Separated-interface nerve electrode

• US 9,498,621 B2
• Filed: 03/16/2015
• Issued: 11/22/2016
• Est. Priority Date: 11/23/2009
• Status: Active Grant

• Current Assignee: Case Western Reserve University
• Original Assignee: Case Western Reserve University
• Inventors: Ackermann, Douglas M., Kilgore, Kevin L., Bhadra, Niloy, Bhadra, Narendra
• Primary Examiner(s): FAIRCHILD, MALLIKA DIPAYAN
• Application Number:
  US14/658,441
• Publication Number:
  US 20150182742A1
• Time in Patent Office: 617 Days
• US Class Current: 1/1
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61N 1/0436 Material of the electrode
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0556 Cuff electrodes
• CPC Class Codes: A61N 1/325 for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body electrodes for external use A61N1/0428
• CPC Class Codes: A61N 1/36067 Movement disorders, e.g. tremor or Parkinson disease stimulating motor muscle A61N1/36003
• CPC Class Codes: A61N 1/36103 Neuro-rehabilitation; Repair or reorganisation of neural tissue, e.g. after stroke

Abstract

Example ionic coupling electrodes are described. One example ionic conducting electrode includes a first portion that can be coupled to a single phase current source. The first portion carries current flow via electrons. The electrode includes a second portion to apply a current to a nerve tissue. The second portion carries current flow via ions. The second portion is positioned between the nerve tissue and the first portion to prevent the first portion from touching the nerve tissue. The current applied to the nerve tissue is produced in the second portion in response to a current that is present in the first portion. The current present in the first portion is provided from a single phase current source. The electrode may be used in applications including, but not limited to, nerve block applications and nerve stimulation applications.

Claims

1. A system comprising:

a current source to provide a monophasic current pulse of a single polarity;

a separated interface electrode, coupled to the current source, to apply the monophasic current pulse to a peripheral nerve to block conduction in the peripheral nerve, the separated interface electrode comprising;

a metal conductor connected to an electrical lead, wherein the electrical lead is connected to the current source; and

an ionically conductive medium (ICM) that is physically coupled to the metal conductor to create a first interface with the metal conductor and a second interface with the peripheral nerve;

wherein the ICM comprises a material designed to maintain a chemical reaction caused by the monophasic current pulse in physical proximity to the first interface to protect the peripheral nerve;

wherein the monophasic current pulse is a prolonged monophasic direct current (DC) waveform.

2. The system of claim 1, wherein the chemical reaction produces a reaction product that is reversible.

3. The system of claim 2, wherein the material at least one of reacts with and neutralizes the reaction product.

4. The system of claim 1, wherein the material comprises a polymer.

5. The system of claim 4, wherein the polymer comprises Nafion.

6. The system of claim 1, wherein the metal conductor has a surface area large enough to deliver a charge sufficient to block conduction in the peripheral nerve for conversion to an ionic signal for transmission to the peripheral nerve.

7. The system of claim 1, wherein the metal conductor is configured to transmit the electrical signal to the ICM.

8. The system of claim 7, wherein the ICM is configured to convert the monophasic current pulse to an ionic signal and deliver the ionic signal to block conduction in the peripheral nerve.

9. The system of claim 1, wherein the ICM is enclosed within a housing structure that exposes the ICM to the peripheral nerve.

10. The system of claim 1, wherein a surface area of the first interface is at least ten times larger than a surface area of the second interface.

11. The system of claim 1, wherein the material comprises a conductive electrolyte.

12. A method comprising:

providing, by a current source, a prolonged monophasic current pulse of a single polarity to a separated interface electrode;

applying, by the separated interface electrode, the prolonged monophasic current pulse to a peripheral nerve; and

blocking conduction in the peripheral nerve by the prolonged monophasic current pulse,

the separated interface electrode comprising;

a metal conductor connected to an electrical lead, wherein the electrical lead is connected to the current source; and

an ionically conductive medium (ICM) that is physically coupled to the metal conductor to create a first interface with the metal conductor and a second interface with the peripheral nerve;

wherein the ICM comprises a material designed to maintain a chemical reaction caused by the monophasic current pulse in physical proximity to the first interface to protect the peripheral nerve;

wherein the monophasic current pulse is a prolonged monophasic direct current (DC) waveform.