Apparatus and method for displaying electrical activity generated within a living body

• US 4,949,725 A
• Filed: 07/01/1988
• Issued: 08/21/1990
• Est. Priority Date: 07/01/1988
• Status: Expired due to Term

• Current Assignee: Bio-Logic Systems Corporation (Natus Medical Incorporated)
• Original Assignee: Bio-Logic Systems Corporation (Natus Medical Incorporated)
• Inventors: Towle, James N., Raviv, Gil, Pal, Ivan, Koester, Dean, Kripal, David
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US07/214,753
• Time in Patent Office: 781 Days
• Field of Search: 128/731-732, 128/699, 364/413.06, 364/413.07, 364/413.13
• US Class Current: 600/544
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: G06F 2218/22 Source localisation; Inverse modelling

Abstract

An apparatus and method for display of biologically induced electrical activity is disclosed. The apparatus includes sensors for measuring EEG or MEG signals from a living body and using these signals to compute one or more dipoles representative of the measured electrical activity. Values of the electrical activity may also be computed for discrete locations in or on the body. The operator has the ability to input a variety of different computational specifications or criteria to facilitate dipole computation. The resulting computed data may be selectively displayed as a dipole within a three-dimensional representation of the body, as a movie-like series of dipoles, as a composite or tracing of dipoles or as various topographic maps. The operator also has the ability to change the display to provide different perspective views or to enlarge the displayed scene.

Claims

1. An apparatus for displaying electrical activity generated within a living body comprising:

a plurality of sensors for sensing a characteristic of said electrical activity at spaced locations on the surface of said body;

means for computing first dipole data representing one or more of the location, direction and magnitude parameters of at least one dipole disposed within said body corresponding to said sensed electrical activity characteristic;

means for receiving and storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said at least one dipole;

video display means for generating and presenting from said first dipole data or from said first and second dipole data a video display showing the location, direction and magnitude of said at least one dipole within a three dimensional representation of said body; and

said video display means being adapted to generate further video displays to present different perspective views of said at least one dipole and said three dimensional representation of said body.

2. The display apparatus of claim 1 wherein said video display means is further adapted to depict rotation of said three dimensional representation of said body and the location, direction and magnitude of said at least one dipole about at least one of the three axes of said three dimensional representation of said body.

3. The display apparatus of claim 1 further including means for operator input of dipole criteria to facilitate said first dipole data computation.

4. The display apparatus of claim 3 wherein said operator input means is adapted to restrict the computation of first dipole data representing location to a predetermined region of said body.

5. The display apparatus of claim 3 wherein said computing means is adapted to compute a sequence of first dipole data and said operator input means includes means to compare successive first dipole data computations and to terminate first dipole data computation when the difference between said successive computations falls below a predetermined value.

6. The display apparatus of claim 3 wherein said computing means is adapted to compute a sequence of model dipole generated fields and said operator input means includes means to compare successive model dipole generated fields with the sensed electrical activity characteristic and to terminate first dipole data computation when the difference between any one model dipole generated field and the sensed electrical activity characteristic falls below a predetermined value.

7. The display apparatus of claim 1 wherein said living body is a human head and said characteristic is electrical potential.

8. The display apparatus of claim 1 wherein said living body is a human head and said characteristic is an electromagnetic field.

32. The display apparatus as defined in claim 1, 9, 16, 19, 20, or 21 further including means for coloring said display whereby different colors indicate different depths and said three dimensional representation of said body is enhanced to provide improved depth perception.

33. The display apparatus as defined in claim 32 wherein said different colors comprise varying intensity levels for one color.

34. The display apparatus as defined in claim 1, 9, 16, 19, 20, or 21 further including means for removing portions of said display to improve depth perception whereby the three dimensional representation of said body is enhanced.

35. The display apparatus as defined in claim 1, 9, 16, 19, 20, 21 or 25 further including means for shading portions of said display to improve depth perception whereby the three dimensional representation of said body is enhanced.

36. The display apparatus as defined in claim 35 further including means for inputting viewpoint, body orientation and illumination source data to said display means.

