Cambridge Research Systems Ltd.

• MRI-compatible monocular and binocular eye tracking at 60Hz
• Extremely fast setup time: cameras with an integrated IR illumination source are mounted directly on the head coil
• Designed to work with CRS BOLDscreen and third-party displays
• No scan artefacts up to 9.4T
• TTL-compatible trigger input port for data synchronisation
• Dedicated eye tracking hardware with USB output makes integration with your software very easy. Works with Presentation, ePrime, MATLAB, Python and your own custom software
• Compatible with Windows, Mac OS X and GNU/Linux

Infrared Optical Path

By using an infrared sensitive camera and IR illumination, the eye tracker is able to operate in total darkness. The illumination source is mounted within the camera housing and positioned close to the eye. This helps to provide more robust tracking compared to remote solutions.

Shielded Copper Cable

The camera uses carefully shielded and filtered circuitry to isolate the video signal from the MR gradients and RF pulses.

Flexible Head Coil Clamps

A very flexible, articulated arm and plastic clamp that work with many birdcage/bar head coil designs is available. It is allows the camera to be sited in many locations, but often at the expense of being within the subject's field of view.

A full range of bespoke mounts are also available and are highly recommended; they include a cold mirror so that the camera can be positioned completely outside the subject's field of view. This optical design makes the setup for each observer fast and repeatable and provides the optimum optical alignment for robust tracking.

Dedicated Image Processing

A self contained image processing computer analyses the video signal and identifies the pupil and corneal reflection. The video image stream, tracked eye position and pupil size data are all returned to the host computer across a USB interface.

External Trigger Input

A separate TTL-compatible signal is recorded with the eye data for easy synchronisation.