SAEVO EVUS 8, Руководство пользователя

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6 Acquiring Images
Basic User Manual 63
To adjust the wall filter:
1. Select
WF
by pressing the corresponding function key.
2. Rotate it to adjust the value.
■ Pulse Repetition Frequency
Pulse repetition frequency is used to adjust the velocity scale.
To adjust the pulse repetition frequency:
●
Flip the PRF switch upwards to increase the value.
●
Flip the PRF switch downwards to decrease the value.
■ Line Density
Line density refers to the amount of ultrasound beam that makes up the image. Increasing the value of line density
improves the resolution and decreases frame rate. Therefore, you have to balance the frame rate and the image
quality when adjusting the line density.
A lower line density is useful in fetal heart beat, adult cardiac applications and in clinical radiology applications. A
higher line density is useful in obtaining a very high resolution, such as for the thyroid or testicles.
To adjust the line density:
1. Select
Line Density by pressing the corresponding function key.
2. Rotate it to adjust the value.
■ Baseline
Baseline represents the position of zero velocity or frequency. The velocity range in one direction can be increased
or decreased by adjusting the baseline.
Baseline is used to eliminate the alias in the color flow imaging, and display higher velocities without reversal of
colors.
To adjust the baseline:
1. Select the
Menu
key in the real time scan. A menu pops up on the screen.
2. Select
Baseline
by using the trackball or the ↑ or ↓ key.
3. Rotate the Menu key or select the ← or → key to move the baseline towards the positive or negative direction.
You can also flip the BASELINE switch on the control panel upward or downward to adjust the baseline position.
■ Color Map
Color map is used to select the method for the color-coding of blood flows.
To change the color map:
1. Select
C Map/DPDI by pressing the corresponding function key.
2. Rotate it to adjust the setting.
NOTE:
When C Map/DPDI
is set to
4
or above in the PDI mode, the system automatically enters the DPDI mode with
a
DPDI
icon. At this time, you can view the flow direction and velocity.
■ Persistence
Persistence is used to average consecutive frames to provide a smoother appearance with less noise. Use lower
persistence values for fast-moving organs or tissues and higher persistence values for smoother appearance.