Changeable electrode polarity stimulation by an implantable medical device

• US 8,565,867 B2
• Filed: 01/25/2008
• Issued: 10/22/2013
• Est. Priority Date: 01/28/2005
• Status: Active Grant

• Current Assignee: LivaNova USA, Inc. (LivaNova Plc)
• Original Assignee: Cyberonics, Inc
• Inventors: Armstrong, Randolph K., Maschino, Steven E., Scott, Timothy L.
• Primary Examiner(s): Getzow, Scott
• Assistant Examiner(s): PATTON, AMANDA K
• Application Number:
  US12/020,097
• Publication Number:
  US 20090192564A1
• Time in Patent Office: 2,097 Days
• Field of Search: 607/2, 607/116, 607/118, 607/139
• US Class Current: 607/2
• CPC Class Codes: A61N 1/36114 Cardiac control, e.g. by vagal stimulation stimulating the heart A61N1/362
• CPC Class Codes: A61N 1/36117 for treating hypertension
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration

Abstract

We disclose a method of treating a medical condition in a patient using an implantable medical device including coupling at least a first electrode and a second electrode to a cranial nerve of the patient, providing a programmable electrical signal generator coupled to the first electrode and the second electrode, generating a first electrical signal with the electrical signal generator, applying the first electrical signal to the electrodes, wherein the first electrode is a cathode and the second electrode is an anode, reversing the polarity of the first electrode and the second electrode, yielding a configuration wherein the first electrode is an anode and the second electrode is a cathode, generating a second electrical signal with the electrical signal generator, applying the second electrical signal to the electrodes, reversing the polarity of the first electrode and the second electrode, yielding a configuration wherein the first electrode is a cathode and the second electrode is an anode, generating a third electrical signal with the electrical signal generator, and applying the third electrical signal to the electrodes. Each of the electrical signals can independently contain one or more pulses or one or more bursts. The number of pulses need not be equal between any two of the electrical signals.

Claims

1. A method of treating one or more medical conditions in a patient, the method comprising:

applying a first electrical signal in a first stimulation mode to a cranial nerve of the patient, via at least first and second electrodes coupled to an electrical signal generator of an implantable medical device and to the cranial nerve, wherein the first electrode operates as a cathode and is proximal to a brain relative to the second electrode that operates as an anode and is distal to the brain, wherein the first stimulation mode performs single polarity stimulation;

receiving an output from a sensor configured to detect one or more bodily parameters of the patient;

entering a second stimulation mode based on the output received from the sensor, wherein the second stimulation mode performs changeable electrode polarity stimulation;

applying a second electrical signal in the second stimulation mode to the cranial nerve of the patient, via the first and second electrodes, wherein the first and second electrodes are configured to switch between a first electrode configuration and a second electrode configuration in the second stimulation mode, wherein the first electrode operates as the cathode and the second electrode operates as the anode in the first electrode configuration, wherein the first electrode operates as the anode and the second electrode operates as the cathode in the second electrode configuration.

2. The method of claim 1, wherein the first electrical signal contains one pulse and the second electrical signal contains one pulse.

3. The method of claim 1, wherein the first electrical signal contains a first number of pulses and the second electrical signal contains a second number of pulses, wherein:

the first number of pulses is not equal to the second number of pulses.

4. The method of claim 1, wherein the first electrical signal contains one burst and the second electrical signal contains one burst.

5. The method of claim 1, wherein the first electrical signal contains a first number of bursts and the second electrical signal contains a second number of bursts,

the first number of bursts is not equal to the second number of bursts.

6. The method of claim 1, wherein the second electrical signal is characterized by having an interpulse interval in a range from about 2 milliseconds to about 4.3 milliseconds for each centimeter of distance between the first electrode and the second electrode.

7. The method of claim 1, wherein at least one of the first electrical signal and the second electrical signal is characterized by having a number of pulses per microburst from 2 pulses to about 25 pulses, an interpulse interval of about 2 milliseconds to about 50 milliseconds, an interburst period of at least 100 milliseconds, and a microburst duration of less than about 1 second.

8. The method of claim 1, wherein the medical condition being treated is at least one of a neurological disorder, neuropsychiatric disorder, gastrointestinal disorder, pancreatic disorder, kidney disorder, or diabetes.

9. The method of claim 1, wherein the cranial nerve is a vagus nerve.

10. The method of claim 1, wherein applying the first electrical signal to the cranial nerve treats a first medical condition of the brain.

