Systems and methods for identifying a contra-ictal condition in a subject

• US 9,898,656 B2
• Filed: 01/25/2008
• Issued: 02/20/2018
• Est. Priority Date: 01/25/2007
• Status: Active Grant

• Current Assignee: Cyberonics, Inc
• Original Assignee: Cyberonics, Inc
• Inventors: Snyder, David, Leyde, Kent W., Harris, John F.
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): BLOCH, MICHAEL RYAN
• Application Number:
  US12/020,450
• Publication Number:
  US 20080183096A1
• Time in Patent Office: 3,679 Days
• Field of Search: 600544-545
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/372 Analysis of electroencephalograms
• CPC Class Codes: A61B 5/375 using biofeedback
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: G06F 2218/00 Aspects of pattern recognition specially adapted for signal processing
• CPC Class Codes: G16B 40/00 ICT specially adapted for biostatistics; ICT specially adapted for bioinformatics-related machine learning or data mining, e.g. knowledge discovery or pattern finding
• CPC Class Codes: G16B 40/30 Unsupervised data analysis
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: G16H 50/70 for mining of medical data, e.g. analysing previous cases of other patients

Abstract

The invention provides a method of monitoring a subject'"'"'s neurological condition. In some embodiments, the method includes the steps of analyzing a physiological signal (such as an EEG) from a subject to determine if the subject is in a contra-ictal condition; and if the subject is in a contra-ictal condition, providing an indication (e.g., to the subject and/or to a caregiver) that the subject is in the contra-ictal condition, such as by activating a green light or other visible output. In some embodiments, if the subject is in a pro-ictal condition, the method includes the step of providing an indication (such as a red light) that the subject is in the pro-ictal condition. The invention also provides neurological system monitors.

Claims

1. A method of identifying a contra-ictal status of a subject, the method comprising:

obtaining, by one or more physiological sensors, an electroencephalogram (EEG) signal dataset from the subject;

using a processor to complete steps of;

generating an N-dimensional feature vector for each of different time points of the EEG signal dataset;

identifying a grouping of contra-ictal feature vectors that is substantially free of pro-ictal feature vectors, wherein the contra-ictal feature vectors are associated with a low susceptibility of having a seizure and the pro-ictal feature vectors are associated with high susceptibility of having a seizure;

identifying a grouping of pro-ictal feature vectors that is substantially free of contra-ictal feature vectors;

using the grouping of contra-ictal feature vectors to provide an output associated with a contra-ictal status and using the grouping of pro-ictal feature vectors to provide an output associated with a pro-ictal status;

comparing the contra-ictal output to at least one threshold to determine a contra-ictal state;

comparing the pro-ictal output to at least one threshold to determine a pro-ictal state;

selecting an indicator from among at least three indicators based on the contra-ictal state and the pro-ictal state, each of the at least three indicators corresponding to a different susceptibility of having a seizure, wherein the selected indicator indicates whether the subject has the contra-ictal status; and

displaying, by a seizure advisory system, the selected indicator.

2. The method of claim 1 further comprising storing the identified grouping of contra-ictal feature vectors or a mathematical representation of the identified grouping of contra-ictal feature vectors in memory.

3. The method of claim 1 further comprising customizing a contra-ictal algorithm for the subject based on the N-dimensional feature vector and the processor using the customized contra-ictal algorithm.

4. The method of claim 1, wherein the displaying of the indicator includes a report that a seizure is unlikely to occur for a time period.

5. The method of claim 4, wherein the time period is at least one of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes, greater than 5 minutes, greater than 15 minutes, greater than 30 minutes, greater than 60 minutes, and greater than 90 minutes.

6. The method of claim 1, wherein the indicator is the identification of the contra-ictal status of the subject and corresponds to a time period that the subject is estimated to remain in the contra-ictal status.

7. The method of claim 6, wherein the time period is at least one of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes, greater than 5 minutes, greater than 15 minutes, greater than 30 minutes, greater than 60 minutes, and greater than 90 minutes.

