Catheter control system having a pulley

• US 5,741,320 A
• Filed: 05/02/1995
• Issued: 04/21/1998
• Est. Priority Date: 05/02/1995
• Status: Expired due to Term

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Heart Rhythm Technologies, Inc. (Boston Scientific Corporation)
• Inventors: Maahs, Tracy D., Thornton, Peter, Taimisto, Miriam H., Hayzelden, Robert C.
• Primary Examiner(s): Bockelman, Mark
• Assistant Examiner(s): GRING, NOELLE K
• Application Number:
  US08/433,229
• Time in Patent Office: 1,085 Days
• Field of Search: 604/95, 604/264, 604/200, 604/202, 600/114, 600/131, 600/146, 600/149, 607/122
• US Class Current: 607/122
• CPC Class Codes: A61M 2025/015 Details of the distal fixation of the movable mechanical means
• CPC Class Codes: A61M 25/0136 Handles therefor
• CPC Class Codes: A61M 25/0144 having flexible regions as a result of inner reinforcement means, e.g. struts or rods
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires

Abstract

A steerable catheter comprising a resilient body member, a manipulation handle attached to the proximal end of the body member, a control wire extending from the handle to the distal end of the catheter for deflection control, and a pulley mechanism for controlling the movement of the control wire. Longitudinal movement of a slide element in the handle causes movement of the control wire and control over the deflection of the distal end of the catheter. The pulley mechanism is connected between the slide element and the control wire to provide greater mechanical advantage to effect deflection of the body member while enhancing deflection control resolution. A stiffening member is also disposed in the catheter body member and its position is controlled by the rotational motion of the slide element. The position of the pulley mechanism is not affected by rotational motion of the slide element.

Claims

1. A catheter having a deflectable distal tip, the catheter comprising:

a resilient body member having a distal end and a proximal end;

a manipulation handle attached to the proximal end of the body member having first and second elements movable in relation to each other;

a pulley bracket mounted in the handle and movable in relation to the first and second elements;

a pulley rotatably mounted to the pulley bracket;

a pulley cable engaged with the pulley having first and second ends, the first end of the cable affixed to the first element and the second end of the cable affixed to the second element;

a deflection control line mounted in the body member and connected at a proximal end to the pulley bracket and extending into and attached at the distal end of the body member; and

whereby movement of the first and second elements in relation to each other results in movement of one end of the pulley cable to cause the pulley bracket to move the control line in the distal end of the body member causing deflection of the distal end of the body member with greater mechanical advantage.

2. The catheter of claim 1 wherein the pulley is positioned between the distal end of the handle and the second end of the pulley cable.

3. The catheter of claim 1 wherein the first element further comprises:

a hand grip and the first element is stationary relative to the second element and to the pulley bracket.

4. The catheter of claim 1 wherein the second element is slidable inside the first element.

5. The catheter of claim 4 further comprising:

a stiffness control member movable in the body member and controllable at its proximal end by interconnection with the second element of the manipulation handle;

wherein rotational movement of the second element controls the position of the stiffness control member;

wherein the pulley bracket is mounted so that it is limited to longitudinal motion and its position is controlled by the sliding movement of the second member.

6. The catheter of claim 1 wherein the manipulation handle further includes a shaft having distal and proximal ends, the proximal end of the shaft affixed to the manipulation handle and the pulley bracket is slidably mounted on the shaft.

7. The catheter of claim 6 wherein the bracket is non-rotatable relative to the shaft.

8. The catheter of claim 7 wherein the shaft includes a longitudinal slot and the pulley bracket is engaged with the slot to restrain rotational movement of the pulley bracket relative to the shaft.

