Thin film implantable electrode and method of manufacture

• US 5,324,322 A
• Filed: 04/20/1992
• Issued: 06/28/1994
• Est. Priority Date: 04/20/1992
• Status: Expired due to Term

• Current Assignee: Case Western Reserve University
• Original Assignee: Case Western Reserve University
• Inventors: Ksienski, David A., Creasey, Graham H., Grill, Warren M. Jr., Veraart, Claude S., Mortimer, J. Thomas
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US07/871,352
• Time in Patent Office: 799 Days
• Field of Search: 128/639, 128/642, 128/644, 128/783-786, 128/804, 607/118
• US Class Current: 607/118
• 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 1/0556 Cuff electrodes

Abstract

A sheet (30) of polymeric material defines a cuff portion (A), a contact portion (B), and an interconnecting elongated lead portion (C). Using physical vapor deposition (PVD), chemical vapor deposition (CVD), or other thin film deposition techniques, a plurality of electrodes (12), contact pads (16), and interconnecting leads (14) are deposited on the base layer. An elastomer covering layer (18) is laminated to the base layer. The elastomeric covering layer is stretched along direction (24) before lamination, such that at least the cuff portion is elastomerically biased to curl into a spiral. Windows (20) are defined in the elastomeric portion to provide for electrical conduction between the electrodes (12) and nerve tissue about which the cuff electrode is wrapped. The electrodes are arced (FIG. 6) such that they are more recessed adjacent sides of the window than adjacent the center in order to provide a substantially uniform flux density across the electrode surface.

Claims

1. A method of manufacturing a cuff electrode comprising:

vapor depositing a thin electrically conductive film which defines electrodes, electrical leads, and electrical contacts on a surface of a flexible, insulating base sheet;

laminating a cover layer to the surface of the base sheet and at least portions of the electrically conductive film;

shaping the base sheet to define a cuff portion containing the electrodes, an electrical contact portion displaced from the cuff portion, the electrical contact portion containing the electrical contacts, and a thin, elongated flexible electrical lead portion connected between the cuff and electrical contact portions and containing at least part of the electrical leads;

contracting the cover layer such that the cover layer, the base sheet, and the electrically conductive film curl into a spiral.

2. The method as set forth in claim 1 further including defining windows through the cover layer in communication with at least portions of the electrodes to provide an electrically conductive path between the electrode and an interior of the spiral.

3. The method as set forth in claim 1 wherein the covering layer is an elastomeric material and wherein in the covering layer laminating step, the elastomeric material is stretched along a first direction and laminated to the cuff portion, the electrical lead portion, and the electrical contact portion, such that the cuff, lead, and contact portions curl into spirals as the covering layer contracts.

4. The method as set forth in claim 1 wherein the base sheet is a polymeric material.

5. The method as set forth in claim 1 further including contouring the electrodes such that the electrodes are arced and are more raised centrally and more recessed adjacent peripheral edges.

6. A method of manufacturing a cuff electrode comprising:

impregnating electrode and lead regions of a polymeric sheet with a first metal;

depositing a thin film of a second metal on the first metal impregnated electrode and lead regions of the polymeric sheet;

covering at least regions of the polymeric sheet surrounding the electrode regions with a cover layer;

contracting the cover layer such that the cover layer, the polymeric sheet, and the second metal film curl into a spiral.

7. The method as set forth in claim 6 wherein the first metal is titanium and the second metal is one of platinum, iridium, rhodium, palladium, nickel, gold, copper, and alloys thereof.

8. A method of manufacturing an electrode comprising:

on a flexible base layer defining an enlarged cuff portion, an enlarged electrical contact portion, and a narrow, elongated lead portion extending therebetween;

positioning a mask adjacent the base layer which mask defines electrodes on the cuff portion, contact pads on the contact portion, and electrical leads extending between the electrodes and contact pads along the elongated lead portion;

thin film vapor depositing electrodes, leads, and contact pads through the mask onto the base layer;

laminating a covering layer to at least the lead portion; and

,

contracting the covering layer along a selected direction such that the lead portion curls into a spiral.

9. The method as set forth in claim 8 further including forming the electrode such that the electrode is arced and more recessed adjacent its edges.

10. A cuff electrode, comprising:

a base layer defining a cuff portion, an electrical connection portion displaced from the cuff portion, and an elongated electrical lead portion extending between the cuff and electrical connection portions;

a plurality of electrode surfaces deposited on the cuff portion;

a plurality of electrical contact pads defined on the connection portion;

a plurality of electrical leads deposited in electrical communication between the electrode surfaces on the cuff portion and the connection pads on the electrical contact portion, the electrical leads being deposited along the electrical lead portion;

a covering layer laminated to at least the lead portion, the covering layer being contracted along a first direction such that the lead portion curls in a spiral.

11. The electrode as set forth in claim 10 wherein the covering layer covers the cuff portion and defines a window in conjunction with each electrode surface such that an electrically conductive path is defined to each electrode surface.

12. The electrode as set forth in claim 10 wherein the electrode surfaces, leads, and contact pads are vapor deposited thin films.

13. The electrode as set forth in claim 11 wherein the electrode surfaces are arced such that the electrodes are more recessed adjacent edges of the windows than adjacent a central portion of the windows.

14. A cuff electrode comprising:

a polymeric base layer defining a cuff including a plurality of electrode regions, a plurality of electrical connection regions, a plurality of elongated electrical lead regions extending between the electrode regions and the electrical connection regions, the electrode regions, the electrical connection regions, and the electrical lead regions being impregnated with first metal ions;

thin film electrodes deposited on the metal ion impregnated electrode regions of the base layer;

thin film electrical leads deposited on the metal ion impregnated electrical lead regions;

thin film electrical connection surfaces deposited on the metal ion impregnated electrical connection regions;

a covering layer which covers at least the thin film electrical leads and non-electrode regions of the base layer, the covering layer being contracted along a first direction such that the base layer, thin film electrodes, and covering layer are resiliently biased to curl into a spiral.