Essential Performance; Acoustic Output - GE Vscan Air Manual

Essential Performance

Acoustic output

Definition of the acoustic output parameters
Thermal Index
Mechanical Index
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Vscan Air User Manual
Direction GP092020-1EN Rev 18
The essential performance of the Vscan Air CL is:
• The ability to display physiological images as input for
diagnosis by qualified and trained healthcare professionals.
• The ability to display quantified data as input for diagnosis
by qualified and trained healthcare professionals.
• The display of ultrasound indices as aid for safe use of the
Vscan Air CL.
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.
Reference to calculation of TI can be found in:
• EN/IEC 60601-2-37. Medical electrical equipment.
Part 2-37: Requirements for the safety of ultrasonic medical
diagnostic and monitoring equipment
• EN/IEC62359: Test methods for the determination of
thermal and mechanical indices related to medical
diagnostic ultrasound fields.
MI is the estimated likelihood of tissue damage due to cavitation.
The absolute maximum limit of the MI is 1.9 as set by the FDA
guidance of June 27, 2019 for diagnostic ultrasound systems
and transducers.
Important safety considerations
2-17