Segal Scan

Mounting Mode

Head Stabilized , Table Mounted

Num. of Cameras

One camera with IR Cloder Lenz

Sampling Rate

500Hz

Gaze Accuracy

1° Optimal conditions

Gaze Precision

0.10° RMS

Calibration procedure

Monocular 9 point Automatic and manual calibration

Data sample output

analogue channels for x, y, pupil size

Gaze recovery time

Under 300ms

Blink recovery time

1 frame (immediate)

Eye tracking devices are generally presented in two modes: desktop or on the head. In some desktop models, the user is allowed to move the head, and in others, the user's head must be fixed by a tool called Chin Rest.

The number of images recorded by the camera in one second is called. A data rate of 500 Hz for a camera means that an image is recorded every 2 milliseconds. The higher this quantity is, the higher the accuracy of the imaging time and, as a result, finer movements. The eye can be measured with greater time resolution. Also, the high quantity puts more pressure on the processing system used, and as a result, a more powerful processor is needed to analyze the data online.

In some eye tracking devices, a separate camera is used to track each eye. (There are two cameras on the device in total) This work is used to check the difference between the two eyes in different movements, and also by using statistical and mathematical methods, it is possible to By combining two images, it reduced the measurement error of the device. In some other models, two cameras are placed for each eye so that all angles of the eye can be evaluated with higher accuracy.

It is called the angular distance between the point reflected by the emitter and the pupil image. In fact, the spatial accuracy of the point of view shows the accuracy of the device and the measurement algorithm.

The amount of deviation from the standard in the registration of a point is said. For example, if the user is asked to look at the previous point several times, how close the points recorded by the device are to the previous record.

The output of the device can be online or the final output. In addition to the final output, the Segal Scan device simultaneously and online displays the eye coordinates and pupil size in an analog form and can be recorded on the recording screen of other devices such as EEG. This is important. It helps to synchronize eye movement data with brain data.

When the user blinks, at that moment it is not possible to record the image of the pupil. As a result, all the algorithms that are continuously estimating the position of the pupil fail. Therefore, there are methods to re-locate the system in the shortest possible time. The BZ-5001 can immediately re-estimate the position of the pupil in the first frame of the image after the blink.