Asymmetric single electrode cuff for generation of unidirectionally propagating action potentials for collision blocking

• US 4,649,936 A
• Filed: 10/11/1984
• Issued: 03/17/1987
• Est. Priority Date: 10/11/1984
• Status: Expired due to Term

• Current Assignee: Case Western Reserve University
• Original Assignee: Case Western Reserve University
• Inventors: Ungar, Ira J., Mortimer, J. Thomas
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US06/659,781
• Time in Patent Office: 887 Days
• Field of Search: 128/784-785, 128/642, 128/419 C, 128/419 R, 128/802, 128/421
• US Class Current: 607/118
• CPC Class Codes: A61N 1/0556 Cuff electrodes

Abstract

A single electrode, asymmetric electrode cuff (B) is disposed around a nerve trunk (A). A signal generator (C) is connected between a cathode (20) disposed asymmetrically in the electrode cuff and an anode (22) disposed in an electrically conductive relationship within the body tissue. The signal generator applies a stimulus signal (FIG. 3) which generates unidirectionally propagating action potentials on the nerve trunk. The electrode cuff includes a dielectric sleeve (10) in which the cathode is positioned a first distance (L1) from an escape end (14) and a second distance (L2) from an arrest end (16). The first distance is at least 1.7, and preferably about 7, times the second distance. This asymmetry causes a primary or forward stimulus signal current (30) to be correspondingly greater than a secondary or reverse current (32).

Claims

1. An asymmetric single electrode cuff system comprising:

a sleeve of electrically non-conductive, biocompatible material, the sleeve defining an axial passage therethrough from a first end to a second end, which passage is adapted to receive a nerve trunk therethrough,

one and only one annular electrode extending radially around an inner surface of the axial sleeve passage, the electrode being disposed closer to the first end than the second end,

a remote electrode physically disconnected and displaced from the axial sleeve, and,

a signal generator electrically connected with the axial sleeve electrode and the remote electrode for applying an oscillating current thereacross.

2. The electrode cuff system as set forth in claim 1 wherein the annular electrode defines a circular passage therethrough.

3. An asymmetric single electrode cuff comprising:

a sleeve of electrically non-conductive, biocompatible material, the sleeve defines an axial passage therethrough from a first end to a second end, which passage is adapted to receive a nerve trunk therethrough, and,

one and only one annular electrode is disposed in the axial sleeve passage, the electrode is disposed a first distance from the first end and a second distance from the second end, the first distance is at least 1.7 times as large as the second distance.

4. The electrode cuff as set forth in claim 3 wherein the first distance is 7 times the second distance.

5. The electrode cuff as set forth in claim 4 wherein the first distance is 21 mm, the second distance is 3 mm, and the electrode has an inner diameter of about 1 mm to 2 mm.

6. An action potential blocking system for selectively, unidirectionally blocking orthodromic action potentials passing along a nerve trunk, the system comprising:

an electrode cuff including only a single electrode encircled by a dielectric sleeve, the dielectric sleeve extending a first distance from one side of the single electrode to an escape end and extending a second distance from the other side of the single electrode to an arrest end, the first distance being greater than the second distance, the single electrode and dielectric sleeve being disposed around the nerve trunk;

a remote electrode disposed physically displaced and separated from the electrode cuff;

a signal generator electrically connected with the electrodes for applying a stimulus current across the electrodes to generate antidromic action potentials in the nerve trunk to collision block the orthodromic action potentials.

7. The blocking system as set forth in claim 6 wherein the signal generator includes an oscillator for generating the stimulus current such that the stimulus current oscillates cylically, each oscillation cycle of the stimulus current having a first polarity portion and an opposite polarity portion.

8. The blocking system as set forth in claim 6 wherein the first distance is at least 1.7 times the second distance.

9. The blocking system as set forth in claim 8 wherein the first distance is about 7 times the second distance.

10. A method of blocking orthodromic action potentials traveling along a nerve trunk in a first direction, the method comprising:

positioning an electrode cuff, which has a dielectric sleeve extending from an escape end to an arrest end and only a single electrode disposed in the dielectric sleeve closer to the arrest end than the escape end, around the nerve trunk such that the orthodromic action potentials travel from the escape end toward the arrest end;

positioning a remote electrode physically separate from the cuff in an electrically conductive relationship with the nerve trunk;

applying an oscillating, bipolar stimulating electric signal across the electrodes, the bipolar signal including a first polarity portion of each cycle for generating antidromic action potentials traveling unidirectionally along the nerve trunk in an opposite direction to the orthodromic action potentials, the antidromic action potentials collision blocking the orthodromic action potentials from traveling past the electrode cuff.

11. An action potential blocking system for selectively, unidirectionally blocking orthodromic action potentials passing along a nerve trunk, the system comprising:

an electrode cuff including one and only one electrode encircled by a dielectric sleeve, the dielectric sleeve extending a first distance from one side of the single electrode to an escape end and extending a second distance from the other side of the single electrode to an arrest end, the single electrode and dielectric sleeve being disposed around the nerve trunk;

a remote electrode displaced separate from the electrode cuff;

an oscillating means for generating a cylically oscillating current which has oscillation cycles that each include a first polarity portion and a second polarity portion, the first and second polarity portions of each cycle having a balanced net change flow; and

,

a means for applying the oscilalting current across the cuff electrode and the remote electrode such that the first polarity portions generate unidirectional antidromic action potentials traveling along the nerve trunk from the electrode cuff escape end and the second polarity portions balance net charge flow in the nerve trunk without generating an action potential.

12. The blocking system as set forth in claim 11 wherein the first distance is at least 1.7 times the second distance.

13. The blocking system as set forth in claim 12 wherein the first distance is about 7 times the second distance.