Design of an Electroocular Computing Interface

Abstract

The human retina consists of an electrically-charged nerve membrane. This potential is a constant value for a given adaptation without stimulation; it is the retinal resting potential. The retinal resting potential causes an electric field around the eyeball, centered on the optical axis, which can be measured by placing electrodes near to the eye. As a result, the motion of the eye causes a measurable change of DC voltage between the surface electrodes. The same vector coordinate system employed in the modern computer mouse may be adapted for use with our electro-ocular interface. Such a device would provide a relative position of gaze and have application in both hands-busy and assistive research. The theory behind our device, hardware design, the experimental results, and efficacy of the system are presented.

Low-cost system based on electro-oculography for communication of disabled people

“…According to the literature [16], eye movement measured using the EOG provides an electrical vector along the horizontal H=<xl, yl> and vertical V=<x2, y2> axes. The resultant vector is…”

Development of a Computer Writing System Based on EOG

“…Once this information has been processed properly, it can be used for controlling devices such as virtual keyboards [ 4 ], powered wheelchairs [ 5 , 6 , 7 ], robots [ 8 , 9 ], medical applications [ 10 , 11 ], etc. An important field of application is the development of assistive technology oriented to various disabled people through the development of human computer interfaces [ 12 , 13 , 14 , 15 , 16 ]. These kinds of people retain the control of their eye movements, which can be translated into commands.…”

A non-intrusive and calibration-free gaze tracking system

“…Electrooculography research has been used to develop eye gaze estimation systems similar to those in [7 ]- [9 ]. These systems consist of electrodes being placed on the skin around the eye to measure the electrical potential generated by eye movements.…”

“…These systems consist of electrodes being placed on the skin around the eye to measure the electrical potential generated by eye movements. This information can be used to form x-axis and y-axis vectors, similar to the output of a computer mouse [7 ]. Head mounted systems have been developed mostly as a method for human computer interaction ([1 0 ]-[1 2 ]).…”

“…For the eye gaze system using the cross-ratios method, Yoo and Chung [6] had to first estimate the image coordinates of the virtual projection points in order to utilize the cross ratio property since they cannot be directly observed. After simplification, the virtual projection point can be estimated with the following equation: uvx = uc + cc(urxuc) (7 ) Where: u*x is the virtual projection point, uc is the coordinate of the pupil center, u™ is the coordinate of the glint from the corner of the monitor, and a is a constant coefficient approximately equal to 2.…”