OPTIKON Keratron Piccolo, Инструкция по установке и эксплуатации

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Keratron
™
Piccolo Installation and operating manual
OPTIKON 2000
5 GENERAL INFORMATION
5.1 SYSTEM DESCRIPTION
The KERATRON
™
PICCOLO is a “Computer Assisted VideoKeratographer”
(also said CAVK in the literature) that, just like the KERATRON
™
and the
KERATRON
™
SCOUT, is designed to measure the shape of the cornea and to
represent it as symbolic colour map of the corresponding axial or refractive powers,
of its local curvatures or of its elevations in several formats (corneal topography)
The KERATRON
™
PICCOLO consists of:
•
A Videokeratoscope (VK) , for the acquisition of the image of mires reflected
on the eye;
•
A Base (to be placed on a table) for powering the VK and the connection of a
control footswitch. Communication with a PC (not included) takes place
through a
USB 2.0 port (Universal Serial Bus).
The monitoring operation during acquisition, by the operator, is performed by
observing the live image from the video camera on the PC’s screen. At the same
time the position of the eye’s apex is indicated by a signal from five virtual LEDs
located to the left of the live image.
The VK carries 28 mires, which are shaped as back-lighted concentric rings,
alternatively 14 black and 14 whites, arranged into the internal conical surface of a
cone, made of transparent perspex, called
Mires Cone which is removable and
which carries a opto-electronic couple, made of an IRED and a photo-transistor, set
at two opposite sides of its external edge.
The Cone is back illuminated by the Lamp Board which contains a tight array of
LEDS. Behind the Lamp Board there are the fixation led, focused at a large distance,
and the TV Camera.
The IRED - phototransistor couple at the edge of the optical head intercepts the eye
vertex when this is at the preset distance from the optical head. . An electronic circuit
(EPCS) eliminates the background light and measures the “degree of coverage”,
which is used to accept the acquisition only within a preset range.
The operator thus can only take images, by pressing a footswitch or the OK
pushbutton, only when the patient eye is at a preset distance, which is the same
distance at which the instrument was formerly calibrated on a sphere having a known
curvature radius.
Cod. 161301EN 5-1
2012-01-17
Rev.D