Vagal nerve stimulation techniques for treatment of epileptic seizures

• US 6,920,357 B2
• Filed: 05/12/2003
• Issued: 07/19/2005
• Est. Priority Date: 04/30/1999
• Status: Expired due to Term

• Current Assignee: Ivan Osorio, Mark G. Frei
• Original Assignee: Ivan Osorio, Mark G. Frei
• Inventors: Frei, Mark G., Osorio, Ivan
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US10/435,832
• Publication Number:
  US 20030195574A1
• Time in Patent Office: 799 Days
• Field of Search: 607/9, 607/45, 607/17
• 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 pacing a heart with a pacemaker comprising:

(a) monitoring a characteristic of the heart;

(b) processing the monitored characteristic of the heart to determine whether there is a possible occurrence of a seizure; and

(c) operating the pacemaker to maintain a heart beat parameter at a predetermined range if a possible occurrence of a seizure is detected.

2. The method of claim 1, further comprising:

(d) alerting the patient of possible occurrence of a seizure.

3. The method of claim 1, wherein monitoring comprises measuring a heart rate of the heart.

4. The method of claim 1, wherein monitoring comprises monitoring an electro-cardiogram signal of the heart.

5. The method of claim 1, wherein monitoring comprises detecting a QRS complex.

6. The method of claim 1, wherein monitoring comprises detecting an R-wave.

7. The method of claim 1, wherein monitoring comprises measuring blood pressure.

8. The method of claim 1, wherein monitoring comprises measuring R-R variability.

9. The method of claim 1, wherein processing comprises processing the signal to determine whether a vagus nerve is being stimulated.

10. The method of claim 1, wherein the step of monitoring comprises the step of measuring a relationship between heart rate and heart rate variability.

11. The method of claim 1, wherein processing comprises determining whether the characteristic of the heart is indicative of a serious or life-threatening state.

12. A system for controlling operation of a heart comprising in combination:

(a) at least one sensor capable of measuring a characteristic of the heart indicative of an occurrence of a seizure wherein the sensor is capable of measuring R-R variability;

(b) means for processing the measured R-R variability to determine whether there is a possible occurrence of a seizure; and

(c) an implantable pacemaker coupled to the at least one sensor to regulate the operation of the heart in response to the characteristic measured by the at least one sensor.

13. A system for controlling operation of a heart comprising in combination:

(a) at least one sensor capable of measuring a characteristic of the heart indicative of an occurrence of a seizure wherein the sensor is capable of measuring a relationship between heart rate and heart rate variability; and

(b) an implantable pacemaker coupled to the at least one sensor to regulate the operation of the heart in response to the characteristic measured by the at least one sensor.

14. A system for controlling the operation of a heart during vagus nerve stimulation comprising in combination:

(a) vagus nerve stimulating means;

(b) an implantable pacemaker coupled to stimulate the heart;

(c) at least one sensor coupled to the pacemaker capable of measuring an electro-cardiogram signal wherein the at least one sensor is capable of measuring R-R variability;

(d) means for processing the signal to determine whether the vagus nerve is being stimulated by the vagus nerve stimulating means; and

(e) means for controlling the heart based on the determination of whether the vagus nerve is being stimulated by the vagus nerve stimulating means.

15. A system for controlling the operation of a heart during vagus nerve stimulation comprising in combination:

(a) vagus nerve stimulating means;

(b) an implantable pacemaker coupled to stimulate the heart;

(c) at least one sensor coupled to the pacemaker capable of measuring an electro-cardiogram signal wherein the at least one sensor is capable of measuring a relationship between heart rate and heart rate variability;

(d) means for processing the signal to determine whether the vagus nerve is being stimulated by the vagus nerve stimulating means; and

(e) means for controlling the heart based on the determination of whether the vagus nerve is being stimulated by the vagus nerve stimulating means.

16. A system for controlling the operation of a heart during vagus nerve stimulation comprising in combination:

(a) vagus nerve stimulating means;

(b) an implantable pacemaker coupled to stimulate the heart;

(c) at least one sensor coupled to the pacemaker capable of measuring an electro-cardiogram signal;

(d) means for processing the signal to determine whether the vagus nerve is being stimulated by the vagus nerve stimulating means for treating epilepsy; and

(e) means for controlling the heart based on the determination of whether the vagus nerve is being stimulated by the vagus nerve stimulating means.

17. A method of pacing a heart with a pacemaker, in a subject with epilepsy, comprising the steps of:

(a) monitoring a signal representative of at least one characteristic of the heart, the monitoring comprising the step of measuring R-R variability;

(b) determining whether the characteristic is outside a normal or baseline range for the subject and indicating the occurrence of a seizure if the characteristic is outside the normal or baseline range; and

(c) operating the pacemaker to restore the characteristic of the heart to the normal or baseline range for the subject.