The g.EYEtracking Interface for Simulink allows to acquire eye gaze and x-, y-coordinates of the eye together with biosignal data. The signals can be visualized, stored and analyzed in real-time in Simulink and off-line in MATLAB.

Therefore a ViewPoint Eyetracker that is fixed on very lightweight glasses must be worn. The device comes with one camera pointing to the eye and another camera pointing in the same direction as the subject's eye. This camera is called the scene camera and allows to capture the environment.

How it works

The infrared light source of the tracker illuminates the eye and provides also a specular reflection from the surface of the eye (from the smooth cornea) that is captured with a camera and video capture device. Then the computer system uses image segmentation algorithms to locate the areas of the pupil and the bright corneal reflection (glint). Additional image processing algorithms locate these areas and calculate a difference vector between the center locations. A mapping function transforms the eye position signals into coordinates. Additionally the program can test if the gaze point is inside of any region of interest (ROI) that was previously defined by the user.

A scene camera captures the environment and allows to project the eye movement on the real situations.

A prerequisite is a calibration system that presents calibration stimuli to the user to measure the eye position signals for each stimulus point. These data are used to compute an optimal mapping function.

  

Highlights

Record and view x-, y-eye-coordinates, velocity, pupil width, ocular torsion, fixation duration in Simulink simultaneously with biosignal data
Monocular or binocular options are available
The eye tracking system can be worn without discomfort for long periods. Easily adjustable in size and compatible with glasses this design is well received by subjects who mostly dislike helmet style systems.
No tracker is required for calibration
Scene camera allows to track gaze position on real world scene videos
On-line signal analysis under Simulink and off-line analysis under MATLAB with g.BSanalyze

What you need

For tracking the eye movement the ViewPoint Eyetracker with monocular or binocular cameras togeter with a frame grabber board are required. The frame grabber card is plugged into a PCI slot of a normal PC. To acquire simultaneously biosignals g.USBamp, g.MOBIlab+ or g.BSamp Highspeed On-line Processing for Simulink must be installed. This package allows to read in the biosignal data into Simulink. The specially developed g.EYEtracking Interface works toegether with the ViewPoint software and allows to acquire both the eye movements and the biosignals together into one MATLAB data file which makes the off-line analysis easy.

g.USBamp and g.EYEtracking Interface

The g.EYEtracking Interface provides a Simulink block that can be easily copied into every model to capture also the eye-movements of the subject. Interfacing the ViewPoint Eyetracker with g.USBamp explains in detail the usage. Important is that the model contains also a g.USBamp, g.MOBIlab+ or g.BSamp block to control the model in real-time.

simulink

Available Products

1 Monocular EyeTracker
2 Binocular EyeTracker
3 Precision Head Positioner
4 g.EYEtracking Interface for Simulink

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