Synchronization of vagus nerve stimulation with the cardiac cycle of a patient

• US 8,219,188 B2
• Filed: 03/29/2007
• Issued: 07/10/2012
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: Catholic Healthcare West (CommonSpirit Health (Illinois))
• Original Assignee: Catholic Healthcare West (CommonSpirit Health (Illinois))
• Inventors: Craig, Arthur D.
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): Stice, Paula J
• Application Number:
  US11/693,499
• Publication Number:
  US 20070233194A1
• Time in Patent Office: 1,930 Days
• Field of Search: 607/2, 607/11, 607/15, 607/18, 607/20, 607/45, 607/62, 607/118
• US Class Current: 607/2
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• 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 5/353 Detecting P-waves
• CPC Class Codes: A61B 5/355 Detecting T-waves
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• 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 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/3611 Respiration control stimulating respiratory organs A61N1/3601
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/36178 Burst or pulse train parameters

Abstract

Methods, systems, and apparatus for treating a medical condition of a patient, involving detecting a physiological cycle or cycles of the patient and applying an electrical signal to a portion of the patient'"'"'s vagus nerve through an electrode at a selected point in the physiological cycle(s). The physiological cycle can be the cardiac and/or respiratory cycle. The selected point can be a point in the cardiac cycle correlated with increased afferent conduction on the vagus nerve, such as a point from about 10 msec to about 800 msec after an R-wave of the patient'"'"'s ECG, optionally during inspiration by the patient. The selected point can be a point in the cardiac cycle when said applying increases heart rate variability, such as a point from about 10 msec to about 800 msec after an R-wave of the patient'"'"'s ECG, optionally during expiration by the patient.

Claims

1. A method of treating a medical condition of a patient having a vagus nerve and a brain using a medical device, the method comprising:

detecting at least a portion of a physiological cycle of the patient, the physiological cycle comprising a cardiac cycle of the patient; and

applying a first electrical signal to a portion of the vagus nerve of the patient through an electrode assembly at a selected point in the physiological cycle, the first electrical signal comprising a plurality of microbursts, each microburst comprising a plurality of pulses, adjacent ones of the plurality of pulses being separated by an interpulse interval, adjacent ones of the plurality of microbursts being separated by an interburst period, the first electrical signal generating vagal afferent activity or augmenting endogenous vagal afferent activity on the vagus nerve conducted to the brain of the patient by the vagus nerve to thereby treat the medical condition,

wherein the selected point in the physiological cycle relates to a point in the physiological cycle of the patient when the application of the first electrical signal increases heart rate variability, and wherein the selected point in the physiological cycle is not correlated with increased efferent conduction on the vagus nerve of the patient.

2. The method of claim 1, further comprising:

selectively applying a second electrical signal to the vagus nerve of the patient through the electrode assembly, wherein the second electrical signal is configured to block electrical activity on the vagus nerve.

3. The method of claim 1, wherein the first electrical signal comprises signal parameters comprising:

a microburst duration,

a number of pulses per microburst,

the interpulse interval,

the interburst period,

a current magnitude,

a pulse frequency,

a signal width,

an on-time, and

an off-time,

wherein at least one of the signal parameters is selected to treat the medical condition.

4. The method of claim 1, wherein the applying of the first electrical signal to the portion of the vagus nerve is performed at a point in the physiological cycle correlated with increased afferent conduction on the vagus nerve.

5. The method of claim 4, wherein the applying of the first electrical signal to the portion of the vagus nerve is performed beginning at a point from about 10 msec to about 800 msec after an R-wave of the patient'"'"'s ECG.

6. The method of claim 5, wherein the applying of the first electrical signal to the portion of the vagus nerve is performed during inspiration by the patient.

7. The method of claim 5, wherein the applying of the first electrical signal to the portion of the vagus nerve is performed during expiration by the patient.

8. The method of claim 1, further comprising applying a second electrical signal to a portion of said vagus nerve of said patient through the electrode assembly without reference to the patient'"'"'s physiological cycle.

9. The method of claim 8, wherein the second electrical signal is different from the first electrical signal in at least one parameter selected from a group consisting of a burst duration, a number of pulses per burst, an interpulse interval, an interburst period, a current magnitude, a pulse frequency, a signal width, an on-time, and an off-time.

10. The method of claim 1, wherein each of the plurality of microbursts comprises a microburst duration of less than about one second.

11. The method of claim 10, wherein each of the plurality of microbursts comprises 2 to 15 pulses.

12. The method of claim 11, wherein the interburst period is at least about 100 millseconds.

13. A method of treating a medical condition of a patient having at least one vagus nerve and a brain, the method comprising:

coupling at least one electrode to the at least one vagus nerve of the patient;

providing a programmable electrical signal generator coupled to the at least one electrode;

detecting at least a portion of a physiological cycle of the patient, the physiological cycle comprising the cardiac cycle of the patient;

generating an electrical signal with the electrical signal generator, the electrical signal comprising a plurality of microbursts, each microburst comprising a plurality of pulses, adjacent ones of the plurality of pulses being separated by an interpulse interval, adjacent ones of the plurality of microbursts being separated by an interburst period; and

applying the electrical signal to the at least one electrode at a selected point in the physiological cycle to treat the medical condition, the electrical signal generating vagal afferent activity or augmenting endogenous vagal afferent activity on the at least one vagus nerve that is conducted to the brain of the patient by the at least one vagus nerve to treat the medical condition;

wherein the selected point in the physiological cycle relates to a point in the physiological cycle of the patient when the application of the electrical signal increases heart rate variability, and wherein the selected point in the physiological cycle is not correlated with increased efferent conduction on the vagus nerve of the patient.

