Electrode construction for implantable medical electrical leads

• US 10,232,167 B2
• Filed: 10/23/2014
• Issued: 03/19/2019
• Est. Priority Date: 05/07/2014
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Nazareth, Vishal R, Boser, Gregory A, Gaunt, Lorraine R
• Primary Examiner(s): Manuel, George
• Application Number:
  US14/521,958
• Publication Number:
  US 20150320995A1
• Time in Patent Office: 1,608 Days
• 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 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/0563 specially adapted for defibrillation or cardioversion
• CPC Class Codes: A61N 1/0565 Electrode heads
• CPC Class Codes: Y10T 29/49206 by powder metallurgy

Abstract

An implantable electrode for electrical stimulation of a body, for example, being a component of an implantable medical electrical lead, is preferably in the form of a coiled conductor wire, wherein the wire is formed by a tantalum (Ta) core directly overlaid with a platinum-iridium (Pt—Ir) cladding. When a maximum thickness of the Pt—Ir cladding defines a cladded zone between an outer, exposed surface of the electrode and the Ta core, a surface of the Ta core encroaches into the cladded zone by no more than approximately 50 micro-inches. The tantalum core may be cold worked to improve surface quality or formed from a sintered and, preferably, grain stabilized tantalum.

Claims

1. An implantable electrode lead for electrical stimulation of a body, comprising:

an elongated insulative lead body;

a conductor within the lead body; and

an electrode coupled to the conductor comprising a coiled wire comprising a platinum-iridium cladding directly overlaying an un-smoothed melt quality tantalum core, the cladding forming an exposed surface of the electrode and having a maximum thickness of less than three microns.

2. An implantable lead according to claim 1 wherein the maximum thickness of the cladding is one micron.

3. An implantable lead according to claim 2 wherein the cladding of about 1 micron does not expose the melt quality tantalum core.

4. An implantable lead according to claim 1 wherein the maximum thickness of the cladding is two microns.

5. A method of producing an implantable electrode lead for electrical stimulation of a body of the type comprising an elongated insulative lead body, a conductor within the lead body;

and an electrode coupled to the conductor, comprising;

including as the electrode a coiled wire comprising a platinum-iridium cladding directly overlaying an un-smoothed melt quality tantalum core, the core wire cladding forming an exposed surface of the electrode and having a maximum thickness of less than three microns.

6. A method of producing an implantable electrode lead for electrical stimulation of a body of the type comprising an elongated insulative lead body, a conductor within the lead body and an electrode coupled to the conductor, comprising:

employing Anomet, Inc to apply a platinum-iridium cladding to a tantalum core to produce an electrode wire in which the cladding forms an exposed surface of the electrode having a maximum thickness of less than three microns; and

coiling the wire to form the electrode and further comprising mounting the coiled wire electrode extending outward from the insulative lead body.

7. A method according to claim 6 comprising mounting the conductor within the lead body extending proximally from the coiled wire electrode.

8. A method according to claim 7 wherein the coiled wire electrode is an exposed distal portion of the conductor.

9. A method according to claim 7 wherein the coiled wire electrode is coupled to the conductor by a crimp joint and/or a weld joint.