Esaote MyLab, Руководство оператора

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M y L a b – S A F E T Y A N D S T A N D A R D
2-14
Indices Equations
Parameter Equation
Soft Tissue at Surface
TIS(scanned
8
)
TIB (scanned
6
)
c
f
W
210
01
Large Aperture (A
aprt
> 1 cm
2
)
TIS (unscanned
9
)
 
 
c
TA
zbp z
f
cm x z I z W
210
1 ) ( ); ( min max
2
3 . 3 .

Small Aperture (A
aprt
 1 cm
2
)
TIS (unscanned
7
)
c
f
W
210
0
Bone at Focus TIB (unscanned
7
)








4 . 4
) (
;
50
) ( ) (
min
3 . 3 .
3 . 3 . 3 . 3 .
B
B TA B
z w
z I z W
where z
B.3
is the depth that maximizes W
.3
(z)I
TA.3
(z), or,
equivalently, the depth of I
SPTAB.3
.
Bone at Surface TIC
eq
D
W
40
0
Mechanical Index (MI)
p z
f
r sp
c
.
( )
3
where p
r.3
(z
sp
) is the peak rarefactional pressure (in
MPa) derated by 0.3 dBcm
-1
MHz
-1
to the point on the
beam axis z
sp
where pulse intensity integral (PII.3) is
maximum, and f
c
is the center frequency (in MHz).
8
The scanned mode (or autoscanning) is the electronic or mechanical steering of successive ultrasonic
pulses or series of pulses, through at least two dimensions.
9
The unscanned mode (or nonautoscanning) is the emission of ultrasonic pulses in a single direction,
where scanning in more than one direction would require moving the transducer assembly manually.