GE Vivid 7 Service Manual page 309

GE H
EALTHCARE
D FC091194, R
IRECTION EVISION
4-3-8-5 Check Horizontal Sweep, PRF, Baseline, LVR and Invert
Table 4-14
Step
1.
2.
3.
4.
5.
11
Color Flow Mode Controls Check
Task
Adjust Horizontal Sweep (Color M-Mode only)
Adjust Baseline
Change PRF (Pulse Repetition Frequency)
Adjust LVR (Low Velocity Rejection
Invert
Chapter 4 - Functional Checks
V
Expected Result(s)
Adjusts the horizontal refresh rate of the M-Mode area
of the display.
Adjusts the color map to emphasize flow either toward
or away from the probe.
Baseline is available in both Live and Freeze.
Adjusts the repetition rate of the Doppler pulses
transmitted to acquire the data for color flow mapping.
The PRF (Nyquist limit) should be adjusted so that no
aliasing occur, while still having a good resolution of
velocities, meaning the Nyquist limit should be
somewhat above the maximum velocity found in the
data.
LVR, also called Wall Motion Filter, enables the extent
of low velocity removal to be adjusted.
Enables the color scheme assigned to positive and
negative velocities to be inverted.
Invert is available in live and Cine Replay.
7 S M
IVID ERVICE ANUAL
4 - 45