GE Vscan Extend, User Manual

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Safety
2-20
Vscan Extend
–
User Manual
5721203-100 Rev. D
Acoustic output and display on Vscan Extend
MI and TI values are displayed on the scanning screen.
The maximum possible MI and Ispta on the Vscan Extend is
within the limits set in Track 3 in the FDA guidance of
September 9, 2008 for diagnostic ultrasound systems and
transducers, MI <1.9 and Ispta <720 mW/cm
2
.
Display Accuracy and Acoustic Measurement Uncertainties
The display accuracy and measurement precision of the output
display are summarized in the table below. Accuracy of the
output display (TI, MI) parameters depends on the
measurement system precision, the acoustic model used to
calculate the parameters and variation in the acoustic output of
probes and systems. The measurement precision and overall
accuracy of the measurements have been assessed by
determining both the random and the systematic uncertainties
and given in percent at 95% confidence level.
a. Accuracy = (Measured value - displayed value)/displayed
value * 100%
Table 2-5: Display accuracy
Parameter Estimated accuracy
a
Measurement precision
black and white/color
Pressure, MI ±25% ±15%
Power, TI ±50% ±40%