LEAD CONDUCTOR WITH PITCH AND TORQUE CONTROL FOR MRI CONDITIONALLY SAFE USE

• US 20120053662A1
• Filed: 06/09/2011
• Published: 03/01/2012
• Est. Priority Date: 08/30/2010
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Foster, Arthur J., Persaud, Neranjan
• Granted Patent: US 8,825,181 B2
• Time in Patent Office: Days
• US Class Current: 607/115
• 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 1/086 Magnetic resonance imaging [MRI] compatible leads

Abstract

A medical device lead includes an insulated lead body including at least one electrode, a helically coiled conductor electrically coupled to the at least one electrode, and one or more polymer coils formed coaxially with the helically coiled conductor. The helically coiled conductor includes a plurality of turns having a conductive coil pitch and including one or more conductive filars each having a conductive filar diameter. The one or more polymer coils provide at least about 25 μN·m of torque transmitting capacity along a length of the medical device lead.

Claims

1. A medical device lead comprising:

an insulated lead body including at least one electrode;

a helically coiled conductor electrically coupled to the at least one electrode, the helically coiled conductor including a plurality of turns having a conductive coil pitch and including one or more conductive filars each having a conductive filar diameter; and

one or more polymer coils each including one or more polymer filars formed coaxially about the helically coiled conductor to provide at least about 25 μ

N·

m of torque transmitting capacity along a length of the medical device lead.

2. The medical device lead of claim 1, wherein the helically coiled conductor is unifilar, and wherein the conductive coil pitch is one to about two times the conductive filar diameter.

3. The medical device lead of claim 1, wherein the one or more polymer coils each have a polymer coil pitch, and wherein the polymer coil pitch is less than or equal to the conductive coil pitch.

4. The medical device lead of claim 1, wherein the one or more polymer filars each has a polymer filar diameter, and wherein the polymer filar diameter is less than or equal to the conductive filar diameter.

5. The medical device lead of claim 1, wherein the one or more polymer filars of at least one of the one or more polymer coils are wound in a direction opposite the one or more conductive filars.

6. The medical device lead of claim 1, wherein the one or more polymer coils comprises two polymer coils wound in opposite directions.

7. The medical device lead of claim 1, wherein the one or more polymer coils are comprised of a material selected from the group consisting of expanded polytetrafluoroethylene (ePTFE), layered ePTFE, polytetrafluoroethylene (PTFE), polyethylene terephthalate (PETE), ethylene/tetrafluoroethylene copolymer (ETFE), fluorinated ethylene propylene (FEP), polyether ether ketone (PEEK), polyamides, polyimides, para-aramid synthetic fibers, and polyurethane.

8. A medical device lead comprising:

an insulated lead body including at least one electrode;

a helically coiled conductor electrically coupled to the at least one electrode, the helically coiled conductor including a plurality of turns having a coil pitch and an outer diameter and including one or more conductive filars each having a filar diameter, wherein the coil pitch and outer diameter are selected based on the filar diameter to minimize heating of the helically coiled conductor in the presence of an MRI field; and

one or more polymer coils each including one or more polymer filars formed coaxially about the helically coiled conductor to increase a torque transmitting capacity of the helically coiled conductor.

9. The medical device lead of claim 8, wherein the helically coiled conductor is unifilar, and wherein the coil pitch is one to about two times the filar diameter.

10. The medical device lead of claim 8, wherein the outer diameter is at least 4.5 times the coil pitch.

11. The medical device lead of claim 8, wherein the one or more polymer coils each have a polymer coil pitch, and wherein the polymer coil pitch is less than or equal to the conductive coil pitch.

12. The medical device lead of claim 8, wherein the one or more polymer filars each has a polymer filar diameter, and wherein the polymer filar diameter is less than or equal to the conductive filar diameter.

13. The medical device lead of claim 8, wherein the one or more polymer filars of at least one of the one or more polymer coils are wound in a direction opposite the one or more conductive filars.

14. The medical device lead of claim 8, wherein the one or more polymer coils comprises two polymer coils wound in opposite directions.

15. A conductor assembly for a medical device lead, the conductor assembly comprising:

a helically coiled conductor including a plurality of turns having a conductive coil pitch and including one or more conductive filars each having a conductive filar diameter; and

one or more polymer coils each including one or more polymer filars formed coaxially about the helically coiled conductor to increase a torque transmitting capacity of the helically coiled conductor.

16. The conductor assembly of claim 15, wherein the helically coiled conductor is unifilar, and wherein the conductive coil pitch is one to about two times the conductive filar diameter.

17. The conductor assembly of claim 15, wherein the one or more polymer coils each have a polymer coil pitch, and wherein the polymer coil pitch is less than or equal to the conductive coil pitch.

18. The conductor assembly of claim 15, wherein the one or more polymer filars each has a polymer filar diameter, and wherein the polymer filar diameter is less than or equal to the conductive filar diameter.

19. The conductor assembly of claim 15, wherein the one or more polymer filars of at least one of the one or more polymer coils are wound in a direction opposite the one or more conductive filars.

20. The conductor assembly of claim 15, wherein the one or more polymer coils comprises two polymer coils wound in opposite directions.