Method and Apparatus for Detecting and Classifying Seizures

• US 20160166208A1
• Filed: 10/22/2015
• Published: 06/16/2016
• Est. Priority Date: 12/02/2013
• Status: Abandoned Application

• Current Assignee: Novela Neurotechnologies, Inc.
• Original Assignee: Brain Sentinel, Inc.
• Inventors: Girouard, Michael R., Herring, Russell M., Cavazos, Jose E.
• Application Number:
  US14/920,665
• Publication Number:
  US 20160166208A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A method of monitoring a patient for seizure activity may include monitoring the patient by collecting an EMG signal and determining whether samples of signal that include regions of elevated signal amplitude are present in the collected signal. The samples may further be qualified based on one or more properties of a clonic-phase portion of a seizure, and if the samples are qualified, a qualified-clonic-phase burst activity level may be determined. A response may then be executed if the qualified-clonic-phase burst activity level exceeds a threshold value. Related apparatuses are also described.

Claims

1. A method of monitoring a patient for seizure activity comprising:

monitoring said patient using one or more EMG electrodes to obtain an EMG signal;

processing with a processor said EMG signal to identify if one or more samples which include an elevated region of signal amplitude are present in said EMG signal;

determining if said one or more samples meet one or more qualification thresholds suitable to identify samples that are indicative of clonic-phase seizure activity;

classifying samples among said one or more samples that meet said one or more qualification thresholds as a first set of one or more qualified-clonic-phase bursts;

wherein said one or more qualification thresholds include one or more duration width thresholds selected from a maximum duration width threshold, a minimum duration width threshold, and a combination of both a maximum duration width threshold and a minimum duration width threshold;

including said first set of one or more qualified-clonic-phase bursts in determining a qualified-clonic-phase burst activity level;

determining if a seizure is present based on said qualified-clonic-phase burst activity level; and

initiating an alarm if said seizure is present.

2. The method of claim 1 wherein said minimum duration width threshold is a minimum duration width of an elevated region of a sample and ranges from about 25 milliseconds to about 100 milliseconds, and said maximum duration width threshold is a maximum duration width of an elevated region of a sample and ranges from about 250 milliseconds to about 400 milliseconds.

3. The method of claim 1 wherein said qualified-clonic-phase burst activity level includes a qualified-clonic-phase burst count;

and

wherein said determining if said seizure is present includes comparing said qualified-clonic-phase burst count to a threshold count number.

4. The method of claim 1 wherein said qualified-clonic-phase burst activity level includes a certainty weighted qualified-clonic-phase burst value;

wherein said determining if said seizure is present includes comparing said certainty weighted qualified-clonic-phase burst value to a threshold value.

5. The method of claim 4 further comprising determining one or more statistical values for how qualified-clonic-phase bursts change throughout the course of said seizure, and providing to a caregiver a statistics summary including the one or more statistical values.

6. The method of claim 1 further comprising:

organizing said one or more samples into one or more groups;

determining one or more aggregate property values for said one or more groups;

comparing said one or more aggregate property values to one or more aggregate qualification threshold values;

determining a second set of qualified-clonic-phase bursts based on the comparing of said one or more aggregate property values to said one or more aggregate qualification threshold values; and

including said second set of qualified-clonic-phase bursts in the determining of said qualified-clonic-phase burst activity level.

8. The method of claim 6 wherein said one or more aggregate qualification threshold values are selected from a maximum deviation threshold value, a minimum deviation threshold value, and a combination thereof.

9. The method of claim 8 wherein said maximum deviation threshold value and said minimum deviation threshold value are percentage average deviation threshold values or standard deviation threshold values.

10. The method of claim 6 wherein said one or more groups include a sample number of between about 3 samples to about 20 samples.

11. The method of claim 6 wherein said one or more groups include samples identified over a time period of about 2 seconds to about 5 seconds.

12. The method of claim 6 wherein said qualified-clonic-phase burst activity level is determined from said first set of one or more-qualified-clonic-phase bursts and said second set of qualified-clonic-phase bursts by taking a union of said first set and said second set.

13. The method of claim 6 wherein said qualified-clonic-phase burst activity level is determined from said first set of one or more qualified-clonic-phase bursts and said second set of qualified-clonic-phase bursts by taking an intersection of said first set and said second set.

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15. The method of claim 14 wherein said one or more statistical values are selected from a number of qualified-clonic-phase bursts, a rate of qualified-clonic-phase burst detection, an average signal-to-noise ratio of qualified-clonic-phase bursts, a spread of signal-to-noise ratio of qualified-clonic-phase bursts, an average duration width for qualified-clonic-phase bursts, a spread of a duration width for qualified-clonic-phase bursts, an average duration width of periods between elevated portions of qualified-clonic-phase bursts, a spread of duration width of periods between elevated portions of qualified-clonic-phase bursts, and combinations thereof.

16. The method of claim 14 wherein said statistical summary includes a description of trends in how qualified-clonic-phase-bursts change across one or more different portions of a clonic phase of said seizure.

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41. A method of monitoring a patient for seizure activity comprising:

monitoring the patient using one or more EMG electrodes to obtain an EMG signal;

processing with a processor said EMG signal to identify if one or more samples which include an elevated region of signal amplitude are present in said EMG signal;

organizing said one or more samples into one or more groups;

determining one or more aggregate property values for said one or more groups;

comparing said one or more aggregate property values to one or more aggregate qualification thresholds;

determining a set of qualified-clonic-phase bursts based on the comparing of said one or more aggregate property values to said one or more aggregate qualification thresholds;

including said set of qualified-clonic-phase bursts in determining a qualified-clonic-phase burst activity level;

determining if a seizure is present based on said qualified-clonic-phase burst activity level; and

initiating an alarm if said seizure is present.

42. The method of claim 41 wherein said one or more aggregate qualification thresholds are selected from a minimum deviation threshold, a maximum deviation threshold, a minimum threshold rate of sample repetition, a maximum threshold rate of sample repetition, and combinations thereof.

43. The method of claim 41 wherein said one or more aggregate qualification thresholds are selected from a maximum deviation threshold, a minimum deviation threshold, and a combination thereof.

44. The method of claim 43 wherein said maximum deviation threshold and said minimum deviation threshold are percentage average deviation thresholds or standard deviation thresholds.

45. The method of claim 41 wherein said one or more groups include a sample number of between about 3 samples to about 20 samples.

46. The method of claim 41 wherein said one or more groups include samples identified over a time period of about 2 seconds to about 5 seconds.

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