GE LOGIQ 7, Basic User Manual

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Safety
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26 LOGIQ 7 Basic User Manual
Direction 2392206-100 Rev. 1
Acoustic Output
Located on the upper right section of the system display monitor,
the acoustic output display provides the operator with real-time
indication of acoustic levels being generated by the system. See
the
Acoustic Output chapter in the Advanced Reference Manual
for more information. This display is based on NEMA/AIUM
Standards for Real-time Display of Thermal and Mechanic
Acoustic Output Indices on Diagnostic Ultrasound Equipment.
Acoustic Output Display Specifications
The display consists of three parts: Thermal Index (TI),
Mechanical Index (MI), and a relative Acoustic Output (AO)
value. Although not part of the NEMA/AIUM standard, the AO
value informs the user of where the system is operating within
the range of available output. Depending on the examination
and type of tissue involved, the TI parameter will be one of three
types:
• Soft Tissue Thermal Index (TIS) . Used when imaging soft
tissue only, it provides an estimate of potential temperature
increase in soft tissue.
• Bone Thermal Index (TIB) . Used when bone is near the
focus of the image as in the third trimester OB examination,
it provides an estimate of potential temperature increase in
the bone or adjacent soft tissue.
• Cranial Bone Thermal Index (TIC) . Used when bone is
near the skin surface as in transcranial examination, it
provides an estimate of potential temperature increase in
the bone or adjacent soft tissue.
The TI and MI is displayed at all times. The MI display starts at a
value of 0.0 and increments in steps of 0.1 while the TI display
starts at a value of 0.4 and increments in steps of 0.1 (values
less than 0.4 are displayed as < 0.4). Display precision is
±
0.1,
and accuracy is
±
50%.