Study on Man-Machine Interface for the Aid of Handicapped People Using Automatic Eye-Tracking Technique

本研究的目的是探讨利用自动眼动追踪技术开发一套辅助残障人士的人机介面系统。首先，我们开发了一个接口系统，将眼动追踪系统与计算机连接起来。眼动追踪系统将被测对象在水平方向和垂直方向上的运动和眼动距离组成的数字信号传递给计算机。然后，对信号进行处理，以便将受试者眼睛的运动叠加为计算机显示器上光标的运动。由于我们几乎没有参考资料，开发处理信号的软件花了很长时间。我们已经成功地实现了控制显示器上光标的运动与受试者眼睛的运动同步。然而，我们还没有通过使用受试者有意识的连续眨眼来开发光标的点击。通过实验，我们已经认识到校准的重要性和受试者头部移动的效果。在实验开始时，必须对眼球追踪系统的信号增益进行校准，以使眼球运动的范围与显示器上光标运动的范围相匹配。由于受试者的头部移动会产生光标位置的移动，因此光标可以移动的区域将偏离显示器上的标准位置。因此，整个系统受到主体头部移动的强烈影响。

The purpose of this research is to investigate the development of a man-machine interface system for the aid of handicapped people by using an automatic eye-tracking technique.Firstly we have developed an interface system that connects the eye-tracking system with the computer. The digital signal from the eye-tracking system that is composed of the motion and the distance of eye movements of the subject toward the horizontal and vertical directions is transferred to the computer. Then, the signal is processed in order to superimpose the movements of the eye of the subject as the movements of the cursor on the computer display. It took long time to develop a software that handle the signal because we have scarcely no references. We have successfully achieved to control the movements of the cursor on monitor that is synchronized with the movements of the eye of the subject. However, we have not developed the click of the cursor by using the consciously successive blinks of the eye of the subjectWe have recognized the importance of the calibration and the effect of shifting the head of the subject through the experiments. At the beginning of the experiment, the calibration has to be made that controls the gain of the signal from the eye-tracking system in order to fit the extent of the eye-movements into the area of the cursor-movements on the monitor. Since the head-shift of the subject produces the shift of the position of the cursor, the area the cursor can move will deviate from the standard position on the monitor. As a result, the whole system is strongly affected by the head-shift of the subject.