MediSono P11 EXP, Руководство пользователя

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P11 EXP
Portable Digital Color Doppler Ultrasound System
1-9
0.3dB cm-1 MHz-1 in homogeneous soft tissue is listed in the following table. An example
is if the user uses 7.5MHz frequency, the power will be attenuated by .0750 at 5cm, or
0.3x7.5x5=-11.25dB. The De-
rated Intensity is also referred to as ’.3’ at the end (e.g.
Ispta.3).
Distance Frequency (MHz)
(cm) 1 3 5 7,5
1 0,9332 0,8128 0,7080 0,5957
2 0,8710 0,6607 0,5012 0,3548
3 0,8128 0,5370 0,3548 0,2113
4 0,7586 0,4365 0,2512 0,1259
5 0,7080 0,3548 0,1778 0,0750
6 0,6607 0,2884 0,1259 0,0447
7 0,6166 0,2344 0,0891 0,0266
8 0,5754 0,1903 0,0631 0,0158
I’=I*RF Where I’ is the intensity in soft tissue, I is the
time-averaged intensity measured in water.
Tissue Model
Tissue temperature elevation depends on power, tissue type, beam width, and scanning
mode. Six models are developed to mimic possible clinical situations.
Thermal
Models
Composition Mode Specification Typ. app
1TIS Soft tissue Unscanned Large aperture
(>1cm )
Liver PW
2TIS Soft tissue Unscanned Small aperture
(<1cm )
Pencil probe
3TIS Soft tissue Scanned Evaluated at surface Breast color
4TIB Soft tissue and Scanned Soft tissue at surface Muscle color
bone
5TIB Soft tissue and Unscanned Bone at focus Fetus head PW
bone
6TIC Soft tissue and Unscanned / Scanned Bone at surface Trans cranial
bone
Soft tissue
Describes low fat content tissue that does not contain calcifications or large gas-filled
spaces.
Scanned: (auto-scan)
Refers to the steering of successive burst through the field of view, e.g. B and color mode.
UnScanned
Emission of ultrasonic pulses occurs along a single line of sight and is unchanged until the
transducer is moved to a new position. For instance, the PW, CW and M mode.
TI
TI is defined as the ratio of the In Situ acoustic power (W.3) to the acoustic power required
to raise tissue temperature by 1oC (Wdeg),
Three TIs corresponding to soft tissue (TIS) for abdominal; bone (TIB) for fetal and neonatal
cephalic; and cranial bone (TIC) for pediatric and adult cephalic, have been developed for
applications in different exams.