5-24 Image Optimization 
5.7.3  PW/CW Doppler Mode Optimization 
Gain 
Description
This function is intended to adjust the gain of spectrum map. The real-time 
gain value is displayed in the image parameter area in the upper left corner 
of the screen. 
Operation  Rotate the <iTouch> knob clockwise to increase the gain, and 
anticlockwise to decrease. 
Or adjust it in the image parameter area. 
The adjusting range is 0-100. 
Effects  Increasing the gain will brighten the image and you can see more received 
signals. However, noise may also be increased. 
Frequency 
Description
Refers to the operating frequency in PW mode of the probe, the real-time 
value of which is displayed in the image parameter area in the upper left 
corner of the screen. 
Operation  Select the frequency value through the [Frequency] item in the soft menu 
or menu. 
Or adjust it in the image parameter area. 
Values of frequency vary depending upon the probe types. 
Select the frequency according to the detection depth and current tissue 
characteristics. 
Effects  The higher the frequency, the better the resolution and sensitivity, and the 
worse the force of penetration.   
Scale 
Description
This function is used to adjust the speed range of color flow, which is 
adjusted through PRF in the system. The real-time PRF value will be 
displayed in the image parameter area in the upper left corner of the 
screen. 
Operation  Adjust the speed range through the [Scale] item in the menu or the soft 
menu. 
The adjusting range varies by frequency, probe and depth; adjust 
according to the actual situation. 
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.