Implantable seizure warning system

• US 6,337,997 B1
• Filed: 12/10/1999
• Issued: 01/08/2002
• Est. Priority Date: 04/30/1998
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Rise, Mark T.
• Primary Examiner(s): LAYNO, CARL HERNANDZ
• Application Number:
  US09/459,184
• Time in Patent Office: 760 Days
• Field of Search: 607/45, 607/3
• US Class Current: 607/45
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61N 1/36064 Epilepsy
• CPC Class Codes: A61N 1/36135 using physiological parameters

Abstract

Techniques for warning a patient of a possible onset of a seizure using a sensor, a signal generator and at least one implantable electrode. The electrodes are positioned to stimulate the spinal cord or under the skin. The sensor senses a parameter of the body indicative of the possible onset of a seizure. The sensor generates a sensing signal which is processed and an algorithm is utilized to determine whether the sensing signal shows a pattern indicative of a possible seizure onset. If such a pattern is recognized, the signal generator provides electrical stimulation via electrodes to generate a sensory stimulus to the body. The stimulation may provide visual, aural or touch stimulus to the patient. The patient is thereby alerted to the possibility of a seizure onset and may take appropriate action

Claims

1. A method of warning a patient of a possible onset of a seizure using a sensor, a signal generator and at least one implantable electrode having a proximal end and a stimulation portion, the method comprising the steps of:

a. surgically implanting the sensor within a body of a patient;

b. coupling the sensor to the signal generator;

c. surgically implanting the electrode in the body, coupling the proximal end to the signal generator, and positioning the stimulation portion to be in communication with neural tissue within the body; and

d. sensing a parameter of the body with the sensor and generating a sensing signal;

e. detecting from the sensor signal a pattern indicative of the onset of a seizure; and

f. in response to a detected possible seizure onset, stimulating the neural tissue with the electrode to generate a sensory stimulus to the body.

2. The method of claim 1, wherein the step of surgically implanting the sensor includes the step of positioning the sensor to be in communication with a predetermined site in a brain.

3. The method of claim 2, wherein the step of positioning includes the step of selecting the predetermined site from the group consisting of the thalamus, internal capsule, hippocampus, cortex and basal ganglia.

4. The method of claim 1, wherein the step of sensing includes the step of sensing electrical activity of a brain.

5. The method of claim 1, wherein the step of sensing includes the step of sensing chemical activity of a brain.

6. The method of claim 1, wherein the step of surgically implanting includes the step of surgically implanting the signal generator.

7. The method of claim 6, wherein the step of surgically implanting the signal generator includes the step of placing the signal generator in a subclavicular, subcutaneous pocket of the body.

8. The method of claim 6, wherein the step of surgically implanting the signal generator includes the step of placing the signal generator in an abdomen of the body.

9. The method of claim 1, wherein the step of detecting includes the step of performing an algorithmic operation.

10. The method of claim 9, further comprising the step of changing the algorithmic operation to a second algorithmic operation.

11. The method of claim 1 wherein the step of stimulating includes the step of providing a type of stimulus selected from the group consisting of touch stimulus, visual stimulus, and aural stimulus.

12. The method of claim 1 wherein the step of surgically implanting the electrode includes the step of positioning the electrode to be in communication with a predetermined part of a spinal cord of the body.

13. The method of claim 12, wherein the step of positioning includes the step of selecting the predetermined part from the group consisting of an epidural space, dorsal aspect, anterolateral aspect, and spinothalamic tract.

14. The method of claim 1 wherein the step of surgically implanting the electrode includes the step of positioning the electrode to be in communication with a somatosensory cortex of the brain.

15. The method of claim 1 wherein the step of surgically implanting the electrode includes the step of positioning the electrode to be in communication neural tissue underneath skin tissue of the body.

16. An apparatus for warning a patient of a possible onset of a seizure comprising:

a. a sensor capable of generating a sensing signal;

b. a signal processor coupled to receive the sensing signal, to process the signal, and to detect a pattern indicating the possible onset of a seizure,

a signal generator for generating a stimulation signal in response to an indication by the signal processor; and

d. at least one electrode having a proximal end and a stimulation portion, the proximal end being coupled to receive the stimulation signal, the stimulation portion coupled to stimulate neural tissue to deliver a sensory stimulus to the body.

17. The apparatus of claim 16, wherein the sensor comprises at least one sensing electrode.

18. The apparatus of claim 17, wherein the sensing electrode is selected from the group consisting of a peg electrode, epidural electrode, subdural electrode, and a subcutaneous electrode.

19. The apparatus of claim 16, wherein the implantable sensor includes a transducer and a sensing electrode having an ion selective coating.

20. The apparatus of claim 16, wherein the sensor has means for sensing physiological changes of a body.

21. The apparatus of claim 16, wherein the signal processor comprises an analog to digital converter, an amplifier and a filter.

22. The apparatus of claim 16, wherein the signal processor includes a microprocessor.

23. The apparatus of claim 16, wherein the sensor is an external device and is capable of telemetrically communicating with the signal processor.

24. The apparatus of claim 16, wherein the signal generator comprises a frequency generator, a digital to analog converter, and a pulse width control module.

