Instrumentation I Flashcards
What is the typical voltage of the pulser?
110 V
Function of the master synchronizer
organizes each component’s functions so they operate correctly
The master synchronizer is also called?
coordinator
Function of the pulser
controls electrical signals sent into transdcuer
The pulser determines?
PRF, amplitude, and PRP
What is the typical PRF of the pulser?
1-10 kHz
Can the pulser be controlled by the sonographer? How?
Yes; adjusting transmit power and depth
The pulser is also called what in phased array systems?
the beam former
Function of the receiver
increases strength of returned signals and processes them for display
What is the order of the receiver functions?
Amplification, Compensation, Compresssion, Demodulation, Rejection
Purpose of amplification
increases strength of received electrical signals
Is amplification adjustable by the sonographer? How?
Yes; b-mode (receiver gain)
How does amplification affect the image?
entire image brightened or darkened
What is the typical range of amplification by the receiver?
50-100 dB
When frequency is increased, amplification must be?
increase
True or False: Amplification does not affected transmitted intensity
True
formula for gain
amplitude in/amplitude out
Function of compensation
creates uniform brightness
Compensation is also called?
time gain compensation (TGC), Depth gain compensation (DGC), swept gain compensation
With higher frequency, is more or less TGC required?
more; more attenuation
Function of compression
reduces amplitude difference between strong and weak signals; allows grey shades to be seen
Can compression be adjusted by the sonographer? How?
No
Compression is also called?
dynamic range log compression
Function of demodulation
rectification and smoothing
Can demodulation be adjusted by the sonographer? How?
No
What are the two steps of demodulation?
rectification and smoothing
Purpose of rectification
Converts analog to digital
