Fundus based eye tracker for optical coherence tomography

Abstract

Current optical coherence tomography (OCT) relies on patient cooperation to maintain fixation. For patients with eye complications, it is extremely difficult to achieve fixation on the eye. Most eye trackers are external and track only the pupils. Such method is not useful for the OCT. The only existing fundus image based tracker is a hardware-based system that is composed of a confocal reflectometer, dither scanner, and tracking galvanometers. The integration of such hardware based system with the OCT is not as desirable nor as portable. Therefore, we want an eye tracking system that can be installed in the computer connected to the OCT. In this paper, a real time internal eye tracking software based system is proposed. By combining intensity based object tracking adaptive mean shift algorithm with Kalman filtering techniques together, a robust real time eye tracking algorithm is proposed. The system is robust in terms of its acceptance to low resolution, coarsely quantized, or extremely noisy images and still able to produce desirable results with no pre-processing of images.