Design of an optokinetic nystagmus system

Optokinetic test is been used both for stimulation of optokinetic nystagmus (OKN) and trying to observe OKN abnormalities. In eye clinics when the patient is checked the OKN test is applied with the other tests. Patient is requested to watch a mechanical drum with white and black stripes on it. The patient is asked to focus on one color and follow the stripe while the drum turns. The eyes of the patient follow the stripe with direction of the rotation. When the stripe cannot be followed the eyes make a quick move (saccadic move) and focus on a new stripe and follows it, this goes back and forth. This continuous move is called optokinetic nystagmus. The number of saccades on both eyes must be the same; otherwise this is accepted as the sign of a problem in eye muscles, brain system or inner ear. The doctors make the diagnosis by observing the patient with his/her eyes.The aim of this thesis is to design an electromechanical optokinetic nystagmus system (optokinetic drum) to overcome the problem of mechanical drum by electronically adjusting the velocity. The advantage of constant velocity is that doctors can make diagnosis not only by their eyes but also with electrooculography (EOG), electronystagmography (ENG) and video nystagmography. Main purpose of the thesis is to design and produce an optokinetic nystagmus system which is able to do OKN tests with the preferred direction and adjusted velocities.