GE LOGIQ A100, Technical Publication

Page: 285 / 408

Probes
269
LOGIQ
t α
100 User Manual
2211157–100 Rev 0
Acoustic Level Notes
1. System Acoustic Power Control set at 100%, with
system parameters adjusted to maximize
individual intensities.
2. Intensities and focal areas measured in water at
locations which correspond to maximized
normalized (in–situ) intensities.
3. The water values can be converted to normalized
(in–situ) values by using the following formula:
I
t
= I
w
e––
0.23a’fz
where:
I
t
= in–situ intensity
a’= tissue attenuation (0.3dB/MHz/cm)
I
w
= measured water intensity
f = Ultrasonic center frequency (MHz)
e = appx.2.7183
z = ultrasound path length (one–way) (cm)
4. In–situ intensity values remain below FDA
specified pre–enactment values for applicable
clinic applications for all control settings.
5. 20dB Beam Area represents the 20dB two–way
beam area of a single vector measured at the
depth of maximum SPTA intensity.
6. Beam Entrance Area represents the area of the
surface of the transducer emitting one acoustic
window. For sector scanners, this is also the
active acoustic area in contact with the patient.