Electroencephalographic system and method using factor structure of the evoked potentials

Claim 1

The method of analyzing the brain waves of a human subject to determine the presence, degree and type of evoked potential abnormality, the method consisting of the steps, in sequence, of: removably securing a plurality of electrodes i to the scalp of the patient, automatically presenting a sequence of stimuli to the patient to evoke brainwave potentials (EP) at the electrodes; detecting the said EP brainwaves, amplifying the detected brainwaves, converting the amplified brainwaves into digital form, averaging the digitized brainwaves to produce average evoked responses (AER) for analysis in a digital processing computer system having computer memory; decomposing the average evoked responses (AER) by factor analysis, in which each AER from each electrode is compared to pre-formulated factor waveforms stored in the computer memory to determine the amount of voltage that each pre-formulated factor waveform contributes to said AER to thereby produce a factor score a ij , quantifying the contribution of each factor j to the AER from any electrode i; subjecting the results of the said factor score to Z-transform, wherein each of said factor scores is compared to norms stored in the computer memory to produce a factor Z-score, corresponding to a determination of waveshape normalcy and the degree of abnormality of each of said AER's and displaying the said normalcy and degree of abnormality on a color-coded topographic map comprising a head diagram in which each area of the head represents an electrode location and the colors represent normalcy and the degree of abnormality reflected by the factor Z-score.

Claim 2

The method of analyzing the brain waves of a human subject to determine the presence, degree and type of evoked potential abnormality, the method consisting of the steps, in sequence, of: removably securing a plurality of electrodes i to the scalp of the patient, automatically presenting a sequence of stimuli to the patient to evoke brainwave potentials (EP) at the electrodes; detecting the said EP brainwaves, amplifying the detected brainwaves, converting the amplified brainwaves into digital form, averaging the digitized brainwaves to produce average evoked responses (AER) for analysis in a digital processing computer system having computer memory; decomposing the average evoked responses (AER) by factor analysis, in which each AER from each electrode is compared to pre-formulated factor waveforms stored in the computer memory to determine the amount of voltage that each pre-formulated factor waveform contributes to said AER to thereby produce a factor score a ij , quantifying the contribution of each factor j to the AER from any electrode i; subjecting the results of the said factor score to Z-transform, wherein each of said factor scores is compared to norms stored in the computer memory to produce a factor Z-score, corresponding to a determination of waveshape normalcy and the degree of abnormality of each of said AER's and displaying the said normalcy and degree of abnormality on a color-coded topographic map comprising a head diagram in which each area of the head represents an electrode location and the colors represent normalcy and the degree of abnormality reflected by the factor Z-score.

Claim 9

A system for analyzing the brainwaves of a human subject to determine the presence, degree and type of evoked potential abnormality, the system consisting of: a plurality of electrodes, means for removably securing the plurality of electrodes to the scalp of the patient, stimuli means for automatically presenting a sequence of stimuli to the patient to evoke brainwave potentials (EP) at the electrodes; amplifier means for amplifying the evoked brainwaves, A/D converter means for converting the amplified brainwaves into digital brainwave form, averaging means for averaging the digitized brainwaves to provide average evoked responses (AER) for analysis in a digital processing computer system; computer means having a computer memory and calculation means for analyzing the average evoked responses by factor analysis, said computer means comparing each AER from each electrode to pre-formulated factor waveforms stored in the computer memory to determine the voltage that each pre-formulated factor waveform contributes to each AER said comparison producing a factor score a ij quantifying the contribution of each factor to the AER from any electrode; Z-transform computer means for subjecting the said factor score to Z-transform, statistical computing means for automatically comparing each of said factor scores to norms stored in the computer memory to produce a factor Z score providing a determination of normalcy versus the degree of abnormality; and display means to display the said normalcy and degree of abnormality on a color coded topographic map comprising a head diagram in which each area of the head represents an electrode location and the color represents normalcy and the degree of abnormality reflected by the factor Z score.

Claim 10

A system for analyzing the brainwaves of a human subject to determine the presence, degree and type of evoked potential abnormality, the system consisting of: a plurality of electrodes, means for removably securing the plurality of electrodes to the scalp of the patient, stimuli means for automatically presenting a sequence of stimuli to the patient to evoke brainwave potentials (EP) at the electrodes; amplifier means for amplifying the evoked brainwaves, A/D converter means for converting the amplified brainwaves into digital brainwave form, averaging means for averaging the digitized brainwaves to provide average evoked responses (AER) for analysis in a digital processing computer system; computer means having a computer memory and calculation means for analyzing the average evoked responses by factor analysis, said computer means comparing each AER from each electrode to pre-formulated factor waveforms stored in the computer memory to determine the voltage that each pre-formulated factor waveform contributes to each AER said comparison producing a factor score a ij quantifying the contribution of each factor to the AER from any electrode; Z-transform computer means for subjecting the said factor score to Z-transform, statistical computing means for automatically comparing each of said factor scores to norms stored in the computer memory to produce a factor Z score providing a determination of normalcy versus the degree of abnormality; and display means to display the said normalcy and degree of abnormality on a color coded topographic map comprising a head diagram in which each area of the head represents an electrode location and the color represents normalcy and the degree of abnormality reflected by the factor Z score.