37. The display apparatus as defined in claim 1, 9, 16, 19, 20, or 21 further including means for generating said display in a stereopsis viewing format.

38. The display apparatus as defined in claim 1, 9, 16, 19, 20, or 21 further including means for inputting to said computing means actual dimensional measurements of said body such that said three dimensional representation in said display corresponds in size and shape to said body.

47. The display apparatus of claims 1, 21 or 25 wherein said at least one dipole is depicted as an obelisk-like image.

9. An apparatus for displaying electrical activity generated within a living body comprising:

a plurality of sensors for sensing a characteristic of said electrical activity at spaced locations on the surface of said body;

means for computing first dipole data representing one or more of the location, direction and magnitude parameters of a plurality of dipoles disposed within said body corresponding to said sensed electrical activity characteristic;

means for receiving and storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said plurality of dipoles;

means for inputting preselected dipole criteria to said computing means to facilitate first dipole data computation, said dipole criteria comprising a relationship between any of said location, direction or magnitude parameters of any one or more of said plurality of dipoles;

video display means for generating and presenting from said first dipole data or from said first and second dipole data a video display showing the location, direction and magnitude of said plurality of dipoles within a three dimensional representation of said body; and

said video display means being adapted to generate further video displays to present different perspective views of said plurality of dipoles and said three dimensional representation of said body.

10. The display apparatus of claim 9 wherein said relationship is that said dipole locations are all symmetrically positioned about a central vertical plane through said body.

11. The display apparatus of claim 10 wherein said relationship is a non-linear mathematical relationship.

12. The display apparatus of claim 9 wherein said relationship is that said dipole directions are all the same.

13. The display apparatus of claim 9 wherein said relationship is that said dipole directions are all normal to a given plane or line within said body.

14. The display apparatus of claim 9 wherein said relationship is that said dipole magnitudes are all the same.

15. The display apparatus of claim 9 wherein said relationship is a linear mathematical relationship.

16. An apparatus for displaying electrical activity generated within a living body comprising:

a plurality of sensors for sensing a characteristic of said electrical activity at spaced locations on the surface of said body over a period of time;

means for computing first dipole data representing one or more of the location, direction and magnitude parameters of a sequence of dipoles disposed within said body and each corresponding to said sensed electrical activity characteristic at successive instants in time during said period;

means for receiving and storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said sequence of dipoles; and

video display means for generating and presenting from said first dipole data or from said first and second dipole data a series of video displays, each successive video display showing the location, direction and magnitude of one of said sequence of dipoles within a three dimensional representation of said body.

17. The display apparatus of claim 16 wherein said series of video displays is displayed at a rate of at least five frames per second.

18. The display apparatus of claim 16 wherein the dipole location, magnitude and direction of each video display remains visible during all successive video displays of said series.

48. The display apparatus of claim 9, 16 or 19 wherein said dipole is depicted as an obelisk-like image.

19. An apparatus for displaying electrical activity generated within a living body comprising;

a plurality of sensors for sensing a characteristic of said electrical activity at spaced locations on the surface of said body over a period of time;

means for computing first dipole data representing one or more of the location, direction and magnitude parameters of a series of dipoles disposed within said body and each corresponding to said sensed electrical activity characteristic at successive instants in time during said period;

means for receiving and storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said series of dipoles;

means for inputting preselected dipole criteria to said computing means for first dipole data computation of one of said series of dipoles at one of said instants in time, and said input means including means for inputting earlier computed first dipole data to provide the dipole criteria for a later first dipole data computation; and

means for generating and presenting from said first dipole data or from said first and second dipole data a video display showing the location, direction and magnitude of said series of dipoles within a three dimensional representation of said body.

20. An apparatus for displaying electrical activity generated within a living body comprising:

a plurality of sensors for sensing a characteristic of said electrical activity at spaced locations on the surface of said body over a period of time;

means for computing first dipole data representing one or more of the location, direction and magnitude parameters of a series of dipoles disposed within said body and each corresponding to said sensed electrical activity characteristic at successive instants in time during said period;

means for receiving and storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said series of dipoles; and

video display means for generating and presenting from said first dipole data or from said first and second dipole data a video display showing a composite defined by said series of dipoles within a three dimensional representation of said body.