25. The apparatus of claim 16, wherein the electrode comprises a steerable electrode.

26. The apparatus of claim 16, wherein the signal generator and signal processor are implantable devices.

27. The apparatus of claim 16, wherein the sensor is an implantable device.

28. A method of warning a patient of a possible onset of a seizure using a sensor, a signal generator and at least one implantable electrode having a proximal end and a stimulation portion, the method comprising the steps of:

a. implanting the electrode in a body of a patient, coupling the proximal end to the signal generator, and positioning the stimulation portion to be in communication with neural tissue within the body;

b. positioning a sensor to sense a characteristic of the body;

c. sensing a parameter of the body and generating a sensing signal;

d. providing the sensing signal to the signal generator to generate a therapy signal based on the sensing signal; and

e. periodically stimulating the neural tissue to generate a sensory stimulus based on the therapy signal.

29. The method of claim 28, wherein the step of positioning includes the step of selecting the predetermined site from the group consisting of the thalamus, internal capsule, hippocampus, cortex and basal ganglia.

30. The method of claim 28, wherein the step of sensing includes the step of sensing electrical activity of a brain.

31. The method of claim 28, wherein the step of sensing includes the step of sensing chemical activity of a brain.

32. The method of claim 28, wherein the step of surgically implanting includes the step of surgically implanting the signal generator.

33. The method of claim 32, wherein the step of surgically implanting the signal generator includes the step of placing the signal generator in a subclavicular, subcutaneous pocket of the body.

34. The method of claim 32, wherein the step of surgically implanting the signal generator includes the step of placing the signal generator in an abdomen of the body.

35. The method of claim 28, wherein the step of detecting includes the step of performing an is algorithmic operation.

36. The method of claim 35, further comprising the step of changing the algorithmic operation to a second algorithmic operation.

37. The method of claim 28 wherein the step of stimulating includes the step of providing a type of stimulus selected from the group consisting of touch stimulus, visual stimulus, and aural stimulus.

38. The method of claim 28 wherein the step of surgically implanting the electrode includes the step of positioning the electrode to be in communication with a predetermined part of a spinal cord of the body.

39. The method of claim 38, wherein the step of positioning includes the step of selecting the predetermined part from the group consisting of an epidural space, dorsal aspect, anterolateral aspect, and spinothalamic tract.

40. The method of claim 28 wherein the step of surgically implanting the electrode includes the step of positioning the electrode to be in communication with a somatosensory cortex of the brain.

41. The method of claim 28 wherein the step of surgically implanting the electrode includes the step of positioning the electrode to be in communication neural tissue underneath skin tissue of the body.

42. The method of preventing the onset of a seizure using a sensor, a signal generator and at least one electrode having a proximal end and a stimulation portion, the method comprising the steps of:

a. positioning the sensor to sense a condition of a patient'"'"'s body;

b. positioning the stimulation portion of the electrode to be in communication with neural tissue of the body

c. coupling the sensor and the proximal end of electrode to the signal generator; and

d. sensing a parameter of the body with the sensor and generating a sensing signal;

e. processing the sensing signal by the signal generator to detect a pattern indicative of a seizure onset; and

f. if the pattern is recognized, providing a sensory stimulus to the neural tissue with the electrode to responsively initiate desynchronization of neural activity.

43. The method of claim 42, wherein the step of providing sensory stimulus includes the step of stimulating a predetermined portion of the neural tissue, the predetermined portion being selected from the group consisting of a dorsal column of a spinal cord, an antero lateral column of the spinal cord, skin nerves, auditory cortex, somatosensory cortex, nuclei of sensory thalamus, and visual cortex.

44. The method of claim 42, wherein the step of positioning includes the step of selecting the predetermined site from the group consisting of the thalamus, internal capsule, hippocampus, cortex and basal ganglia.

45. The method of claim 42, wherein the step of sensing includes the step of sensing electrical activity of a brain.

46. The method of claim 42, wherein the step of sensing includes the step of sensing chemical activity of a brain.

47. The method of claim 42, further comprises the step of surgically implanting the signal generator.

48. The method of claim 47, wherein the step of surgically implanting the signal generator includes the step of placing the signal generator in a subclavicular, subcutaneous pocket of the body.

49. The method of claim 47, wherein the step of surgically implanting the signal generator includes the step of placing the signal generator in an abdomen of the body.

50. The method of claim 42, wherein the step of detecting includes the step of performing an algorithmic operation.

51. The method of claim 50, further comprising the step of changing the algorithmic operation to a second algorithmic operation.

52. The method of claim 42 wherein the step of stimulating includes the step of providing a type of stimulus selected from the group consisting of touch stimulus, visual stimulus, and aural stimulus.

53. The method of claim 42 wherein the step positioning the stimulation portion of the electrode includes the step of positioning the electrode to be in communication with a predetermined part of a spinal cord of the body.

54. The method of claim 53, wherein the step of positioning includes the step of selecting the predetermined part from the group consisting of an epidural space, dorsal aspect, anterolateral aspect, and spinothalamic tract.

55. The method of claim 42 wherein the step positioning the stimulation portion of the electrode includes the step of positioning the electrode to be in communication with a somatosensory cortex of the brain.

56. The method of claim 42 wherein the step positioning the stimulation portion of the electrode includes the step of positioning the electrode to be in communication neural tissue underneath skin tissue of the body.