No. 2A201-519EN*A
64
2. Countermeasures for the ultrasound system
Cause/route
Cause/route
identification procedure
Countermeasures
Radiation noise
Move the ultrasound system to a
location far from the CT system.
Check whether or not the noise is
reduced.
Ask the customer to use the ultrasound
system at a location away from the CT
system if possible.
Conduction noise via
cables
Disconnect all the cables of
optional units (printer, VCR,
imager, etc.) connected to the
ultrasound system. Insert a
power-supply filter in the power-
supply line of the ultrasound
system.
If the noise vanishes as a result of these
actions, the route of entry of the noise
lies in one of the cables.
Connect the cables of the optional units
one by one to identify which cables are
the noise routes, and perform the
following countermeasure. (Since
several cables may be noise routes,
check all the cables.)
•
Use power-supply filters with the
power supplies of the optional units
from which the cables serving as the
noise entry routes come.
•
Insert a core and filter between the
ultrasound system and each of the
cables serving as a noise entry route.
(For the BNC cable of the imager, a
filter for BNC connectors is provided.)
Radiation noise due to
the transducer acting as
an antenna
If the noise does not vanish, the
transducer could also be the
cause. Change the transducer of
the ultrasound system to a
transducer with reinforced
shielding (for example, a double-
shielded transducer).
Replace the transducer.
Conduction noise from
the power-supply line or
the ground
Remove the power-supply filter in
the above status (status in which
conduction noise via cables is
checked) and check the result.
Insert the power-supply filter.