21. An apparatus for displaying electrical activity generated within a living body comprising:

a plurality of sensors for sensing a characteristic of said electrical activity at spaced locations on the surface of said body;

means for generating electrical activity signals responsive to said sensed electrical activity characteristic;

means for selecting a portion of said electrical activity signals, thereby leaving a remainder of signals;

first means for computing first dipole data representing one or more of the location, direction and magnitude parameters of at least one dipole disposed within said body corresponding to said sensed electrical activity characteristic represented by said portion of electrical activity signals;

means for receiving and storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said at least one dipole;

second means for computing from said computed first dipole data or from said first and second dipole data model values of said electrical activity characteristic for a plurality of discrete locations on said body; and

video display means for generating and presenting a video display showing the location, direction and magnitude of said at least one dipole or said computed model values of said electrical activity characteristic in association with a three dimensional representation of said body.

22. The display apparatus of claim 21 further including means for comparing said computed model values of said electrical activity characteristic with said remainder of signals to thereby verify the accuracy of said first dipole data computation.

23. The apparatus of claim 21 wherein said video display shows both computed model values and sensed values of said electrical activity characteristic.

24. The apparatus of claim 21 further including means for mathematically comparing said computed values of said electrical activity characteristic with sensed values of said electrical activity characteristic, and wherein said video display means is further adapted to present the product of said mathematical comparison as a topographic map.

25. An apparatus for displaying electrical activity generated within a living body comprising:

a plurality of sensors for sensing a characteristic of said electrical activity at spaced locations on the surface of said body;

first means for computing first dipole data representing one or more of the location, direction and magnitude parameters of at least one dipole disposed within said body corresponding to said sensed electrical activity characteristic;

means for receiving and storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said at least one dipole;

second means for computing from said first dipole data or from said first and second dipole data a model value of said electrical activity characteristic for each of a plurality of discrete locations on said body; and

video display means for generating and presenting a video display showing said computed model value of said electrical activity characteristic at each of said discrete locations within one of either a two-dimensional or a three-dimensional representation of said body.

26. The display apparatus of claim 25 wherein said plurality of discrete locations all lie on said surface of said body.

27. The display apparatus of claim 25 wherein said plurality of discrete locations all lie on a curved plane located within said body.

28. The display apparatus of claim 25 wherein said plurality of discrete locations all lie on a cross-sectional plane of said body.

29. The display apparatus of claim 25 wherein said video display shows the computed model values of electrical activity characteristic at said discrete locations and additional interpolated values of electrical activity characteristic at locations between said discrete locations.

30. The display apparatus of claim 25 wherein the number of sensors is eight or less.

31. The display apparatus of claim 30 wherein said video display shows the computed model values of electrical activity characteristic at said discrete locations and additional interpolated values of electrical activity characteristic at locations between said discrete locations.

39. An apparatus for displaying a topographic map of computed model values of brain electrical activity comprising:

means for receiving dipole data representing the location, direction and magnitude parameters that define at least one dipole;

means for computing from said dipole data model values of brain electrical activity for a plurality of locations; and

means for displaying said computed model values of brain electrical activity as a topographic map.

40. A method for display electrical activity generated within a living body comprising:

sensing a characteristic of said electrical activity at spaced locations on the surface of said body;

computing first dipole data representing one or more of the location, direction and magnitude parameters of at least one dipole disposed within said body corresponding to said sensed electrical activity characteristic;

storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said at least one dipole;

generating and presenting from said first dipole data or from said first and second dipole data a video display showing the location, direction and magnitude of said at least one dipole;

within a three dimensional representation of said body; and

changing said display to depict rotation of said three dimensional representation of said body and said at least one dipole about at least one of the three axes of said three dimensional representation of said body;

to thereby provide different perspective views of said dipole within said body.

