Shenzhen Mindray Bio-Medical Electronics Co., Ltd. DC-N2, Руководство оператора

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Image Optimization 5-19
Operations
Adjust through the <Steer> key on control panel or [Steer] item on image
menu.
Effects This feature is used to steer the direction of the beam so as to change the
angle between the beam and flow direction with immobility of the linear probe.
Values of steer angles vary by probe.
Impacts PW Steer is available only for linear probes.
Invert
Description This function is used to set the display manner of spectrum.
Operations Turn on or off the function through the [Invert] item on the image menu.
Select “Auto Invert” in the “[Setup]
→
[System Preset]
→
[Image]”, thus the
spectrum can automatically invert when the color flow is steered to a certain
angle to accommodate operator’s habit of distinguishing flow direction.
Scale
Description This function is used to adjust the speed range of flow, which is adjusted
through PRF in the system.
The real-time PRF value is displayed in the image parameter area in the
upper right corner of the screen.
Operations
Press the <Scale> key on the control panel (the <Scale> key backlight is on)
and rotate the Multifunctional Knob on the right to adjust.
Effects To provide a much clearer color flow image.
Use low PRF to observe low-velocity flows, and use high PRF to observe
high-velocity flows.
Impacts Aliasing may occur if low velocity scale is used and high velocities are
encountered.
Low velocities may not be identified when a high velocity scale is used.
Wall Filter
Description It filters out low-velocity signals to provide effective information, and this
function is used to adjust the filtered frequency. The real-time value is
displayed in the image parameter area in the upper right corner of the screen.
Operations
Select through the [WF] item on the image menu.
There are 6 levels of wall filter function provided.
Impacts Signals of low-velocity flow may be missing.
T/F Res
Description
This function is used to adjust for a balance between time resolution and
spatial resolution.
Operations Adjust through the [T/F Res] item on the image menu.
There are 4 levels of T/F Res values available.
Dynamic Range
Description The dynamic range conveys the information that being transformed from echo
intensity to gray scale.