Acoustic Output 15-3
15.4.2 MI/TI Display
TI and MI values are displayed in the upper part of the screen in real-time. The operator should
monitor these index values during examinations and ensure that exposure time and output values
are maintained at the minimum amounts needed for effective diagnosis.
If there is a value of MI or TI exceeds 1.0, you must be careful to practice the ALARA
principle.
The display precision is 0.1.
Real-time Display accuracy: M ≤28.5%, TI≤38.7%
15.5 Acoustic Power Setting
Acoustic power adjustment
Rotate the [A.power] knob to adjust the acoustic power percentage, and its value is displayed
on the corresponding item, as well as at the top of the screen. The greater the acoustic power
percentage, the greater the current acoustic output. When the image is frozen, the system
stops transmitting acoustic power.
Default setting of acoustic power
Selection of diagnostic applications is the most important factor for controlling ultrasound
output. The permissible level of intensity of ultrasound differs depending on the region of
interest. For fetal examinations, in particular, much care must be exercised.
In this system, imaging setups can be created using the ultrasound output set by you. Once
you perform preset settings, default setting values of the system may be changed and
invalid. It is the user’s responsibility for any change to the default settings.
Adjusting range
Initial power: 3.2% to 100%*
Definition of 100%: The maximum acoustic power of a probe determined by the increase in
probe surface temperature in the selected mode and the acoustic power restrictions specified
by the FDA.
Default settings of acoustic power value refer to the best image quality of the probe. The larger
the acoustic power value, the better the image quality.
This system automatically returns to the settings whenever changes are made to the
values (when you turn on the power, switch between probes, press <End Exam>, or
select OK or Cancel in the Setup menu). In the factory default settings, the Acoustic
Output is limited below 100%. Following the ALARA restriction, you are allowed to
increase the acoustic power under FDA 510(k) Guidance-Track3 limits and to set it in
the image preset screen.
The acoustic output of the system has been measured and calculated in accordance with
IEC60601-2-37: 2007, FDA 510(K) GUIDANCE, Acoustic Output Measurement Standard for
Diagnostic Ultrasound Equipment (NEMA UD-2 2004) and the Standard for Real-Time Display
of Thermal and Mechanical Acoustic Output Indices on Diagnostic Ultrasound Equipment
(AIUM and NEMA UD-3 2004).
15.6 Acoustic Power Control
The qualified operator may use the system controls to limit the ultrasound output and to adjust the
quality of the images. There are three categories of system controls relative to output. They are,
Controls that have direct effect on the output
To Next Page
Loading...
