Chison ECO 6, Руководство по эксплуатации

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ECO 6 Digital Color Doppler Ultrasound System
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Non-diagnostic use of ultrasound equipment is not generally recommended. Examples of non-diagnostic
uses of ultrasound equipment include repeated scans for operator training, equipment demonstration using
normal subjects, and the production of souvenir pictures or videos of a fetus. For equipment of which the
safety indices are displayed over their full range of values, the TI should always be less than 0.5 and the MI
should always be less than 0.3. Avoid frequent repeated exposure of any subject. Scans in the first trimester of
pregnancy should not be carried out for the sole purpose of producing souvenir videos or photographs, nor
should their production involve increasing the exposure levels or extending the scan times beyond those
needed for clinical purposes.

Diagnostic ultrasound has the potential for both false positive and false negative results. Misdiagnosis is far
more dangerous than any effect that might result from the ultrasound exposure. Therefore, diagnostic
ultrasound system should be performed only by those with sufficient training and education.
2.6.2 Understanding the MI/TI Display
Track-3 follows the Output Display Standard for systems that include fetal Doppler applications. The acoustic
output will not be evaluated on an application-specific basis, but the global maximum de-rated Ispta must be ≤
720 mW/ cm
2
and either the global maximum MI must be ≤ 1.9 or the global maximum de-rated Isppa must be
≤ 190 W/cm
2
. An exception is for ophthalmic use, in which case the TI = max (TIS_as, TIC) is not to exceed
1.0; Ispta.3 ≤50mW/cm
2
, and MI ≤ 0.23. Track-3 gives the user the freedom to increase the output acoustic
power for a specific exam, and still limit output acoustic power within the global maximum de-rated Ispta ≤
720 mW/cm
2
under an Output Display Standard.
For any diagnostic ultrasonic systems, Track-3 provides an Output Indices Display Standard. The diagnostic
ultrasound systems and its operation manual contain the information regarding an ALARA (As Low As
Reasonably Achievable) education program for the clinical end-user and the acoustic output indices, MI and TI.
The MI describes the likelihood of cavitations, and the TI offers the predicted maximum temperature rise in
tissue as a result of the diagnostic examination. In general, a temperature increase of 2.5°C must be present
consistently at one spot for 2 hours to cause fetal abnormalities. Avoiding a local temperature rise above 1°C
should ensure that no thermally induced biologic effect occurs. When referring to the TI for potential thermal
effect, a TI equal to 1 does not mean the temperature will rise 1 degree C. It only means an increased potential
for thermal effects can be expected as the TI increases. A high index does not mean that bioeffects are
occurring, but only that the potential exists and there is no consideration in the TI for the scan duration, so
minimizing the overall scan time will reduce the potential for effects. These operator control and display
features shift the safety responsibility from the manufacturer to the user. So it is very important to have the
Ultrasound systems display the acoustic output indices correctly and the education of the user to interpret the
value appropriately.
RF: (De-rating factor)
In Situ intensity and pressure cannot currently be measured. Therefore, the acoustic power measurement is
normally done in the water tank, and when soft tissue replaces water along the ultrasound path, a decrease in
intensity is expected. The fractional reduction in intensity caused by attenuation is denoted by the de-rating
factor (RF),
RF = 10 (-0.1 a f z)
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