14. A medical condition treatment system comprising:

at least one electrode adapted to be coupled to at least one vagus nerve of a patient having a brain;

.

an implantable device operatively coupled to the at least one electrode and comprising an electrical signal generator capable of applying one or more electrical signals to the at least one vagus nerve at a selected point in a physiological cycle comprising a cardiac cycle of the patient, each electrical signal comprising a plurality of microbursts, each microburst comprising a plurality of pulses, adjacent ones of the plurality of pulses being separated by an interpulse interval, adjacent ones of the plurality of microbursts being separated by an interburst period, each electrical signal being configured to generate vagal afferent activity or augment endogenous vagal afferent activity on the at least one vagus nerve that is conducted to the brain of the patient by the at least one vagus nerve to treat the medical condition, wherein the selected point in the physiological cycle relates to a point in the physiological cycle of the patient when the application of the electrical signal increases heart rate variability, and wherein the selected point in the physiological cycle is not correlated with increased efferent conduction on the vagus nerve of the patient; and

a device configured to detect the selected point in the patient'"'"'s physiological cycle operatively coupled to the at least one electrode.

15. The medical condition treatment system of claim 14, wherein the at least one vagus nerve comprises at least one of a left vagus nerve and a right vagus nerve.

16. The medical condition treatment system of claim 14, wherein the first and second electrical signals each comprises signal parameters comprising:

the interburst period,

a number of pulses per microburst,

the interpulse interval,

a microburst duration,

a current magnitude,

a pulse frequency,

a signal width,

an on-time, and

an off-time,

wherein at least one of the signal parameters is selected to treat the medical condition.

17. The medical condition treatment system of claim 14, wherein each of the plurality of microbursts in each electrical signal comprises a microburst duration of less than about one second.

18. The medical condition treatment system of claim 17, wherein each of the plurality of microbursts in each electrical signal comprises 2 to 15 pulses.

19. The medical condition treatment system of claim 18, wherein the interburst period in each electrical signal is at least about 100 millseconds.

20. A method of treating a brain disorder of a patient having a vagus nerve, the method comprising:

detecting at least a portion of a physiological cycle of the patient, the physiological cycle comprising a cardiac cycle of the patient; and

applying a first electrical signal to a portion of the vagus nerve of the patient through an electrode assembly at a selected point in the physiological cycle, the first electrical signal comprising a plurality of microbursts, each microburst comprising a plurality of pulses, adjacent ones of the plurality of pulses being separated by an interpulse interval, adjacent ones of the plurality of microbursts being separated by an interburst period, the first electrical signal generating vagal afferent activity or augmenting endogenous vagal afferent activity on the vagus nerve conducted to the brain of the patient by the vagus nerve to thereby treat the brain disorder,

wherein the selected point in the physiological cycle relates to a point in the physiological cycle of the patient when the application of the first electrical signal increases heart rate variability.

21. The method of claim 20, wherein the first electrical signal comprises signal parameters comprising:

a microburst duration,

a number of pulses per microburst,

the interpulse interval,

the interburst period,

a current magnitude,

a pulse frequency,

a signal width,

an on-time, and

an off-time,

wherein at least one of the signal parameters is selected to treat the brain disorder.

22. The method of claim 20, wherein the applying of the first electrical signal to the portion of the vagus nerve is performed at a point in the physiological cycle correlated with increased afferent conduction on the vagus nerve.

23. The method of claim 22, wherein the applying of the first electrical signal to the portion of the vagus nerve is performed beginning at a point from about 10 msec to about 800 msec after an R-wave of the patient'"'"'s ECG.

24. The method of claim 20, further comprising applying a second electrical signal to a portion of said vagus nerve of said patient through the electrode assembly without reference to the patient'"'"'s physiological cycle.

25. The method of claim 24, wherein the second electrical signal is different from the first electrical signal in at least one parameter selected from a group consisting of a burst duration, a number of pulses per burst, an interpulse interval, an interburst period, a current magnitude, a pulse frequency, a signal width, an on-time, and an off-time.

26. A system for treating a brain disorder of a patient having at least one vagus nerve, comprising:

at least one electrode configured for operative coupling to the at least one vagus nerve of the patient;

an implantable device operatively coupled to the at least one electrode and comprising an electrical signal generator capable of applying one or more electrical signals to the at least one vagus nerve at a selected point in a physiological cycle comprising a cardiac cycle of the patient, each electrical signal comprising a plurality of microbursts, each microburst comprising a plurality of pulses, adjacent ones of the plurality of pulses being separated by an interpulse interval, adjacent ones of the plurality of microbursts being separated by an interburst period, each electrical signal being configured to generate vagal afferent activity or augment endogenous vagal afferent activity on the at least one vagus nerve that is conducted to the brain of the patient by the at least one vagus nerve to treat the brain disorder, wherein the selected point in the physiological cycle relates to a point in the physiological cycle of the patient when the application of the electrical signal increases heart rate variability; and

a device configured to detect the selected point in the patient'"'"'s physiological cycle, wherein the device is operatively coupled to the at least one electrode.

27. The system of claim 26, wherein each of the plurality of microbursts in each electrical signal comprises a microburst duration of less than about one second.

28. The system of claim 27, wherein each of the plurality of microbursts in each electrical signal comprises 2 to 15 pulses.

29. The system of claim 28, wherein the interburst period in each electrical signal is at least about 100 millseconds.