U.S. Patent No. 7,357,507 - Impairment Determination System – Imaged Based System To Observe And Document Eye Responses (Apr. 15, 2008)

The image-based system to observe and document eye responses includes a headset that has a faceplate against which the subject places their face.  The subject’s eye responses, in tracking a stimulus target as it is moved by the test administrator, are recorded on an image recording device along with audio annotations from the test administrator.  The data processing system may be used to perform an analysis of the image generated by the imaging devices to quickly and accurately localize the pupil’s boundaries, area, and center coordinates in close-up video imagery of the subject’s eyes as captured with the imaging devices.  These eye responses include both ocularmotor and pupillary responses to illumination and target tracking which are used to calculate impairment of the subject.  Involuntary eye movements and/or pupil reactions are an indicator of physiological impairment, which is directly related to safety and fitness-for-duty issues in the workplace, on the highways, etc.