| CPC A61B 5/4884 (2013.01) [A61B 5/004 (2013.01)] | 5 Claims |
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1. A system comprising:
a camera configured to capture an image of a subject, the image including an eye of the subject;
a display device;
a memory storing instructions; and
one or more processors configured to execute the instructions to:
acquire the image of the subject captured by the camera;
detect an eye opening degree of the subject from the acquired image, the eye opening degree being a first time series signal;
determine an awakening degree of the subject based on the eye opening degree of the subject, the awakening degree being a second time series signal;
calculate a feature amount of the acquired awakening degree;
estimate stress from the calculated feature amount using a stress model;
determine whether the stress is greater than a threshold; and
display a message on the display device prompting the subject to take a rest when the stress has been determined to be greater than the threshold,
wherein the feature amount is a ratio at which a temporal change of the awakening degree is within a predetermined range, or information that defines a histogram indicating a distribution of the temporal change of the awakening degree, and
wherein the temporal change of the awakening degree is a first-order differential or a second-order differential of the awakening degree.
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