RPSGT Exam Instrumentation/
Waveforms
According to the principles of differential amplification, electrical interference can best
be prevented if - ans The impedances of input elecrodes are similar
During a recording, the technologist notices that the HFF on an EOG channel is set at
15Hz. Which of the following is correct? - ans Rapid eye movement signals will be
attenuated
G1 receives an input voltage of -100uv while G2 simultaneously receives -50uv. The
polysomnograph sensitivity is set at 10uv/mm. What will be the pen deflection? - ans 5
mm upward
Sensitivity can be explained in which of the following equations? - ans Sensitivity =
voltage/pen deflection
Which of the following is a function of a differential amplifier? - ans To record the
differences in the voltages of two inputs
Which of the following low/high filter settings are most appropriate for these channels? -
ans 0.3/35
0.1/35
1.0/35
10/70
Changing the sensitivity of an amplifier from 5uv/mm to 10uv/mm will - ans Reduce the
pen deflection by one half
What is an example of a transducer signal? - ans flow channels and respiratory effort
channels
G1 = -25uv. G2 = -25uv. What is the output voltage? - ans 0uv
The technician notices equal time constant settings for the chin EMG and the EEG
channels during the initial calibrations. What sort of effects might one see in the EMG
channel? - ans Respiratory artifacts in the EMG
G1 = -80uv. The output voltage is 20uv. What is the voltage at G2? - ans -100uv
