Implantable medical lead designs

• US 20040088034A1
• Filed: 04/21/2003
• Published: 05/06/2004
• Est. Priority Date: 10/31/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Smits, Karel F.A.A., Rutten, Jean J.G., Adams, Paul G.
• Granted Patent: US 8,010,207 B2
• Time in Patent Office: Days
• US Class Current: 607/122
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/0539 Anchoring of brain electrode systems, e.g. within burr hole
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0565 Electrode heads

Abstract

The invention is directed to medical leads for use with implantable medical devices. Various features of medical leads are described, many of which may be useful in a variety of different leads, e.g., used in a variety of different applications. In one embodiment, the invention provides a medical lead of varying stiffness characteristics. In another embodiment, the invention provides a medical lead having a semi-conical shaped distal tip that becomes wider at more distal tip locations. In either case, described lead features may be particularly useful for J-shaped lead configurations used for implantation in a patient'"'"'s right atrium. Many other types of leads, however, could also benefit from various aspects of the invention.

Claims

1. A medical lead comprising:

a first coiled portion including N filar(s) extending along a first segment of the lead; and

a second coiled portion electrically coupled to the first coiled portion, the second coiled portion including N+M filars extending along a second segment of the lead, the N+M filars producing increased stiffness of the second coiled portion relative to the first coiled portion, wherein N and M are positive integers.

2. The medical lead of claim 1, further comprising an electrically conductive bus to electrically couple the N filar(s) of the first coiled portion to the N+M filars of the second coiled portion.

3. The medical lead of claim 1, further comprising a weld to electrically couple the M filar(s) of the second coiled portion to the N filar(s) of the first coiled portion, the N filar(s) of the second coiled portion being the same as the N filar(s) of the second coiled portion.

4. The medical lead of claim 1, further comprising:

a proximal end to be coupled to a medical device; and

a distal end to be implanted at a location in a patient, the second coiled portion being located at the distal end.

5. The medical lead of claim 1, further comprising a detectable indicator ring attached in proximity to the distal end.

6. The medical lead of claim 4, further comprising:

a lumen defined by inner diameters of the first and second coiled portions between the proximal and distal ends; and

an insulating tubing covering the first and second coiled portions between the proximal and distal ends.

7. The medical lead of claim 6, further comprising an electrode on the distal end and electrically coupled to the second coiled portion.

8. The medical lead of claim 6, the distal end having a stiffness sufficient to maintain a J-shape following insertion and removal of a J-shaped stylet through the lumen.

9. The medical lead of claim 1, wherein a pitch of the first coiled portion is less than a pitch of the second coiled portion.

10. The medical lead of claim 1, wherein a coil diameter of the first coiled portion is less than a coil diameter of the second coiled portion.

11. The medical lead of claim 1, wherein one or more of the N filar(s) of the first coiled portion have a filar diameter that is different than a filar diameter of one or more of the N+M filars of the second coiled portion.

12. The medical lead of claim 1, further comprising a third coiled portion electrically coupled to the second coiled portion, the third coiled portion including N+M+O filars extending along a third segment of the lead to produce different stiffness in the third coiled portion relative to the second coiled portion, wherein O is an integer.

13. The medical lead of claim 1, further comprising a fourth coiled portion electrically coupled to the third coiled portion, the fourth coiled portion including N+M+O+P filars extending along a fourth segment of the lead to produce different stiffness in the fourth coiled portion relative to the third coiled portion, wherein P is an integer.

14. The medical lead of claim 1, wherein the medical lead is a bipolar lead, wherein the first and second coiled portions collectively define an outer coil of a the bipolar lead, the medical lead further comprising an inner coil.

15. The medical lead of claim 1, wherein N=1 and M=1.

16. The medial lead of claim 1, wherein N=1 and M=2.

17. The medial lead of claim 1, wherein N=2 and M=1.

18. An implantable medical device comprising:

a housing to house circuitry; and

a medical lead electrically coupled to the circuitry, the medical lead including;

a first coiled portion including N filar(s); and

a second coiled portion electrically coupled to the first coiled portion, the second coiled portion including N+M filars to produce increased stiffness relative to the first coiled portion, wherein N and M are positive integers.

