Systems and methods for reducing the likelihood of inducing collateral neural activity during neural stimulation threshold test procedures

• US 20040019370A1
• Filed: 01/24/2003
• Published: 01/29/2004
• Est. Priority Date: 10/15/2001
• Status: Active Grant

• Current Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Northstar Neuroscience, Inc.
• Inventors: Gliner, Bradford Evan, Leyde, Kent
• Granted Patent: US 7,024,247 B2
• Time in Patent Office: Days
• US Class Current: 607/48
• CPC Class Codes: A61N 1/0531 Brain cortex electrodes
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0553 Paddle shaped electrodes, e.g. for laminotomy
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/36025 for treating a mental or cerebral condition
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Test procedures for determining a neural stimulation threshold of a patient. In one embodiment, the procedure includes applying a test stimulation signal to the patient and monitoring the patient for a response to the test stimulation signal. The procedure can further include determining a first neural stimulation threshold and calculating a second neural stimulation threshold. The first neural stimulation threshold corresponds to the lowest intensity test stimulation signal that evokes a patient response. The second neural stimulation threshold corresponds to a treatment stimulation signal directed toward affecting a neural activity within the patient.

Claims

1. A method of determining a neural stimulation threshold for a patient comprising the steps of:

applying a test stimulation signal to the patient;

monitoring the patient for a response to the test stimulation signal;

determining a first neural stimulation threshold corresponding to a lowest intensity test stimulation signal that evokes a patient response; and

calculating a second neural stimulation threshold based upon the first neural stimulation threshold, the second neural stimulation threshold corresponding to a treatment stimulation signal directed toward affecting a neural activity within the patient.

2. The method of claim 1, wherein the calculating step is performed using a transformation equation.

3. The method of claim 1, wherein the treatment stimulation signal differs from the test stimulation signal with respect to a plurality of parameters.

4. The method of claim 1, wherein the treatment stimulation signal has a different pulse repetition frequency than the test stimulation signal.

5. A method of determining a neural stimulation threshold for a patient comprising the steps of:

applying a plurality of limited duration test stimulation signals to the patient;

monitoring the patient for a response to a test stimulation signal; and

determining a first neural stimulation threshold corresponding to a lowest intensity test stimulation signal that evokes a patient response.

6. The method of claim 5, wherein at least one test stimulation signal has a duration between approximately 10 milliseconds and approximately 5 seconds.

7. The method of claim 5, wherein at least one test stimulation signal has a duration of less than approximately 5 seconds.

8. The method of claim 5, wherein at least one test stimulation signal has a duration between approximately 2 seconds and approximately 3 seconds.

9. The method of claim 5, wherein at least one test stimulation signal has a duration of approximately 1 second.

10. The method of claim 5, wherein each test stimulation signal has a duration between approximately 10 milliseconds and approximately 5 seconds.

11. The method of claim 5, wherein each test stimulation signal has a duration of less than approximately 5 seconds.

12. The method of claim 5, wherein each test stimulation signal has a duration between approximately 2 seconds and approximately 3 seconds.

13. The method of claim 5, wherein each test stimulation signal has a duration of approximately 1 second.

14. The method of claim 5, wherein at least one test stimulation signal has a duration that is dependent upon a cumulative number of test stimulation signals that have been applied to the patient.

15. The method of claim 5, wherein at least one test stimulation signal has a duration that corresponds to a type of patient response under consideration.

16. The method of claim 5, wherein at least two test stimulation signals are temporally separated by a minimum time interval.

17. The method of claim 5, wherein at least two test stimulation signals are temporally separated by a minimum time interval ranging between approximately 10 seconds and 4 minutes.

18. The method of claim 5, wherein at least two test stimulation signals are temporally separated by a minimum time interval of approximately 1 minute.

19. The method of claim 5, wherein each test stimulation signal is temporally separated by a minimum time interval.

20. The method of claim 5, further comprising the step of calculating a second neural stimulation threshold based upon the first neural stimulation threshold, the second neural stimulation threshold corresponding to a treatment stimulation signal directed toward affecting neural activity within the patient.

21. A method of determining a neural stimulation threshold for a patient comprising the steps of:

applying a plurality of test stimulation signals to the patient;

monitoring the patient for a response to a test stimulation signal; and

determining a first neural stimulation threshold corresponding to a lowest intensity test stimulation signal that evokes a patient response,

wherein successive test stimulation signals applied to the patient are temporally separated by a minimum time interval.

22. The method of claim 21, wherein the minimum time interval is greater than approximately 10 seconds.

23. The method of claim 21, wherein the minimum time interval is less than approximately 4 minutes.

24. The method of claim 21, wherein the minimum time interval is greater than approximately 10 seconds and less than approximately 4 minutes.

