MRI-SAFE HIGH IMPEDANCE LEAD SYSTEMS

• US 20130245741A1
• Filed: 04/29/2013
• Published: 09/19/2013
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation), MRI Interventions, Inc. (Clearpoint Neuro, Inc.)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation), MRI Interventions, Inc. (Clearpoint Neuro, Inc.)
• Inventors: Atalar, Ergin, Allen, Justin, Bottomley, Paul, Edelstein, William, Kamarkar, Parag V.
• Granted Patent: US 8,688,226 B2
• Time in Patent Office: Days
• US Class Current: 607/148
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/06 for high-frequency therapy
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads

Abstract

Some embodiments are directed to MRI/RF compatible medical interventional devices. A plurality of spaced apart high impedance circuit segments are configured to have a high Impedance at a high range of radiofrequencies and a low impedance at a low range of frequencies. The high impedance circuit segments may comprise co-wound coiled inductors and can reduce, block or inhibit RJ-transmission along the lead system (20) during exposure to RF associated with a high-Held magnet MRI systems, while permuting passage of low frequency physiologic signals, treatments and/or stimuli. The devices can include at least one electrode.

Claims

1. An MRI safe lead, comprising:

an elongate flexible body, the body having distal and proximal portions;

a plurality of conductors extending along the flexible body, each conductor comprising a plurality of axially spaced-apart coiled segments and a plurality of linear segments residing between adjacent coiled segments;

at least one electrode disposed along the distal portion of the body and coupled to the plurality of conductors;

a dielectric disposed over the conductors;

a conductive shield disposed over the dielectric with the dielectric residing between the conductors and the conductive shield; and

a plurality of first capacitors, each first capacitor electrically connecting a respective one of the conductors to the shield to define a RF short and low frequency open circuit,

wherein the coiled segments of the conductors, the dielectric, the conductive shield, and the plurality of capacitors define a plurality of high impedance segments that are tuned to a target RF frequency associated with an MRI system.

2. The lead of claim 1, wherein each of the plurality of first capacitors is coupled to the respective one of the conductors before a proximal end of one of the coiled segments of the respective one of the conductors.

3. The lead of claim 2, further comprising a plurality of second capacitors, each second capacitor coupled to a respective one of the conductors after a distal end of one of the coiled segments of the respective one of the conductors.

4. The lead of claim 3, wherein the second capacitors are tuning capacitors.

5. The lead of claim 1, wherein the target RF frequency is in a range from 1 MHz to 250 MHz.

6. The lead of claim 1, wherein the high impedance segments are positioned along the conductors so that adjacent high impedance segments are separated by a distance of less than one quarter of a wavelength of the target RF frequency.

7. The lead of claim 1, wherein at least some of the coiled segments of different conductors are co-wound together.

8. An MRI safe lead, comprising:

an elongate flexible body, the body having distal and proximal portions;

a plurality of conductors extending along the flexible body, each conductor comprising a plurality of axially spaced-apart coiled segments and a plurality of linear segments residing between adjacent coiled segments;

at least one electrode disposed along the distal portion of the body and coupled to the plurality of conductors;

a dielectric disposed over the conductors;

a conductive shield disposed over the dielectric with the dielectric residing between the conductors and the conductive shield; and

a plurality of first capacitors, each first capacitor electrically connecting a respective one of the conductors to the shield,

wherein the coiled segments of the conductors, the dielectric, the conductive shield, and the plurality of capacitors define a plurality of RF traps that are tuned to a target RF frequency associated with an MRI system.

9. The lead of claim 8, wherein each of the plurality of first capacitors is coupled to the respective one of the conductors before a proximal end of one of the coiled segments of the respective one of the conductors.

10. The lead of claim 9, further comprising a plurality of second capacitors, each second capacitor coupled to a respective one of the conductors after a distal end of one of the coiled segments of the respective one of the conductors.

11. The lead of claim 10, wherein the second capacitors are tuning capacitors.

12. The lead of claim 8, wherein the target RF frequency is in a range from 1 MHz to 250 MHz.

13. The lead of claim 8, wherein the high impedance segments are positioned along the conductors so that adjacent high impedance segments are separated by a distance of less than one quarter of a wavelength of the target RF frequency.

14. The lead of claim 8, wherein at least some of the coiled segments of different conductors are co-wound together.

15. An MRI safe lead, comprising:

an elongate flexible body, the body having distal and proximal portions;

a plurality of conductors extending along the flexible body, each conductor comprising a plurality of axially spaced-apart coiled segments and a plurality of linear segments residing between adjacent coiled segments, wherein the conductors form a plurality of cowound arrangements, each arrangement comprises one of the coiled segments of each conductor axially cowound together;

at least one electrode disposed along the distal portion of the body and coupled to the plurality of conductors;

a dielectric disposed over the conductors; and

a conductive shield disposed over the dielectric with the dielectric residing between the conductors and the conductive shield;

wherein the coiled segments of the conductors are electrically coupled to the conductive shield.

16. The lead of claim 15, further comprising a plurality of first capacitors, each first capacitor electrically connecting a respective one of the conductors to the shield to define a RF short and low frequency open circuit.

17. The lead of claim 16, wherein each of the plurality of first capacitors is coupled to the respective one of the conductors before a proximal end of one of the coiled segments of the respective one of the conductors.

18. The lead of claim 17, further comprising a plurality of second capacitors, each second capacitor coupled to a respective one of the conductors after a distal end of one of the coiled segments of the respective one of the conductors.

19. The lead of claim 15, wherein the coiled segments of the conductors, the dielectric, and the conductive shield define a plurality of RF traps that are tuned to a target RF frequency associated with an MRI system.

20. The lead of claim 15, wherein the coiled segments of the conductors, the dielectric, and the conductive shield define a plurality of high impedance segments that are tuned to a target RF frequency associated with an MRI system.