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Doppler
LOGIQ 500 Basic Users Manual
2276612–100 Rev. 0
5–50
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Doppler
Introduction
Time zero (the start of the trace) appears on the left side of the
graph. As time progresses, the trace moves to the right. The
baseline of the graph (representing zero velocity, zero
frequency shift or no detected flow) appears as a solid line
running horizontally across the display. By convention,
movement toward the probe is positive frequencies or velocities
which appear above the baseline. Movement away from the
probe is negative frequencies or velocities which appear below
the baseline.
Typically, blood flow is not uniform but is composed of a mix of
blood cells moving at different velocities and in different
directions. Thus, the display is composed of a spectrum of gray
scale values. Strong signals are displayed as bright shades of
gray while weak signals are displayed as darker shades.
Information about the Doppler display is automatically written
on the screen and updated when scanning parameters are
changed.
The following can be used:
Pulsed Wave (PW) Doppler
Continuous Wave (CW) Doppler
CW Non-Imaging Doppler