Huntleigh SONICAID FREEDOM SF1-EUR, Инструкция по эксплуатации

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38
Ultr
asound Saf
ety Consider
ations
Table 1
Acoustic Output Reporting Table for Track 1 – Non-Auto-scanning Mode
Sonicaid Freedom Wireless Fetal Monitoring System
Operating Mode: PWD
Application(s): Fetal Monitoring
Acoustic Output MI
I
SPTA.3
(mW/cm 2 )
I
SPPA.3
(mW/cm 2 )
Global Maximum Value*
0.0261 4.64 17.5
Associated
Acoustic
Parameters
Pr
.3
(MPa)*
0.0258
W
o
total (mW)*
27.5 27.5
f
c
(MHz)
1.024 1.024 1.024
Z
sp
(cm)
4.50 4.50 4.50
Beam
Dimensions
x
-6
(cm)
4.64 4.64
y
-6
(cm)
4.95 4.95
PD ( μ S)
91.5 91.5
PRF (Hz)
2900 2900
Overall EBD
(cm)
Az. (cm)
5.0
Elev. (cm)
5.0
* Note: The Global Maximum Values of MI and intensity, and also pressure
and power, are statistical maxima calculated using a one-sided tolerance
analysis for normal distributions using test data from three samples taken from a
production batch.
Table 2: Acoustic Output Parameters for Unfocused Fetal Heart Rate Monitors
Parameter Value
I
SATA
@ Transducer Face (Note 1) 3.92 mW/cm 2
I
SATA
@ Transducer Face / DF (Note 1) 14.8 mW/cm 2
Area of Entrance Beam Dimensions (A
EBD
) (Note 2) 7.02 cm
2
Note1: The values I
SATA
are statistical maxima calculated using a one-sided
tolerance analysis for normal distributions using test data from three samples
taken from a production batch. See table 3 below.
Note 2: This is the area of the radiating elements, which is used in the
calculation of I
SATA
@ Transducer Face.
The derated pressure and intensity values were calculated in accordance
with NEMA UD 2-2004 (R2009),
Acoustic Output Measurement Standard for
Diagnostic Ultrasound Equipment, Revision 3 , from pressures measured in
water using a derating factor of 0.3dB cm -1 MHz -1 . Searches for the global
maximum acoustic output were performed using derated values, because
the derated maxima usually occur at a shorter axial range than the in-water
maxima. The derating factor for pressure is exp (-0.115 * 0.3 * f
c
* z) and for
intensity the factor is exp (-0.23 * 0.3 * f
c
* z) where f
c
is center frequency in MHz
and z is axial distance in cm.