State-of-attention determination apparatus

Patent metadata

Field	Value
Publication number	US-9480429-B2
Application number	US-201113207547-A
Country	US
Kind code	B2
Filing date	Aug 11, 2011
Priority date	Nov 9, 2009
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

The apparatus includes: a detection section for detecting a time period during which an operator is making preparations prior to beginning a driving operation; an adjustment section for adjusting a determination criterion for determining a state of attention of the operator during a driving operation, which calculates an eye fixation related potential of the electroencephalogram signal of the operator measured at least in the time period by using the measured oculomotor signal of the operator, and which adjusts the determination criterion based on the calculated eye fixation related potential; a determination section for calculating an eye fixation related potential from the electroencephalogram signal and the oculomotor signal of the operator measured after beginning the driving operation, which determines a state of attention of the operator during the driving operation based on the calculated eye fixation related potential and the adjusted determination criterion; and an output section for acting to call attention of the operator based on a result of determination.

First claim

What is claimed is:

1. A state-of-attention determination apparatus comprising:
an electroencephalograph configured to measure an electroencephalogram signal of an operator;
an electrooculograph configured to measure an oculomotor signal indicating an oculomotor movement of the operator;
a processor configured to:
detect a time period during which the operator is making preparations prior to beginning a driving operation by receiving information concerning a start of a setting manipulation for a car navigation system provided in a vehicle, detecting a setting manipulation for the car navigation system, and determining the time period based on a time of the setting manipulation for the car navigation system;
adjust a determination criterion for determining a state of attention while the operator is performing a driving operation by extracting a portion of the electroencephalogram signal during the time period, obtaining a portion of the oculomotor signal during the time period to determine a first eye fixation, acquiring a first eye fixation related potential within the extracted portion of electroencephalogram signal by using the obtained first eye fixation, and adjusting the determination criterion based on the first eye fixation related potential; and
extract a portion of the electroencephalogram signal measured after the time period, obtain a portion of the oculomotor signal measured after the time period to determine a second eye fixation, acquire a second eye fixation related potential from the portion of the electroencephalogram signal and the second eye fixation measured after the operator begins a driving operation, and determine a state of attention of the operator performing the driving operation based on the second eye fixation related potential and the adjusted determination criterion; and

an output processor configured to output at least one of a visual, audio, vibration, or air indicator to call attention of the operator based on a result of the state of attention determination.

2. The state-of-attention determination apparatus of claim 1 , wherein processor adjusts the determination criterion further based on a frequency power spectrum value of the electroencephalogram signal measured in the time period.

3. The state-of-attention determination apparatus of claim 2 , wherein the processor sets a higher determination criterion as the power spectrum value of α waves contained in the electroencephalogram signal measured in the time period increases, and sets a lower determination criterion as the power spectrum value of β waves contained in the electroencephalogram signal measured in the time period increases.

4. The state-of-attention determination apparatus of claim 1 , wherein the processor determines the state of attention of the operator by comparing an amplitude value of a lambda response of an arithmetic-mean of the second eye fixation related potential against a determination threshold which is the determination criterion.

5. The state-of-attention determination apparatus of claim 4 , wherein, as the determination criterion, the processor sets a higher determination threshold as the lambda response amplitude value of the second eye fixation related potential increases, and sets a lower determination threshold as the lambda response amplitude value decreases.

6. The state-of-attention determination apparatus of claim 4 , wherein, based on the oculomotor signal, the processor detects a start time of the eye fixation for either the first or second eye fixation related potentials to be a point in time at which the oculomotor movement of the operator has become smaller than a predetermined threshold.

7. The state-of-attention determination apparatus of claim 4 , wherein the processor acquires the first and second eye fixation related potentials which is 50±100 milliseconds from a start time of the eye fixation in the electroencephalogram signal.

8. The state-of-attention determination apparatus of claim 4 , wherein, as the amplitude value of the lambda response, the processor utilizes a local maximum contained within 50±100 milliseconds of the arithmetic-mean of the second eye fixation related potential based on an eye fixation start time as a starting point.

9. The state-of-attention determination apparatus of claim 1 , wherein the processor determines that the operator is in a state of being focused on driving when an amplitude value of a lambda response of an arithmetic-mean of the second eye fixation related potential is equal to or greater than a determination threshold which is the determination criterion, and determines that the operator is in a state of being distracted when an amplitude value of a lambda response of the arithmetic-meaned eye fixation related potential is smaller than the determination threshold which is the determination criterion.

10. The state-of-attention determination apparatus of claim 1 , wherein the processor detects the time period by defining as an end time at least one of the flowing points in time: completion of a setting manipulation for the car navigation system, detection of a vehicle speed of the vehicle being equal to or greater than a predetermined value, and a predetermined time after a start time.

11. The state-of-attention determination apparatus of claim 1 , wherein, based on the oculomotor signal, the processor detects a start time of the eye fixation for either the first or second eye fixation related potentials to be a point in time at which the oculomotor movement of the operator has become smaller than a predetermined threshold.

12. The state-of-attention determination apparatus of claim 1 , wherein the processor acquires the first and second eye fixation related potentials which is 50±100 milliseconds from a start time of the eye fixation in the electroencephalogram signal.

13. A state-of-attention determination apparatus comprising:
an electroencephalograph configured to measure an electroencephalogram signal of an operator;
an electrooculograph configured to measure an oculomotor signal indicating an oculomotor movement of the operator;
a processor configured to:
detect a time period during which the operator is making preparations prior to beginning a driving operation by receiving information concerning a release of a brake of a vehicle, detecting a release of the brake, and determining the time period based on a time of the release of the brake;
adjust a determination criterion for determining a state of attention while the operator is performing a driving operation by extracting a portion of the electroencephalogram signal during the time period, obtaining a portion of the oculomotor signal during the time period to determine a first eye fixation, acquiring a first eye fixation related potential within the extracted portion of electroencephalogram signal by using the obtained first eye fixation, and adjusting the determination criterion based on the first eye fixation related potential; and
extract a portion of the electroencephalogram signal measured after the time period, obtain a portion of the oculomotor signal measured after the time period to determine a second eye fixation, acquire a second eye fixation related potential from the portion of the electroencephalogram signal and the second eye fixation measured after the operator begins a driving operation, and determine a state of attention of the operator performing the driving operation based on the second eye fixation related potential and the adjusted determination criterion; and

an output processor configured to output at least one of a visual, audio, vibration, or air indicator to call attention of the operator based on a resu

Assignees

• Nakada Toru
• Morikawa Koji
• Panasonic Corp

Inventors

• Nakada Toru
• Morikawa Koji

Classifications

• A61B5/163

  by tracking eye movement, gaze, or pupil change · CPC title

• A61B5/6816

  Ear lobe · CPC title

• A61B5/6803

  Head-worn items, e.g. helmets, masks, headphones or goggles · CPC title

• G08G1/166

  for active traffic, e.g. moving vehicles, pedestrians, bikes · CPC title

• A61B5/18 Primary

  for vehicle drivers {or machine operators} · CPC title