DEVICE AND METHODS FOR NON-INVASIVE ELECTRICAL STIMULATION AND THEIR USE FOR VAGAL NERVE STIMULATION

• US 20110230938A1
• Filed: 03/30/2011
• Published: 09/22/2011
• Est. Priority Date: 03/20/2009
• Status: Active Grant

• Current Assignee: Electrocore, Llc
• Original Assignee: Electrocore, Llc
• Inventors: Raffle, John T., Errico, Joseph P., Simon, Bruce
• Granted Patent: US 8,874,205 B2
• Time in Patent Office: Days
• US Class Current: 607/63
• CPC Class Codes: A61N 1/36014 External stimulators, e.g. with patch electrodes external pacemakers A61N1/3625
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/36034 specified by the stimulation parameters
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals

Abstract

A non-invasive electrical stimulation device shapes an elongated electric field of effect that can be oriented parallel to a long nerve, such as a vagus nerve in a patient'"'"'s neck, producing a desired physiological response in the patient. The stimulator comprises a source of electrical power, at least one electrode and a continuous electrically conducting medium in which the electrode(s) are in contact. The stimulation device is configured to produce a peak pulse voltage that is sufficient to produce a physiologically effective electric field in the vicinity of a target nerve, but not to substantially stimulate other nerves and muscles that lie between the vicinity of the target nerve and patient'"'"'s skin. Current is passed through the electrodes in bursts of preferably five sinusoidal pulses, wherein each pulse within a burst has a duration of preferably 200 microseconds, and bursts repeat at preferably at 15-50 bursts per second.

Claims

1. An apparatus for applying energy transcutaneously to a target region within a patient comprising:

a source of energy for generating an electric field;

a conduction medium through which an electrical current penetrates the outer skin surface of the patient;

at least one electrode; and

wherein the source of energy and the conduction medium are configured to shape the electrical field such that energy from the electric current is sufficient to modulate a nerve at the target region; and

wherein the electric current is not sufficient to substantially modulate a nerve or muscle between the outer skin surface and the target region.

2. The apparatus of claim 1 wherein the source of energy, the electrode, and the conduction medium are configured to orient the electric field substantially parallel with the nerve at the target region.

3. The apparatus of claim 1 further comprising an enclosure for housing the source of energy and the conduction medium, wherein the source of energy comprises a source of electrical energy coupled to first and second electrodes.

4. The apparatus of claim 3 wherein the conduction medium is positioned in electrical contact with a portion of an outside surface of the enclosure to at least partially restrict the direction of the electric field.

5. The apparatus of claim 1 wherein the target region is a nerve located at least 1-2 cm beyond the outer skin surface.

6. The apparatus of claim 1 where the target region is a nerve is located at least 2-5 cm beyond the outer skin surface.

7. The apparatus of claim 1 wherein the electrical field has an amplitude of greater than 10 V/m.

8. The apparatus of claim 1 wherein the electrical field has a gradient of greater than 2 V/m/mm.

9. The apparatus of claim 1 wherein the electrical field comprises bursts of pulses with a frequency of about 5 to about 100 bursts per second.

11. The apparatus of claim 1 wherein the electrical field comprises bursts of between 1 and 20 pulses with each pulse about 50-1000 microseconds in duration.

12. The apparatus of claim 1 wherein the conductive medium comprises a solution of electrolytes.

13. The apparatus of claim 1 wherein the conduction medium comprises a conductive gel.

14. The apparatus of claim 1 wherein at least a portion of the outer enclosure comprises material that is permeable to charged particles.

15. The apparatus of claim 14 wherein the portion of the outer enclosure comprises an ion-permeable material.

10. The apparatus of claim 10 wherein the pulses are full sinusoidal waves.

16. A method for modulating one or more nerves at a target region within a body of a patient comprising:

positioning an electrically permeable surface of an enclosure in contact with an outer skin surface of the patient'"'"'s body;

generating an electric field within the enclosure; and

conducting an electric current from one or more electrodes in the enclosure through a conductive medium within the enclosure and through the outer skin surface of the patient'"'"'s body such that the electric current is sufficient to modulate one or more nerves at the target region.

17. The method of claim 16 wherein the positioning step is carried out by positioning a portion of a handheld device in contact with the outer skin surface of the patient'"'"'s body.

