Training in VNG
Performing calibration for VNG testing
How to instruct your patient
I'd like to go through how to perform a calibration on the VisualEyes™ 525 software. The calibration process is a pretty straightforward task.
We're going to ask the patient to look at the center dot on the screen. That dot is going to move left, right, up, down, and then back in the center. We're going to ask our patient to follow that dot, whilst keeping your head still and only following the dot with your eyes.
In the software, there is a default calibration. So if our patient isn't able to perform such a task, then we can use the default calibration. But we always recommend attempting to get an individualized calibration, as this is going to give us the most accurate results.
Do you have any questions before we begin testing? No. Fantastic.
Calibration procedure
Okay. So let me come over and we'll start the test.
If you can look center. Look left. Look right. Look center. Look up. Look down. And that's the calibration process complete.
What you see on the screen is a calibration report where we see five green ticks indicating that the patient looked at all five dots correctly. This allows us to say that the calibration is sufficient and we're now ready to start testing.
Description
Calibration is an essential step in VNG. In order to measure eye movements accurately, the VNG system needs to know how far the eyes are from the camera, and how far they need to move to look at a target of known position. This is achieved by going through the calibration process, which is detailed and demonstrated in this video.
Presenter
