Alertness monitor
AssigneeSleep Diagnostics Pty., Ltd.
InventorMurray Johns
Life of this patent
Estimating the term…
Abstract
An alertness monitoring system includes: means to measure velocity and amplitude of eyelid and eye movement; and storage means to continuously record the measurements. A data processor calculates the blink amplitude to velocity ratio and/or the saccade amplitude to velocity ratio and compares the measurements against a predetermined scale. The scale is derived from averaged measurements of the eye and eyelid movement parameters for a sample population measured against predetermined incremental blood alcohol levels. The output of the system can include a display for showing the alertness measurement based on the scale, or an alarm means triggered by the scale reading reaching a predetermined limit based an the blood alcohol level scale.
Claims18
An alertness monitoring system which includes:
- a) means to measure velocity and amplitude of eyelid and eye movement;
- b) storage means to continuously record the measurements;
- c) a data processor to calculate the blink amplitude to velocity ratio and/or the saccade amplitude to velocity ratio and 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.
A method of measuring alertness in which the eye movements of a subject are analyzed using reflected infrared light pulses to obtain measurements of the blink amplitude to velocity ratio and/or the saccade amplitude to velocity ratio averaged over predetermined periods of time and measuring the deviation of the average from a predetermined average for alert subjects.
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 die detector signals and to subtract a 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 measurement;
- e) said data processing means analyzing said reflectance measurement to calculate the blink amplitude to velocity ratio and/or the saccade amplitude to velocity ratio and compare the measurements against a predetermined scale.
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 analyzed 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 analyzed measurements;
- or
- e) an alarm means triggered when a predetermined measurement threshold is crossed.
A method of measuring alertness, the method comprising:
- measuring velocity and amplitude of eyelid and eye movement of a subject;
- calculating an eyelid movement amplitude to velocity ratio and/or an eye movement amplitude to velocity ratio;
- calculating an average of one or both ratios over at least one predetermined period of time;
- and
- determining a deviation of the calculated averages from predetermined averages for alert subjects;
- and
- triggering an alarm if the deviation of the determined average from a predetermined average reaches or exceeds a predetermined limit.
Dependencies are inferred from the claim text.