Method of making a judgment on emotional positivity or negativity by detecting asymmetry of brain waves of left and right cerebral hemispheres

• US 6,609,024 B1
• Filed: 10/13/1999
• Issued: 08/19/2003
• Est. Priority Date: 11/12/1998
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Ryu, Chang-Su, Song, Yoon-Seon
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): Natnithithadha, Navin
• Application Number:
  US09/417,978
• Time in Patent Office: 1,406 Days
• Field of Search: 600/544, 600/545, 128/925, 128/924
• US Class Current: 600/544
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• 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 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: Y10S 128/925 Neural network

Abstract

A method of making a judgment on emotional positivist or negativity of a person, comprises the steps of obtaining asymmetry ratio between the brain waves of the left and right cerebral hemisphere measured in a given unit time by means of electrodes attached to the left and right side of the scalp, calculating asymmetry ratio versus time at each frequency of the measured brain waves if the time taken for measuring the brain waves exceeds a given time interval, calculating an increase and a decrease of the asymmetry ratio of the previous step with time, and entering the increase and decrease into an artificial neural network to make a judgment on the emotional positivity or negativity.

Claims

1. A method of making a judgment on emotional positivity or negativity of a person, comprising the steps of:

obtaining asymmetry ratio between the brain waves of the left and right cerebral hemisphere measured in a given unit time by means of electrodes attached to the left and right side of the scalp;

calculating asymmetry ratio versus time at each frequency of said measured brain waves if the time taken for measuring said brain waves exceeds a given time interval;

calculating a slope of the asymmetry ratio of the previous step with time; and

entering a sign of said slope into an artificial neural network to make a judgment on said emotional positivist or negativity.

2. A method as defined in claim 1, wherein the first step includes further steps of:

measuring said brain waves from said electrodes;

subjecting said brain waves to Fourier transformation; and

obtaining said asymmetry ratio between the left and right brain waves based on the previous Fourier transformation.

3. A method as defined in claim 1, wherein the second step includes further steps of:

performing the first step if the time taken for measuring said brain waves does not exceed said given time interval; and

calculating asymmetry ratio versus time at each frequency of said measured brain waves if the time taken for measuring said brain waves exceeds a given time interval.

4. A method as defined in claim 2, wherein said electrodes are two respectively attached to the left and right sides of the scalp with the left side one positioned at F3 and the right side one at F4 according to 10-20 international electrode system.

5. A method as defined in one of the claims 1 to 4, wherein the third step includes further steps of:

smoothing out said asymmetry ratio versus time; and

calculating an increase and a decrease of the smoothed asymmetry ratio with time.

6. A method as defined in claim 5, wherein the step of smoothing out said asymmetry ratio is to reduce fluctuations for a short time little concerned with emotional response.

7. A method as defined in claim 5, wherein said an increase and a decrease is the slope of said asymmetry ratio with time or the positive or negative sign of said slope.

8. A computer storage medium for storing a computer program executed by a computer, wherein said computer program is composed of performing the functions of obtaining asymmetry ratio between the brain waves of the left and right cerebral hemisphere measured in a given unit time by means of electrodes attached to the left and right side of the scalp;

calculating asymmetry ratio versus time at each frequency of said measured brain waves if the time taken for measuring said brain waves exceeds a given time interval;

calculating an increase and a decrease of the asymmetry ratio of the previous step with time; and

entering said an increase and a decrease into an artificial neural network to make a judgment on said emotional positivity or negativity.