Implantable neural electrode

• US 5,282,468 A
• Filed: 01/08/1992
• Issued: 02/01/1994
• Est. Priority Date: 06/07/1990
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Klepinski, Robert J.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US07/818,063
• Time in Patent Office: 755 Days
• Field of Search: 128/642, 128/784, 128/785, 128/802, 128/419 C, 607/118
• US Class Current: 600/377
• CPC Class Codes: A61N 1/0556 Cuff electrodes

Abstract

An electrode for establishing electrical contact with nerve tissue. The electrode is chronically implantable. The outer substrate of the electrode is a semi-rigid, body compatible, insulating material such as a chronically implantable polymer. The outer substrate is molded as a single structure having a central spine along the longitudinal axis of the electrode. A plurality of fingers extend orthogonally from the central spine, and are bent circularly about a radius of curvature approximating that of the nerve to be contacted. Each of the plurality of fingers is of sufficient length to extend approximately one-half of the distance around the outer circumference of the nerve tissue. The plurality of fingers extend from the central spine in one of two opposite directions causing the electrode structure to encompass a hollow cylinder having an inside diameter the same as the nerve. Because the plurality of fingers are not attached to each other, but to the central spine only, and the fingers are semi-rigid, the diameter of the hollow cylinder encompassed by the electrode structure can be readily increased by spreading the fingers during the implantation procedure. Also the diameter of the electrode is expandable to accommodate any swelling of the nerve tissue following implant. The inside surface of the encompassed cylinder is rendered conductive by the bonding or attachment of a conductor to the fingers and/or the central spine. An insertion tool spreads the fingers during the implant procedure and permits a minimum of exposure of the nerve tissue.

Claims

1. An electrode for providing electrical contact with a nerve comprising:

a. a first electrically insulative substrate having a first end and having a second end and having a length less than the circumference of a first circle having a first radius of curvature wherein said first radius of curvature is less than the radius of curvature of said nerve;

b. a second electrically insulative substrate having a first end and having a second end and having a length less than the circumference of a second circle having a second radius of curvature;

c. means coupled to said first end of said first electrically insulative substrate and said first end of said second electrically insulative substrate for releasably maintaining said first electrically insulative substrate and said second insulative substrate in position with respect to said nerve; and

,

d. first means coupled to said first electrically insulative substrate for establishing electrical contact with said nerve whenever said releasably maintaining means maintains said first electrically insulative substrate and said second insulative substrate in position with respect to said nerve.

2. An electrode according to claim 2 wherein said releasably maintaining means positions said first electrically insulative substrate in spaced relation to said second electrically insulative substrate.

3. An electrode according to claim 2 wherein said releasably maintaining means positions said first electrically insulative substrate away from contact with said second electrically insulative substrate.

4. An electrode according to claim 3 wherein said first radius of curvature is equal to second radius of curvature.

5. An electrode according to claim 4 wherein said releasably maintaining means is a central spine having a first edge and a second edge.

6. An electrode according to claim 5 wherein said central spine is attached to said first end of said first electrically insulative substrate at a right angle to said first edge.

7. An electrode according to claim 6 wherein said first electrically insulative substrate is semi-rigid.

8. An electrode according to claim 7 wherein said second electrically insulative substrate is semi-rigid.

9. An electrode according to claim 8 wherein said second electrically insulative substrate is attached to said central spine at a right angle to said first edge.

10. An electrode according to claim 8 wherein said second electrically insulative substrate is attached to said central spine at a right angle to said second edge.