected to a proximal portion of the working catheter;

measuring the forces on a proximal region of the working catheter through at least one dithering cycle; and

estimating the force on the distal end of the working catheter based on the measured force over the at least one dithering cycle.

2. The method of claim 1, wherein the working catheter is dithered with respect to the guide catheter.

3. The method of claim 1, wherein the guide catheter is dithered with respect to the working catheter.

4. The method of claim 1, wherein the working catheter and guide catheter are dithered together.

5. The method of claim 1, wherein the dither motion is longitudinal.

6. The method of claim 1, wherein the dither motion is rotational.

7. The method of claim 1, wherein the force is measured using one or more force sensors.

8. The method of claim 1, wherein the force is measured by the load applied to the dithering device.

9. The method of claim 1, wherein the dithering device is driven in a reciprocating manner by one of a speaker coil, air cylinder, hydraulic actuator, electric motor, solenoid, and piezoelectric element.

10. The method of claim 1, wherein the estimated force is based at least in part on an average of the measured force obtained in a portion of a withdrawal and an insertion stroke.

11. The method of claim 1, wherein the estimated force is obtained after subtracting a baseline force level obtained when the distal end of the working catheter is dithered without contacting a surface.

12. The method of claim 11, wherein the baseline force level comprises an average over at least one dithering cycle.

13. The method of claim 12, further comprising determining an error associated with the estimated force, the error being based on one or more parameters of the group consisting of sheath angle, articulating angle, rate of change of articulating angle, insertion distance, and magnitude of force applied to the distal end of the working catheter.

14. The method of claim 1, further comprising the step of displaying the estimated force on a display.

15. The method of claim 14, wherein the estimated force is displayed along with a visual cue indicative of the estimated error in the estimated force.

16. The method of claim 15, wherein the visual cue comprises one or more colors.

17. The method of claim 15, wherein the visual cue comprises one or graphical elements displayed on the display.

18. The method of claim 17, wherein the graphical element is selected from the group consisting of an error bar, a warning indicator, a textual message, and a pointer.

19. The method of claim 1, further comprising comparing the estimated force against a pre-determined threshold value and initiating a warning when the estimated force exceeds the pre-determined threshold value.

20. The method of claim 19, wherein the warning comprises an audible signal.

21. The method of claim 19, wherein the warning comprises a visual signal displayed on a display.

22. The method of claim 19, wherein the warning comprises a haptic signal.

23. The method of claim 1, further comprising comparing the estimated force against a pre-determined threshold value and temporarily disabling one or both of the robotically controlled guide catheter and working catheter if the estimated force exceeds the pre-determined threshold value.

24. The method of claim 1, wherein the distal end of the working catheter is dithered through a stroke displacement of 1.5 mm or less.

25. The method of claim 1, wherein the robotically controlled guide catheter comprises an articulating inner guide catheter and an outer sheath.

26. The method of claim 1, wherein the working catheter comprises an ablation catheter.

27. The method of claim 1, wherein the working catheter comprises an ablation catheter.

28. The method of claim 1, wherein the dither rate is adjustable.

29. The method of claim 1, wherein the dither rate between 0 to 10 Hz.

30. A method of sensing force on a distal end of a working catheter passing through a robotically controlled guide catheter adapted for insertion into a body lumen comprising:

positioning a portion of the robotically controlled guide catheter and working catheter into the body lumen, wherein the distal end of the working catheter projects distally from a distal end of the guide catheter;

dithering the working catheter with respect to the guide catheter using a dithering device operatively connected to a proximal portion of the working catheter; and

measuring the force on the proximal portion of the guide catheter using at least one force sensor, the at least one force sensor measuring insertion and withdrawal forces between the dithering device and the proximal portion of the guide catheter.

31. The method of claim 30, further comprising the step of determining the average of the insertion and withdrawal forces of the working guide catheter over a portion of one insertion and one withdrawal cycle.

32. The method of claim 31, further comprising the step of subtracting a baseline average of the insertion and withdrawal forces of the working guide catheter over the portion of the one insertion and one withdrawal cycle from the average of non-baseline insertion and withdrawal forces, the baseline average being obtained when the distal end of the working catheter is not in contact with a surface.

33. The method of claim 32, further comprising the step of calculating an estimated force by adding the subtracted values from the portion of the one insertion and one withdrawal cycle and dividing by 2.

