Definitions - Siemens Acuson S1000 Instructions For Use Manual

A p p e n d i x F A c o u s t i c O u t p u t R e f e r e n c e

Definitions

Symbol
FDA IEC
MI MI
TIS TIS Scan
scan
TIS TIS Non-scan
non-scan
TIB TIB
TIC TIC
A
A
aprt aprt
P p
r.3 ra
W
P
o
W (z ) P (z )
.3 1 α s
I (z ) I (z )
TA.3 1 ta, α s
z z
1 s
z z
bp bp
z z
sp b
z@PII z at max. I
.3max pi,α
d (z) d (z)
eq eq
f f
c awf
Dim. of A Dim. of A
aprt aprt
PD t
d
PRF prr
p @PII p at max. I
r max r pi
d @PII d at max. I
eq max eq pi
FL FL
I @MI at max. MI
I
PA.3 max pa,α
Note: Pulse-average intensity (I
duration (t ).
d
F - 8
FDA
Mechanical Index
Soft Tissue Thermal Index in autoscanning mode
Soft Tissue Thermal Index in non-autoscanning mode
Bone Thermal Index
Cranial Thermal Index
Area of the active aperture
Derated peak rarefactional pressure
Ultrasonic power, except for TIS
scan
ultrasonic power passing through a one centimeter
window
Derated ultrasonic power at axial distance z
Derated spatial-peak, temporal-average intensity at axial
distance z
1
Axial distance corresponding to the location of the
2
max [min (W (z), I (z) x 1 cm )], where z > z
.3 TA.3
1/2
1.69 (A )
aprt
Axial distance at which TIB is a maximum (i.e., z
The axial distance corresponding to the maximum of the
derated spatial-peak pulse intensity integral
(megapascals).
Equivalent beam diameter as a function of axial distance


  W
4
 
  o

z, and is equal to
I (z)
 π 



TA
the temporal-average intensity as a function of z
Center frequency
Active aperture dimensions for the azimuth and
elevational planes
Pulse duration
Pulse repetition frequency
Peak rarefactional pressure at the point where the free-
field, spatial-peak pulse intensity integral is a maximum
Equivalent beam diameter at the point where the
free-field, spatial-peak pulse intensity integral is a
maximum
Focal Length, or azimuthal and elevational lengths, if
different
Derated pulse-average intensity at the point of global
maximum reported MI
) is the ratio of the pulse-intensity integral (I
pa
Definition
Same as FDA
Same as FDA
Same as FDA
Same as FDA
Same as FDA
-12dB output beam area
Attenuated peak-rarefactional
acoustic pressure
in which case it is the Output power
Attenuated output power at z
1
Attenuated temporal-average
intensity at z
Depth for TIS
bp
Break-point depth
= z ) Depth for TIB
sp B.3
Depth at the point where the
free-field, attenuated pulse intensity
integral is a maximum
Equivalent beam diameter at axial
distance z
0.5


 

where I (z) is
TA



Acoustic working frequency
Same as FDA
Same as FDA
Pulse repetition rate
Same as FDA
Same as FDA
Same as FDA
Same as FDA
) to the pulse
pi
Units
IEC
n/a
n/a
n/a
n/a
n/a
2
cm
MPa
mW
mW
s
mW/cm
s
2
cm
cm
cm
cm
cm
MHz
cm
μs
Hz
MPa
cm
cm
2
W/cm
I n s t r u c t i o n s f o r U s e
2