Implantable neural electrode

• US 5,095,905 A
• Filed: 06/07/1990
• Issued: 03/17/1992
• 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:
  US07/536,286
• Time in Patent Office: 649 Days
• Field of Search: 128/784, 128/785, 128/802, 128/419 C, 128/642
• 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 implatable 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 system for coupling neural tissue to an electrical circuit comprising:

a. a central spine of an electrically insulating material;

b. a plurality of semi-rigid fingers of an electrically insulating material orthogonally attached to said central spine and curved about the same radius of curvature as said neural tissue wherein each of said plurality of semi-rigid fingers has an inner surface and wherein each of said plurality of semi-rigid fingers has a length less than a circumference of a circle having said same radius of curvature;

c. an electrical conductor positioned on said inner surface of a one of said plurality of fingers; and

d. means electrically coupled to said electrical conductor for electrically coupling said neural tissue to said electrical circuit.

2. An electrode system according to claim 1 wherein said plurality of semi-rigid fingers are molded with said central spine as a single piece.

3. An electrode system according to claim 2 wherein a first number of said semi-rigid fingers are attached to a first side of said central spine, and a second number of said semi-rigid fingers are attached to a second side of said central spine.

4. An electrode system according to claim 3 wherein said plurality of said semi-rigid fingers each have a length about one-half of the circumference of said same radius of curvature as said neural tissue.

5. An electrode system according to claim 4 wherein each of said first number of said semi-rigid fingers are staggered with respect to said second number of said semi-rigid fingers.

6. An electrode for mounting on a nerve comprising:

a. a generally cylindrical body comprising a longitudinal element and a plurality of flexible circumferentially directed elements mounted on the longitudinal element for forming said generally cylindrical body where each of said plurality of flexible circumferentially directed elements has a length less than the circumference of said generally cylindrical body; and

,

b. means mounted on the circumferential elements for delivering electricity to a nerve.

7. The method of stimulating a nerve with an implantable electrode comprising:

a. providing an electrode having curved flexible fingers;

b. spreading the fingers to form a longitudinal opening for receiving the nerve;

c. placing the electrode over the nerve and releasing the fingers to form a generally cylindrical shape around the nerve wherein said generally cylindrical shape is not completely enclosed; and

d. supplying an electrical signal to said electrode to stimulate said nerve.