DEVICES AND METHODS FOR MONITORING NON-INVASIVE VAGUS NERVE STIMULATION

• US 20130245486A1
• Filed: 04/28/2013
• Published: 09/19/2013
• Est. Priority Date: 03/20/2009
• Status: Active Grant

• Current Assignee: Electrocore, Llc
• Original Assignee: Electrocore, Llc
• Inventors: Simon, Bruce J., Errico, Joseph P.
• Granted Patent: US 9,254,383 B2
• Time in Patent Office: Days
• US Class Current: 600/546
• CPC Class Codes: A61B 2090/3941 Photoluminescent markers
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/394 specially adapted for electroglottography or electropalatography
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61B 5/4041 Evaluating nerves condition
• CPC Class Codes: A61B 5/4803 Speech analysis specially adapted for diagnostic purposes
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/687 Oesophagus
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: A61N 1/36021 for treatment of pain
• CPC Class Codes: A61N 1/36031 using physiological parameters for adjustment
• CPC Class Codes: A61N 1/36034 specified by the stimulation parameters
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: G16H 50/70 for mining of medical data, e.g. analysing previous cases of other patients

Abstract

Devices and methods are disclosed that treat a medical condition, such as migraine headache, by electrically stimulating a nerve noninvasively, which may be a vagus nerve situated within a patient'"'"'s neck. Preferred embodiments allow a patient to self-treat his or her condition. Disclosed methods assure that the device is being positioned correctly on the neck and that the amplitude and other parameters of the stimulation actually stimulate the vagus nerve with a therapeutic waveform. Those methods comprise measuring properties of the patient'"'"'s larynx, pupil diameters, blood flow within an eye, electrodermal activity and/or heart rate variability.

Claims

1. A system for treating a medical condition of a patient, comprising:

a stimulator comprising a housing having an electrically permeable contact surface for contacting an outer skin surface of the patient;

an energy source within the housing configured to generate an electric field sufficient to transmit an electric current through the outer skin surface of the patient to a nerve at a target region within the patient; and

a device configured to detect whether said electric current is being transmitted to said nerve;

wherein the electric current is sufficient to treat the medical condition of the patient.

2. The system of claim 1 wherein the nerve is a vagus nerve.

3. The system of claim 2 wherein the device measures a property of the patient'"'"'s voice and/or a laryngeal electromyographic signal and/or an electroglottographic signal.

4. The system of claim 1 wherein the device measures a pupil diameter and/or a blood flow within an eye.

5. The system of claim 1 wherein the device measures electrodermal activity and/or heart rate variability.

6. The system of claim 1 wherein the device measures a property of the patient'"'"'s autonomic nervous system.

7. The system of claim 1 wherein the device measures a vagal artery blood flow.

8. The system of claim 1 wherein the device measures a cerebral blood flow.

9. The system of claim 1 wherein the device measures an evoked potential and/or an electroencephalogram.

10. The system of claim 1 wherein the device measures a pain threshold and/or a sway and/or a chemical within the patient'"'"'s blood.

11. The system of claim 1 wherein the device comprises a support vector machine.

12. The system of claim 1 further comprising an optical device configured to detect fluorescent material that has been applied onto or under a skin of the patient.

13. The system of claim 1 further comprising an accelerometer or a gyroscope.

14. The system of claim 1 wherein the electric field comprises bursts of pulses with a frequency of about 1 to about 100 bursts per second.

15. The system of claim 14 wherein the electric field comprises bursts of between 1 and 50 pulses per burst, with each pulse being about 50 to 1000 microseconds in duration.

16. The system of claim 14 wherein the pulses are full sinusoidal waves.

17. The system of claim 1 wherein the electric field at the nerve fiber at the target region is configured to be between about 10 to 600 V/m.

18. The system of claim 17 wherein the electric field is configured to be less than 100 V/m.

19. The system of claim 1 wherein the electrical field is sufficient to modulate a nerve fiber at the target region;

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

20. The system of claim 2 wherein the electric current is configured to generate an electric field at a vagus nerve above a threshold for generating action potentials within A and B fibers of the vagus nerve and below a threshold for generating action potentials within C fibers of the vagus nerve.

21. The system of claim 1, further comprising:

a docking station configured to convey or transmit to the energy source of said stimulator a specified amount of energy.

22. A method of testing a branch of a vagus nerve in a patient comprising:

electrically stimulating said branch of a vagus nerve; and

having the patient vocalize a glissando.

23. The method of claim 22 wherein the branch of the vagus nerve is a recurrent laryngeal nerve.

24. The method of claim 22 wherein the glissando passes through a plurality of voice registers.

25. The method of claim 22 wherein a plurality of electrical stimulation amplitudes stimulate the nerve.

26. The method of claim 25 wherein a stimulation amplitude is a control having no or zero stimulation amplitude

27. The method of claim 22 wherein one or more acoustic indices are measured, and wherein said acoustic indices comprise a fundamental frequency, a jitter, a shimmer, a noise-to-harmonic ratio, a sound pressure level, or a power within a harmonic.

28. The method of claim 22 wherein electromyography is performed.

29. The method of claim 22 wherein electroglottography is performed.

30. The method of claim 22 wherein a plurality of time-segments within the glissando are analyzed.

31. A method of testing a branch of a vagus nerve in a patient comprising:

electrically stimulating said branch of a vagus nerve; and

measuring a diameter of a pupil of an eye of a patient.

32. The method of claim 31 wherein diameters of pupils of left and right eyes of the patient are measured.

33. The method of claim 31 wherein a pupil response latency is measured.

34. The method of claim 31 wherein a plurality of electrical stimulation amplitudes stimulate the nerve.

35. The method of claim 32 wherein a stimulation amplitude is a control having no or zero stimulation amplitude.

36. The method of claim 31 wherein the patient is exposed to a plurality of ambient light intensities.

37. A method of testing a branch of a vagus nerve in a patient comprising:

electrically stimulating said branch of a vagus nerve; and

measuring a blood flow within an eye of a patient.

38. The method of claim 37 wherein blood flow within left and right eyes of the patient are measured.

39. The method of claim 37 wherein blood flow latency is measured.

40. The method of claim 37 wherein a plurality of electrical stimulation amplitudes stimulate the nerve.

41. The method of claim 40 wherein a stimulation amplitude is a control having no or zero stimulation amplitude.

42. The method of claim 37 wherein the patient is exposed to a plurality of ambient light intensities.