41. A method for displaying electrical activity generated within a living body comprising:

sensing a characteristic of said electrical activity at spaced locations on the surface of said body over a period of time;

computing first dipole data representing one or more of the location, direction and magnitude parameters of a sequence of dipoles, disposed within said body and each corresponding to said sensed electrical activity characteristic at one of successive instants in time during said period;

storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said sequence of dipoles; and

generating and presenting from said first dipole data or from said first and second dipole data a series of video displays each showing the location, direction and magnitude of one of said sequence of dipoles within a three dimensional representation of said body.

42. A method for displaying electrical activity generating within a living body comprising:

sensing a characteristic of said electrical activity at spaced locations on the surface of said body over a period of time;

computing first dipole data representing one or more of the location, direction and magnitude parameters of a sequence of dipoles disposed within said body and each corresponding to said sensed electrical activity characteristic at one of successive instants in time during said period;

storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said sequence of dipoles; and

generating and presenting from said first dipole data or from said first and second dipole data a video display showing a tracing defined by said sequence of dipoles within a three dimensional representation of said body.

43. A method for displaying electrical activity generating within a living body comprising:

sensing a characteristic of said electrical activity at spaced locations on the surface of said body;

computing first dipole data representing one or more of the location, direction and magnitude parameters of at least one dipole within said body corresponding to said sensed electrical activity characteristic;

storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said at least one dipole;

computing from said computed first dipole data or from said first and second dipole data a model value of said electrical activity characteristic for each of a plurality of discrete locations on said body; and

generating and presenting a video display showing said computed model value of said electrical activity characteristic at each of said discrete locations without one of either a two-dimensional or a three-dimensional representation of said body.

44. A method for displaying electrical activity generated within a living body comprising:

sensing a characteristic of said electrical activity at spaced locations on the surface of said body;

computing first dipole data representing one or more of the location, direction and magnitude parameters of a plurality of dipoles disposed within said body corresponding to said sensed electrical activity characteristic;

inputting preselected dipole criteria to facilitate first dipole data computation, said dipole criteria comprising a relationship between said location, direction or magnitude parameters of said plurality of dipoles;

storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said plurality of dipoles;

generating and presenting from said first dipole data or from said first and second dipole data a video display showing the location, direction and magnitude of said plurality of dipoles within a three dimensional representation of said body; and

means for changing said display to provide different perspective views of said dipoles within said three dimensional representation of said body.

45. A method for displaying electrical activity generated within a living body comprising:

sensing a characteristic of said electrical activity at spaced locations on the surface of said body over a period of time;

computing first dipole data representing one or more of the location, direction and magnitude parameters of a series of dipoles within said body and each corresponding to said sensed electrical activity characteristic at one of successive instants in time during said period;

inputting preselected dipole criteria for dipole data computation, and inputting an earlier computed dipole as the dipole criteria for a later dipole data computation;

storing second dipole data representing assumed values for one or more of the location, direction and magnitude parameters of said at least one dipole; and

generating and presenting a video display from said first dipole data or from said first and second dipole data showing said series of dipoles within a three dimensional representation of said body.

46. A method for displaying electrical activity generated within a living body comprising:

sensing a characteristic of said electrical activity at spaced sensor locations on the surface of said body;

generating electrical activity signals responsive to said characteristic for each said sensor location;

selecting a portion of said electrical activity signals, thereby leaving a remainder of signals;

computing first dipole data representing one or more of the location, direction and magnitude parameters of at least one dipole disposed within said body corresponding to said sensed electrical activity characteristic represented by said portion of electrical activity signals;

computing from said computed dipole data a model value of said electrical activity characteristic for each of a plurality of discrete locations on said body; and

generating and presenting a video display showing the location, direction and magnitude of said dipole or said computed model values of said electrical activity characteristic in associating with a three dimensional representation of said body.

49. An apparatus for displaying a topographic map of model values of brain electrical activity comprising:

means for receiving dipole data representing the location, direction and magnitude parameters that define at least one dipole;

means for computing from said dipole data model values of brain electrical activity for a plurality of locations;

means for generating interpolated model values of brain electrical activity from said computed model values; and

means for displaying said computed and interpolated model values of brain electrical activity as a topographic map.