ADJUSTABLE NERVE ELECTRODE

• US 20110125216A1
• Filed: 11/18/2010
• Published: 05/26/2011
• Est. Priority Date: 11/23/2009
• Status: Active Grant

• Current Assignee: Case Western Reserve University
• Original Assignee: Case Western Reserve University
• Inventors: Bhadra, Narendra, Ackermann, Douglas Michael JR., Bhadra, Niloy, Payer, Joe, KILGORE, Kevin
• Granted Patent: US 8,843,188 B2
• Time in Patent Office: Days
• US Class Current: 607/46
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0556 Cuff electrodes
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration

Abstract

Example adjustable electrodes are described. One example adjustable electrode includes two or more contacts configured to selectively deliver high frequency alternating current (HFAC) to a nerve in an amount sufficient to produce an HFAC nerve conduction block in the nerve. The example adjustable electrode also includes a logic configured to selectively control which of the two or more contacts deliver HFAC to the nerve to control whether the nerve electrode is in a first (e.g., onset response mitigating) configuration or in a second (e.g., HFAC nerve conduction block maintenance) configuration. The electrode may be used in applications including, but not limited to, nerve block applications, and nerve stimulation applications. The electrode may be adjusted by changing attributes including, but not limited to, the number, length, orientation, distance between, surface area, and distance from a nerve of contacts to be used to deliver the HFAC.

Claims

1. A method, comprising:

controlling an adjustable nerve electrode to enter a first configuration;

while the adjustable nerve electrode is in the first configuration, applying a first high frequency alternating current (HFAC) through the adjustable nerve electrode, where the first HFAC has a threshold current sufficient to establish an HFAC nerve conduction block in a nerve;

controlling the adjustable nerve electrode to enter an HFAC nerve conduction block maintenance configuration; and

while the adjustable nerve electrode is in the HFAC nerve conduction block maintenance configuration, applying a second HFAC through the adjustable nerve electrode, where the second HFAC has a current sufficient to maintain the HFAC nerve conduction block in the nerve.

2. The method of claim 1, where the first configuration is an onset response mitigating configuration.

3. The method of claim 1, where controlling the adjustable nerve electrode to enter the onset response mitigating configuration comprises controlling the geometry of a set of contacts in the adjustable nerve electrode, where the set of contacts are configurable to selectively apply HFAC to the nerve.

4. The method of claim 3, where controlling the geometry of the set of contacts comprises selecting a first subset of the set of contacts to deliver the first HFAC.

5. The method of claim 4, where the first subset is selected as a function of one or more of:

a desired number of contacts to be used to deliver the first HFAC,

a desired length of a contact to be used to deliver the first HFAC,

a desired orientation of a contact to be used to deliver the first HFAC;

a desired distance between contacts to be used to deliver the first HFAC,

a desired surface area of a contact to be used to deliver the first HFAC,

a desired shape of a contact to be used to deliver the first HFAC, and

a desired distance between a contact and the nerve.

6. The method of claim 5, where the first subset is selected to minimize the threshold current.

7. The method of claim 5, where the first subset is selected to maximize one or more of, neuronal membrane depolarization in the nerve, extracellular activation function produced by the electrode, and the degree of synergistic contribution to membrane depolarization by sodium currents at multiple nodes of Ranvier in the nerve.

8. The method of claim 5, where the first subset is selected to minimize power consumption.

9. The method of claim 3, where the first subset is selected to minimize one or more of, a duration of the onset response, and an intensity of the onset response.

10. The method of claim 1, where the adjustable nerve electrode is controlled to enter the first configuration in response to a control signal provided by one of, a switch, a circuit external to the electrode, a circuit internal to the electrode, a control logic external to the electrode, and a control logic internal to the electrode.

11. The method of claim 1, where controlling the adjustable nerve electrode to enter the HFAC nerve conduction block maintenance configuration comprises controlling the geometry of the set of contacts in the adjustable nerve electrode.

12. The method of claim 11, where controlling the geometry of the set of contacts comprises selecting a second subset of the set of contacts to deliver the second HFAC.

13. The method of claim 12, where the second subset is selected as a function of one or more of:

a desired number of contacts to be used to deliver the second HFAC,

a desired length of a contact to be used to deliver the second HFAC,

a desired orientation of a contact to be used to deliver the second HFAC;

a desired distance between contacts to be used to deliver the second HFAC,

a desired surface area of a contact to be used to deliver the second HFAC,

a desired shape of a contact to be used to deliver the second HFAC, and

a desired distance between a contact and the nerve.

