Chapter 12 - System Safety and Maintenance
Acoustic Output Indices
Terason t3000 / Echo Ultrasound System User Guide
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For these transducers, operation in the intended clinical applications is without significant
tissue-heating risk from ultrasound energy. No real-time monitoring of TI values is
required, and the transducer can be used without concern for minimizing any displayed TI
value.
Some other transducers used with the Terason Ultrasound System may produce the
following thermal index display:
Since the label for TIS and TIC is still shown in standard video format and no value is
displayed, no real-time monitoring of TIS or TIC values is required. The TIB index
display, however, indicates that the controls for the transducer in use can be set so that the
Bone Thermal Index exceeds 1.0. (In the example shown, the current real-time TIB value
is approximately 0.8).
Another group of transducers used the Terason Ultrasound System might produce the
following thermal index display:
The display of the Thermal Index labels indicates that the controls for the transducer in use
may sometimes be set so that either the TIS, the TIB, the TIC, or any combination may
exceed 1.0.cp
Control of Acoustic Index Parameters
For any transducer used with the Terason Ultrasound System in which all relevant acoustic
indices are displayed in standard video (without an associated real-time value), operation
in the intended clinical applications of the active transducer is considered normally
without significant risk due to mechanical effects or heating of tissues by ultrasound
energy. No real-time MI or TI values need be monitored, and the transducer may be used
without concern for minimizing the displayed value of any index.
Note:
In M-mode, some transducers also show the mechanical index. If the transducer in
use is one of those, MI is displayed. Otherwise, MI does not display.
TIB: 0.8
TIS:
TIC:
TIB: 0.8
TIS: 0.6
TIC: 0.4
