Implantable neurostimulator with refractory stimulation

• US 20080103532A1
• Filed: 10/27/2006
• Published: 05/01/2008
• Est. Priority Date: 10/27/2006
• Status: Active Grant

• Current Assignee: LivaNova USA, Inc. (LivaNova Plc)
• Original Assignee: Cyberonics, Inc
• Inventors: Armstrong, Randolph K., Armstrong, Scott A.
• Granted Patent: US 7,869,867 B2
• Time in Patent Office: Days
• US Class Current: 607/2
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/36064 Epilepsy
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease

Abstract

In some embodiments, a method comprises providing an electrical signal to a nerve to evoke an action potential. The nerve thereby enters a refractory period in which the nerve is in a refractory state. The method further comprises, during the refractory period, providing an electrical signal to the nerve thereby altering the refractory period of the nerve or non-target tissues.

Claims

1. A method, comprising:

applying a first electrical signal to a nerve to evoke an action potential, said nerve thereafter entering a refractory period in which the nerve is refractory to further induction of action potentials; and

during said refractory period, applying a second electrical signal to said nerve thereby altering said refractory period.

2. The method of claim 1 wherein providing said second electrical signal during said refractory period comprises providing current during a relative refractory period.

3. The method of claim 1 wherein providing said second electrical signal during said refractory period comprises providing current for a period of time that extends past the nerve'"'"'s intrinsic refractory period.

4. The method of claim 1 wherein said refractory period comprises an absolute refractory period and a relative refractory period, and wherein applying said second electrical signal to said nerve during said refractory period comprises beginning to apply said second electrical signal to said nerve during said relative refractory period.

5. The method of claim 1 wherein applying said first electrical signal to said nerve comprises applying an electrical signal having a first polarity and wherein applying said second electrical signal comprises applying an electrical signal having a different polarity than said first polarity, thereby shortening said refractory period of said nerve.

6. The method of claim 1 wherein applying said first electrical signal to said nerve comprises applying an electrical signal having a first polarity and wherein applying said second electrical signal comprises applying an electrical signal having the same polarity as the first polarity, thereby extending said refractory period of said nerve.

7. The method of claim 1 wherein applying said second electrical signal to said nerve comprises applying said second electrical signal during a relative refractory period of a select nerve fiber type while not applying said second electrical signal during the refractory period of another nerve fiber type.

8. The method of claim 1 wherein applying said second electrical signal to said nerve comprises applying an electrical signal at a magnitude insufficient to generate an action potential.

9. A method, comprising:

applying a first electrical signal to a nerve to evoke an action potential;

wherein said first electrical signal or said action potential evokes action potentials in non-target tissue;

said non-target tissue thereafter entering a refractory period in which the non-target tissue is refractory to further induction of action potentials; and

during said refractory period, applying a second electrical signal to said nerve thereby altering said refractory period of the non-target tissue.

10. The method of claim 9 wherein providing said second electrical signal during said refractory period comprises providing current during a relative refractory period.

11. The method of claim 9 wherein providing said second electrical signal during said refractory period comprises providing current for a period of time that extends past the non-target tissue'"'"'s intrinsic refractory period.

12. The method of claim 9 wherein said refractory period comprises an absolute refractory period and a relative refractory period, and wherein applying said second electrical signal to said nerve during said refractory period comprises beginning to apply said second electrical signal to said nerve during said relative refractory period.

13. The method of claim 9 wherein applying said first electrical signal to said nerve comprises applying an electrical signal having a first polarity and wherein applying said second electrical signal comprises applying an electrical signal having a different polarity than said first polarity, thereby shortening said refractory period.

14. The method of claim 9 wherein applying said first electrical signal to said nerve comprises applying an electrical signal having a first polarity and wherein applying said second electrical signal comprises applying an electrical signal having the same polarity as the first polarity, thereby extending said refractory period.

15. The method of claim 9 wherein applying said second electrical signal to said nerve comprises applying said second electrical signal during a relative refractory period of a select nerve fiber type while not applying said second electrical signal during the refractory period of another nerve fiber type.

16. The method of claim 9 wherein applying said second electrical signal to said nerve comprises applying an electrical signal at a magnitude insufficient to generate an action potential.

17. An implantable neurostimulator, comprising:

an electrical signal generator; and

an electrode coupled to said electrical signal generator and adapted to couple to a nerve;

wherein said electrical signal generator applies a first electrical signal to a nerve to evoke an action potential, said nerve thereby entering a refractory period in which the nerve is in a refractory state, and during said refractory period, said electrical signal generator applies a second electrical signal to said nerve thereby altering said refractory period.

18. The implantable neurostimulator of claim 17 wherein said electrical signal generator extends said refractory period of said nerve.

19. The implantable neurostimulator of claim 17 wherein said electrical signal generator extends a relative refractory period of said nerve.

20. The implantable neurostimulator of claim 17 wherein said electrical signal generator shortens said refractory period of said nerve.

21. The implantable neurostimulator of claim 17 wherein said electrical signal generator shortens a relative refractory period of said nerve.

22. The implantable neurostimulator of claim 17 wherein said electrical signal generator applies said second electrical signal during a refractory period of a select nerve fiber type while not applying said second electrical signal during the refractory period of another nerve fiber type.

23. An implantable neurostimulator, comprising:

an electrical signal generator; and

an electrode coupled to said electrical signal generator and adapted to couple to a nerve to thereby provide therapy to a target nerve fiber;

wherein said electrical signal generator applies a first electrical signal to a nerve to evoke an action potential in the target nerve which causes an action potential to be evoked in a non-target nerve fiber or tissue, said non-target nerve fiber or tissue thereby entering a refractory period in which the non-target nerve fiber or tissue is in a refractory state, and during said refractory period, said electrical signal generator applies a second electrical signal to said target nerve thereby altering said refractory period of said non-target nerve fiber or tissue.

24. The implantable neurostimulator of claim 23 wherein said first and second electrical signals have opposite polarities to each other and said refractory period is thereby shortened.

25. The implantable neurostimulator of claim 23 wherein said first and second electrical signals have a common polarity to each other and said refractory period is thereby extended.