Brain wave source network location scanning method and system

• US 4,736,751 A
• Filed: 12/16/1986
• Issued: 04/12/1988
• Est. Priority Date: 12/16/1986
• Status: Expired due to Term

• Current Assignee: EEG Systems Laboratory
• Original Assignee: EEG Systems Laboratory
• Inventors: Greer, Douglas S., Morgan, Nelson H., Gevins, Alan S.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/942,204
• Time in Patent Office: 483 Days
• Field of Search: 128/731-732
• US Class Current: 600/545
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 5/0017 transmitting optical signals transmission by light H04B10/00
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• 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: G06F 2218/22 Source localisation; Inverse modelling

Abstract

A method and system is provided for the analysis of a human subject'"'"'s brain wave activity on a statistical basis using a digital computer. The location of portions of the subject'"'"'s brain and the location of at least 32, and for example 265, external scalp sensors are digitally recorded and stored in computer memory. The subject receives a set of stimuli which evoke brain waves (evoked potential EP or evoked magnetic fields EF) which, along with the location data, are statistically analyzed to indicate the brain sites giving rise to the activity. The brain site activity, and the time interrelationships of brain waves as they progress between brain sites, are displayed on a three-dimensional model or other three-dimensional perspective display.

Claims

1. A method to display the location and inter-area temporal relationships of a human subject'"'"'s brain neural activity, comprising the steps of:

(i) determining and recording the three-dimensional location of selected portions of the subject'"'"'s head and internal portions of the subject'"'"'s brain and recording said locations using a three-dimensional anatomical scan instrument to provide anatomical location data;

(ii) positioning a plurality of at least 32 sensors external to the subject'"'"'s scalp and proximate to the subject'"'"'s scalp to detect analog brain neural activity detectable proximate to the surface of the scalp;

(iii) determining the three-dimensional positions of the sensors, converting the said sensor position determinations into digital data, and storing the said sensor position digital data in computer storage means;

(iv) providing a set of predetermined stimuli to the subject;

(v) detecting the subject'"'"'s analog brain signals at the sensors during delivery of said stimuli and amplifying said analog signals;

converting the analog signals into digital data and storing said digital data in computer storage means;

(vi) statistically analyzing (a) the said anatomical location data, (b) the said sensor position data, and (c) said stored brain signal digital data, to provide a set of statistical indications which represent generators of brain neural activity at sites within the brain and their temporal interrelationship; and

(vii) displaying said statistical indications on a three-dimensional perspective display of at least part of a human brain, the brain portions of said display corresponding in location to the brain portion locations provided by the scan instrument.

2. The method as in claim 1 wherein the location of the selected portions of the brain is obtained by scanning the brain to provide magnetic resonance images (MRI).

3. A method as in claim 1 wherein the brain wave signals are improved in their signal-noise ratio to reduce contaminants and reduce brain activity not related to said stimulus by comparing trial sets of said brain wave digital data to statistically determined norms of uncontaminated and non-stimulus related brain wave digital data in a pattern recognition classification to eliminate those data which are contaminated or which do not have strong stimulus-related brain wave signals.

4. A method as in claim 1 wherein the sensors are electrodes positioned on the internal face of a removable hat.

5. A method as in claim 1 wherein the sensors are electrodes of an electroencephalograph (EEG) system.

6. A method as in claim 1 wherein the sensors are detectors of a magnetoencephalograph (MEG) system.

7. A method as in claim 1 wherein the stimuli are automatically presented under computer program control.

8. A method as in claim 1 wherein the stimuli include a set of motor tasks to be performed by the subject.

9. A method as in claim 8 wherein the tasks include a task in which the subject must respond with left or right hands to a visual cue.

10. A method as in claim 8 wherein the subject must respond with one hand to sound and visual cues.

11. A method as in claim 1 wherein said display includes color coded lines and areas in which color of lines indicates time delays and color or areas indicates current flow through the scalp.

12. A method as in claim 1 wherein the display is a model based on the subject'"'"'s brain and head.

13. A method as in claim 1 wherein the electrical brain wave digital data is processed to reduce distortion due to passage from the originating sites to the sensors, said processing including the use of a spatial deconvolution algorithm.

14. A method as in claim 1 wherein the electrical brain digital data is processed to extract source network properties using compartmentalization, subset selection, and linear least squares methods.

