SEIZURE DETECTION ALGORITHM ADJUSTMENT

• US 20100121215A1
• Filed: 04/29/2009
• Published: 05/13/2010
• Est. Priority Date: 11/11/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Giftakis, Jonathon E., Torgerson, Nathan A.
• Granted Patent: US 10,543,359 B2
• Time in Patent Office: Days
• US Class Current: 600/544
• 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 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease

Abstract

A medical system implements a seizure detection algorithm to detect a seizure based on a first patient parameter. The medical system monitors a second patient parameter to adjust the seizure detection algorithm. In some examples, the medical system determines whether a seizure for which therapy delivery is desirable occurred based on a second patient parameter. If a target seizure occurred, and the seizure detection algorithm did not detect the target seizure, the medical system adjusts the seizure detection algorithm to detect the target seizure. For example, the medical system may determine a first patient parameter characteristic indicative of the target seizure detected based on the second patient parameter and store the first patient parameter characteristic as part of the seizure detection algorithm. In some examples, the first patient parameter is an electrical brain signal and the second patient parameter is patient activity (e.g., patient motion or posture).

Claims

1. A method comprising:

receiving a bioelectrical brain signal of a patient sensed by a medical device;

receiving a patient activity signal indicative of motor activity of the patient;

automatically identifying a target seizure based on the patient activity signal; and

determining a characteristic of the bioelectrical brain signal that is indicative of the target seizure.

2. The method of claim 1, wherein the target seizure includes a motor seizure.

3. The method of claim 1, wherein the receiving the patient activity signal comprises receiving the patient activity signal generated by an activity sensor implanted within the patient.

4. The method of claim 1, wherein the receiving the patient activity signal comprises receiving the patient activity signal generated by an activity sensor that is external to the patient.

5. The method of claim 1, further comprising programming the medical device to at least one of deliver seizure disorder therapy to the patient or generate a patient notification upon detecting the characteristic of the bioelectrical brain signal.

6. The method of claim 1, wherein determining the characteristic of the bioelectrical brain signal indicative of the target seizure comprises:

identifying a first portion of the bioelectrical brain signal temporally correlating to a second portion of the patient activity signal that is indicative of the target seizure; and

determining the characteristic based on the first portion of the bioelectrical brain signal.

7. The method of claim 1, wherein the characteristic of the bioelectrical brain signal comprises at least one of a signal amplitude, signal frequency, signal pattern, slope or frequency band characteristic of the bioelectrical brain signal.

8. The method of claim 1, further comprising:

determining whether the medical device, while implementing a seizure detection algorithm, identified the target seizure based on the bioelectrical brain signal, wherein the seizure detection algorithm does not use the patient activity signal to detect seizures; and

adjusting the seizure detection algorithm based on the characteristic of the bioelectrical brain signal if the medical device did not identify the target seizure based on the bioelectrical brain signal.

9. The method of claim 1, wherein identifying a target seizure based on the patient activity signal comprises determining whether an amplitude of the patient activity signal is greater than or equal to a threshold value, wherein the amplitude being greater than or equal to the threshold value indicates the occurrence of the target seizure.

10. The method of claim 1, wherein identifying the target seizure based on the patient activity signal comprises comparing the patient activity signal to a template and determining whether a portion of the patient activity signal substantially correlates to the template, the substantial correlation indicating the occurrence of the target seizure.

11. The method of claim 1, further comprising determining whether the target seizure is an actual seizure by at least determining whether a portion of the bioelectrical brain signal associated with the target seizure is indicative of a non-seizure state of the patient, wherein if the brain signal is not indicative of the non-seizure state of the patient, the target seizure is the actual seizure.

12. A method comprising:

receiving a first signal indicative of a physiological parameter of a patient;

receiving a second signal indicative of a patient parameter of the patient; and

adjusting a seizure detection algorithm of a medical device based on the first and second signals, wherein the medical device implements the seizure detection algorithm to detect the target seizure based on the first signal.

13. The method of claim 12, wherein the physiological parameter comprises a bioelectrical brain signal.

14. The method of claim 12, wherein the patient parameter comprises patient motion or patient posture.

15. The method of claim 12, further comprising:

identifying a target seizure based on the second signal;

determining whether a medical device, while implementing the seizure detection algorithm, identified the target seizure based on the first signal; and

adjusting the seizure detection algorithm if the medical device did not identify the target seizure based on the first signal.

16. The method of claim 15, further comprising determining whether the target seizure is an actual seizure by at least determining whether a portion of the first signal associated with the target seizure is indicative of a non-seizure state of the patient, wherein adjusting the seizure detection algorithm comprises adjusting the seizure detection algorithm if the first signal is not indicative of the non-seizure state of the patient.

17. The method of claim 15, wherein determining whether the medical device identified the target seizure comprises determining whether the medical device delivered therapy to the patient or generated a patient notification prior to or upon occurrence of the target seizure.

18. The method of claim 15, wherein adjusting the seizure detection algorithm comprises:

determining a characteristic of the first signal that is indicative of the target seizure; and

storing the characteristic as part of the seizure detection algorithm.

19. The method of claim 18, wherein determining the characteristic of the first signal indicative of the target seizure comprises:

identifying a first portion of the first signal temporally correlating to a second portion of the second signal that is indicative of the target seizure; and

determining the characteristic based on the first portion of the first signal.

20. The method of claim 12, further comprising:

temporally correlating the first and second signals;

identifying a target seizure based on the first signal;

determining whether the second signal temporally correlated with the first signal is indicative of the target seizure; and

adjusting the seizure detection algorithm if the second signal is not indicative of the target seizure.

