Brain electrical activity topographical mapping

• US 4,649,482 A
• Filed: 08/31/1984
• Issued: 03/10/1987
• Est. Priority Date: 08/31/1984
• Status: Expired due to Fees

• Current Assignee: Bio-Logic Systems Corporation (Natus Medical Incorporated)
• Original Assignee: Bio-Logic Systems Corporation (Natus Medical Incorporated)
• Inventors: Raviv, Gabriel, Raviv, Gil
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/646,613
• Time in Patent Office: 921 Days
• Field of Search: 364/413, 364/415, 364/417, 128/731
• US Class Current: 600/544
• CPC Class Codes: A61B 5/374 Detecting the frequency distribution of signals, e.g. detecting delta, theta, alpha, beta or gamma waves
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: Y10S 128/92 Computer assisted medical diagnostics

Abstract

An apparatus for monitoring and operating on brain input activity signals to provide topographical maps characteristic of patient brain activity. The apparatus senses the brain input activity signals and processes the signals to provide detailed information on patient brain activity. Complete topographical maps of the patient brain are activity constructed by a line-by-line interpolation method. A color coded scale adjacent the topographical map is utilized to provide additional information on patient brain activity. The user has a number of options available to select various information for display and analysis.

Claims

1. An apparatus for displaying a topographical map of brain electrical acitivity of a patient, comprising:

sensor means disposed on a patient'"'"'s head for providing changeable amplitude sign input activity signals responsive to said brain electrical activity;

processing means responsive to said changeable amplitude sign input activity signals for providing an amplified and digitized form of said input activity signals;

means for providing a video output responsive to said amplified and digitized input activity signals, said video output incluidng a set of interpolated input activity signals for positions between the locations of said sensor means with said positions including selected locations along at least two interpolated lines generated between adjacent pairs of lines formed by connecting the locations of said sensor means and at least two of said interpolated lines between each said adjacent pairs of lines being generated from distinguishable appropriate combinations of said input activity signals, said interpolated input activity signals generated line--by--line and displayed while a next successive adjacent line for display is being generated; and

means for displaying said topographical map of said brain electrical activity responsive to said video output.

2. The apparatus as defined in claim 1 wherein said sensor means comprises a plurality of electrode sensors.

3. The apparatus as defined in claim 1 wherein said set of interpolated input activity signals are generated from linear weighted appropriate pairs of said amplified and digitized input activity signals.

4. The apparatus as defined in claim 1 further comprising means for providing statistically averaged values for said input activity signals responsive to said amplified and digitized input activity signals.

5. The apparatus as defined in claim 4 wherein said means for providing averaged values comprises a computer having a random access memory.

6. The apparatus as defined in claim 1 further including color code means for displaying alongside said topographical maps a predetermined set of colors displayable on said topographical maps, each of said colors representing an associated fixed relative value within a selected closed data set of said input activity signals.

7. The apparatus as defined in claim 6 wherein said color code means alongside each said topographical map includes at least said colors being displayed on each said topographical map associated with said color code means.

8. The apparatus as defined in claim 1 wherein said means for displaying includes a display processing unit having a display memory which is updated for display of selected ones of said lines of said topographical maps responsive to said input activity signal.

9. The apparatus as defined in claim 1 wherein said topographic maps are constructed from pixels having a plurality of distinguishable colors, wherein each of said colors is selectively comprised of one unique color and of at least two unique colors mixed in a predetermined manner among near neighbors of said pixels.

10. An apparatus for displaying a topographical map of brain electrical activity sensed by a plurality of electrode sensors disposed on a patient'"'"'s head, wherein said electrode sensors provide an associated plurality of input activity signals, said apparatus comprising:

processing means for providing an amplified and digitized form of said plurality of input activity signals;

computer means for providing a video output responsive to said plurality of amplified and digitized input activity signals, said video output including a set of interpolated input activity signals for positions between the locations of said electrode sensors with said positions including selected locations along at least two interpolated lines generated between adjacent pairs of lines formed by connecting the locations of said electrode sensors and at least two of said interpolated lines between each said adjacent pairs of lines being generated from distinguishable appropriate combinations of said input activity signals;

means for displaying said topographical maps of said brain electrical activity responsive to said video output; and

color code means for displaying near each of said topographical maps a predetermined set of colors displayable on an associated one of said topographical maps, each of said colors representing an associated fixed relative value within a selected closed data set of said input activity signals.

11. The apparatus as in claim 10 further characterized in that said interpolated input activity signals have changeable amplitude sign and are generated line--by--line, wherein display of each line is provided while a next successive adjacent line for display is being generated.

12. The apparatus as defined in claim 10 wherein said predetermined set of colors is positionable along a portion of said topographical map.

13. The apparatus as defined in claim 10 wherein said predetermined set of colors is positionable on the display along at least one of a vertical scale and a horizontal scale.

14. The apparatus as defined in claim 10 further including indicator means responsive to a user input for supplying an input signal for actuating selected software programs to control said video output on said display means.

15. The apparatus as defined in claim 14 further comprising map magnifying means responsive to said input signal for selectively enlarging a predetermined portion of said topographical map for display.