19. The implantable medical device of claim 18, further comprising an electrically conductive bus to electrically couple the N filar(s) of the first coiled portion to the N+M filars of the second coiled portion.

20. The implantable medical device claim 18, further comprising a weld to electrically couple the M filar(s) of the second coiled portion to the N filar(s) of the first coiled portion, the N filar(s) of the second coiled portion being the same as the N filar(s) of the second coiled portion.

21. The implantable medical device of claim 18, further comprising:

a proximal end to be coupled to a medical device; and

a distal end to be implanted at a location in a patient, the second coiled portion being located at the distal end.

22. The implantable medical device of claim 21, further comprising a detectable indicator ring attached in proximity to the distal end of the medical lead.

23. The implantable medical device of claim 21, further comprising:

a lumen defined by inner diameters of the first and second coiled portions between the proximal and distal ends; and

an insulating tubing covering the first and second coiled portions between the proximal and distal ends.

24. The implantable medical device of claim 23, further comprising an electrode on the distal end and electrically coupled to the second coiled portion.

25. The implantable medical device of claim 23, the distal end defining a stiffness sufficient to maintain a J-shape following insertion and removal of a J-shaped stylet through the lumen.

26. The implantable medical device of claim 18, wherein a pitch of the first coiled portion is less than a pitch of the second coiled portion.

27. The implantable medical device of claim 18, further comprising a third coiled portion electrically coupled to the second coiled portion, the third coiled portion including N+M+O filars to define different stiffness relative to the second coiled portion, wherein O is an integer.

28. The implantable medical device of claim 18, further comprising a fourth coiled portion electrically coupled to the third coiled portion, the fourth coiled portion including N+M+O+P filars to define different stiffness relative to the third coiled portion, wherein P is an integer.

29. The implantable medical device of claim 18, wherein the medical lead is a bipolar lead, wherein the first and second coiled portions collectively define an outer coil of a the bipolar lead, the medical lead further comprising an inner coil.

30. The implantable medical device of claim 18, wherein the device is selected from the group consisting of:

an implantable cardiac pacemaker, an implantable defibrillator, an implantable cardioverter, an implantable pacemaker-defibrillator-cardioverter, an implantable sensing device;

an implantable monitor;

an implantable muscular stimulator;

an implantable nerve stimulator;

an implantable deep brain stimulator, an implantable gastric stimulator, an implantable colon stimulator, an implantable agent dispenser, and an implantable recorder.

31. An apparatus comprising:

a first coiled portion including N filar(s);

a second coiled portion including N+M filars to produce increased stiffness in the second coiled portion relative to the first coiled portion, wherein N and M are positive integers; and

means for electrically coupling the first coiled portion to the second coiled portion.

32. The apparatus of claim 31, further comprising:

a third coiled portion including N+M+O filars to produce different stiffness of the second coiled portion relative to the first coiled portion, wherein O is an integer; and

means for electrically coupling the second coiled portion to the third coiled portion.

33. A method comprising:

coiling a first set of N filar(s) to define a first portion of a medical lead;

coiling a second set of N+M filars to define a second portion of a medical lead having increased stiffness relative to the first portion, wherein N and M are positive integers; and

electrically coupling the first set of N filar(s) to the second set of N+M filars.

34. The method of claim 33, wherein electrically coupling the first set of N filar(s) to the second set of N+M filars includes:

coiling the first set of N filar(s) around a first end of an electrically conductive bus; and

coiling the second set of N+M filars around a second end of the electrically conductive bus.

35. The method of claim 33, wherein electrically coupling the first set of N filar(s) to the second set of N+M filars includes welding the M filar(s) to the N filar(s), the N filar(s) of the first set being the same as the N filar(s) of the second set, wherein a weld defines a transition between the first portion and the second portion.