FujiFilm VisualSonics Vevo MD, User Manual

Page: 420 / 463

Terminology in acoustic output tables
A
aprt
Area of the active aperture measured in cm
2
.
d
eq
(z)
Equivalent beam diameter as a function of axial distance
z, and is equal to , where I
TA
(z) is the temporal-average intensity as a function of z in
centimeters.
d
eq
@PII
max
Equivalent beam diameter at the point where the free-field,
spatial-peak pulse intensity integral is a maximum in
centimeters.
Dim. of A
aprt
Active aperture dimensions for the azimuthal (x) and
elevational (y) planes in centimeters.
fc Center frequency in MHz.
FL
Focal length, or azimuthal (x) and elevational (y) lengths, if
different measured in centimeters.
I
pa.3
@MImax
Derated pulse average intensity at the maximum MI in
units of W/cm
2
.
I
SPTA.3
Derated spatial peak, temporal average intensity in units
of milliwatts/cm
2
.
I
SPTA.3
(z1)
Derated spatial-peak temporal-average intensity at axial
distance z
1
(milliwatts per square centimeter).
MI Mechanical index.
PD
Pulse duration (microseconds) associated with the
transmit pattern giving rise to the reported value of MI.
420 Glossary