Polysomnography Questions And
Answers
Which filter settings are most appropriate for the associated channel types?
A. EEG 0.1/15, EOG 0.1/15, ECG 0.3/15, EMG 1.0/100
B. EEG 0.3/35, EOG 0.1/35, ECG 0.1/35, EMG 10/70
C. EEG 1.0/70, EOG 1.0/70, ECG 0.3/15, EMG 1.0/35
D. EEG 1.0/70, EOG 1.0/70, ECG 1.0/70, EMG 5.0/35 - correct answers-B
An EEG LFF of 0.1 may increase the perception of stage N3 due to slow wave or sweat
artifact. The LFF of 1.0 for the EMG in C is too low and may allow slow waves to be
recorded, and the HFF of 35 in the EMG in D is too low, and may attenuate the EMG
amplitude.
The E2 electrode is placed out and up from the outer canthus of the right eye, and E1 is
placed out and down from the outer canthus of the left eye. If the E2 channel on the
PSG is channel 4, and E1 is channel 5, what will the waves on these channels do when
the patient looks up?
A. Move toward each other
B. Both move up
C. Both move down
D. Move away from each other - correct answers-A.
Eye movement toward an electrode results in a positive (downward) pen deflection,
because of the cornea of the eye is positive with respect to the retina.
What is the purpose of the LFF?
A. Eliminating undesired fast frequencies
B. Eliminating undesired slow frequencies
C. Adjusting signal amplitude
D. Calibrating DC amplifiers - correct answers-B
The LFF is designed to eliminate unwanted slow frequencies. DC amplifiers do not have
low frequency filters.
What should a technician do first to make sure the proper test is being performed?
A. Contact the physician
B. Review the chart for the physician's order
C. Ask the patient for a chief complaint
D. Perform physiological calibrations - correct answers-B
Medical testing and treatments always require a physician's order. The sleep tech
should review the patient chart before any type of testing is performed in the sleep lab.
The symbol "G1" respresents
A. The exploring electrode
B. The reference electrode
C. The patient ground
D. The output of a differential amplifier to the polysomnograph - correct answers-A
G1 is the exploring electrode, or the first signal input. G2 is the second input, or the
reference electrode.
, If G1 receives a signal of -100 uV at the same time G2 receives a signal of -50 uV, what
is the output signal?
A. -50 uV
B. +50 uV
C. -150 uV
D. +150 uV - correct answers-A
Output voltages are determined by subtracting G2 from G1: -100 - -50= -50
Which of the following is a process performed by a differential amplifier?
A. Recording the differences in the voltages of two inputs
B. Recording the differences in the voltages of the active input and ground
C. Recording the differences in the voltages received by its two inputs
D. Recording only identical voltages received by its two inputs - correct answers-A
Differential amplifiers measure the difference between two signals
If G1 and G2 simultaneously receive an input of 50 uV, what is the ouput signal?
A. 0
B. -100 uV
C. +100 uV
D. -50 uV - correct answers-A
Signal output is determined by subtracting G2 from G1
The frequency of an EEG signal
A. Can be determined by counting the number of waveforms recorded during one
second
B. Can be determined by counting the number of waveforms recorded during one epoch
C. Cannot be determined without using a water column manometer
D. Depends upon the paper speed - correct answers-A
Frequency is measured in cycles per second, or hertz (Hz). The easiest method of
determining the frequency is to count the number of cycles in one second.
How is the amplitude of a wave determined?
A. By reading the sensitivity setting on the PSG
B. By comparing the relative height of the sleep waveforms against the patient's awake
EEG
C. By comparing the height of the patient's EEG slow waves to the patient's alpha
waves
D. By comparing the height of the waveform against a calibration signal of known value
- correct answers-D
Calibrations are performed for a number of purposes, one of which is to produce a wave
to use as a measuring standard.
The purpose of a HFF is
A. To attenuate undesirable fast frequencies
B. To attenuate undesirable slow frequencies
C. To eliminate undesirable DC voltages from the signal output
D. B and C are both correct - correct answers-A
HFF are used to eliminate undesired fast frequencies
In polysomnography, what is the sensitivity setting?
A. The offset between the electrical and the mechanical baselines
B. The ratio of pen response to the settings of the low and high frequency filter settings
Answers
Which filter settings are most appropriate for the associated channel types?
