Olympus BF-UC180F - Acoustic Output Table with Hitachi Diagnostic Ultrasound System; Symbol Key

Appendix C: Acoustic Output Information in Accordance with the FDA Guidance: “Information for Manufacturers
157
ULTRASONIC BRONCHOFIBERVIDEOSCOPE BF-UC180F
Acoustic output table with Hitachi diagnostic
ultrasound system
 Symbol key
MI Mechanical index.
TISscan Soft tissue thermal index in an autoscanning mode.
TISnon-scan Soft tissue thermal index in a non-autoscanning mode.
TIB Bone thermal index.
TIC Cranial thermal index.
A
aprt
Area of the active aperture (cm
2
).
p
r0.3
Derated peak rarefactional pressure (megapascals).
W
0
Ultrasonic power except for TISscan, in that case it is the ultrasonic
power passing through a one centimeter window (mW).
W
0.3
Derated ultrasonic power at axial distance z
1
.
I
ta0.3 (z1)
Derated spatial peak, temporal average intensity at axial distance z
1
.
z
1
Axial distance corresponding to the location of max [min (W
0.3
(z
1
),
I
ta0.3
(z
1
) × 1 cm
2
)] where z >= Z
bp
. (centimeters).
z
dp
1.69 (A
arpt
). For MI, z
sp
is the axtial distance at that p
r0.3
is measured;
for TIB, z
sp
is the axial distance at that TIB is maximum (z
sp
= z
p0.3
)
(centimeters)
d
ep
(z) Equivalent beam diameter as a function of axial distance z, and equal
to [(4/) (W
0
/I
ta
(z))], where I
ta
(z) is the temporal-average intensity as
a function of z.
fc The center frequency of the ultrasonic pulse.
Dim.of.A
aprt
Active aperture dimensions for azimuthal and elevational planes
(centimeters).
PD Pulse duration.
PRF Pulse repetition frequency.
p
r
at PII
max
Peak rarefactional pressure at the point where the free-field,
spatial-peak pulse intensity integral is a maximum (megapascals).
FL Focal length, or azimuthal and elevational length.
d
eq
at PII
max
Equivalent beam diameter at the point where the free-field,
spatial-peak pulse integral is maximum.