Electroencephalogram interface system

• US 8,818,498 B2
• Filed: 11/29/2010
• Issued: 08/26/2014
• Est. Priority Date: 01/19/2009
• Status: Expired due to Fees

• Current Assignee: Sovereign Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Terada, Yoshihisa, Morikawa, Koji
• Primary Examiner(s): Kahelin, Michael
• Assistant Examiner(s): ALTER, MITCHELL E
• Application Number:
  US12/955,016
• Publication Number:
  US 20110071416A1
• Time in Patent Office: 1,366 Days
• Field of Search: 600/383, 600/544, 600/545
• US Class Current: 600/544
• CPC Class Codes: A61B 5/1103 Detecting eye twinkling
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/378 Visual stimuli
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• 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

An eyeglass-type electroencephalogram interface system is worn on the head of a user. The system includes: an output section for presenting a visual stimulation to the user; an ear electrode portion disposed at a position coming in contact with an ear of the user when the system is worn; a facial electrode portion disposed at a position coming in contact with the face below a straight line connecting an external canthus and an internal canthus of an eye of the user, such that the mass of the system is supported at the position, when the system is worn; and an electroencephalogram measurement and determination section for measuring an event-related potential on the basis of a potential difference between the ear electrode portion and the facial electrode portion based on the visual stimulation being presented by the output section as a starting point.

Claims

1. An eyeglass-type electroencephalogram interface system having an endpiece portion, a rim portion, and a nose pad portion, and to be worn on a head of a user, comprising:

an output section, disposed at the rim portion, and configured to present a visual stimulation to the user;

an ear electrode portion disposed at a position coming in contact with an ear of the user when the eyeglass-type electroencephalogram interface system is worn;

a facial electrode portion disposed at the nose pad portion coming in contact with a face of the user below a straight line connecting an external canthus and an internal canthus of an eye of the user, such that the mass of the eyeglass-type electroencephalogram interface system is supported at the nose pad portion, when the eyeglass-type electroencephalogram interface system is worn;

an electroencephalogram measurement and determination section configured to measure an event-related potential on the basis of a potential difference between the ear electrode portion and the facial electrode portion, based on a timing of presenting the visual stimulation as a starting point; and

a facial electrode position determination section configured to determine a position of the facial electrode portion based on whether, in the electroencephalogram signal of the user, an amplitude of a signal associated with a blink of the user falls between a predetermined upper threshold value and a predetermined lower threshold value;

wherein the facial electrode position determination section determines that the position of the facial electrode portion has shifted in a lower direction if the amplitude of the signal is greater than the upper threshold value, and that the position of the facial electrode portion has shifted in an upper direction if the amplitude of the signal is equal to or less than the lower threshold value.

2. The electroencephalogram interface system of claim 1, wherein the ear electrode portion is disposed on a same side as the facial electrode portion with respect to the straight line connecting the external canthus and the internal canthus of an eye of the user.

3. The electroencephalogram interface system of claim 1, wherein the ear electrode portion comes in contact with the user behind an ear.

4. The electroencephalogram interface system of claim 1, wherein,

the electroencephalogram measurement and determination section holds a determination criterion database storing data of a plurality of waveforms concerning event-related potentials;

the determination criterion database stores data of a waveform of an event-related potential appearing when wishing to make a selection and data of a waveform of an event-related potential appearing when not wishing to make a selection; and

the electroencephalogram measurement and determination section causes a process associated with the visual stimulation to be executed when determining that a waveform of the measured event-related potential is closest to that of the event-related potential when wishing to make a selection.

5. The electroencephalogram interface system of claim 1, wherein,

the electroencephalogram measurement and determination section measures the electroencephalogram signal based on a potential difference between the ear electrode portion and the facial electrode portion;

and

in the measured electroencephalogram signal, the facial electrode position determination section regards a signal in a predetermined frequency band as a signal associated with a blink of the user.

6. The electroencephalogram interface system of claim 5, wherein, in the measured electroencephalogram signal, the facial electrode position determination section regards a signal in a frequency band of 1.7 Hz to 2.2 Hz as a signal associated with a blink of the user.

7. The electroencephalogram interface system of claim 6, wherein, when an amplitude of a signal associated with a blink of the user is greater than the upper threshold value or smaller than the lower threshold value, the output section presents an alarm indicating that the eyeglass-type electroencephalogram interface system is shifted in position.

8. The eyeglass-type electroencephalogram interface system of claim 1, wherein the mass of the electroencephalogram interface system acting on the nose pad portion is greater than that acting on the endpiece portion when the eyeglass-type electroencephalogram interface system is worn.

9. The eyeglass-type electroencephalogram interface system of claim 1, wherein the ear electrode portion is disposed at the endpiece portion.