Please enable JavaScript.
Coggle requires JavaScript to display documents.
VEP ((Montage, you missed that), Two inputs for every ampl, number 1 is…
VEP
(Montage, you missed that)
Two inputs for every ampl, number 1 is different
Active goes to each ampl on its own, common goes to all at the same time.
Most careful on electrodes in the back, as they are recording electrodes. Noise of 50 hz has to be conducted away. If not, signals on the back of the head will be tainted by artefacts.
-
-
Talk to the patient, quiet tone “clo eyes and keep closed” , switch to light off (bigger physiological signal) (easier to remove the background and signals averaging)
Wait 20’, only the pros. Clinics.
We can check the distance from the screen etc. 70 cm from screen, angle? Macula angle, 20*
-
Orizontal distance, tangent
1 degree is fine, but we don’t usually use just that. We check size of the squares for patient visual acuity of that individual patient.
Check luminance and contrast, must be checked but you can’t do that easily
Rate of reversal. When you turn on the signal you should turn on the amplifyiers. They pulse it because every ti e you change pattern you start recording again.
Eeg signal, look at it to see noise. And also do impedence check.
-
Keep talking to patients to keep them alert, as drowsiness can influence the eeg.
-
-
-
-
-
-
Second run might be slower, they will be getting drowsy, but also less artefacts
-
Combining signals weeds out artefacts, when you can do it. You are dubling the sweeps: increasing signal to noise ratio
P100 a dip around 100 milliseconds, shallowish curve might present difficulties in putting the p100 cursor in the exact middle
Depth is due to depolarisation at the same time. It is where optic radiation get processed by neurons in visual cortex, it takes 99 millisecond to travel all the way to visual cortex