14. The method of claim 13, where the second subset is selected to minimize the second HFAC.

15. The method of claim 5, where the second subset is selected as a function of one or more of:

a desired number of contacts to be used to deliver the second HFAC,

a desired length of a contact to be used to deliver the second HFAC,

a desired orientation of a contact to be used to deliver the second HFAC;

a desired distance between contacts to be used to deliver the second HFAC,

a desired surface area of a contact to be used to deliver the second HFAC,

a desired shape of a contact to be used to deliver the second HFAC, and

a desired distance between a contact and the nerve;

and

where the second subset is selected to minimize the second HFAC.

16. A method, comprising:

suppressing conduction in a nerve by applying an HFAC block through a variable geometry nerve electrode having a set of contacts that are configurable to selectively apply HFAC to a nerve,

where the HFAC block and the variable geometry nerve electrode are configured to facilitate recovery of conduction in the nerve substantially instantaneously after removal of the HFAC block.

17. The method of claim 16, where suppressing conduction comprises establishing the HFAC block by applying a first HFAC to the nerve, where the first HFAC has a threshold current sufficient to establish the HFAC block.

18. The method of claim 17, where the first HFAC is applied while the variable geometry nerve electrode is in a first geometry, where the first geometry is defined by one or more of, a first number of contacts used to apply the first HFAC, a first distance between contacts used to apply the first HFAC, a first surface area of contacts used to apply the first HFAC, a first shape of a contact used to apply the first HFAC, a first length of a contact used to apply the first HFAC, a first orientation of a contact used to apply the first HFAC, and a first distance between a contact and the nerve.

19. The method of claim 18, where suppressing conduction comprises maintaining the HFAC block by applying a second HFAC to the nerve, where the second HFAC has a current sufficient to maintain the HFAC block.

20. The method of claim 19, where the second HFAC is applied while the variable geometry nerve electrode is in a second geometry, where the second geometry is defined by one or more of, a second number of contacts used to apply the second HFAC, a second distance between contacts used to apply the second HFAC, a second surface area of contacts used to apply the second HFAC, a second shape of a contact used to apply the second HFAC, a second length of a contact used to apply the second HFAC, a second orientation of a contact, and a second distance between a contact and the nerve.

21. The method of claim 20, where the first geometry is selected to minimize the threshold current by maximizing neuronal membrane depolarization in the nerve, and where the second geometry is selected to minimize the second HFAC.

22. The method of claim 20, where the first geometry is selected to minimize power consumption and where the second geometry is selected to minimize power consumption.

23. An electrode, comprising:

two or more contacts configured to selectively deliver high frequency alternating current (HFAC) to a nerve in an amount sufficient to produce an HFAC nerve conduction block in the nerve; and

a logic configured to selectively control which of the two or more contacts deliver HFAC to the nerve to control whether the nerve electrode is in an onset response mitigating configuration or an HFAC nerve conduction block maintenance configuration.

24. The electrode of claim 23, where the onset response mitigating configuration is configured to minimize a threshold current required to establish the HFAC nerve conduction block by controlling one or more of,

a desired number of contacts to be used to deliver the HFAC,

a desired length of a contact to be used to deliver the HFAC,

a desired orientation of a contact to be used to deliver the HFAC,

a desired distance between contacts to be used to deliver the HFAC,

a desired surface area of a contact to be used to deliver the HFAC,

a desired shape of a contact to be used to deliver the HFAC, and

a desired distance between a contact and the nerve.

25. The electrode of claim 24, where the HFAC nerve conduction block maintenance configuration is configured to minimize a current required to maintain the HFAC nerve conduction block by controlling one or more of,

a desired number of contacts to be used to deliver the HFAC,

a desired length of a contact to be used to deliver the HFAC,

a desired orientation of a contact to be used to deliver the HFAC,

a desired distance between contacts to be used to deliver the HFAC,

a desired surface area of a contact to be used to deliver the HFAC,

a desired shape of a contact to be used to deliver the HFAC, and

a desired distance between a contact and the nerve.

26. The electrode of claim 23, where the onset response mitigating configuration is configured to maximize neuronal membrane depolarization in the nerve.

27. The electrode of claim 23, where the logic is controlled to select contacts to apply HFAC to the nerve in response to one or more of, an external signal originating external to the electrode, and an internal signal originating internal to the electrode.