A. EEG 0.1/15, EOG 0.1/15, ECG 0.3/15, EMG 1.0/100
B. EEG 0.3/35, EOG 0.1/35, ECG 0.1/35, EMG 10/70
C. EEG 1.0/70, EOG 1.0/70, ECG 0.3/15, EMG 1.0/35
D. EEG 1.0/70, EOG 1.0/70, ECG 1.0/70, EMG 5.0/35 - correct answers-B
An EEG LFF of 0.1 may increase the perception of stage N3 due to slow wave or sweat
artifact. The LFF of 1.0 for the EMG in C is too low and may allow slow waves to be
recorded, and the HFF of 35 in the EMG in D is too low, and may attenuate the EMG
amplitude.
The E2 electrode is placed out and up from the outer canthus of the right eye, and E1 is
placed out and down from the outer canthus of the left eye. If the E2 channel on the
PSG is channel 4, and E1 is channel 5, what will the waves on these channels do when
the patient looks up?
A. Move toward each other
B. Both move up
C. Both move down
D. Move away from each other - correct answers-A.
Eye movement toward an electrode results in a positive (downward) pen deflection,
because of the cornea of the eye is positive with respect to the retina.
What is the purpose of the LFF?
A. Eliminating undesired fast frequencies
B. Eliminating undesired slow frequencies
C. Adjusting signal amplitude
D. Calibrating DC amplifiers - correct answers-B
The LFF is designed to eliminate unwanted slow frequencies. DC amplifiers do not have
low frequency filters.
What should a technician do first to make sure the proper test is being performed?
A. Contact the physician
B. Review the chart for the physician's order
C. Ask the patient for a chief complaint
D. Perform physiological calibrations - correct answers-B
Medical testing and treatments always require a physician's order. The sleep tech
should review the patient chart before any type of testing is performed in the sleep lab.
The symbol "G1" respresents
A. The exploring electrode
B. The reference electrode
C. The patient ground
D. The output of a differential amplifier to the polysomnograph - correct answers-A
G1 is the exploring electrode, or the first signal input. G2 is the second input, or the
reference electrode.
, If G1 receives a signal of -100 uV at the same time G2 receives a signal of -50 uV, what
is the output signal?
A. -50 uV
B. +50 uV
C. -150 uV
D. +150 uV - correct answers-A
Output voltages are determined by subtracting G2 from G1: -100 - -50= -50
Which of the following is a process performed by a differential amplifier?
A. Recording the differences in the voltages of two inputs
B. Recording the differences in the voltages of the active input and ground
C. Recording the differences in the voltages received by its two inputs
D. Recording only identical voltages received by its two inputs - correct answers-A
Differential amplifiers measure the difference between two signals
If G1 and G2 simultaneously receive an input of 50 uV, what is the ouput signal?
A. 0
B. -100 uV
C. +100 uV
D. -50 uV - correct answers-A
Signal output is determined by subtracting G2 from G1
The frequency of an EEG signal
A. Can be determined by counting the number of waveforms recorded during one
second
B. Can be determined by counting the number of waveforms recorded during one epoch
C. Cannot be determined without using a water column manometer
D. Depends upon the paper speed - correct answers-A
Frequency is measured in cycles per second, or hertz (Hz). The easiest method of
determining the frequency is to count the number of cycles in one second.
How is the amplitude of a wave determined?
A. By reading the sensitivity setting on the PSG
B. By comparing the relative height of the sleep waveforms against the patient's awake
EEG
C. By comparing the height of the patient's EEG slow waves to the patient's alpha
waves
D. By comparing the height of the waveform against a calibration signal of known value
- correct answers-D
Calibrations are performed for a number of purposes, one of which is to produce a wave
to use as a measuring standard.
The purpose of a HFF is
A. To attenuate undesirable fast frequencies
B. To attenuate undesirable slow frequencies
C. To eliminate undesirable DC voltages from the signal output
D. B and C are both correct - correct answers-A
HFF are used to eliminate undesired fast frequencies
In polysomnography, what is the sensitivity setting?
A. The offset between the electrical and the mechanical baselines
B. The ratio of pen response to the settings of the low and high frequency filter settings
