Brain function scan system

• US 6,385,486 B1
• Filed: 11/23/1999
• Issued: 05/07/2002
• Est. Priority Date: 08/07/1997
• Status: Expired due to Term

• Current Assignee: New York University
• Original Assignee: New York University
• Inventors: John, Erwin Roy, John, Michael Sasha
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/447,369
• Time in Patent Office: 896 Days
• Field of Search: 600/544-545
• US Class Current: 600/544
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/38 Acoustic or auditory stimuli
• CPC Class Codes: A61B 5/407 Evaluating the spinal cord A61B5/4896 takes precedence
• CPC Class Codes: A61B 5/4076 Diagnosing or monitoring particular conditions of the nervous system A61B5/4821, A61B5/4824 take precedence
• CPC Class Codes: A61B 5/7257 using Fourier transforms

Abstract

A portable EEG (electroencephalograph) instrument, especially for use in emergencies and brain assessments in physicians'"'"' offices, detects and amplifies brain waves and converts them into digital data for analysis by comparison with data from normal groups. In one embodiment, the EEG electrodes are in a headband which broadcasts the data, by radio or cellular phone, to a local receiver for re-transmission and/or analysis. In another embodiment, the subject is stimulated in two modes, i.e., aural and sensory, at two different frequencies to provide the subject'"'"'s EPs (Evoked Potentials), assessing transmission through the brainstem and thalamus.

Claims

1. A medical system to analyze brain waves of a subject comprising:

(a) at least one active EEG (electroencephalograph) electrode means to detect a subject'"'"'s brain waves;

(b) stimulus means to provide concurrent sense stimuli in two or more different stimulus modes (sensory modalities) to the subject, the stimuli in one mode being at frequency F₁ and the stimuli in the other modes(s) being at a different frequency F₂, F₃, etc.;

(c) amplification means to amplify and digitize the detected brain waves;

(d) ratio means to receive the digitized brain waves from (c) and produce subject brain wave F ratio data based on the power of brain responses at each of F₁ and F₂ in the presence and absence of stimulation;

(e) a receiver including a computer means to compare the subject brain wave F ratio data from (d) with brain wave F ratio data based upon a normal group of patients or in the presence or absence of stimulation; and

(f) a warning means in the receiver to warn if the comparison of (e) indicates one of injury to and dysfunction of one of the subject'"'"'s spinal cord, brain stem and brain.

2. A medical system as in claim 1 and including FFT means to perform Fast Fourier Transform (FFT) of the digitized brain waves to generate a power spectrum.

3. A medical system as in claim 2 wherein the F ratio data is an F ratio based on the generated power spectrum and the power of brain responses at each of F₁ and F₂ in the presence and absence of stimulation.

4. A medical system as in claim 2 wherein the FFT is a very narrow band FFT in increments in the range of 0.05-0.5 Hz.

5. A medical system as in claim 1 wherein the F ratio data is an F ratio between the power at F₁ or F₂:

P(Fi)/P(AV) where average power P(AV) is across N bins above and below F, or F₂.

6. A medical system as in claim 1 and including means to validate the digitized brain waves by comparing odd and even split-half segments of data from the same electrode, under the same stimulus and about the same time and rejecting segments that are atypical, using a fiducial electrode to assess stationarity.

7. A medical system as in claim 1 and, in the receiver, report means to generate a report on the comparison of (e) and transmission means to transmit the report to a base station.

8. A medical system as in claim 1 and means to modulate a carrier wave to modulate the amplified brain waves and to generate an audio signal therefrom.

9. A medical system as in claim 1 wherein the stimulus means includes means to generate an audio click and a somatosensory stimulus produced by applying one of a constant current, a constant voltage, and a tactile vibration to sensitive regions of the subject.

10. A medical system as in claim 1 wherein the statistical evaluation of computed measures from the patient (P) is by computing the Z-score, where Z =(M−

P)/6 and M is the mean value of a normative distribution, P is the current measure from the patient and 6 is the standard deviation of the normal age-matched population.

11. A medical system as in claim 1 and including a headband carrying thereon the electrode means and amplification means.

12. A medical system as in claim 1 including a plurality of homologous pairs of electrodes and means to determine asymmetry above a threshold level of the subject'"'"'s brain waves at the homologous pairs of electrodes.

13. A medical system as in claim 1 and including a headband having thereon the electrode means, amplifier means and a radio broadcast transmitter.

14. A medical method as in claim 1 and generating a report, in the hand-held receiver, on the comparison of (e) and transmitting the report to a base station.

15. A medical system for analyzing brain waves of a subject, the device comprising:

(a) an attachment means to removably attach an electrode to the subject'"'"'s head, at least one EEG (electroencephalograph) electrode means carried on the attachment means to detect the subject'"'"'s brain waves;

(b) amplification means in functional connection with the electrode means to amplify the detected brain waves and analog/digital convertor means to digitize the detected brain waves and to product the subject'"'"'s digitized brain wave data therefrom;

(c) a brain wave computer analyzer means on the attachment means to compare the subject'"'"'s brain wave data with a brain wave data based upon a normal group of subjects stored in the analyzer means; and

(d) a warning means on the attachment means to warn if the comparison of (c) indicates one of injury to and dysfunction of one of the subject'"'"'s spinal cord, brain stem and brain.

16. A medical system as in claim 15 and including means to validate the digitized brain waves by comparing split-half segments of data from the same electrode and under the same stimulus and about the same time and rejecting segments that do not match.

17. A medical system as in claim 15, wherein the warning means includes one of a plurality of lights and an alphanumeric display panel.

18. A medical system as in claim 15 wherein the attachment means is a patch and the electrode means is a single electrode.

19. A medical method to analyze the brain waves of a subject comprising the steps of:

(a) attaching to a subject at least one EEG (electroencephalograph) electrode means to detect the subject'"'"'s brain waves;

(b) providing concurrent sense stimuli in two or more different stimulus modes to the subject, the stimuli in one mode being at frequency and the stimuli in the other mode(s) being at a different frequency F₂, F₃,. etc.;

(c) amplifying and digitizing the detected brain waves;

(d) receiving the digitized brain waves from (c) and producing subject brain wave F ratio data based on the power of brain responses at each of F₁ and F₂ in the presence and absence of stimulation;

(e) comparing one of the subject brain wave F ratio data from (d) corresponding to the presence of stimulation to subject brain wave F ratio data corresponding to the absence of stimulation and the subject brain wave F ratio data from (d) with brain wave F ratio data based upon a normal group of subjects; and

(f) generating a warning signal to warn if the comparison of (e) indicates one of injury to and dysfunction of one of the subject'"'"'s spinal cord, brain stem and brain.

20. A medical method as in claim 19 and including performing Fast Fourier Transform (FFT) of the digitized brain waves and generating a power spectrum therefrom.

21. A medical method as in claim 20 wherein the F ratio data is an F ratio based on the generated power spectrum and the power of brain responses at each of F₁ and F₂ in the presence and absence of stimulation.

22. A medical method as in claim 20 wherein the FFT is a very narrow band FFT in increments in the range of 0.05-0.5 Hz.

23. A medical method as in claim 19 wherein the F ratio data is an F ratio between the power at F₁ or F₂:

P(Fi) / P(AV) where average power P_(AV) is across N bins above and below F₁ or F₂.

24. A medical method as in claim 19 and validating the digitized brain waves by comparing odd and even split-half segments of data from the same electrode, under the same stimulus and about the same time and rejecting segments that do not satisfy criteria for stationarity.