Devices and methods for non-invasive capacitive electrical stimulation and their use for vagus nerve stimulation on the neck of a patient
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.
1. An apparatus for modulating a nerve within a body of a patient, the apparatus comprising:
a source of energy that generates a single signal comprising an electrical impulse;
a first electrode and a second electrode coupled to the source of energy;
an interface coupled to the first electrode and the second electrode, wherein the interface comprises a first membrane and a second membrane; and
wherein the source of energy delivers the electrical impulse, based on the single signal, from the electrode through the interface and the outer skin surface to the nerve, as the interface contacts an outer skin surface of the patient, and thereby modulates the nerve, wherein the electrical impulse comprises bursts of pulses with a silent intra-burst interval between each of the bursts based on the single signal, wherein each of the bursts has a frequency of about 5 Hz to about 100 Hz and each of the pulses has a duration from about 50 microseconds to about 1000 microseconds,
wherein the first electrode corresponds to the first membrane and the second electrode corresponds to the second membrane and wherein each electrode is spaced from its corresponding membrane by a distance of about 0.25 to about 4 times a diameter of its corresponding membrane.
2. The apparatus of claim 1 , further comprising a housing having an outer enclosure housing the electrode and the source of energy, wherein at least a portion of the outer enclosure comprises the interface.
3. The apparatus of claim 2 , wherein the interface comprises a material that is permeable to charged particles.
4. The apparatus of claim 2 , wherein the interface comprises a dielectric material.
5. The apparatus of claim 2 , wherein the interface comprises a porous material.
6. The apparatus of claim 2 , wherein the interface comprises stainless steel.
7. An apparatus for modulating a vagus nerve within a body of a patient, the apparatus comprising:
a source of energy that generates a single signal comprising an electrical impulse;
an electrode coupled to the source of energy;
an interface coupled to the electrode; and
wherein the source of energy delivers the electrical impulse, based on the single signal, from the electrode through the interface and the outer skin surface to the vagus nerve, as the interface contacts an outer skin surface of a neck of the patient, and thereby modulates the vagus nerve, wherein the electrical impulse comprises bursts of pulses with a silent intra-burst interval between each of the bursts based on the single signal, wherein each of the bursts has a frequency of about 5 Hz to about 100 Hz and each of the pulses has a duration from about 50 microseconds to about 1000 microseconds.
8. The apparatus of claim 7 , further comprising a housing having an outer enclosure housing the electrode and the source of energy, wherein at least a portion of the outer enclosure comprises the interface.
9. The apparatus of claim 8 , wherein the interface comprises a material that is permeable to charged particles.
10. The apparatus of claim 8 , wherein the interface comprises a dielectric material.
11. The apparatus of claim 8 , wherein the interface comprises a porous material.
12. The apparatus of claim 8 , wherein the interface comprises stainless steel.
13. A device for modulating a nerve within a body of a patient, the device comprising:
an enclosure with an interior;
an interface that contacts an outer skin surface of the patient, wherein the enclosure supports the interface;
a source of energy housed within the interior, wherein the source of energy generates a single signal comprising an electrical impulse;
an electrode housed within the interior; and
wherein the source of energy applies the electrical impulse, based on the single signal, through the interface, as the interface contacts the outer skin surface, transcutaneously, through the outer skin surface to the nerve, and thereby modulates the nerve, wherein the electrical impulse comprises bursts of pulses with a silent intra-burst interval between each of the bursts based on the single signal, wherein each of the bursts has a frequency of about 5 Hz to about 100 Hz and each of the pulses has a duration from about 50 microseconds to about 1000 microseconds, wherein the electrical impulse modulates a vagus nerve within the patient and is insufficient to modulate a nerve in a vicinity of the outer skin surface.
14. The device of claim 13 , wherein the bursts of pulses have a frequency of about 5 Hz to about 100 Hz.
15. The device of claim 13 , wherein the interface comprises a material that is permeable to charged particles.
16. The device of claim 13 , wherein the interface comprises a dielectric material.
17. The device of claim 13 , wherein the interface comprises a porous material.
18. The device of claim 13 , wherein the interface comprises stainless steel.
19. The device of claim 13 , wherein each of the bursts of pulses comprises between about 2 to about 20 pulses.
20. A device for modulating a nerve within a body of a patient, the device comprising:
an enclosure with an interior;
an interface that contacts an outer skin surface of the patient, wherein the enclosure supports the interface;
a source of energy housed within the interior, wherein the source of energy generates a single signal comprising an electrical impulse and an electric field at the nerve having an amplitude of greater than about 10 V/m;
an electrode housed within the interior; and
wherein the source of energy applies the electrical impulse, based on the single signal, through the interface, as the interface contacts the outer skin surface, transcutaneously, through the outer skin surface to the nerve, and thereby modulates the nerve, wherein the electrical impulse comprises bursts of pulses with a silent intra-burst interval between each of the bursts based on the single signal, wherein each of the bursts has a frequency of about 5 Hz to about 100 Hz and each of the pulses has a duration from about 50 microseconds to about 1000 microseconds.
21. The device of claim 20 , wherein the amplitude is about 600 V/m or less.
22. A device for modulating a nerve within a body of a patient, the device comprising:
an enclosure with an interior;
an interface that contacts an outer skin surface of the patient, wherein the enclosure supports the interface;
a source of energy housed within the interior, wherein the source of energy generates a single signal comprising an electrical impulse;
an electrode housed within the interior; and
wherein the source of energy applies the electrical impulse, based on the single signal, through the interface, as the interface contacts the outer skin surface of the neck of the patient, transcutaneously, through the outer skin surface to the nerve, and thereby modulates the nerve, wherein the electrical impulse comprises bursts of pulses with a silent intra-burst interval between each of the bursts based on the single signal, wherein each of the bursts has a frequency of about 5 Hz to about 100 Hz and each of the pulses has a duration from about 50 microseconds to about 1000 microseconds.
23. The device of claim 22 , wherein the bursts of pulses have a frequency of about 5 Hz to about 100 Hz.
24. The device of claim 22 , wherein the interface comprises a material that is permeable to charged particles.
25. The device of claim 22 , wherein the interface comprises a dielectric material.
26. The device of claim 22 , wherein the interface comprises a porous material.
27. The device of claim 22 , wherein the interface comprises stainless steel.
28. The device of claim 22 , wherein each of the bursts of pulses comprises between about 2 to about 20 pulses.