DI 140503 : Headstar VNG

VIDEONYSTAGMOGRAPHY

The videonystagmography performed by a camera and infra red light measures and records the eye movement, which is analyzed by the software. HEADSTAR is the essential tool to study the various functions of balance, namely the oculomotricity (ocular saccades, pursuit, optokinetic nystagmus), the study of the vestibular system (spontaneous and positional nystagmi, rotary tests, caloric tests) more over HEADSTAR enables to run Video Head Impulse Tests (VHIT). The Head Impulse Test (HIT) has been used for years to identify vestibular deficit using unpredictable examiner applied, rapid horizontal head movements while observing compensatory catch up saccades indicative of a vestibular loss in the stimulated semicircular canal.
HEADSTAR is a nystagmography system and is able to record simultaneously movements of one eye, as well horizontal, as vertical as torsionnal (on option) and movements of the head. The calibration carried out by camera is stable and should only be made once at the beginning of the examination. The recording by camera removes all artefacts due to the changes of polarity between the electrodes and the skin like with the interferences of electric and electrophysiological origin.

DISOFT II

HEADSTAR has to be accompanied by a software. Two possibilities are available: EasyVNG or DISOFT II. Easy VNG is a simple click and play solution. DISOFT II is the fully configurable and customizable software. Both are powerful data-processing softwares, which simplifiy the task of the doctor. According to the tests carried out, the software analyzes and measures various parameters:

• number of jolts or ocular movements

• amplitude, frequency

• slow phase speed of nystagmus

• latency, phase, distortion

• gain

• symmetry or asymmetry of the responses

• paresis or labyrintic hypoexitability, directional

• preponderance of nystagmus

• measure of ocular fixation indices

HEADSTAR SYSTEM

Connected to a computer, HEADSTAR permits to localize the center of each pupil in real time and to register head movements.
HEADSTAR is built around a digital camera (USB 2.0) with a native resolution of 307200 pixels and a high sensitivity (0.1 lux).The use of Region Of Interest (ROI) on the camera avoid any mechanical adjustment needs to center the pupil in the video. HEADSTAR is even able to detect, in option, the torsional eye movement. Regarding the recording frequency, HEADSTAR is able to record eye movement with a frequency of maximum 200Hz in VNG and 250Hz in vHIT mode.

Certified biocompatible cushions foams (phtalate free, hypoallergenic) helps HEADSTAR goggle to be comfortable and adapted for children too.
HEADSTAR is provided in its case with its accessories: mask, cap and 3 sets of foams. 

TECHNICAL SPECIFICATION

• Number of channels: up to 3 (horizontal and/or vertical, torsion(option))

• Camera resolution: 307200 pixels

• Sampling rate: 50 Hz - 250 Hz (option)

• Connection: USB 2.0

• Sensitivity: 0.1 lux

• Built in fixation light

• Built in 3D gyroscope and accelerometer

• Requires a computer following Difra's specification available on request
  

HEADSTAR meets EN 60601-1 Standard and Directive 93/42/EEC

Version 1.1 - 2022-10