GE Voluson 730 - Safety Precaution Messages

Safety
2.13.8 Notes for Acoustic Output Tables for Track 3
Operating Conditions: means the adjustment of the scan parameters on the ultrasound console
MI: is the Mechanical Index in an auto-scanning mode.
TIS
scan
:
is the Soft Tissue Thermal Index in an auto-scanning mode.
TIS
non-scan
:
is the Soft Tissue Thermal Index in a non-auto scanning mode.
TIB: is the Bone Thermal Index.
TIC: is the Cranial Thermal Index.
A
aprt
:
is the area of the active aperture (square centimeters).
p
r.3
:
is the derated Peak Rare factional Pressure (megapascals).
W
0
: is the ultrasonic power, except for TIS
scan
, in which case it is the ultrasonic power
passing through a one-centimeter window (mill watts).
W
.3
(z
1
): is the derated ultrasonic power at axial distance z
1
.
I
SPTA.3
(z
1
): is the derated spatial-peak, temporal-average intensity at axial distance z
1
(mill watts
per square centimeters).
z
1
: is the axial distance corresponding to the location of max[min(W
.3
(z).I
TA.3
(z) * 1
cm
2
)], where z³z
bp
(millimeters).
z
bp
:
is 1.69(A
aprt
)
1/2
.
For MI, z
sp
: is the axial distance at which p
r.3
is measured; for TIB, z
sp
is the axial distance at
which TIB is a maximum (i.e. z
sp
= z
b.3
) (millimeters).
d
eq
(z):
is the equivalent beam diameter as a function of axial distance z, and is equal to
[(4/p)(W
0
/I
TA
(z))]
1/2
, where I
TA
(z) is the temporal-average intensity as a function
of z (millimeters).
f
c
:
is the center frequency (megahertz).
EBD:
1 - 12
are the entrance beam dimensions for the azimuthal and elevational planes
(millimeters).
PD: is the pulse duration (microseconds).
PRF: is the pulse repetition frequency (kilohertz).
Voluson
®
730 - Instruction Manual
105838 Rev. 3 2-17