Tracking Eye Movement May Work

2015-0904 Eye Tracking

New technology that tracks the eye movements of patients may be a more accurate measure of brain injury than any other diagnostic measurements currently in use, according to a study recently published in the journal Concussion. Dr. Uzma Samadani, who recently joined the faculty at Hennepin County Medical Center, in collaboration with researchers at the Steven and Alexandra Cohen Veterans Center at NYU Langone Medical Center, developed the technology that can serve as a biomarker for concussion by tracking patients’ eye movements as they watch music videos.

The eye tracking technology works by having patients watch a music video for 220 seconds while eye movements are measured using a tracking camera. Multiple measures of each eye’s movement, followed by comparisons of their positions over time are used to distinguish between normal subjects and those with concussion.

In the work, led by Uzma Samadani, MD PhD, Charles Marmar, MD, and Eugene Laska PhD, the investigators built a classifier based on 34 emergency room patients with brain injury and 34 uninjured healthy control subjects of similar age. A classifier is a mathematical model that converts a patient’s eye movement measures into a prediction of the concussive status of the individual. They then tested the models on a dataset of 255 subjects, of whom 8 had concussions.

According to Dr. Samadani, the major challenge for any technology proposed as a biomarker for concussion is first defining concussion. “When doctors look for a biomarker for heart attack, it is relatively easy to check the accuracy of a potential candidate because they can perform a cardiac catheterization and confirm that the heart vessel is blocked and an attack has occurred. There is no analogous capability with brain injury – there is no gold standard diagnostic, no blood test, and no imaging study for definitively concluding that a patient has experienced a concussion. We use symptom severity scales and standardized cognitive examination assessments but the imperfect nature of these may result in incorrect subject classification. Potentially, eye tracking may be more accurate than it appears, because of its objective appraisal of a complicated process of coordination that may be impaired.”

Credits

Thanks to Hennepin County Medical Center for releasing data in the article; Google for helping me find the article; and all the people who, directly or indirectly, made it possible for me to include the picture and text in this post.

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