Vagal nerve stimulation techniques for treatment of epileptic seizures

• US 6,961,618 B2
• Filed: 11/13/2003
• Issued: 11/01/2005
• Est. Priority Date: 04/30/1999
• Status: Active Grant

• Current Assignee: Flint Hills Scientific, LLC
• Original Assignee: Flint Hills Scientific, LLC
• Inventors: Frei, Mark G., Osorio, Ivan
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US10/712,975
• Publication Number:
  US 20040138721A1
• Time in Patent Office: 719 Days
• Field of Search: 607/9, 607/17, 607/45
• US Class Current: 607/45
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/02455 provided with high/low alarm devices
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61N 1/36053 adapted for vagal stimulation A61N1/36114 takes precedence
• CPC Class Codes: A61N 1/36064 Epilepsy
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36135 using physiological parameters

Abstract

The present invention uses electrical stimulation of the vagus nerve to treat epilepsy with minimized or no effect on the heart. Treatment is carried out by an implantable signal generator, one or more implantable electrodes for electrically stimulating a predetermined stimulation site of the vagus nerve, and a sensor for sensing characteristics of the heart such as heart rate. The heart rate information from the sensor can be used to determine whether the vagus nerve stimulation is adversely affecting the heart. Once threshold parameters are met, the vagus nerve stimulation may be stopped or adjusted. In an alternative embodiment, the invention may include a modified pacemaker to maintain the heart in desired conditions during the vagus nerve stimulation. In yet another embodiment, the invention may be simply a modified pacemaker having circuitry that determines whether a vagus nerve is being stimulated. In the event that the vagus nerve is being stimulated, the modified pacemaker may control the heart to maintain it within desired conditions during the vagus nerve stimulation.

Claims

1. A method of minimizing effects to a heart of a patient comprising:

(a) implanting at least one electrode to be communication with a vagus nerve of the body;

(b) stimulating the vagus nerve with the at least one electrode;

(c) identifying at least one phase of a heart pulse during which vagus nerve stimulation has reduced effect on the heart; and

(d) providing stimulation only during the at least one identified phase of the heart pulse.

2. The method of claim 1, further comprising:

(e) sensing an indication of a possible onset of a seizure.

3. The method of claim 2, wherein (e) includes sensing an electroencephalogran patient.

4. The method of claim 2, wherein (e) includes sensing a cortical signal.

5. The method of claim 2, wherein (e) includes sensing an electrocardiogram (E for an indication of a possible onset of a seizure.

6. The method of claim 2, wherein (e) includes sensing a characteristic of a hear group consisting of an instantaneous heart rate (IHR) and a heart rate variability.

7. The method of claim 2, further comprising:

(f) if a possible seizure onset is detected, providing a warning of the onset.

8. The method of claim 7, wherein (f) includes providing an audio signal.

9. The method of claim 7, wherein (f) includes providing a vibrating signal.

10. The method claim 1, further comprising:

(e) determining whether the measured characteristic of the heart is within a predetermined range; and

(f) if the heart is operating outside the predetermined range, alerting the patient by way of a sensory signal.

11. The method claim 1, further comprising:

(e) determining whether the measured characteristic of the heart is within a predetermined range; and

(f) if the heart is operating outside the predetermined range, adjusting stimulation of a vagus nerve to bring the heart within the normal range.

12. The method claim 1, further comprising:

(e) determining whether the measured characteristic of the heart is within a predetermined range; and

(f) if the heart is operating outside the predetermined range, turning off stimulation to the vagus nerve.

13. A system for treating epileptic seizures comprising in combination:

(a) at least one electrode having a proximal end and a distal end adapted to provide stimulation to a vagus nerve of a patient;

(b) a sensor for generating a sensor signal indicative of a characteristic of a heart;

(c) an implantable signal generator coupled to the proximal end of the at least one electrode and providing stimulation energy in response to said sensor signal; and

(d) a switch coupled to the signal generator and operable by the patient, whereby the patient may manually turn on or off the vagus nerve stimulation.

14. A system for treating epileptic seizures comprising in combination:

(a) at least one electrode having a proximal end and a distal end adapted to provide stimulation to a vagus nerve of a patient;

(b) a sensor for generating a sensor signal indicative of a characteristic of a heart;

(c) an implantable signal generator coupled to the proximal end of the at least one electrode and providing stimulation energy in response to said sensor signal; and

(d) a second sensor generating a second sensor signal indicative of a possible onset of a seizure, and wherein the signal generator is responsive to the second sensor signal, wherein the second sensor is implantable to be in communication with a brain of the patient.

15. A system for treating epileptic seizures comprising in combination:

(a) at least one electrode having a proximal end and a distal end adapted to provide stimulation to a vagus nerve of a patient;

(b) a sensor for generating a sensor signal indicative of a characteristic of a heart wherein the signal generated by the sensor is of a heart pulse or a rate of change of a heart pulse; and

(c) an implantable signal generator coupled to the proximal end of the at least one electrode and providing stimulation energy in response to said sensor signal.

16. A method of minimizing effects to a heart of a patient comprising:

(a) stimulating a vagus nerve;

(b) measuring a characteristic of a heart selected from the group consisting of an instantaneous heart rate (IHR) and a heart rate variability;

(c) determining whether the measured characteristic of the heart is within a normal range for the patient; and

(d) if the heart is operating outside the normal range, adjusting, including turning off, stimulation of the vagus nerve to bring the heart within the normal range.

17. A method of minimizing effects to a heart of a patient comprising:

(a) stimulating a vagus nerve;

(b) measuring a characteristic of a heart selected from the group consisting of an instantaneous heart rate (IHR) and a heart rate variability;

(c) determining whether the measured characteristic of the heart is within a predetermined range;

(d) if the heart is operating outside the predetermined range, alerting the patient by way of a sensory signal of effects to the heart caused by the vagus nerve stimulation; and

(e) turning off stimulation to the vagus nerve.