Visible Eye™ is a fully integrated Eye Tracking and Visual Stimulation system for  fMRI/MEG applications.

Visible Eye™ combines the Real Eye RE-4501 eye imaging system and the SV-7021 Fiber Optic Visual System supplied by Avotec, Inc. with the XView eye tracking system supplied by SensorMotoric Instruments, GmbH. 

Visible Eye™ Applications:

• High resolution visual stimulation
• Video-based eye tracking
• Contact-free evaluation of movement and gaze position
• Real-time image processing
• Objective verification of experimental results
• Eye movement experiments
• Interface to standard stimulus

Eye Tracking information:

• Gaze position
• Pupil size
• Automatic fixations--user-adjustable
• Online feedback available

• Printed or exported documentation

The Visible Eye™ system consists of three subsystems:

The Avotec Silent Vision^TM SV-7021 Fiber Optic Visual System allows patients to watch video material or computer generated images simply by using a pair of lightweight fiber optic glasses.  A color LCD projector, located just outside the MRI bore, generates high resolution color images that are transmitted to the glasses by fiber optic image guides.  A video interface, located in the control room, accepts video and computer inputs, and sends them to the projector via a fiber optic link.  It also provides control monitors for the operator. 

The new Avotec Real Eye^TM fiber optic subsystem which is integrated with the Silent Vision^TM glasses, relays real time images of the patient eye out of the magnet environment.  Near infrared eye illumination ensures optimum eye image quality without interfering with visual stimulation.  A low profile design ensures minimal interference with the typically cramped space around the patient's head.  All parts of the system placed inside the magnet are composed entirely of glass and plastic, so the system is truly inert even in particularly high magnetic fields.

The iView^TM eye tracking system analyzes the eye images provided by RealEye^TM. The iView sampling rate is 50 Hz.  Either the left or right eye can be tracked.  An automatic calibration procedure is integrated into the system.  The operator unit, located in the control room, allows live monitoring of gaze position overlaid on stimulus images, as well as digital recording and digital or analog on-line output of eye movement data.
 

SMI iView-fMRI Eye^TM Tracking System Performance Specifications, System Version 0.91 (when used as part of Visible Eye System, for example in combination with Avotec Real Eye^TM eye imaging unit and Avotec Silent Vision^TM stimulus display for fMRI):

Temporal Resolution:  Sampling rate 60 Hz (NTSC version, US and Japan) / 50 Hz (PAL version, Europe)

Tracking Range:  15-20 degrees horizontally, 10-15 degrees vertically (subject dependent)

Gaze Position Accuracy:  3 degrees visual angle (2 minutes after calibration)

Avotec, Inc.
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Stuart, FL  USA 34994
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avotec@avotecinc.com
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