Instrumentation and Electronics Flashcards
What is impedance?
The measure of the opposition to electrical flow or alternating current expressed by the letter Z.
What is resistance?
Resistance is the measurement of opposition WITHIN the circuit.
What is Ohm’s law?
Current equals voltage divided by resistance (I=V/R)
What is a differential amplifier?
A system that differentiates between two signals on the basis of potential current/voltage and amplifies the signal.
What is gain?
Gain is the ratio output signal voltage to input signal voltage which
is expressed in dB.
What is a common mode rejection ratio?
The degree to which an amplifier will reject a common mode signal (i.e. 60Hz interference).
What is Nyquist’s Principle?
Nyquist’s theorem states that a periodic signal must be
sampled at more than twice the highest frequency component of
the signal.
What is the minimum required sampling rate for an EEG?
200 samples per second.
What is alaising?
When an amplifier does not take enough samples giving the wrong information about a waveform.
What is a montage?
Montages are arrays or combinations of multiple derivations of electrode recording combinations.
Includes ACTIVE sites or recording sites and REFERENCE which should be electrically quiet.
What does LORETA stand for?
Low Resolution
Electromagnetic Tomography
What are artifacts in EEG?
Signals of non-cerebral origin.
