S2/S2BW
Digital Color Doppler Ultrasound System
The threshold under optimum conditions of pulsed ultrasound is predicted by the ratio of the peak pressure to
the square root of the frequency.
MI = Pr
0
/
p
f c
Pr’ is the de-rated (0.3) peak rare-fractional pressure in Mpa at the point where PII is the maximum, and fc
is the center frequency in MHz. PII is the Pulse Intensity Integral that the total energy per unit area carried
by the wave during the time duration of the pulse.
The peak rare-fractional pressure is measured in hydrophone maximum negative voltage normalized by
the hydrophone calibration parameter.
Display Guideline
For different operation modes, different indices must be displayed. However, only one index needs to be
shown at a time. Display is not required if maximum MI is less than 1.0 for any setting of the operating mode,
or if maximum TI is less than 1.0 for any setting of the operating mode. For TI, if the TIS and TIC are both
greater than 1.0, the scanners need not be capable of displaying both indices simultaneously. If the index falls
below 0.4, no display is needed. The display increments are no greater than 0.2 for index value less than one
and no greater than 1.0 for index values greater than one (e.g. 0.4, 0.6, 0.8, 1, 2, 3).
Display and Report in Different Mode
For B-Scan Mode
Only display and report MI, and start from 0.4 if maximum MI > 1.0
For Color Mode
Only display and report TIS or TIB and start from 0.4 if maximum TI > 1.0
For Doppler Mode
Only display and report TIS or TIB and start from 0.4 if maximum TI > 1.0
Below is a simple guideline for the user when TI exceeds one limit exposure time to 4(6-TI) minutes based on
the National Council on Radiation Protection. Exposure Criteria for Medical Diagnostic Ultrasound: I. Criteria
Based on Thermal Mechanisms. Report No.113 1992:
Operator Control Features
The user should be aware that certain operator controls may affect the acoustic output. It is recommended
to use the default (or lowest) output power setting and compensate using Gain control to acquire an image.
Other than the output power setting in the soft-menu, which has the most direct impact on the power; the
PRF, image sector size, frame rate, depth, and focal position also slightly affect the output power. The default
setting is normally around 70% of the allowable power depending on the exam icon.
2.6 Environmental Requirements
The environmental requirements for using the ultrasound system are listed below.
Operation
Temperature: 10°C ∼ 40°C
Relative Humidity: 30%∼75%, no condensation
Atmospheric Pressure: 700∼1060hPa
Transport & Storage
Temperature: -20°C ∼ 55°C
Relative Humidity: 20% ∼90 %, no condensation
Atmospheric Pressure: 700∼1060hPa
Strong radiation sources or powerful electromagnetic waves (e.g. electromagnetic waves from radio broad-
casting) may result in image ghosting or noise. The system should be isolated from such radiation sources or
P/N: 4710.00149A01
2-7
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