11. The method of claim 1, wherein applying the second electrical signal to the cranial nerve treats a non-brain medical condition.

12. An implantable medical device to treat medical conditions in a patient, the implantable medical device comprising:

a controller configured to receive an output from a sensor configured to detect one or more bodily parameters of the patient;

a stimulation unit coupled to the controller, the stimulation unit configured to generate and deliver electrical signals to a cranial nerve of the patient via first and second electrodes coupled to the cranial nerve, wherein the stimulation unit is configured to deliver a first electrical signal in a first stimulation mode to the cranial nerve via the first electrode and the second electrode, the first electrode operating as a cathode and proximal to a brain relative to the second electrode, the second electrode operating as an anode and distal to the brain, wherein the first stimulation mode performs single polarity stimulation;

wherein the controller is configured to enter a second stimulation mode based on the output received from the sensor, wherein the second stimulation mode performs changeable electrode polarity stimulation;

wherein the stimulation unit is configured to deliver a second electrical signal to the cranial nerve, via the first and second electrodes, wherein the first and second electrodes are configured to switch between a first electrode configuration and a second electrode configuration in the second stimulation mode, wherein the first electrode operates as the cathode and the second electrode operates as the anode in the first electrode configuration, wherein the first electrode operates as the anode and the second electrode operates as the cathode in the second electrode configuration.

13. The implantable medical device of claim 12, wherein the first electrical signal contains one pulse and the second electrical signal contains one pulse.

14. The implantable medical device of claim 12, wherein the first electrical signal contains a first number of pulses and the second electrical signal contains a second number of pulses, wherein

the first number of pulses is not equal to the second number of pulses.

15. The implantable medical device of claim 12, wherein the first electrical signal contains one burst and the second electrical signal contains one burst.

16. The implantable medical device of claim 12, wherein the first electrical signal contains a first number of bursts and the second electrical signal contains a second number of bursts, wherein

the first number of bursts is not equal to the second number of bursts.

17. The implantable medical device of claim 12, wherein the stimulation unit is configured to provide for an interpulse interval, between delivery of the first electrical signal and the second electrical signal, in a range from about 2 milliseconds to about 4.3 milliseconds for each centimeter of distance between the first electrode and the second electrode.

18. The implantable medical device of claim 12, wherein at least one of the first electrical signal and the second electrical signal is characterized by having a number of pulses per microburst from 2 pulses to about 25 pulses, an interpulse interval of about 2 milliseconds to about 50 milliseconds, an interburst period of at least 100 milliseconds, and a microburst duration of less than about 1 second.

19. The implantable medical device of claim 12, wherein the medical condition being treated is at least one of a neurological disorder, neuropsychiatric disorder, gastrointestinal disorder, pancreatic disorder, kidney disorder, or diabetes.

20. The implantable medical device of claim 12, wherein the cranial nerve is a vagus nerve.

21. The implantable medical device of claim 12, wherein delivering the first electrical signal to the cranial nerve treats a first medical condition of the brain.

22. The implantable medical device of claim 12, wherein delivering the second electrical signal to the cranial nerve treats a non-brain medical condition.

23. A method of treating at least one medical condition in a patient, the method comprising:

applying a first electrical signal in a first stimulation mode to a cranial nerve of the patient, via at least first and second electrodes coupled to an electrical signal generator of an implantable medical device and to the cranial nerve, wherein the first electrode operates as a cathode and is proximal to a brain relative to the second electrode that operates as an anode and is distal to the brain, wherein the first stimulation mode performs single polarity stimulation;

receiving an output from a sensor configured to detect one or more bodily parameters of the patient, the one or more bodily parameters including at least one of heart rate, respiration rate, blood pressure, and blood glucose;

entering a second stimulation mode based on the output received from the sensor, wherein the second stimulation mode performs changeable electrode polarity stimulation;

applying a second electrical signal in the second stimulation mode to the cranial nerve of the patient, via the first and second electrodes coupled to the electrical signal generator and to the cranial nerve, wherein the first and second electrodes are configured to switch between a first electrode configuration and a second electrode configuration in the second stimulation mode, wherein the first electrode operates as the cathode and the second electrode operates as the anode in the first electrode configuration, wherein the first electrode operates as the anode and the second electrode operates as the cathode in the second electrode configuration.