Metrovision Model MonPackONE
It is a universal and compact stimulator allowing ganzfeld flash, pattern and multifocal ERG and VEP exams.
It includes several highly innovative features:
the luminance controlled LED monitor that eliminates the luminance artifact produced by standard LCD monitors (patented).
the near infra red cameras for monitoring eye fixation and pupil size for 30 cm and 1 meter tests
the compressed recording of the camera video and its synchronous replay allowing the invalidation of individual responses
Pattern ERG and VEP
Constant luminance cannot be achieved with standard LCD monitors. One important characteristic of pattern stimulations is that the average luminance should be constant (ISCEV standards for pattern ERG and for pattern VEP).
There should be no change in luminance, even transient when reversing the stimulus or when switching from the "on" to the "off" pattern.
If constant luminance is not achieved, the PERG stimulus generates a response not only from the ganglion cells but also from other layers of the retina. In a similar way the PVEP stimulus activates different types of cortical cells. This may results in a diagnosis error.
Standard LCD monitors produce a transient light flash at each pattern reversal or pattern on-off. This is due to a different velocity of the liquid crystals between the on-off and off-on transitions.
Flash ERG and VEP
In the ganzfeld mode, flashes of light are produced by LEDs from the backlight and from the surrounding to produce a full field uniform illumination of the eye.
MonPackONE uses LEDs with 3 different wavelengths. Each of them can be programmed over a dynamic range of 5 log units. They can be combined to produce white light or any combination of 8 million colors.
Multi focal ERG and VEP: Highly innovative stimulation technology
Controlling stimulus luminance and timing is very important for multifocal exams. This is achieved thanks to the proprietary LED technology of the MonPackONE.
It produces very high luminance stimulations (up to 600 cd/m2) resulting in responses of high signal to noise ratio and reduced examination time
The LED backlight produces short flashes of light interespaced with dark intervals, resulting in a timing accuracy better than 1 ms.