16. An apparatus for displaying a plurality of topographical maps of brain electrical activity sensed by a plurality of electrode sensors disposed on a patient'"'"'s head, wherein said sensors provide an associated plurality of changeable amplitude sign input activity signals responsive to said brain electrical activity, said apparatus comprising:

processing means connected to be responsive to said changeable amplitude sign input activity signal for providing an amplified and digitized form of said input activity signals;

means for providing a video output responsive to said amplified and digitized input activity signals, said video output including a set of interpolated input activity signals for positions between the locations of said plurality of sensors with said positions including selected locations along at least two interpolated lines generated between adjacent pairs of lines formed by connecting the locations of said sensors and at least two of said interpolated lines between each said adjacent pairs of lines being generated from distinguishable appropriate combinations of said input activity signals and said interpolated input activity signals are generated and displayed line--by--line while a next successive adjacent line for display is being generated by said means for providing a video output; and

means for displaying simultaneously a display of a plurality of said topographical maps of said brain electrical activity responsive to said video output.

17. The apparatus as defined in claim 16 wherein said plurality of topographical maps comprises a plurality of different selectable states of said brain electrical activity.

18. The apparatus as defined in claim 17 wherein said different selectable states comprise an evoked potential response, an integrated time segment of evoked potential response and a Fourier transform of EEG input activity signals.

19. An apparatus for displaying topographical maps of brain electrical activity of a patient'"'"'s head comprising:

a plurality of electrode sensors disposed on said patient'"'"'s head, said sensors providing an associated plurality of changeable amplitude sign input activity signals in response to said brain electrical activity;

processing means connected to be responsive to said input activity signals for providing an amplified and digitized form of said changeable amplitude sign input activity signals;

means for providing a video output responsive to said plurality of amplified and digitized input activity signals, said video output including a set of interpolated input activity signals for positions between the locations of said plurality of sensors with said positions including selected locations along at least two interpolated lines generated between adjacent pairs of lines formed by connecting the locations of said sensors and at least two of said interpolated lines between each said adjacent pairs of lines being generated from distinguishable appropriate combinations of said input activity signals;

input means for supplying an input signal responsive to a user input, said input means controlling the information characterized by said video output; and

means for displaying said topographical maps of said brain electrical activity responsive to said video output, said display means including display processing means having a display memory which can be updated for display of user selected lines of said topographical maps responsive to said input activity signal.

20. The apparatus as defined in claim 19 wherein said means for providing a video output comprises logic means responsive to computer software programs for providing said video output responsive to said amplified and digitized input activity signals.

21. The apparatus as defined in claim 19 further including color code means for displaying near each of said topographical maps at least a portion of a predetermined set of colors, each of said colors appearing on an associated one of said topographical maps and each of said colors having an associated fixed relative value within a selected closed data set of said input activity signals.

22. The apparatus as defined in claim 21 wherein said predetermined set of colors is arrangeable for display alongside a portion of said topographical map.

23. The apparatus as defined in claim 21 wherein said predetermined set of colors is arrangeable for display along at least one of a vertical scale and a horizontal scale.

24. The apparatus as defined in claim 19 further characterized in that said display includes at least one evoked potential response waveform plotted near each of said topographical maps, each said waveform characteristic of an amplitude and time response for a selected location on said topographical map.

25. An apparatus for displaying a topographical map of EEG brain electrical activity in a plurality of frequency bands of a patient, comprising:

a plurality of electrode sensors disposed on a patient'"'"'s head for measuring EEG input activity signals at each of said plurality of electrode sensors;

processing means connected to be responsive to said input activity signals for providing an amplified and digitized form of said input activity signals;

means for sampling said amplified and digitized form of said EEG inout activity signals at predetermined intervals responsive to said amplified and digitized form of said input activity signals to provide sampled forms of said EEG input activity signals;

means for performing a Fourier transform of said sampled forms of EEG input activity signals responsive thereto to provide a frequency band energy output characteristic of the energy in each of said plurality of frequency bands;

computer means responsive to said frequency band energy output for generating a set of interpolated frequency band energy output signals for positions between the locations of said plurality of sensors, said output signals generated for said positions including selected locations along at least two interpolated lines generated between adjacent pairs of lines formed by connecting the locations of said sensors and at least two of said interpolated lines between each said adjacent pairs of lines being generated from distinguishable appropriate combinations of said input activity signals; and

display means for displaying said topographical map responsive to said frequency band energy output signals.

26. The apparatus as defined in claim 25 further including a display of at least one EEG curve plotted near each said topographical map, each said EEG curve characteristic of the amplitude within each said frequency band.

27. The apparatus as defined in claim 26 wherein said display of EEG curves can be color coded by positioning selected color coded segments along the frequency axis of said EEG curve, each of said color coded segments associated with a preselected one of said frequency bands.

28. An apparatus for displaying a topographical map of brain electrical activity sensed by a plurality of electrode sensors disposed on a patient'"'"'s head, wherein said electrode sensors provide an associated plurality of input activity signals, said apparatus comprising:

processing means for providing an amplified and digitized form of said plurality of input activity signals;

computer means for providing a video output responsive to said plurality of amplified and digitized input activity signals;

means for displaying said topographical maps of said brain electrical activity responsive to said video output; and

input means for supplying an input signal responsive to a user input and indicator means connected to be responsive to said input signal for actuating selected software programs to control said video output on said means for displaying, said indicator means able to select a line on said topographical map and actuate said computer means to display amplitudes of said input activity signals along said line.