Apparatus and method for expanding a stimulation lead body in situ

• US 20010023367A1
• Filed: 05/21/2001
• Published: 09/20/2001
• Est. Priority Date: 04/30/1998
• Status: Active Grant

• Current Assignee: Gary W. King, Mark T. Rise, Michael J. Schendel, Richard Schallhorn
• Original Assignee: Gary W. King, Mark T. Rise, Michael J. Schendel, Richard Schallhorn
• Inventors: Schendel, Michael J., Schallhorn, Richard, Rise, Mark T., King, Gary W.
• Granted Patent: US 6,442,435 B2
• Time in Patent Office: Days
• US Class Current: 607/117
• CPC Class Codes: A61M 2209/045 for filling, e.g. for filling reservoirs
• CPC Class Codes: A61M 2210/0693 Brain, cerebrum
• CPC Class Codes: A61M 2210/1003 Spinal column
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0558 Anchoring or fixation means therefor
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems

Abstract

An implantable lead is provided with at least one extendable member to position therapy delivery elements, which may be electrodes or drug delivery ports, after the lead has been inserted into the body. The lead may formed as a resilient element which is contained in a retainer tube that may be removed to permit the lead to deploy. Alternatively, a non-resilient lead may be provided with a slotted retainer tube. A series of mechanical linkages for expanding and retracting the lead within the human body may be actuated with various mechanisms. A control system may be provided for closed-loop feedback control of the position of the extendable members. The invention also includes a method for expanding an implantable lead in situ.

Claims

1. An implantable lead for providing therapy to a body comprising:

an elongate central portion; and

at least one extendable member having an end, the extendable member depending from the central portion and being adapted to assume a compact position, in which the end is disposed in close proximity to the central portion, and an extended position, in which the end is disposed at a location distal from the central portion;

at least one therapy delivery element disposed on the extendable member for delivering therapy to the body.

2. The implantable lead according to

claim 1

, wherein the extendable member is a span adapted to coil around the central portion when the span is in the compact position.

3. The implantable lead according to

claim 2

, wherein the span incorporates a resilient material to urge the span towards the extended position.

4. The implantable lead according to

claim 3

, further comprising therapy delivery elements disposed on the span for delivering therapy to the body.

5. The implantable lead according to

claim 2

, further comprising a central passage in the central portion for accommodating a centering stylet to stabilize and center the lead.

6. The implantable lead according to

claim 2

, further comprising a retainer tube having a notch for guiding the span to its extended position.

7. The implantable lead according to

claim 2

, wherein the span is adapted to be folded in such a manner that the therapy delivery elements are disposed one on top of the other in the compact position.

8. The implantable lead according to

claim 1

, wherein the extendable member is formed as a coaxial accessory tube mounted over a distal end of the central portion, the accessory tube including a central slot forming at least two flexible leaf portions.

9. The implantable lead according to

claim 8

, wherein a lower end of the accessory tube is adapted to slide with respect to the central portion, the flexible leaf portions adapted to extend outward as the lower end slides.

10. The implantable lead according to

claim 1

, wherein the extendable member is formed as a series of telescoping elements.

11. The implantable lead according to

claim 10

, wherein the telescoping elements are provided with therapy delivery elements thereon.

12. The implantable lead according to

claim 1

, wherein the extendable member is formed as a resilient transverse span adapted to bend to a compact position in which the extendable member extends in a direction substantially parallel to an axis of the lead and wherein the extendable member is adapted to extend in an extended position at an angle of 90 degrees or less to the axis of the lead.

13. The implantable lead according to

claim 1

, further comprising a linkage assembly for expanding the lead.

14. The implantable lead according to

claim 13

, wherein the linkage assembly comprises a first and second actuating members adapted to move in a direction substantially parallel to an axis of the lead.

15. The implantable lead according to

claim 14

, further comprising a mechanism for adjusting the relative positions of the first and second actuating members.

16. The implantable lead according to

claim 15

, wherein the mechanism comprises a rotatable circular component cooperatively associated with the first and second actuating members.

17. The implantable lead according to

claim 15

, wherein the mechanism comprises a rack gear and pinion gear, the rack gear being cooperatively associated with one of the first and second actuating members.

18. The implantable lead according to

claim 15

, wherein the mechanism comprises a hydraulic cylinder adapted to adjust the relative positions of the first and second actuating members.

19. The implantable lead according to

claim 13

, wherein the linkage assembly comprises a rotatable shaft.

20. The implantable lead according to

claim 19

, further comprising a gear mechanism for imparting rotational movement to the shaft.

21. An implantable lead for providing therapy to a body comprising:

an elongate central portion; and

at least one extendable member having an end, the extendable member depending from the central portion and being adapted to assume a compact position, in which the end is disposed in close proximity to the central portion, and an extended position, in which the end is disposed at a location distal from the central portion;

at least one therapy delivery element disposed on the extendable member for delivering therapy to the body; and

a linkage assembly for permitting adjustment of the position of the extendable member in situ.

22. The implantable lead according to

claim 21

, wherein the extendable member is a span adapted to coil around the central portion when the span is in the compact position.

23. The implantable lead according to

claim 22

, wherein the span is adapted to be folded in such a manner that the therapy delivery elements are disposed one on top of the other in the compact position.

24. The implantable lead according to

claim 21

, wherein the extendable member is formed as a coaxial accessory tube mounted over a distal end of the central portion, the accessory tube including a central slot forming at least two flexible leaf portions.

25. The implantable lead according to

claim 24

, wherein a lower end of the accessory tube is adapted to slide with respect to the central portion, the flexible leaf portions adapted to extend outward as the lower end slides.

26. The implantable lead according to

claim 25

, further comprising a screw mechanism for adjusting the position of the lower end of the accessory tube.

27. The implantable lead according to

claim 21

, wherein the extendable member is formed as a series of telescoping elements.

28. The implantable lead according to

claim 21

, wherein the linkage assembly comprises a first and second actuating members adapted to move in a direction substantially parallel to an axis of the lead.

29. The implantable lead according to

claim 28

, further comprising a mechanism for adjusting the relative positions of the first and second actuating members.

30. The implantable lead according to

claim 29

, wherein the mechanism comprises a rotatable circular component cooperatively associated with the first and second actuating members.

31. The implantable lead according to

claim 29

, wherein the mechanism comprises a rack gear and pinion gear, the rack gear being cooperatively associated with one of the first and second actuating members.

32. The implantable lead according to

claim 29

, wherein the mechanism comprises a hydraulic cylinder adapted to adjust the relative positions of the first and second actuating members.

33. The implantable lead according to

claim 21

, wherein the linkage assembly comprises a rotatable shaft.

34. The implantable lead according to

claim 33

, further comprising a gear mechanism for imparting rotational movement to the shaft.

35. An implantable lead system for providing therapy to a body comprising:

an elongate central portion;

at least one extendable member having an end, the extendable member depending from the central portion and being adapted to assume a compact position, in which the end is disposed in close proximity to the central portion, and an extended position, in which the end is disposed at a location distal from the central portion;

at least one therapy delivery element disposed on the extendable member for delivering therapy to the body;

an actuating assembly for permitting adjustment of the position of the extendable member in situ;

a sensor for sensing a stimulation parameter;

a closed-loop feedback controller for operating the actuating assembly to maintain the stimulation parameter at a predetermined value.

36. A method for expanding an implantable lead in situ in the body, the lead including an expandable member having therapy delivery elements thereon, the method comprising the steps of:

inserting the lead into the body;

expanding the lead while the lead is in the body to thereby expand the expandable member such that the relative positions of the therapy delivery elements may be adjusted.