Doppler
LOGIQ 500 Basic Users Manual
2233658–100 Rev. 0
5–61
PW Doppler Mode Sub-Menu Page 3
40
Preset
PWD
CFM
Shrink
CFM/PWD
Ratio
Rejectn
HPRF
Set Up
ECG
1/2
Figure 5–25. PW Doppler Mode Sub-Menu Page 3
HPRF
Rejection (Rejectn)
Description
HPRF allows the operator to enable or
disable the High Pulse Repetition
Frequency function while in PWD Mode.
Refer to
5–45.
Rejection allows for the elimination of low
level echoes from the display. This is
generally used to clear noise out of
vessels or cysts. (Also found in the CWD
soft menu.)
Benefits
Allows for higher frequencies to be
detected with aliasing artifacts.
Allows for the elimination from the display
image of low level echoes caused by
noise.
Values
HPRF is highlighted when enabled (on).
HPRF is not highlighted when disabled
(off).
Off and 4 through 40 in increments of 4.
Post-processing function.
Affects on
Other Controls
Frame rate (image update) may decrease
when HPRF is active.
Rejection affects real-time imaging, frozen,
Cine, or VCR playback images.
CFM/PWD Ratio
CFM Shrink
Description
CFM/PWD Ratio is active in triplex mode.
It is used to set the velocity ratio between
PWD and CFM.
Reduces the CFM window to the size
specified in Set Up/Custom Display
page 4.
CFM Shrink can be turned on/off in
Setup/Custom Display page 4.
Benefits
Used to optimize frame rate in Triplex
mode. Without changing CFM or PDI
velocity scale, PWD velocity scale can be
changed to decrease aliasing.
Used to optimize frame rate in Triplex
mode.
Values
Choose from 1/1, 1/2 or 1/4.
1/1 CFM and PWD Velocity the same.
1/2 PWD Velocity twice the CFM
Velocity.
1/4 PWD Velocity four times the CFM
Velocity.
When On is selected, CFM Window size is
set by the value selected in Set Up/
Custom Display page 4.
When Off is selected, CFM window size is
adjusted by scan area function.
Affects on
Other Controls
Affects display frame rate.
Affects display frame rate.