Implantable medical lead

• US 20060089697A1
• Filed: 04/29/2005
• Published: 04/27/2006
• Est. Priority Date: 10/21/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Olsen, James M., Bolea, Stephen L., Cross, Thomas E. Jr.
• Granted Patent: US 7,831,311 B2
• Time in Patent Office: Days
• US Class Current: 607/122
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems

Abstract

An implantable lead has a lead body construction designed to accommodate loading forces exerted on the lead body during patient movement. The lead body described herein is sufficiently stretchable to resist forces that could otherwise cause lead failure, axial migration of the electrodes, anchor damage, or tissue damage. The lead body may include a variety of features that reduce the axial stiffness of the lead without significantly impacting the operation and structural integrity of lead components, such as electrodes, conductors and insulators.

Claims

1. A medical lead for use with an implantable medical device, the medical lead comprising:

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

one or more electrodes at the distal end of the lead body;

one or more electrical contacts at the proximal end of the lead body; and

one or more conductors electrically coupling the electrodes and the electrical contacts,

wherein lead body has an axial stiffness of no greater than approximately 0.35 kg/cm/cm.

2. The medical lead of claim 1, wherein the medical lead has an axial stiffness within a range of approximately 0.105 kg/cm/cm to 0.35 kg/cm/cm.

3. The medical lead of claim 1, wherein the medical lead has an axial stiffness within a range of approximately 0.105 kg/cm/cm to 0.23 kg/cm/cm.

4. The medical lead of claim 1, wherein the medical lead has an axial stiffness of no greater than approximately 0.35 kg/cm/cm in the presence of elastic deformation under an axial elongation of approximately ten percent to approximately thirty percent.

5. The medical lead of claim 1, wherein the lead body includes an outer jacket and a stylet guide tube, and the conductors are disposed between the outer jacket and the stylet guide tube.

6. The medical lead of claim 5, wherein the outerjacket comprises one of a polyurethane material or a silicone material.

7. The medical lead of claim 5, wherein each of the conductors comprises insulated braided silver cored wire.

8. The medical lead of claim 1, wherein each of the conductors is formed of a material selected from the group consisting of stainless steel, nickel-cobalt-chromium-molybdenum alloy, titanium, and nitinol.

9. The medical lead of claim 1, wherein each of the conductors comprises a multi-filar coil.

10. The medical lead of claim 1, wherein the medical lead has a length of approximately 30 to 36 centimeters.

11. The medical lead of claim 1, wherein the medical lead has a length of approximately 33 centimeters.

12. The medical lead of claim 1, wherein the lead body includes:

an outerjacket; and

a helical reinforcement within the outer jacket, wherein the helical reinforcement comprises a tubular outer surface and a raised helical thread that rises from the tubular outer surface, wherein the conductors are wound around the helical reinforcement in a helical channel defined by the raised helical thread.

13. The medical lead of claim 12, further comprising a reinforcement wire embedded within the raised helical thread.

14. The medical lead of claim 1, wherein the lead body includes:

an outer jacket; and

a stylet guide tube inside the outer jacket, wherein the stylet guide tube comprises a coiled wire,

wherein the conductors are disposed between the outer jacket and the stylet guide tube.

15. The medical lead of claim 14, wherein the stylet guide tube comprises an insulated metal wire.

16. The medical lead of claim 14, further comprising a helical reinforcement wound around the stylet guide tube and inside the outer jacket, wherein the conductors are wound around the stylet guide tube in a channel defined by the helical reinforcement.

17. The medical lead of claim 16, wherein the coiled wire of the stylet guide tube is coiled in a first direction and the conductors are wound in a second direction different from the first direction.

18. The medical lead of claim 14, further comprising a stylet disposed within the stylet guide tube.

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

an outer jacket, wherein the outer jacket comprises a first insulative layer, a second insulative layer inside the first insulative layer, and a coiled wire embedded between the first layer and the second layer of the outer jacket; and

conductors inside the outer jacket.

33. The device of claim 15, further comprising a stylet disposed within the stylet guide tube.

20. An implantable medical device comprising:

a housing;

an implantable pulse generator, within the housing, that generates electrical stimulation pulses; and

a medical lead, extending from the housing, and comprising a lead body having a proximal end and a distal end, one or more electrodes at the distal end of the lead body, one or more electrical contacts at the proximal end of the lead body, and one or more conductors electrically coupling the electrodes and the electrical contacts, wherein the lead body has an axial stiffness of no greater than approximately 0.35 kg/cm/cm.

21. The device of claim 20, wherein the medical lead has an axial stiffness within a range of approximately 0.105 kg/cm/cm to 0.35 kg/cm/cm.

22. The device of claim 20, wherein the medical lead has an axial stiffness within a range of approximately 0.105 kg/cm/cm to 0.23 kg/cm/cm.

23. The device of claim 20, wherein the medical lead has an axial stiffness of no greater than approximately 0.35 kg/cm/cm in the presence of elastic deformation under an axial elongation of approximately ten percent to approximately thirty percent.

24. The device of claim 20, wherein the lead body includes an outer jacket and a stylet guide tube, and the conductors are disposed between the outer jacket and the stylet guide tube.

25. The device of claim 20, wherein each of the conductors is formed of a material selected from the group consisting of stainless steel, nickel-cobalt-chromium-molybdenum alloy, titanium, and nitinol.

26. The device of claim 20, wherein each of the conductors comprises a multi-filar coil.

27. The device of claim 20, wherein the medical lead has a length of approximately 30 to 36 centimeters.

28. The device of claim 20, wherein the medical lead has a length of approximately 33 centimeters.

29. The device of claim 20, wherein the lead body includes:

an outerjacket; and

a helical reinforcement within the outerjacket, wherein the helical reinforcement comprises a tubular outer surface and a raised helical thread that rises from the tubular outer surface, wherein the conductors are wound around the helical reinforcement in a helical channel defined by the raised helical thread.

30. The device of claim 29, further comprising a reinforcement wire embedded within the raised helical thread.

31. The device of claim 20, wherein the lead body includes:

an outer jacket; and

a stylet guide tube inside the outer jacket, wherein the stylet guide tube comprises a coiled wire,

wherein the conductors are disposed between the outer jacket and the stylet guide tube.

32. The device of claim 31, further comprising a helical reinforcement wound around the stylet guide tube and inside the outer jacket, wherein the conductors are wound around the stylet guide tube in a channel defined by the helical reinforcement.