TECHNOLOGY NEWS   

Otorinolaringologia 1998 March;48(1):45-8

Copyright © 2000 EDIZIONI MINERVA MEDICA

language: Italian

A new infrared vision system for the study of nystagmus and ocular movements

Castello E., Di Gioia F.

Ospedale San Martino - Genova Dipartimento Regionale Testa Collo I Divisione ORL (Direttore: Prof. E. A. Pallestrini)

During the last decades ocular movements and nystagmus have been studied with electronystagmography. Recently new infrared optic systems and other newer methodologies have been developed in neurotology. These systems allow the monitoring and recording of ocular movements in absolute dark avoiding fixation effects and are not subjected to electrical interference as electronystagmography. Among the newer most sophisticated technologies infrared videooculography is more sensible than electronystagmography, allows the analysis of nystagmus parameters and makes possible the recordings of position nystagmus. A low-cost infrared vision system which allows the observation of ocular movements in the absolute dark has been developed. This system includes 2 main parts: a 18 cm diameter infrared filter coupled with a 150 W lamp for the IR-illumination and the visor. IR visor is composed by 4 elements: a 29.35 mm special lens (1:1.4); a wide-angle ocular with 24 mm focus; a IR converter and a Ni-Cd battery (input 1.25 V- output 16 KV). These four elements were mounted in a monocular tube of 24 cm of length. the visor allows a 70 cm of minimum focusing. This infrared vision system allows the binocular vision of eyes in absolute dark; with this system it is possible therefore to observe of nystagmus and ocular movements without fixation and the observation of body sway in the dark.