I-H. Obtaining acceptable impedances Flashcards
Balanced impedances allow you to:
A) Eliminate artifact rejection
B) Optimize horizontal resolution
C) Minimize common mode rejection
D) Maximize common mode rejection
Maximize common mode rejection
Extremely low voltage due to phase cancellation may be caused by
A) Pulse artifact
B) Sweat artifact
C) 60 Hz artifact
D) Salt bridge
Salt bridge
Impedance can best be described as the
A) resistance to alternating current
B) resistance to direct current
C) ability to store an electrical charge
D) current produced by a wire coil in a magnetic field
resistance to alternating current
Short interelectrode distance between electrodes will cause which of the following changes to the EEG waveform?
A) Decrease amplitude
B) Increase frequency
C) Increase amplitude
D) Decrease frequency
Decrease amplitude
Balanced electrode impedances are important to:
A) ABRET Guidelines
B) make filters more effective
C) increase patient safety
D) lessen 60 Hz interference
lessen 60 Hz interference
EEG is most useful in
A) encephalopathy
B) acoustic neuroma
C) migraine
D) cardiac arrhythmia
encephalopathy.
Impedance is the resistance of a part of the circuit to the passage of
A) leakage current
B) direct or alternating current
C) alternating current
D) direct current
alternating current.
Which of the following occurs with unbalanced electrode impedances of greater than 20 KOhms?
A) Marked decrease in 60 Hz activity
B) Marked decrease in EEG amplitude
C) Marked increase in EEG amplitude
D) Marked increase in 60 Hz activity
Marked increase in 60 Hz activity
Which of the following measures the opposition to current flow when a known voltage is applied?
A) Impedance Meter
B) Differential Amplifier
C) Fast Fourier Transform
D) A/D Converter
Impedance Meter
A single attenuated channel of EEG may be the result of
A) Inter-electrode spacing too close
B) 60 cycle interference
C) Inter-electrode spacing too distant
D) Low input impedance
Inter-electrode spacing too close
