Method for fabrication of low-polarization implantable stimulation electrode

• US 8,155,754 B2
• Filed: 01/25/2005
• Issued: 04/10/2012
• Est. Priority Date: 01/25/2005
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Nygren, Lea A., Coles, James A. Jr., Brabec, Scott J., Rose, Randy G.
• Primary Examiner(s): Getzow, Scott
• Assistant Examiner(s): PATTON, AMANDA K
• Application Number:
  US11/042,649
• Publication Number:
  US 20060167536A1
• Time in Patent Office: 2,632 Days
• Field of Search: 607/121, 607/119, 607/122
• 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: B24C 1/06 for producing matt surfaces, e.g. on plastic materials, on glass
• CPC Class Codes: B24C 3/322 for electrical components
• CPC Class Codes: C23C 28/32 including at least one pure metallic layer
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing

Abstract

A method for fabricating an implantable medical electrode includes roughening the electrode substrate, applying an adhesion layer, and depositing a valve metal oxide coating over the adhesion layer under conditions optimized to minimize electrode impedance and post-pulse polarization. The electrode substrate may be a variety of electrode metals or alloys including titanium, platinum, platinum-iridium, or niobium. The adhesion layer may be formed of titanium or zirconium. The valve metal oxide coating is a ruthenium oxide coating sputtered onto the adhesion layer under controlled target power, sputtering pressure, and sputter gas ratio setting optimized to minimize electrode impedance and post-pulse polarization.

Claims

1. An implantable medical electrode, comprising:

an electrode substrate roughened using a mechanical, non-chemical technique,

an adhesion layer covering at least a portion of the mechanically-roughened electrode substrate, and

an outer valve metal oxide coating comprising ruthenium oxide covering the adhesion layer to minimize post-pulse polarization voltage of the electrode,

the adhesion layer preventing delamination of the outer valve metal oxide coating during application of an electrical load.

2. The electrode of claim 1 wherein the adhesion layer being a layer of one of titanium and zirconium.

3. The electrode of claim 1 wherein the adhesion layer being less than about 1500 angstroms in thickness.

4. The electrode of claim 3 wherein the valve metal oxide coating is up to about 15 microns in thickness.

5. The implantable medical electrode of claim 1 wherein the electrode comprises an active fixation hook type electrode.

6. An implantable medical electrode, comprising:

an electrode substrate roughened using a mechanical, non-chemical technique,

a layer consisting of one of titanium and zirconium, the layer covering the mechanically-roughened electrode substrate to eliminate the effects of spontaneous oxide layer formation on the electrode substrate, and

a ruthenium oxide coating covering the layer to minimize post-pulse polarization voltage of the electrode,

the layer preventing delamination of the ruthenium oxide coating during application of an electrical biphasic load.

7. An implantable medical electrode, comprising:

an electrode substrate, wherein the electrode substrate is a grit-blasted mechanically-roughened electrode substrate,

an adhesion layer covering at least a portion of the mechanically-roughened electrode substrate, and

an outer valve metal oxide coating comprising ruthenium oxide covering the adhesion layer to minimize post-pulse polarization voltage of the electrode,

the adhesion layer preventing delamination of the outer valve metal oxide coating during application of an electrical load.