EEG seizure analysis
AssigneeNatus Medical Incorporated
InventorMichael Alexander Navakatikyan
Life of this patent
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Abstract
Automated seizure detection from within an electroencephalogram (EEG) by instrumental means employs novel algorithms within software, using specific measurements of individual waves in trains, rather than any “bulk” process. The acquired signal is filtered, the wave shapes are individually described within a number of parallel runs using a variety of parameters, then criteria (including regularity criteria) are calculated and applied in order to create raw detection results. Finally the raw results are “integrated” for display. As a result, reported seizures closely follow the incidence and duration of seizures detected by trained clinicians. The invention is useful in intensive-care monitoring of EEGs from neonates and in EEG monitoring in general.
Claims52
A method of detecting seizures in an electroencephalogram (EEG) signal comprising the steps of:
- i) generating an EEG signal from a set of electrodes applied to an animal's cranium and obtaining an inverted version of the EEG signal;
- ii) obtaining representative numerical data from the EEG signal, wherein the representative numerical data is obtained by comparing the EEG signal to an averaged EEG signal to locate intersection positions to determine the location of each peak or trough of the EEG signal and recording the position of each trough, subsequent peak and two corresponding intersection points in respective data groups, wherein obtaining representative numerical data is carried out on the inverted version of the EEG signal, and the representative numerical data from both the EEG signal and inverted version of the EEG signal are combined;
- iii) characterizing the waveform shape of the EEG signal at a plurality of times within the EEG signal;
- iv) carrying out at least one calculation on at least some of the representative numerical data to produce related numerical data indicative of at least two individual oscillations identified within the EEG signal;
- v) comparing the related numerical data indicative of at least two individual oscillations identified to a predetermined criteria;
- and
- vi) determining that a seizure event has taken place at a particular time or times in the EEG signal if the related numerical data indicative of at least two individual oscillations identified at said particular time or times in the EEG signal are within the predetermined criteria;
- wherein a computer is configured to perform the steps i)-vi) above.
A non-transitory computer readable medium on which a computer program is stored, the computer program, when executed on a computer, enabling the computer to detect seizures in an electroencephalogram (EEG) signal by:
- i) generating an EEG signal from a set of electrodes applied to an animal's cranium, obtaining representative numerical data from the EEG signal and characterising the waveform shape of the EEG signal at a plurality of times within the EEG signal, the representative numerical data obtained by comparing the EEG signal to an averaged EEG signal to locate intersection positions to determine the location of each peak or trough of the EEG signal and record the position of each trough, subsequent peak and two corresponding intersection points in respective data groups, wherein obtaining representative numerical data is carried out on the inverted version of the EEG signal, and the representative numerical data from both the EEG signal and inverted version of the EEG signal are combined;
- ii) carrying out at least one calculation on at least some of the representative numerical data to produce related numerical data indicative of individual oscillations identified within the EEG signal;
- iii) comparing the related numerical data indicative of at least two individual oscillations identified to a predetermined criteria;
- and
- iv) determining that a seizure event has taken place at a particular time or times in the EEG signal if the related numerical data indicative of individual oscillations identified at said particular time or times in the EEG signal are within the predetermined criteria;
- wherein a computer is configured to perform the steps i)-iv) above.
A computer implemented device incorporating and implementing a non-transitory computer readable medium for detecting seizures in an electroencephalogram (EEG) signal, the device configured to:
- i) generate an EEG signal from a set of electrodes applied to an animal's cranium and to obtain an inverted version of the EEG signal;
- ii) obtain representative numerical data characterising the waveform shape of the EEG signal at a plurality of times within the EEG signal, the representative numerical data obtained by comparing the EEG signal to an averaged EEG signal to locate intersection positions to determine the location of each peak or trough of the EEG signal and record the position of each trough, subsequent peak and two corresponding intersection points in respective data groups, wherein obtaining representative numerical data is carried out on the inverted version of the EEG signal, and the representative numerical data from both the EEG signal and inverted version of the EEG signal are combined;
- iii) carry out a calculation or calculations on at least some of the representative numerical data to produce related numerical data indicative of individual oscillations identified within the EEG signal;
- iv) compare the related numerical data of at least two individual oscillations identified to a predetermined criteria;
- and
- v) determine that a seizure event has taken place at a particular time or times in the EEG signal if the related numerical data of individual oscillations identified at said particular time or times in the EEG signal are within the predetermined criteria;
- wherein a computer is configured to perform the steps i)-v) above.
Dependencies are inferred from the claim text.