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Abstract

Attention deficit hyperactivity disorder (ADHD) is a commonly diagnosed psychiatric disorder characterized by lack of focus, self-control,and hyperactivity. ADHD is difficult to diagnose without extensive observation by an expert, and even then is often misdiagnosed. Current methods of pediatric diagnosis rely on subjective measures of activity and behavior relative to other children [3]. Proper diagnosis is critical in preventing unnecessary prescription of the powerful, habit-forming nature of the drugs used to manage ADHD, such as Adderall and Ritalin [1][5]. Research has shown that patients with ADHD show abnormalities in reading tests and antisaccade tests, as these tests gauge ability to focus and suppress impulsive behavior [2][6][4]. This project proposes to create a dedicated device that will use eye movement analysis to accurately and objectively screen children for ADHD. The device will be inexpensive and easy to use for school nurses, optometrists, and primary care physicians.

First, research was conducted to decide the type of eye tracker to build, the tests that would be run, the layout of the device, and the type of headgear to use. After the preliminary research was completed, it was decided that a limbus eye tracker would best fit the needed functionality of the device. Limbus tracking is both more accurate in horizontal tracking and less costly than other systems. A basic circuit diagram has been created and circuit parts have been ordered. The IR LED and phototransistors have been tested and appear to be working properly, but further testing will be conducted and mounting for the components will be constructed.

One problem encountered was the selection of a computational module that incorporates our needs for digital I/O, A/D conversion, significant processing power and speed, DOS-basedoperating system, and VGA output. No single board computer yet found incorporates all these features in one module without being too costly. The team is awaiting a decision concerning Sternheimer funding before exploring the use of more cost-effective strategies. Another point of discussion among the team was how to affix the device to a child’s head or keep a child’s head still enough for the eye tracker to be accurate. The result was a preliminary design utilizing safety glasses. The next steps in this project include deciding upon a single board computer and ordering it and ordering more circuit parts and safety glasses. While these parts come in, the circuit design can be enhanced, an approach for the programming portion will be created.

Publication Date

2015

Keywords

biomedical engineering, ADHD

Disciplines

Biomedical Engineering and Bioengineering | Engineering

Faculty Advisor/Mentor

Paul Wetzel

VCU Capstone Design Expo Posters

Rights

© The Author(s)

Date of Submission

July 2015

A device for the objective assessment of ADHD using eye movements

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