Instrumentation & Electrical Concepts

If _____ is relatively more negative than Input 2, the pen will go _____

Input 1, upward

If input 1 is relatively more positive than _____, the pen will go ______

Input 2, downward

If the differential amplifier is cancelling out EEG signal, it’s called cancellation. If it’s cancelling unwanted signals, it’s called common mode rejection

True

What can you do if you think your abnormality is end of chain?

Change it to circumferential montage

How do you localize a focus in bipolar montage?

Phase reversal

How do you localize a focus in a referential montage?

Amplitude differences

Cancellation

When the inputs are the same or close to the same resulting in the output being 0 or minimal

Summation

When one input is positive and one input is negative or when the inputs are very different

Electrical field

The area of the brain where electrical activity spreads out from the focal area to surrounding areas

Dipole

A pair of equal and oppositely charged poles separated by a distance

The human eye is an example of a dipole because the ____ is positive and the ______ is negative

Cornea, retinal

Solve the number sentence: FP1 (30uv) - F3 (50uv)

-20 uv

C3 (100uv) - P3 (-50uv)

150 uv

Attenuation

Reduction in the amplitude of a wave

Accentuation

Increase in the amplitude of a wave

Bandwidth

High and low range of frequencies affected by a specific filter

Frequency response curve

A graphic chart used to understand the behavior of an amplifier or a filter

Changing the _______ is best to use when blocking is occurring on an EEG, but isn’t always the best solution as it diminishes all EEG activity equally

Sensitivity

Filters affect the ______ of EEG waves, not the _____

Amplitude, frequency

The low frequency filter is used to attenuate or accentuate ______

Slow waves

The time constant is part of the low frequency filter and each low frequency filter setting has its own corresponding time constant

True

The high frequency filter is used to reduce or eliminate ________

Fast activity

This illustration shows a ________ focus at ______

Negative, C3

This illustration shows a _____ focus at ______

Positive, T3

Channel 1: Input 1 (Fp1) is more_______ than input 2 (F3) because the pen is going ______

Positive, downward

Channel 2: Input 1 (F3) is more _____ than input 2 (C3) because the pen is going _____

Negative, upward

Channel 3: Input 1 (C3) is more ______ than input 2 (P3) because the pen is going _____

Negative, upward

Channel 4: No deflection so this is ______

equipotential

Where is this focus in this illustration?

A negative focus at F3

What type of montage is pictured below?

Referential montage/ Ipsilateral