18. The method of claim 16 wherein the conducting step is carried out by spacing the one or more electrodes away from the outer skin surface and conducting the electric current from the electrodes through the conductive medium and through the electrically permeable surface of the enclosure to the outer skin surface.

19. The method of claim 16 wherein the electrical field has an amplitude of greater than 10 V/m.

20. The method of claim 16 wherein the generating step is carried out by generating bursts of pulses with a frequency of about 5 to about 100 bursts per second.

21. The method of claim 20 wherein the pulses are full sinusoidal waves.

22. The method of claim 20 wherein the electrical field comprises bursts of between 1 and 20 pulses with each pulse about 50-1000 microseconds in duration.

23. The method of claim 16 further comprising substantially constraining the electric current from modulating one or more nerves in a second region between the outer skin surface and the target region.

24. The method of claim 23 wherein the constraining step comprises positioning the conducting medium around a portion of the electrode such that the direction of the electrical field is constrained within the conducting medium.

25. The method of claim 23 wherein the constraining step comprises positioning an electrical insulator around a portion of the electrode such that the component of the electric field normal to the surface of the insulator is zero.

26. A device for modulating one or more nerves within a body of a patient comprising:

a handheld device having an outer housing with an interior and an electrically permeable surface configured for contact with an outer skin surface of a patient; and

a source of electrical energy housed within the interior of the outer housing and configured to apply an electrical impulse through the electrically permeable surface of the outer housing transcutaneously through an outer skin surface of the patient to a nerve at a target region beneath the outer skin surface.

27. The device of claim 26 wherein the electrical impulse is sufficient to modulate a nerve within the target region and insufficient to substantially modulate nerve(s) in the vicinity of the outer skin surface.

28. The device of claim 26 wherein the electrical impulse is sufficient to modulate a nerve at least approximately 1-2 cm below the outer skin surface.

29. A device for directing a therapeutic electric current in tissue comprising:

at least two electrodes within an enclosure configured to generate electric fields;

a conduit containing a conductive medium located outside of the at least two electrodes, said conducting medium configured to contact the tissue at two spatially distinct locations; and

wherein said conduit is positioned relative to the at least electrodes such that electric fields drive a current through the conductive medium and through the tissue.

30. A therapeutic device for applying an electric field to a region of tissue, comprising:

a plurality of first elements, each of said first elements producing an electric field; and

a second element containing a conductive medium positioned relative to the first elements such that an electric field is produced in said conductive medium by the electric field in each of said first elements.

31. The device of claim 30 further comprising first and second conductive interfacing elements disposed at different positions on the surface of said second element, said interfacing elements being positioned to carry electrical current to and from said conductive medium, such that contact between the interfacing elements and tissue permits electrical current to flow through the tissue.

32. A device for applying a therapeutic electric signal to tissue, comprising:

a first element containing an electric field;

a volume of conductive medium;

a non-conductive housing element containing said first element and the volume of conductive medium; and

a pair of electrically conductive ports in said housing, positionable against the tissue and configured to allow electric current to flow between the volume of conductive medium and the tissue, through the ports.

33. The device of claim 32 wherein the conductive medium is contained within the non-conductive housing such that current produced by the first element cannot flow solely within the non-conductive housing when the ports are positioned against the tissue.

34. A device for applying a therapeutic electric signal to a target region within a patient'"'"'s body comprising:

at least two first elements, each containing an electrode;

a non-conductive housing element containing each of the first elements and a volume of electrically conductive medium;

and a pair of electrically conductive ports in said housing, positionable against tissue of the patient'"'"'s body and configured to allow electric current to flow between the volume of conductive medium and the tissue, through the ports;

wherein each of said first elements is positionable relative to the tissue such that electrical fields penetrate into said tissue and such that current cannot flow solely within said housing.

35. A device for applying a therapeutic electric signal to a target region within a patient'"'"'s body, comprising:

a first element containing an electric field;

a non-conductive housing containing the first element that is positionable in close proximity to an outer skin surface of the patient'"'"'s body such that an electric field exists beneath the outer skin surface;

a volume of conductive medium having a shape that is constrained by the non-conductive housing; and

one or more electrically conductive ports in the non-conductive housing, positionable against the outer skin surface and configured to allow electric current to flow between the volume of conductive medium and the target region, through the outer skin surface.