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This instrument uses the video-oculography technique and is designed for the clinical evaluation of adult subjects.

It includes an eye movement sensor combined with a high resolution color generator for static and dynamic images

applications :

• fixation monitoring during visual electrophysiology exams : hemifield VEP, multifocal VEP, pattern ERG, multifocal ERG
• study of oculomotricity (fixations, saccades, pursuits, optokinetic nystagmus )
• study of eye gaze strategies (reading, ..)
• study of pupil responses

This instrument uses the video-oculography technique and is designed for the clinical evaluation of young subjects (0 to 3 years).

It includes an eye movement sensor combined with a high resolution color generator for static and dynamic images

applications :

• study of oculomotricity (fixations, saccades, pursuits, optokinetic nystagmus )
• study of eye gaze strategies (visual exploration, ..)
• study of pupil responses
• estimation of visual acuity

This instrument uses the electro-oculography technique

It includes an eye movement sensor combined with a high resolution color generator for static and dynamic images

applications :

• study of oculomotricity (fixations, saccades, pursuits, optokinetic nystagmus )
• study of visual behavior in infants

Gaze direction is measured from the distance between the corneal reflex and the pupil center.

This technique provides measurements which are :

• absolute (no drift)
• easily quantified
• reliable in all gaze directions (horizontal, vertical and oblique
• independant from head movements.

Images of the eye in primary position(a),
after head shifting (b)
after eye movements (c, d)

Eye movements are measured from the bioelectrical potentials measured between two cutanous electrodes located on each side of the corneo-retinal axis.

• EOG uses the same recording equipment than visual electrophysiology examinations.
• both eyes can be recorded simultaneously
• it is limited to horizontal and vertical movements

strabismus

• fixations
• saccades
• pursuits
• vergences

Exams are realized with binocular and monocular viewing conditions.

neurology

• saccades
• pursuits
• nystagmus

The program allows the simultaneous acquisition and selective display of 14 channels :

• 2 for the visual stimulus( horizontal and vertical)
• 4 for eye position
• 4 for eye velocity
• 4 for eye acceleration

This application allows the calibration and the quantitative analysis of different motor responses :

• for saccades : velocity and latency
• for pursuits and nystagmus : duration and gain of slow phases, amplitude of fast phases.

example of
analysis of saccades

Evaluation of visuospatial functions in sensory, motor and cognitive disorders

• reading difficulties
• pre and post op evaluation (macular surgery, ...)
• low vision rehabilitation
• hemianopsia and hemineglect

recording of eye movements during reading
showing the localization
and duration of fixations
click here for a video

Several calibration protocols are proposed, which are adapted to different clinical situations : 5 points or 1 point simplified calibration, default calibration.

Eye movement exploration is displayed in real time, superimposed over the image viewed by the patient.

eye movement recording
of a patient with macular degeneration
click here for a video

This application provides a quantitative analysis of the eye movement exploration which determines for each "area of interest" of the image :

• the number and duration of fixations
• the number and average amplitude of saccades, globally and for each orientation.

This program display the test image projected over the retina, superimposed with the visual field of the subject, allowing a direct understanding of how the remaining iland of vision is used to accomplish a visual task

dynamic display of eye movement data
superimposed with the visual field
click here for the video

The program can also display the test image projected over the retina, superimposed with the image of tehe eye fundus.

dynamic display of eye movement data
superimposed with the image of the eye fundus
click here for the video

Objective determination of visual acuity

This examination is achieved by recording visual tracking eye movements of a moving structured stimulus. Visual acuity corresponds to the highest resolution stimulus eliciting a tracking response.

visual stimuli used
for the objective determination of visual acuity

Neurologic evaluation

Study of the maturation and assymmetries of visual pursuit and optokinetic nystagmus.

Record of tracking eye movement
in a one week old baby

The EOG and VOG techniques can both be used for testing very young infants. VOG has for advantage that its measurements are contact free and independant from head movements (which are very frequent in infants).

Before 3 years of age,VOG requires a specific setup allowing records to be made on a lying subject, without any distracting object in the subject's vicinity.

This application provides a quantitative analysis of the slow and fast phases present in pursuits and optokinetic nystagmus.

• assessment of the visual pathways
• drug studies

• objective visual field
  (pupillary responses elicited by local stimulations)
• study of the sympathic and parasympathic systems.

The resting pupil diameter and the pupillary responses to various visual stimuli is studied by combining the VOG sensor to one of the visual stimulator of the Vision Monitor.

response of the pupil to a flash of light

This application provides a quantitative analysis of the following parameters :

• resting pupil diameter
• characteristics of the averaged pupil response (latency, constriction and dilation velocities, contraction amplitude)

VISIOBOARD is a gaze controlled multimedia computer designed for subjects who have disabled body movements and voice.

The operation of the Eye Tracker is quite simple : after a few seconds of installation, the visitor selects a presentation topic : advertising, art ... After that, he/she watches a presentation of slides while his/her eye movements are recorded. Thereafter, he/she can watch a replay of his/her eye movement scan path superimposed upon the image that was initially viewed.

Metrovision's eye tracker has been in operation
at the Cité des Sciences de La Villette, Paris

Applications :

• visual ergonomy
• advertisement research
• marketing studies