34. The method of claim 33, further comprising determining an error associated with the estimated force, the error being based on one or more parameters of the group consisting of sheath angle, articulating angle, rate of change of articulating angle, insertion distance, and magnitude of force applied to the distal end of the working catheter.

35. The method of claim 33, further comprising the step of displaying the estimated force on a display.

36. The method of claim 35, wherein the estimated force is displayed along with a visual cue indicative of the estimated error in the estimated force.

37. The method of claim 36 wherein the visual cue comprises one or more colors.

38. The method of claim 36, wherein the visual cue comprises one or graphical elements displayed on the display.

39. The method of claim 38, wherein the graphical element is selected from the group consisting of an error bar, a warning indicator, a textual message, and a pointer.

40. The method of claim 33, further comprising comparing the estimated force against a pre-determined threshold value and initiating a warning when the estimated force exceeds the pre-determined threshold value.

41. The method of claim 40, wherein the warning comprises an audible signal.

42. The method of claim 40, wherein the warning comprises a visual signal displayed on a display.

43. The method of claim 40, wherein the warning comprises a haptic signal.

44. The method of claim 33, further comprising comparing the estimated force against a pre-determined threshold value and temporarily disabling one or both of the robotically controlled guide catheter and working catheter if the estimated force exceeds the pre-determined threshold value.

45. The method of claim 30, wherein the distal end of the working catheter is dithered through a stroke displacement of about 1.5 mm or less.

46. The method of claim 30, wherein the robotically controlled guide catheter comprises an articulating inner guide catheter and an outer sheath.

47. A method of sensing force on a distal end of a working catheter passing through a robotically controlled guide catheter adapted for insertion into a body lumen comprising:

positioning a portion of the robotically controlled guide catheter and working catheter into the body lumen, wherein the distal end of the working catheter projects distally from a distal end of the guide catheter;

dithering the working catheter with respect to the guide catheter using a dithering device operatively connected to a sealing member disposed on a proximal portion of the guide catheter, the sealing member being fixedly secured to the working catheter; and

measuring the force on the sealing member of the guide catheter using at least one force sensor, the at least one force sensor measuring insertion and withdrawal forces between the dithering device and the sealing member.

48. The method of claim 47, further comprising the step of determining the average of the insertion and withdrawal forces of the working guide catheter over a portion of one insertion and one withdrawal cycle.

49. The method of claim 48, further comprising the step of subtracting a baseline average of the insertion and withdrawal forces of the working guide catheter over the portion of the one insertion and one withdrawal cycle from the average of non-baseline insertion and withdrawal forces, the baseline average being obtained when the distal end of the working catheter is not in contact with a surface.

50. The method of claim 49, further comprising the step of calculating an estimated force by adding the subtracted values from the portion of the one insertion and one withdrawal cycle and dividing by 2.

51. The method of claim 50, further comprising determining an error associated with the estimated force, the error being based on one or more parameters of the group consisting of sheath angle, articulating angle, rate of change of articulating angle, insertion distance, and magnitude of force applied to the distal end of the working catheter.

52. The method of claim 50, further comprising the step of displaying the estimated force on a display.

53. The method of claim 52, wherein the estimated force is displayed along with a visual cue indicative of the estimated error in the estimated force.

54. The method of claim 53, wherein the visual cue comprises one or more colors.

55. The method of claim 53, wherein the visual cue comprises one or graphical elements displayed on the display.

56. The method of claim 55, wherein the graphical element is selected from the group consisting of an error bar, a warning indicator, a textual message, and a pointer.

57. The method of claim 50, further comprising comparing the estimated force against a pre-determined threshold value and initiating a warning when the estimated force exceeds the pre-determined threshold value.

58. The method of claim 57, wherein the warning comprises an audible signal.

59. The method of claim 57, wherein the warning comprises a visual signal displayed on a display.

60. The method of claim 57, wherein the warning comprises a haptic signal.

61. The method of claim 50, further comprising comparing the estimated force against a pre-determined threshold value and temporarily disabling one or both of the robotically controlled guide catheter and working catheter if the estimated force exceeds the pre-determined threshold value.

62. The method of claim 47, wherein the distal end of the working catheter is dithered through a stroke displacement of 1.5 mm or less.

63. The method of claim 47, wherein the robotically controlled guide catheter comprises an articulating inner guide catheter and an outer sheath.

64-89. -89. (canceled)