Pw And Cw Doppler Controls - GE Vivid S5 User Manual

PW and CW Doppler controls

PW and CW Doppler assignable controls
Horizontal sweep
Adjusts the horizontal refresh rate of the Doppler area of the
display. Horizontal sweep is available in live and cine replay.
Baseline
Enables the Doppler baseline to be shifted up and down. The
default Doppler baseline is set at the center of the vertical
aspect of the Doppler display, dividing evenly the flow toward
and away from the probe. By adjusting the baseline a larger
portion of the analysis is assigned to the flow direction present.
Baseline is available in live and cine replay.
Scale
Maximum velocity
depends on sample
Enables the vertical scale of the Doppler spectrum and the
volume size, sample
maximal detectable velocity to be modified. Velocity range
volume position
directly controls the pulse repetition frequency, which is
and frequency set-
responsible for the setting of the Nyquist limit (the ability to
tings.
detect maximum velocity without aliasing).
Low velocity reject
Enables the low velocity portions of the spectrum to be filtered,
since the Doppler spectrum and audio may contain strong
wall-motion signals. The amount of Low Velocity Reject. is
indicated by the green vertical bar at the right end of the
baseline.
Audio Vol.
Occasionally, high
audio volume may
Enables the loudspeaker volume control.
cause interruptions
or horizontal tonal
noise in CW dis-
play, in such a case
lower the audio
gain.
Invert
If the Doppler mode
is combined with
Enables the Doppler spectrum to be flipped 180 degrees, so
Color mode, the col-
that negative velocities are displayed above the baseline and
or map will be also
positive velocities below the baseline. Invert in PW is available
inverted.
in live and cine replay; invert in CW is available only in live
mode.
Vivid S5/Vivid S6 User Manual
R2424458-100 Rev. 2
Scanning Modes
165