25. The method of claim 21, wherein the minimum time interval is approximately 1 minute.

26. The method of claim 21, wherein the test stimulation signals comprise electrical stimulation signals.

27. The method of claim 21, wherein at least one test stimulation signal has a duration between approximately 10 milliseconds and approximately 5 seconds.

28. The method of claim 21, wherein each test stimulation signal has a duration between approximately 10 milliseconds and approximately 5 seconds.

29. The method of claim 21, further comprising the step of calculating a second neural stimulation threshold based upon the first neural stimulation threshold, the second neural stimulation threshold corresponding to a treatment stimulation signal directed toward affecting neural activity within the patient.

31. The method of claim 23, wherein the treatment stimulation signal has a different pulse repetition frequency than at least one test stimulation signal.

30. A method of determining a neural stimulation threshold for a patient comprising the steps of:

selecting a set of test stimulation signal parameters that reduce a likelihood of inducing seizure activity in the patient;

applying a plurality of test stimulation signals to the patient;

monitoring the patient for a response to a test stimulation signal;

determining a first neural stimulation threshold corresponding to a lowest intensity test stimulation signal that evokes a patient response; and

calculating a second neural stimulation threshold based upon the first neural stimulation threshold, the second neural stimulation threshold corresponding to a treatment stimulation signal directed toward affecting neural activity within the patient,

wherein the treatment stimulation signal differs from at least one test stimulation signal with respect to a plurality of parameters.

32. A neuro-stimulation system comprising:

a stimulus unit configured to deliver a set of test stimulation signals to a patient; and

a controller operatively coupled to the stimulus unit, the controller including

a computer operable medium containing instructions that define a set of parameters corresponding to each test stimulation signal and at least one from the group of a maximum duration corresponding to each test stimulation signal and a minimum time interval between at least two test stimulation signals.

33. The neuro-stimulation system of claim 32, wherein the duration corresponding to each test stimulation signal is between approximately 10 milliseconds and approximately 5 seconds.

34. The neuro-stimulation system of claim 32, wherein the duration corresponding to each test stimulation signal is less than approximately 5 seconds.

35. The neuro-stimulation system of claim 32, wherein the duration corresponding to each test stimulation signal is between approximately 2 seconds and approximately 3 seconds.

36. The neuro-stimulation system of claim 32, wherein the minimum time interval is greater than approximately 10 seconds.

37. The neuro-stimulation system of claim 32, wherein the minimum time interval is less than approximately 4 minutes.

38. The neuro-stimulation system of claim 32, wherein the minimum time interval is greater than approximately 10 seconds and less than approximately 4 minutes.

39. The neuro-stimulation system of claim 32, wherein the minimum time interval is approximately 1 minute.

40. The neuro-stimulation system of claim 32, wherein the stimulus unit is additionally configured to deliver a set of treatment stimulation signals to the patient, at least one treatment stimulation signal directed toward affecting a neural activity within the patient.

41. The neuro-stimulation system of claim 40, wherein the treatment stimulation signal has a different frequency than a test stimulation signal.

42. The neuro-stimulation system of claim 32, wherein the stimulus unit comprises:

an electrode array configured for implantation into the patient; and

a pulse system coupled to deliver the set of test stimulation signals to the electrode array.

43. The neuro-stimulation system of claim 32, further comprising a sensing unit configured to detect a patient response to a test stimulation signal.

44. The neuro-stimulation system of claim 32, wherein the sensing unit comprises at least one form the group of an EMG device, an EEG device, an MEG device, a neural imaging device, and a motion detection device.

45. The neuro-stimulation system of claim 32, wherein the computer operable medium contains program instructions for causing the controller to perform the steps of:

applying a test stimulation signal to the patient; and

using a first neural stimulation threshold corresponding to a lowest intensity test stimulation signal that evokes a patient response to determine a second neural stimulation threshold, the second neural stimulation threshold corresponding to a treatment stimulation signal directed toward affecting a neural activity within the patient.

46. The system of claim 45, wherein the treatment stimulation signal differs from the test stimulation signal with respect to a plurality of parameters.

47. The system of claim 45, wherein the treatment stimulation signal has a different pulse repetition frequency than the test stimulation signal.

48. The system of claim 32, wherein the computer operable medium contains program instructions for causing the controller to perform the step of applying a plurality of limited duration test stimulation signals to the patient, wherein at least one test stimulation signal has a duration of less than approximately 5 seconds.

49. The system of claim 48, wherein each test stimulation signal has a duration of less than approximately 5 seconds.

50. The system of claim 48, wherein the computer operable medium contains program instructions for causing the controller to separate successive test stimulation signals by a minimum time interval.

51. The system of claim 50, wherein the minimum time interval is greater than approximately 10 seconds.

52. The system of claim 50, wherein the minimum time interval is less than approximately 4 minutes.

53. The system of claim 52, wherein the minimum time interval equals approximately 1 minute.