BRAIN-COMPUTER INTERFACES AND USE THEREOF

• US 20130130799A1
• Filed: 07/19/2011
• Published: 05/23/2013
• Est. Priority Date: 07/30/2010
• Status: Abandoned Application

• Current Assignee: Katholieke Universiteit Leuven
• Original Assignee: Katholieke Universiteit Leuven
• Inventors: Van Hulle, Marc, Manyakov, Nikolay V., Van Vliet, Marijn
• Application Number:
  US13/813,096
• Publication Number:
  US 20130130799A1
• Time in Patent Office: Days
• US Class Current: 463/36
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• 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 5/378 Visual stimuli
• CPC Class Codes: G06F 3/01 Input arrangements or combined input and output arrangements for interaction between user and computer G06F3/16 takes precedence
• CPC Class Codes: G06F 3/015 Input arrangements based on nervous system activity detection, e.g. brain waves [EEG] detection, electromyograms [EMG] detection, electrodermal response detection

Abstract

A computerized method for decoding visual evoked potentials involves obtaining a set of brain activity signals, the brain activity signals being recorded from a subject'"'"'s brain during displaying a set of targets on a display having a display frame duration, at least one target being modulated periodically at a target-specific modulation parameter and decoding a visual evoked potential (VEP) from the brain activity signals. The decoding includes, at least for the at least one target being modulated at a target-specific modulation parameter, determining a representative time track from the obtained brain activity signals, the representative time track having a length being integer multiples of the display frame duration, analyzing at least one amplitude feature in the representative time track, and determining a most likely target of interest or absence thereof based on said analyzing.

Claims

1-25. -25. (canceled)

26. A computerized method for decoding visual evoked potentials, the method comprising

obtaining a set of brain activity signals, the brain activity signals being recorded from a subject'"'"'s brain during displaying a set of targets on a display having a display frame duration, at least one target being modulated periodically using a target-specific modulation parameter,

decoding a visual evoked potential (VEP) from the brain activity signals, wherein said decoding comprises

at least for the at least one target being modulated at a target-specific modulation parameter, determining a representative time track from the obtained brain activity signals, the representative time track having a length being integer multiples of the display frame duration,

analyzing at least one amplitude feature in the representative time track, and

determining a most likely target of interest or absence thereof based on said analyzing.

27. The computerized method for decoding according to claim 26, wherein determining a representative time track in the obtained brain activity signals for a target-specific modulation parameter comprises deriving from the obtained brain activity signals a set comprising one or more subsequent time tracks, locked to the stimulus phase, and averaging the set of time tracks for obtaining the representative time track for the target-specific frequency modulation parameter.

28. The computerized method according to claim 26, wherein a modulation parameter is any of a target-specific frequency, a target-specific set of frequencies, a target specific phase, or a combination thereof.

29. The computerized method according to claim 26, wherein the visual evoked potential is a steady state evoked potential.

30. The computerized method for decoding according to claim 26, wherein determining a representative time track comprises determining a representative time track having a length being substantially smaller than a time length required by a frequency analysis of the signal in order for the target to be distinguishable, with a comparable precision, from one or more other targets.

31. The computerized method for decoding according to claim 26, wherein the brain activity signals are captured using two or more electrodes.

32. The computerized method according to claim 31, wherein the brain activity signals are electro encephalogram (EEG) signals.

33. The computerized method according to claim 26, the set of targets comprising a target being a VEP stimulus for the subject to keep gaze at and the set of targets furthermore comprising sequentially displayed targets presenting options displayed in the periphery of the VEP stimulus at different presentation moments in time, wherein

determining a representative time track comprises frequently updating a representative time track of the target the subject currently gazes at during the period of said sequentially displaying targets presenting options and wherein—

analyzing one or more amplitude features in the representative time track comprises detecting a moment at which a change in one or more amplitude features of the representative time track occurs, and

wherein for determining a most likely target of interest, the method comprises linking the moment at which a change in one or more amplitude features of the representative time track occur to the presentation moment for a target presenting an option and identifying that target as most likely target of interest.

34. The computerized method according to claim 33, wherein said determining a most likely target of interest is based on covert attention of the subject.

35. The computerized method according to claim 33, wherein detecting a moment at which a change in one or more amplitude features occurs comprises analyzing if the value of one or more amplitude features crosses a predetermined threshold.

36. The computerized method for decoding according to claim 26, wherein each of the targets of the set of targets is displayed modulated at a target-specific modulation parameter, and whereby decoding a visual evoked potential from the brain activity signals comprises,

for one or more target-specific modulation parameter determining a representative time track,

selecting a most likely representative time track or absence thereof based on one or more amplitude features in the representative time track for the one or more target-specific modulation parameter, and

determining the most likely target of interest or absence thereof based on the most likely representative track or absence thereof.

37. The computerized method according to claim 36, wherein determining a representative time track is performed for each target in the set of targets.

38. The computerized method according to claim 36, wherein selecting a most likely representative time track or absence thereof is based on evaluating amplitude features in the representative time track for the one or more target-specific modulation parameter according to predetermined criteria.

39. The computerized method according claim 26, wherein the obtained brain activity signals are recorded on the occipital pole.

40. A system for decoding visual evoked potentials, the system comprising

an input arranged to obtain a set of brain activity signals, the brain activity signals being recorded from the subject'"'"'s brain during displaying of a set of targets, at least one target being modulated at a target-specific modulation parameter,

a processor configured to decode a visual evoked potential (VEP) from the brain activity signals, the processor comprising

a representative time track determining arrangement configured to determine, at least for the at least one target being modulated at a target-specific modulation parameter, a representative time track from the obtained brain activity signals, the representative time track having a length being integer multiples of frame duration

an analyzer arranged to analyze at least one amplitude feature in the representative time track, and

a target determination arrangement configured to determine a most likely target of interest or absence thereof based on said analyzing.

41. The system according to claim 40, comprising a display arranged to display a set of targets, at least one target of said set being modulated at a target-specific modulation parameter.

42. The system according to claim 40, wherein the system comprises a controller programmed to control decoding of a visually evoked potential.

43. A computer program product for performing, when executed on a computer, a method for decoding visual evoked potentials, the method comprising

obtaining a set of brain activity signals, the brain activity signals being recorded from a subject'"'"'s brain during displaying a set of targets on a display having a display frame duration, at least one target being modulated periodically using a target-specific modulation parameter,

decoding a visual evoked potential (VEP) from the brain activity signals, wherein said decoding comprises

at least for the at least one target being modulated at a target-specific modulation parameter, determining a representative time track from the obtained brain activity signals, the representative time track having a length being integer multiples of the display frame duration,

analyzing at least one amplitude feature in the representative time track, and

determining a most likely target of interest or absence thereof based on said analyzing.

44. The computer program product according to claim 43, stored on a machine readable data storage device.

45. The computer program product according to claim 43, the computer program product being transmitted over a local or wide area telecommunications network.