GE T8, Basic Service Manual

Page: 186 / 349

General Procedures and Functional Checks
4-28 Vivid T9/Vivid T8 – Basic Service Manual
5795591-100 English Rev. 3
4-3-21 Adjust the PW/CW Doppler Mode controls
Adjust the Active mode gain to set the gain in the spectral
Doppler area.
• Adjust Low velocity reject to reduce unwanted low velocity
blood flow and tissue movement.
In PW mode, adjust Sample volume to low setting for better
resolution, or higher setting to more easily locate the
disturbed flows.
Adjust the
Compress setting to balance the effect of
stronger and weaker echoes and obtain the desired intensity
display.
Adjust
Frequency to optimize flow display. Higher setting
will improve resolution and the lower setting will increase the
depth penetration.
Adjust
Frame rate to a higher setting to improve motion
detection, or to a lower setting to improve resolution.
NOTE: Frequency and Frame rate settings may affect the Low
Velocity Reject.
Adjust Power to obtain an acceptable image using the
lowest setting possible. This is particularly important in CW
mode, as the energy duty cycle is 100% (constant).
NOTE: The Doppler Power setting affects only Doppler operating
modes.
Adjust the following settings to further optimize the display
of the image.
Use the
Horizontal sweep to optimize the sweep speed.
To view signal detail, adjust Scale to enlarge the vertical
spectral Doppler trace.
Use
Invert to reverse the vertical component of the spectral
Doppler area of the display.
Use
Angle correction to steer the ultrasound beam to the
blood flow to be measured.