21. The method of claim 20, wherein adjusting the seizure detection algorithm comprises:

determining a characteristic of the first signal that is indicative of the target seizure; and

removing the characteristic from the seizure detection algorithm.

22. A system comprising:

a first sensor that senses a bioelectrical brain signal of a patient;

a second sensor that generates a patient activity signal indicative of motor activity of the patient; and

a processor that receives the bioelectrical brain signal and the patient activity signal, identifies a target seizure based on the patient activity signal, and determines a characteristic of the bioelectrical brain signal that is indicative of the target seizure.

23. The system of claim 22, wherein the target seizure includes a motor seizure.

24. The system of claim 22, wherein the second sensor is implanted within the patient.

25. The system of claim 22, further comprising an implantable medical device that includes at least one of the first or second sensors, wherein the medical device at least one of delivers therapy to the patient or generates a patient notification upon detecting the characteristic of the first signal.

26. The system of claim 22, wherein the processor determines the characteristic of the bioelectrical brain signal indicative of the target seizure by at least identifying a first portion of the bioelectrical brain signal temporally correlating to a second portion of the patient activity signal that is indicative of the target seizure and determining the characteristic based on the first portion of the bioelectrical brain signal.

27. The system of claim 22, wherein the characteristic of the bioelectrical brain signal comprises at least one of a signal amplitude, signal frequency, signal pattern, slope or frequency band characteristic of the first signal.

28. The system of claim 22, further comprising a medical device, wherein the processor determines whether the medical device, while implementing a seizure detection algorithm, identified the target seizure based on the bioelectrical brain signal and adjusts the seizure detection algorithm based on the determined characteristic of the bioelectrical brain signal if the medical device did not identify the target seizure based on the bioelectrical brain signal.

29. The system of claim 22, wherein the processor determines whether an amplitude of the patient activity signal is greater than or equal to a threshold value, and identifies the target seizure if the amplitude is greater than or equal to the threshold value.

30. The system of claim 22, wherein the processor compares the patient activity signal to a template and determines whether a portion of the second signal substantially correlates to the template, wherein the processor identifies the target seizure if the portion of the patient activity signal substantially correlates to the template.

31. The system of claim 22, wherein the processor determines whether the target seizure is an actual seizure by at least determining whether a portion of the bioelectrical brain signal associated with the target seizure is indicative of a non-seizure state of the patient, wherein if the brain signal is not indicative of the non-seizure state of the patient, the target seizure is the actual seizure.

32. A system comprising:

a first sensor that generates a first signal indicative of a physiological parameter of a patient;

a second sensor that generates a second signal indicative of a patient parameter of the patient; and

a processor that receives the first and second signals and adjusts a seizure detection algorithm of a medical device based on the first and second signals, wherein the medical device implements the seizure detection algorithm to detect the target seizure based on the first signal.

33. The system of claim 32, wherein the physiological parameter comprises a bioelectrical brain signal.

34. The system of claim 32, wherein the patient parameter comprises patient motion or patient posture.

35. The system of claim 32, further comprising the medical device, wherein the processor identifies a target seizure based on the second signal, determines whether the medical device, while implementing the seizure detection algorithm, identified the target seizure based on the first signal, and adjusts the seizure detection algorithm if the medical device did not identify the target seizure based on the first signal.

36. The system of claim 35, wherein the processor determines whether the target seizure is an actual seizure by at least determining whether a portion of the first signal associated with the target seizure is indicative of a non-seizure state of the patient, and adjusts the seizure detection algorithm if the first signal is not indicative of the non-seizure state of the patient.

37. The system of claim 35, wherein the processor adjusts the seizure detection algorithm by at least determining a characteristic of the first signal that is indicative of the target seizure based on the first and second signals and storing the characteristic as part of the seizure detection algorithm.

38. The system of claim 32, wherein the processor temporally correlates the first and second signals, identifies a target seizure based on the first signal, determining whether the second signal temporally correlated with the first signal is indicative of the target seizure, and adjusts the seizure detection algorithm if the second signal is not indicative of the target seizure.

39. The system of claim 38, wherein the processor adjusts the seizure detection algorithm by at least determining a characteristic of the first signal that is indicative of the target seizure, and removing the characteristic from the seizure detection algorithm.

40. A system comprising:

means for receiving a bioelectrical brain signal of a patient sensed by a medical device;

means for receiving a patient activity signal indicative of motor activity of the patient;

means for identifying a target seizure based on the patient activity signal; and

means for determining a characteristic of the bioelectrical brain signal that is indicative of the target seizure.

41. The system of claim 40, further comprising:

means for determining whether a medical device, while implementing a seizure detection algorithm, identified the target seizure based on the bioelectrical brain signal; and

means for adjusting the seizure detection algorithm of the medical device based on the characteristic of the patent activity signal if the medical device did not identify the target seizure based on the bioelectrical brain signal.

42. A system comprising:

means for generating a first signal indicative of a physiological parameter of a patient;

means for generating a second signal indicative of a patient parameter of the patient; and

means for adjusting a seizure detection algorithm of a medical device based on the first and second signals, wherein the medical device implements the seizure detection algorithm to detect the target seizure based on the first signal.

43. The system of claim 42, further comprising:

means for identifying a target seizure based on the second signal; and

means for determining whether the medical device, while implementing the seizure detection algorithm, identified the target seizure based on the first signal, wherein the means for adjusting the seizure detection algorithm adjusts the seizure detection algorithm if the medical device did not identify the target seizure based on the first signal.