9. A catheter having a deflectable distal tip, the catheter comprising:

a resilient body member having a distal end and a proximal end;

a manipulation handle attached to the proximal end of the body member having first and second elements movable in relation to each other;

a pulley bracket slidably mounted in the handle for movement in an axial direction relative to the first and second elements;

a pulley rotatably mounted to the pulley bracket;

a pulley cable engaged with the pulley having first and second ends, the first end of the cable affixed to the first element and the second end of the cable affixed to the second element;

a deflection control line mounted in the body member and connected at a proximal end to the pulley bracket and extending into and attached at the distal end of the body member; and

whereby movement of the first and second elements in relation to each other results in movement of one end of the pulley cable to cause the pulley bracket to move the control line in the distal end of the body member causing deflection of the distal end of the body member with greater mechanical advantage.

10. The catheter of claim 9 wherein the pulley is positioned between the distal end of the handle and the second end of the pulley cable.

11. The catheter of claim 9 wherein the first element further comprises:

a hand grip and the first element is stationary relative to the second element and to the pulley bracket.

12. The catheter of claim 9 wherein the second element is slidable and rotatable inside the first element.

13. The catheter of claim 9 further comprising:

a stiffness control member movable in the body member and controllable at its proximal end by interconnection with the second element of the manipulation handle;

wherein rotational movement of the second element controls the position of the stiffness control member;

wherein the pulley bracket is mounted so that it is limited to longitudinal motion and its position is controlled by the sliding movement of the second member.

14. The catheter of claim 13 further comprising means for decoupling the rotation movement of the second element from the sliding movement of the second element.

15. The catheter of claim 14 wherein the shaft includes a longitudinal slot and the pulley bracket is engaged with the slot to restrain rotational movement of the pulley bracket relative to the shaft.

16. The catheter of claim 9 wherein the manipulation handle further includes a shaft having distal and proximal ends, the proximal end of the shaft affixed to the manipulation handle and the pulley bracket is slidably mounted on the shaft.

17. A catheter, comprising:

a body member having a proximal end and a distal end;

a deflectable tip mounted on the distal end of the body member;

a manipulation handle mounted to the proximal end of the body member;

a deflection controller having a pulley mechanism mounted to the manipulation handle; and

a deflection control line mounted in and extending through the body member, the deflection control line having a distal end attached to the deflectable tip and a proximal end attached to the pulley mechanism such that movement of the deflection controller is transmitted to the deflection control line by the pulley mechanism resulting in movement of the deflection control line causing a deflection of the deflectable tip with greater mechanical advantage.

18. The catheter of claim 17, wherein:

the manipulation handle comprises a gripping surface and a shaft mounted so that the gripping surface and the shaft are stationary in relation to each other; and

the deflection controller comprises a second element connected to the pulley mechanism and movable in relation to the gripping surface and the shaft such that movement of the second element causes movement of the control line with greater mechanical advantage.

19. The catheter of claim 18, wherein the pulley mechanism comprises:

a bracket slidably mounted on the shaft and connected to the proximal end of the deflection control line; and

a cable engaging the bracket and having a first end affixed to the first element and a second end affixed to the second element.

20. The catheter of claim 19, wherein the cable engages a bearing surface formed on the bracket.

21. The catheter of claim 19, wherein:

the pulley mechanism further comprises a pulley mounted on the bracket; and

the cable engages the pulley.

22. The catheter of claim 19 wherein the bracket is non-rotatable relative to the shaft.

23. The catheter of claim 22 wherein the shaft includes a longitudinal slot and the bracket is engaged with the slot to restrain rotational movement of the bracket relative to the shaft.

24. The catheter of claim 19 further comprising:

a second control line movable in the body member and controllable at its proximal end by interconnection with the second element of the manipulation handle;

wherein rotational movement of the second element controls the position of the second control line; and

wherein the bracket is mounted so that it is limited to longitudinal motion and its position is controlled by a sliding movement of the second element.

25. The catheter of claim 24 further comprising means for decoupling the rotational movement of the second element from the sliding movement of the second element.

26. The catheter of claim 25 wherein the means for decoupling comprises a sleeve slidably mounted within the gripping surface and attached to the second element and mounted on the shaft such that the sleeve and second element slide longitudinally along the shaft.

