P3V Veterinary Digital Ultrasonic Diagnostic Imaging System User Manual
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frequency (PRF).
The imaging mode determines whether the ultrasound beam is scanning or non-scanning.
Thermal bioeffect is closely associated with M, PW and Color mode.
Acoustic attenuation of tissue is directly connected to probe frequency.
The focus number/position is related to active aperture of probe and beam width.
The higher PRF (pulse repetition frequency), the more output pulses occur over a period of time.
Receiver Controls
The receiver controls (such as gain, TGC, dynamic range and image processing), which are used
to improve image quality, have no effect on acoustic output. Thus these controls should be
optimized before increasing acoustic output.
It is recommended to use the default (or lowest) output power setting and compensate using Gain
control to acquire an image. The default setting is normally around 70% of the allowable power
which will not cause any harm to users and is validated to be the most effective for all the
transducers.
A2.6: Prudent Use Statement
Although no confirmed bioeffects on patients caused by exposure from present diagnostic
ultrasound equipment have ever been reported, the potential exists that such bioeffects may be
identified in the future. Therefore, the ultrasound should be used prudently. High levels of
acoustic output and long exposure time should be avoided while acquiring necessary clinical
information.
A2.7: References for Acoustic Output and Safety
1. “Bioeffects and Safety of Diagnostic Ultrasound” issued by AIUM in 1993
2. “Medical Ultrasound Safety” issued by AIUM in 1994
3. "Acoustic Output Measurement Standard for Diagnostic Ultrasound Equipment,
Revision 3" issued by AIUM/NEMA in 2004
4. "Standard for real-time display of thermal and mechanical acoustic output indices on
diagnostic ultrasound equipment, Revision 2" issued by AIUM/NEMA in 2004
5. "Information for Manufacturers Seeking Marketing Clearance of Diagnostic
Ultrasound Systems and Transducers" issued in 2008.
6. “Medical electrical equipment – Part 2-37: Particular requirements for the safety of
ultrasonic medical diagnostic and monitoring equipment” issued by IEC in 2005.
