Shielded implantable medical lead with guarded termination

• US 9,216,286 B2
• Filed: 04/28/2010
• Issued: 12/22/2015
• Est. Priority Date: 04/30/2009
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stone, Richard T., Conroy, Mark J., Liu, Wanzhan, Salminen, Gary W.
• Primary Examiner(s): LEVICKY, WILLIAM J
• Application Number:
  US13/265,098
• Publication Number:
  US 20120035697A1
• Time in Patent Office: 2,064 Days
• Field of Search: 607/116
• US Class Current: 1/1
• CPC Class Codes: A61B 2090/3966 Radiopaque markers visible in an X-ray image
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61N 1/048 Electrodes characterised by a specific connection between lead and electrode
• CPC Class Codes: A61N 1/0488 Details about the lead
• 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 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/08 Arrangements or circuits for monitoring, protecting, controlling or indicating for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/3752 Details of casing-lead connections
• CPC Class Codes: A61N 2001/058 Fixing tools
• CPC Class Codes: A61N 2001/0582 Suture sleeves
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/4921 with bonding
• CPC Class Codes: Y10T 29/49227 Insulator making
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Implantable medical leads include a shield that is guarded at a termination by having a first portion and second portion of the shield, where the first portion is between a termination of the shield at the second portion and an inner insulation layer surrounding the filars. The first portion may reduce the coupling of RF energy from the termination of the shield at the second portion to the filars. The first and second portions may be part of a continuous shield, where the first and second portions are separated by an inversion of the shield. The first and second portions may instead be separate pieces. The first portion may be noninverted residing between the termination at the second portion and inner layers, or the first portion may be inverted to create first and second sub-portions. The shield termination at the second portion is between the first and second sub-portions.

Claims

1. An implantable medical system, comprising:

an implantable medical device;

an implantable medical lead connected to the implantable medical device, the implantable medical lead comprising;

an inner insulation layer surrounding at least one filar that is electrically connected to an electrode;

a shield surrounding the inner insulation layer, the shield comprising a first portion comprising braided wires and a second portion comprising braided wires, the first portion being positioned between the second portion and the inner insulation layer while being spaced apart from the second portion, wherein the first portion is axially longer than the second portion, the shield including an inversion that separates the first portion and the second portion, the second portion providing a point of termination of the shield with the first portion being located between the point of termination and the inner insulation layer; and

a first outer insulation layer that is electrically insulative and that is at least positioned between the first portion and the second portion of the shield with the first outer insulation layer being in direct contact with the second portion of the shield at the point of termination; and

an outer insulation layer surrounding the shield.

2. A method of shielding an implantable medical lead, comprising:

providing an inner insulation layer surrounding at least one filar that is electrically connected to an electrode;

providing a shield surrounding the inner insulation layer, the shield comprising a first portion and a second portion, the first portion being positioned between the second portion and the inner insulation layer while being spaced apart from the second portion, wherein providing the shield comprises providing a continuous shield that forms the first portion and the second portion, providing an inversion of the continuous shield that separates the first portion from the second portion, the second portion providing a point of termination of the shield with the first portion being located between the point of termination and the inner insulation layer; and

providing a first outer insulation layer that is electrically insulative and that is at least positioned between the first portion and the second portion of the shield with the first outer insulation layer being in direct contact with the second portion of the shield at the point of termination;

providing a second outer insulation layer surrounding the first portion and the second portion of the shield and surrounding the first outer insulation layer at least where the first outer insulation layer is positioned between the first and second portions of the shield.

3. The method of claim 2, wherein the first portion and the second portion comprise braided metal wires.

4. The method of claim 2, wherein the first portion is axially longer than the second portion.

5. An implantable medical lead, comprising:

an inner insulation layer surrounding at least one filar;

a shield surrounding the inner insulation layer, the shield comprising a first portion comprising braided wires and a second portion comprising braided wires, the first portion being positioned between the second portion and the inner insulation layer while being spaced apart from the second portion, wherein the first portion and the second portion are separate pieces, wherein the second portion provides a point of termination of the shield with the first portion being located between the point of termination and the inner insulation layer, wherein the first portion includes an inversion that separates the first portion into a first sub-portion and a second sub-portion, the first sub-portion being located between the second portion and the inner insulation layer and the second sub-portion being located on a side of the second portion opposite the first sub-portion such that the termination point of the second portion is between the first sub-portion and the second sub-portion;

a first outer insulation layer that is electrically insulative and that is between the second sub-portion and the second portion with the second sub-portion being in direct contact with the electrically insulative layer; and

an outer insulation layer surrounding the shield.

6. The implantable medical lead of claim 5, wherein the outer insulation surrounds the first portion and the second portion of the shield.

7. The implantable medical lead of claim 5, wherein the first sub-portion and the second sub-portion are axially shorter than the second portion.