27. The catheter of claim 26 wherein the means for decoupling further comprises a hollow screw having a threaded exterior and a longitudinal bore sized to be slidably mounted on the shaft, the hollow screw having a mount for attaching the proximal end of the second control line thereto;

and

a second sleeve having a longitudinal bore sized to mount on the shaft and attached to the second element, the bore having grooves configured to threadedly engage the threaded exterior of the hollow screw, wherein rotational movement of the second element is converted by the second sleeve and hollow screw to cause the second control line to move in a linear direction.

28. The catheter of claim 27 wherein shaft includes a longitudinal slot and the hollow screw is engaged with the slot to restrain rotational movement of the hollow screw relative to the shaft.

29. A catheter comprising:

a body member having a proximal end and a distal end;

a manipulation handle mounted to the proximal end of the body member having a controller having a pulley mechanism; and

a control line mounted in and extending through the body member, the control line having a distal end extending to the distal end of the body member and a proximal end attached to the pulley mechanism such that movement of the controller is transferred by the pulley mechanism to the control line resulting in movement of the control line.

30. The catheter of claim 29 wherein:

the manipulation handle comprises a first gripping member and a second gripping member with the second gripping member being movable in relation to the first gripping member;

wherein the pulley mechanism is connected to the second gripping member to transmit movement of the second gripping member to the control line.

31. The catheter of claim 30 wherein the pulley mechanism comprises:

a pulley mounted between the second gripping member and the control line, wherein the pulley transmits movement of the second gripping member to the control line with mechanical advantage.

32. The catheter of claim 31 wherein the manipulation handle further comprises:

a shaft rigidly mounted to the first gripping member;

a bracket slidably mounted on the shaft, connected to the pulley, and connected to the proximal end of the control line; and

a pulley cable engaging the pulley and having a first end affixed to the first gripping element and a second end affixed to the second gripping element.

33. The catheter of claim 32 wherein the bracket is mounted to the shaft such that it is non-rotatable about the shaft.

34. The catheter of claim 33 wherein the shaft includes a longitudinal slot and the bracket is engaged with the slot to restrain rotational movement of the bracket relative to the shaft.

35. The catheter of claim 29 further comprising:

a second control line movable in the body member and controllable at its proximal end by interconnection with the controller;

wherein rotational movement of the controller controls the position of the second control line; and

wherein the pulley mechanism is mounted so that it is limited to longitudinal motion and its position is controlled by a sliding movement of controller.

36. The catheter of claim 35 further comprising means for decoupling the rotational movement of the controller from the sliding movement of the controller.

37. A method of transmitting movement of a movable member located at a manipulation handle of a catheter to the distal end of the catheter through an elongated control device disposed through the length of the catheter body, comprising the steps of:

moving a first control member in relation to a second control member located in the manipulation handle;

coupling the movement of the first control member to move a pulley mechanism located at the manipulation handle;

coupling the movement of the pulley mechanism to the elongated control device to thereby transmit the movement of the first control member to the distal end of the catheter through the elongated control device.

38. The method of claim 37 wherein the step of coupling the movement of the first control member comprises the step of mounting a pulley to a bracket;

mounting the bracket to a shaft fixed in position in relation to the second control member;

attaching the proximal end of the elongated control device to the bracket; and

engaging the pulley with a cable attached at a first end to the first control member and at a second end to the second control member.

39. The method of claim 38 wherein the step of mounting the bracket comprises the steps of:

providing a longitudinal slot in the shaft; and

engaging the bracket with the slot to restrain rotational movement of the bracket relative to the shaft.

40. The method of claim 37 further comprising the steps of:

rotating the first control member in relation to the second control member;

coupling the rotational movement of the first control member to a second elongated control device to cause the second elongated control device to move in a linear direction to thereby transmit the rotational movement of the first control member to the distal end of the catheter through the second elongated control device.

41. The method of claim 40 further comprising the step of decoupling the movement of the first control member to move the pulley from the rotating movement of the first control member.