Neurostimulation lead design with varying RF impedance filars

• US 8,880,187 B2
• Filed: 03/13/2013
• Issued: 11/04/2014
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: McDonald, Matthew Lee, Gupta, Gaurav, Muhleman, Jacob Matthew, Venook, Ross Daniel
• Primary Examiner(s): Holmes, Rex R
• Application Number:
  US13/801,608
• Publication Number:
  US 20130245734A1
• Time in Patent Office: 601 Days
• Field of Search: 607115-122
• US Class Current: 607/116
• 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

An implantable stimulation lead includes a lead body having a proximal end and a distal end; a plurality of electrodes disposed along the distal end of the lead body; a plurality of terminals disposed along the proximal end of the lead body, and a plurality of conductors disposed in the lead body and including a first conductor and a second conductor. Each conductor electrically couples at least one of the electrodes to at least one of the terminals. The first conductor has a RF impedance that is at least 25% greater in magnitude than the second conductor.

Claims

1. An implantable stimulation lead, comprising:

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

a plurality of electrodes disposed along the distal end of the lead body;

a plurality of terminals disposed along the proximal end of the lead body, and

a plurality of conductors disposed in the lead body and comprising a first conductor and a second conductor, each conductor electrically coupling at least one of the electrodes to at least one of the terminals, wherein, at 65 MHz, the first conductor has a RF impedance comprising an imaginary part that is at least 25% greater in magnitude than an imaginary part of a RF impedance of the second conductor, wherein at least a portion of the first conductor is coiled and the second conductor is straight.

2. The implantable stimulation lead of claim 1, wherein the first conductor has a different material composition from the second conductor.

3. The implantable stimulation lead of claim 2, wherein the first conductor and the second conductor each comprise an inner core and an outer layer disposed around the inner core, wherein a composition of at least one of the inner core or outer layer differs between the first conductor and the second conductor.

4. The implantable stimulation lead of claim 3, wherein the outer layers of the first and second conductors have a same composition and the inner cores of the first and second conductors have different compositions.

5. The implantable stimulation lead of claim 1, wherein, at 65 MHz, the imaginary part of the RF impedance of the first conductor is at least 50% greater in magnitude than the imaginary part of the RF impedance of the second conductor.

6. The implantable stimulation lead of claim 1, wherein, at 65 MHz, the imaginary part of the RF impedance of the first conductor is at least 100% greater in magnitude than the imaginary part of the RF impedance of the second conductor.

7. The implantable stimulation lead of claim 1, wherein the first conductor has a diameter that is at least 10% smaller than a diameter of the second conductor.

8. The implantable stimulation lead of claim 7, wherein the first conductor has a different material composition from the second conductor.

9. The implantable stimulation lead of claim 1, wherein the first conductor has a diameter that is at least 15% smaller than a diameter of the second conductor.

10. The implantable stimulation lead of claim 1, wherein the first conductor has a diameter that is at least 25% smaller than a diameter of the second conductor.

11. The implantable stimulation lead of claim 1, wherein the first conductor and the second conductor each having a different insulating material disposed around the conductor.

12. The implantable stimulation lead of claim 1, wherein the first conductor is a multi-filar conductor.

13. The implantable stimulation lead of claim 1, wherein a length of the first conductor is at least 10% greater than a length of the second conductor.

14. The implantable stimulation lead of claim 1, wherein a length of the first conductor is at least 25% greater than a length of the second conductor.

15. An implantable stimulation system comprising:

a control module for producing electrical pulses; and

the implantable stimulation lead of claim 1 coupleable to the control module.

16. A method for tissue stimulation, the method comprising:

implanting the implantable stimulation lead of claim 1 within a body; and

providing electrical stimulation signals to the electrodes of the implantable stimulation lead to stimulate adjacent tissue.

17. The method of claim 16, further comprising coupling the implantable stimulation lead to a control module.

18. The method of claim 17, further comprising implanting the control module.

19. The method of claim 16, further comprising exposing the implanted stimulation lead to a RF field generated during an MRI procedure.