Alertness monitor
5 Assignments
0 Petitions
Accused Products
Abstract
An alertness monitoring system uses reflectance measurement of infrared light pulses to monitor eye movement of a vehicle or machine operator. The-data is used to measure eye and eyelid movement for presence slow or drifting eye movements, and/or eyelid closure and optionally one or more of, absence of saccadic movement, loss of eye co-ordination, wavering eyelids, partial eye closure, and drooping eyelids as indicators of loss of attention and drowsiness. The eye movements of a subject are analysed using reflected infra red light to obtain measures of the blink amplitude velocity ratio and the saccade amplitude velocity ratio. The readings are continuously compared with eye movement data indicative of degrees of alertness which correlate to blood alcohol content values so that the monitor provides an indication of the operator'"'"'s legal fitness to operate the vehicle or machine from the point of view of drowsiness no matter how it is caused.
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Citations
28 Claims
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1-13. -13. Cancelled.
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14. An alertness monitoring system which includes
a) means to measure eyelid and eye movement for presence of one or more of relatively slow eye and eyelid movements in relation to their amplitude, wavering eyelids, partial eye closure, drooping eyelids; - slow or drifting eye movements, slow and prolonged eyelid closure, absence of saccadic movement and loss of eye co-ordination
b) storage means to continuously record the measurements c) a data processor to compare the measurements against a predetermined scale, said scale being averaged measurements of the eye and eyelid movement parameters for a sample population measured against predetermined incremental blood alcohol levels d) a display for showing the alertness measurement based on the scale or e) an alarm means triggered by the scale reading reaching a predetermined limit based on the blood alcohol level scale. - View Dependent Claims (15, 16)
- slow or drifting eye movements, slow and prolonged eyelid closure, absence of saccadic movement and loss of eye co-ordination
- 17. A method of measuring alertness in which the eye movements of a subject are analysed using reflected infra red light pulses to obtain measures of the blink amplitude to velocity ratio and/or the saccade amplitude to velocity ratio averaging these over predetermined periods of time and measuring the deviation of the average from a predetermined average for alert subjects.
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21. An alertness measuring system for a subject which includes
a) an infrared pulse emitter adapted to be located adjacent at least one eye of a subject b) at least one reflected light detector located adjacent said emitter c) means to transmit the detector signals d) data processing means to receive the detector signals and to subtract the total level of light immediately before each pulse is transmitted from the combined level of the measured reflectance after the pulse to provide a reflectance measure e) said data processing means analyzing said reflectance measure to assess eyelid and eye movement for presence of one or more of relatively slow eye and eyelid movements in relation to their amplitude, wavering eyelids, partial eye closure, drooping eyelids; - slow or drifting eye movements, slow and prolonged eyelid closure, absence of saccadic movement and loss of eye co-ordination.
- View Dependent Claims (22, 23, 24, 25, 26, 28)
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27. An alertness monitoring system which includes
a) means to measure eyelid and eye movement b) storage means to continuously record the measurements c) a data processor in which the recorded measurements are analysed to obtain measures of the blink amplitude to velocity ratio and/or the saccade amplitude to velocity ratio and measuring the deviation from a predetermined average for alert subjects. d) a display for showing the analysed measurements or e) an alarm means triggered when a predetermined measurement threshold is crossed.
Specification