Siemens Acuson S2000, Instructions For Use Manual

Page: 46 / 518

2 Safety and Care
2 - 16 Instructions for Use
Mechanical and Thermal Indices
The ultrasound system displays the Mechanical and Thermal Indices during real-time imaging,
in all imaging modes, when the Mechanical Index or the Thermal Indices are equal to or exceed
a value of 0.4.
Note: During exams using contrast agent imaging, the system always displays values for the
Mechanical Index (MI) and the Maximum of Mechanical Indices measured at the active focal zones
(MIF).
Indices display in the abbreviated form shown below:

MI: Mechanical Index

MIF: Maximum of the Mechanical Indices measured at the active focal zones (displayed
during contrast agent imaging exams only)

TIB: Bone Thermal Index (fetal application)

TIS: Soft Tissue Thermal Index

TIC:
Cranial Thermal Index
Transmit Power Control
Adjust the transmit power and the corresponding acoustic pressure delivered through the
transducer to the patient by using the designated control on the ultrasound system. It is the
main system function that determines the transmitted intensity of ultrasound for all transducers
and imaging modes during real-time imaging, though it is not the only function that affects the
mechanical and thermal indices. The range and especially the maximum level of the
mechanical and thermal indices differ depending on the transducers. In addition, each
diagnostic exam type has preset values for mechanical and thermal indices.
Note: Maximum transmit acoustic intensity and the mechanical index for each exam type is limited in
accordance with the United States Food and Drug Administration's (FDA) recommendations and
guidelines. System default transmit intensity and mechanical index values are always below the FDA
recommendations for each exam type. Although some exam types may default to a condition of
maximum allowable transmit power, there are other system controls or functions that could raise
acoustic output levels.
To increase the transmit power during real-time imaging:
● Rotate the [ Transmit Power ] control located below the touch screen clockwise to increase
transmit power.
○ For systems without a touch screen, press the TX POWER control on the control panel
upward to increase transmit power.
To decrease the transmit power during real-time imaging:
● Rotate the [ Transmit Power ] control located below the touch screen counterclockwise to
decrease transmit power.
○ For systems without a touch screen, press the TX POWER control on the control panel
downward to decrease transmit power.