15. A method as in claim 1 wherein the subject performs a predetermined task consisting of a series of trials substantially involving the voluntary movement of a portion of the subject'"'"'s body in response to the stimulus and the detection of the subject'"'"'s brain waves continues during each trial.

16. A method as in claim 1 wherein the display is of the spatial and temporal brain wave properties of stimulus-or response-related signals, including preparation, stimulus encoding, feature-extraction, decision, response preparation, response execution, feedback-updating, and other cognitive processes.

17. A method as in claim 1 in which the display is a model of the subject'"'"'s brain and head, the scan is a magnetic resonance image (MRI) and the model is based on the said subject'"'"'s MRI.

18. A system to display the location and inter-area temporal relationships of a human subject'"'"'s brain neural activity, comprising:

(i) a plurality of at least 32 sensors adapted to be positioned proximate the subject'"'"'s scalp to detect analog brain neural activity detectable proximate to the surface of the scalp;

(ii) means for determining the three-dimensional positions of the sensors, converting the said position determinations into digital data, and storing the said position digital data in computer storage means;

(iii) means connected to said sensors for detecting and amplifying the subject'"'"'s analog brain signals;

converting the analog signals into brain signal digital data and storing said brain signal digital data in computer storage;

(iv) means for statistically analyzing the stored brain signal digital data to provide a set of statistical indications of brain activity representing temporal interrelationships between sensor positions;

(v) a three-dimensional perspective display means having head and brain portions for displaying said statistical indications as lines between sensor positions;

where the said head and brain portions on said display means correspond in location to the sensor positions.

19. A system as in claim 18 and further including brain scan means to determine and record the three-dimensional location of internal portions of the subject'"'"'s brain, wherein the brain scan means is a magnetic resonance image (MRI) system.

20. A system as in claim 18 and including a pattern recognition classification means to eliminate those data set trials which do not have strong stimulus-related brain wave signals.

21. A system as in claim 18 and including a removable hat on which are mounted at least 32 of said sensors.

22. A system as in claim 18 and including a computer program control means to automatically present said stimuli.

23. A system as in claim 18 wherein the display is a model based on the subject'"'"'s brain.

24. A system as in claim 18 wherein the sensors are electrodes of an electroencephalograph (EEG) system.

25. A system as in claim 18 wherein the sensors are detectors of a magnetoencephalograph (MEG) system.

26. A method as in claim 18 wherein the electrical brain wave digital data is processed to extract source network properites using compartmentalization, subset selection, and linear least squares methods.

27. A system to display the location and inter-area temporal relationships of a human subject'"'"'s brain neural activity, comprising:

(i) brain scan means to determine and record the three-dimensional location of selected internal portions of the subject'"'"'s brain and head by viewing said selected brain portions in a three-dimensional scan;

(ii) a plurality of at least 32 sensors adapted to be positioned proximate the subject'"'"'s scalp to detect analog brain neural activity detectable proximate to the surface of the scalp;

(iii) means for determining the three-dimensional positions of the sensors, converting the said position determinations into digital data, and storing the said position digital data in computer storage means;

(iv) means for providing a set of predetermined stimuli to the subject;

(v) means connected to said sensors for detecting and amplifying the subject'"'"'s analog brain signals which are responsive to said stimuli, converting the analog signals into brain signal digital data and storing said brain signal digital data in computer storage;

(vi) means for statistically analyzing the stored brain signal digital data to provide a set of statistical indications of brain activity representing temporal interrelationships between sensor positions; and

(vii) a three-dimensional perspective display means having head and brain portions for displaying said statistical indications as lines between sensor positions;

wherein the said head and brain portions on said display means correspond in location to the sensor positions.

28. A system as in claim 27 wherein the sensors are electrodes of an electroencephalograph (EEG) system.

29. A system as in claim 27 wherein the sensors are detectors of a magnetoencephalograph (MEG) system.

30. A method as in claim 27 wherein the electrical brain wave digital data is processed to extract source network properties using compartmentalization, subset selection, and linear least squares methods.

31. A system as in claim 27 wherein the brain scan means is a magnetic resonance image (MRI) system.

32. A system as in claim 27 and including a pattern recognition classification means to eliminate those data set trials which do not have strong stimulus-related brain wave signals.

33. A system as in claim 27 wherein said sensors are mounted on a removable hat.

34. A system as in claim 27 and including a computer program control means to automatically present said stimuli.

35. A system as in claim 27 wherein the display is a model based on the subject'"'"'s brain.