Systems and methods of reducing artifact in neurological stimulation systems

• US 20080114417A1
• Filed: 11/14/2006
• Published: 05/15/2008
• Est. Priority Date: 11/14/2006
• Status: Active Grant

• Current Assignee: Cyberonics, Inc
• Original Assignee: Cyberonics, Inc
• Inventors: Leyde, Kent W.
• Granted Patent: US 8,295,934 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease

Abstract

The present invention relates to neurological systems and methods of use which acquire physiological signals from a subject and stimulate the subject. The system is adapted to control the timing at which the system acquires the physiological signals from the subject and the timing of the stimulation signal to reduce the amount of stimulation induced artifact that is acquired by the system.

Claims

1. A system to reduce artifact in a signal acquired from a subject, the system comprising:

a sensing assembly adapted to acquire a signal from a subject indicative of the subject'"'"'s brain activity;

a stimulation assembly adapted to stimulate one or more neurons of the subject; and

a timing controller programmed to control the time at which the sensing assembly acquires the signal to be substantially different than when the stimulation assembly stimulates the subject.

2. The system of claim 1 wherein the timing controller is programmed to control the time at which the sensing assembly acquires the signal to be multiple discrete acquisition times and to control the time at which the stimulation assembly stimulates the one or more neurons to be multiple discrete stimulation times.

3. The system of claim 2 wherein the timing controller is programmed to control the sensing assembly to acquire the signal in between the stimulation assembly stimulating the one or more neurons.

4. The system of claim 3 wherein the multiple discrete acquisition times and the multiple discrete stimulation times each occur in a regular pattern.

5. The system of claim 4 wherein the acquisition times and the stimulation times provide epochs of time between the acquisition times and stimulation times in which no acquisition or stimulation occurs.

6. The system of claim 2 wherein the multiple discrete acquisition times are about 0.25 seconds to about 5 minutes.

7. The system of claim 6 wherein the multiple discrete acquisition times are about 5 seconds.

8. The system of claim 2 wherein the multiple discrete stimulation times are about 0.5 seconds to about 5 minutes.

9. The system of claim 8 wherein the multiple discrete stimulation times are about 20 seconds.

10. The system of claim 1 wherein the sensing assembly and the stimulation assembly each comprise an electrode array.

11. The system of claim 10 wherein the same electrode array is used to stimulate the one or more neurons and acquire the signal from the subject.

12. The system of claim 10 wherein the stimulation assembly comprises an electrode array adapted to be coupled to a peripheral nerve.

13. The system of claim 12 wherein the peripheral nerve is a vagus nerve.

14. The system of claim 1 wherein the signal is an EEG signal from the subject.

15. The system of claim 2 wherein the system further comprises a control assembly adapted to adjust the multiple discrete acquisition times and the multiple discrete stimulation times.

16. The system of claim 15 wherein the control assembly is in communication with a device external to the subject, wherein the device is adapted to allow adjustment of the stimulation and acquisition times.

17. The system of claim 15 wherein the control assembly is adapted to dynamically adjust the stimulation or acquisition times.

18. The system of claim 1 wherein the subject'"'"'s brain activity is analyzed to predict an onset of a seizure.

19. The system of claim 1 further comprising a signal processor in communication with the sensing assembly adapted to process the signal to estimate an epileptic neural state.

20. The system of claim 19 wherein the signal processor comprises an observer algorithm operative when the sensing assembly is acquiring the signal.

21. The system of claim 20 wherein the observer algorithm comprises one or more feature extractors and a classifier.

22. A method of reducing artifact in a signal acquired from a subject, the method comprising:

acquiring a signal from a subject indicative of the subject'"'"'s brain activity;

stimulating the subject; and

controlling the time at which the acquiring the signal occurs to be substantially different than the stimulating the subject.

23. The method of claim 22 wherein the acquiring comprises acquiring the signal at multiple discrete acquisition times and the stimulating comprises stimulating the one or more neurons at multiple discrete stimulation times.

24. The method of claim 23 wherein the acquiring the signals occurs between the stimulating the subject.

25. The method of claim 24 wherein the acquiring and stimulating each occur in a regular pattern.

26. The method of claim 23 wherein the multiple discrete acquisition times are about 0.25 seconds to about 5 minutes.

27. The method of claim 26 wherein the multiple discrete acquisition times are about 5 seconds.

28. The method of claim 23 wherein the multiple discrete stimulation times are about 0.5 seconds to about 5 minutes.

29. The method of claim 28 wherein the multiple discrete stimulation times are about 20 seconds.

30. The method of claim 23 wherein the acquiring comprises acquiring an EEG signal from the subject.

31. The method of claim 23 wherein the stimulating comprises stimulating a peripheral nerve.

32. The method of claim 31 wherein the peripheral nerve is a vagus nerve.

33. The method of claim 24 further comprising adjusting the multiple discrete acquisition times and/or the multiple discrete stimulation times.

34. The method of claim 23 wherein the subject'"'"'s brain activity is processed to measure the subject'"'"'s susceptibility to a seizure.

35. The method of claim 23 further comprising processing the signal to estimate an epileptic neural state.

36. A method of managing seizures, the method comprising:

acquiring an EEG signal from a subject during multiple discrete acquisition times occurring in a regular pattern;

stimulating one or more neurons of the subject during multiple discrete stimulation times occurring in a regular pattern; and

controlling the times at which the acquiring the EEG signal occurs to be substantially different than the stimulating the one or more neurons of the subject.