8. The method of claim 1, wherein selecting the indicator comprises:

selecting a first indicator of the at least three indicators in response to the contra-ictal output being above at least one threshold and the pro-ictal output being below at least one threshold, the first indicator corresponding to a low susceptibility of having a seizure;

selecting a second indicator of the at least three indicators in response to the contra-ictal output being below at least one threshold and the pro-ictal output being above at least one threshold, the second indicator corresponding to a high susceptibility of having a seizure;

selecting a third indicator of the at least three indicators in response to the contra-ictal output being below at least one threshold and the pro-ictal output being below at least one threshold, the third indicator corresponding to neither the contra-ictal state nor the pro-ictal state; and

selecting the third indicator of the at least three indicators in response to the contra-ictal output being above at least one threshold and the pro-ictal output being above at least one threshold.

9. The method of claim 8, wherein the first indicator is a green light, the second indicator is a red light, and the third indicator is a yellow light.

10. A method of identifying a contra-ictal status of a subject, the method comprising:

obtaining, by one or more physiological sensors, an electroencephalogram (EEG) signal dataset from the subject, the EEG signal dataset including contra-ictal data corresponding to a contra-ictal status of the subject in which the subject has a low susceptibility of having a seizure for a time period, the EEG signal dataset further including pro-ictal data corresponding to a pro-ictal status of the subject in which the subject has a high susceptibility of having a seizure;

using a processor to complete steps of;

distinguishing the contra-ictal data from the pro-ictal data within the EEG signal dataset;

providing an output associated with the contra-ictal status and providing an output associated with the pro-ictal status based on the distinguished data;

comparing the contra-ictal output to at least one threshold to determine a contra-ictal state;

comparing the pro-ictal output to at least one threshold to determine a pro-ictal state;

selecting an indicator from among at least three indicators based on the contra-ictal state and the pro-ictal state, each of the at least three indicators corresponding to a different susceptibility of having a seizure, wherein the selected indicator indicates whether the subject has the contra-ictal status;

displaying, by a seizure advisory system, the selected indicator; and

reporting, by the processor, the contra-ictal status of the subject.

11. The method of claim 10, wherein the time period is at least one of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes, greater than 5 minutes, greater than 15 minutes, greater than 30 minutes, greater than 60 minutes, and greater than 90 minutes.

12. The method of claim 10, wherein the reporting is to the subject or a care provider of the subject.

13. The method of claim 10, wherein the reporting includes reporting the time period.

14. The method of claim 13, wherein the time period is at least one of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes, greater than 5 minutes, greater than 15 minutes, greater than 30 minutes, greater than 60 minutes, and greater than 90 minutes.

15. The method of claim 10, further comprising:

providing a therapeutic response to the subject.

16. A method of identifying a contra-ictal status of a subject, the method comprising:

obtaining, by one or more physiological sensors, an electroencephalogram (EEG) signal dataset from the subject, the EEG signal dataset corresponding to a normal non-seizure status of the subject;

using a processor to complete steps of;

distinguishing contra-ictal data from pro-ictal data within the EEG signal dataset, wherein the contra-ictal data is associated with a low susceptibility of having a seizure and the pro-ictal data is associated with a high susceptibility of having a seizure;

in response to distinguishing the contra-ictal data from the pro-ictal data, providing an output associated with a contra-ictal status for a time period and providing an output associated with a pro-ictal status for the time period, the time period being a future period of time;

comparing the contra-ictal output to at least one threshold to determine a contra-ictal state for the time period;

comparing the pro-ictal output to at least one threshold to determine a pro-ictal state for the time period;

selecting an indicator from among at least three indicators based on the contra-ictal state and the pro-ictal state, each of the at least three indicators corresponding to a different susceptibility of having a seizure for the time period, wherein the selected indicator indicates whether the subject has the contra-ictal status; and

displaying, by a seizure advisory system, the selected indicator.

17. The method of claim 16, wherein the time period is at least one of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes, greater than 5 minutes, greater than 15 minutes, greater than 30 minutes, greater than 60 minutes, and greater than 90 minutes.

18. The method of claim 16, further comprising:

providing a therapeutic response to the subject.