Design of laser eye tracking system

number: 
1683
إنجليزية
Degree: 
Author: 
Samer Basim Yousuf
Supervisor: 
Dr. Mohammed A. Hussain
Dr. Anwar Abdul Satar Abdul Razaq Al-Dergazely
year: 
2007
Abstract:

Laser is so important in medical applications especially for eye correction surgery to make the vision clear and keeps the eyes healthy. An eye tracking arrangement is required for precise and safe eye surgery. This work presents the design and implementation of an experimental eye tracking system. The design of the eye tracker system is essentially a specialized flying-spot scanner consists of the following: a 1mW He:Ne laser (632.8 nm wavelength) as laser source; a laser beam steering system consists of two ordinary plane steering mirrors, stepper motors and controllers , a sensor which measures the reflected light from the eye, consisting of four phototransistor sensors where the signals from the photo transistor are passed through an amplifier and fed to the computer control which stores, processes data, interfaces with the user and controls the beam steering devices. The eye has been simulated with a plan mirror. The eye tracker program has been written in Quick Basic language to control the collection, processing, and storage of scan information. The eye tracker program tracks the mirror simulating the eye in real time and directs the beam-steering mirrors to keep the scan pattern centered on the mirror simulating the eye. The spot of the laser beam can be determined from the top, bottom, left, and right edges of the horizontal and vertical sweeps using the four detectors which feed the data to the computer then move the laser beam towards the new location of the mirror simulating the eye.