Mindray DP-18 - Parameters Affecting Acoustic Power

Acoustic Power Principle
14-3
14.6 Parameters Affecting Acoustic Power
Acoustic Power is affected by transmission conditions (focus, drive frequency, voltage applied
to piezoelectric elements, etc.), scan conditions, settings, etc.
14.7 Imaging Functions Changing Acoustic Output
Power
Changes of imaging mode and adjustments to controls also affect the acoustic output power.
Specific information is provided in the following table.
Operation Effect on the acoustic output power
Transducer
change
The acoustic output power will change as the operator changes the
active transducer.
Imaging Mode
change
Since B and M modes use difference default imaging parameters,
changing the mode will change the acoustic output power of the
system. No changes occur when switching from B to B/B, since the
basic imaging parameters remain the same. In most cases, the
acoustic output power for M-mode is larger than in B-mode.
Field of view
(sector Angle or
scan Width)
Change the sector angle or scan width may result in change to the
frame rate, and thus change the acoustic output power.
Image depth
change
Changing the image depth changes the PRF, and thus changes the
acoustic output power.
Number of
focuses
Since the number of focuses influences the frame rate and the actual
position of the focuses, changing the number of focuses changes the
acoustic output power.
Focus location The transmit focus location change will cause the acoustic output
power change, even though the transmitting electrical energy level and
the aperture remains the same. In most cases, the acoustic output
power will increase if the focus is moved closer to the transducer.
Freeze Active the freeze function stops the electrical energy transmit part of
the system, thus disabling the system from generating ultrasound
wave.
Transmit power The transmit power level change will change the electrical output of the
system to the transducer, and thus change the acoustic output power.
Frequency
change
Changing the operating frequency changes the focal characteristics of
the acoustic waves, thus changes the acoustic output power.
Line density Changing the number of acoustic lines generated (line density) affects
the acoustic output power.
Preset Since the system and user presets contain all of the above imaging
parameters, changing the preset will change the acoustic output power.