GE Vivid S70, User Manual

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Safety
2-4
Vivid S70 / S60
–
User Manual
BC092760-1EN 01
Acoustic output
Definition of the acoustic output parameters
Thermal Index
TI is an estimate of the temperature increase of soft tissue or
bone. There are three thermal index categories:
• TIS: Soft tissue thermal index. The main TI category. Used
for applications that do not image bone.
• TIB: Bone thermal index (bone located in a focal region).
Used for fetal application.
• TIC: Cranial bone thermal index (bone located close to the
surface). Used for transcranial application.
The Vivid S70 / S60 has an internal limit of 3.0 on TI for the
chosen index category.
Mechanical Index
MI is the estimated likelihood of tissue damage due to cavitation.
The absolute maximum regulatory limit of the MI is 1.9 as set by
the FDA 510(k) guidance of September 9, 2008.
The maximum MI values obtainable with Vivid S70 / S60 in
relevant operating modes, and with available ultrasound probes,
are found in the Reference manual.
Ispta
The Ispta is the Spatial Peak Temporal Average Intensity. The
absolute maximum regulatory limit of Ispta is 720 mW/cm
2
as
set by the FDA 510(k) guidance of September 9, 2008.