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HD11 XE Getting Started
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Device Standards
As an example, if a portable transmitter has maximum radiated power of 1 W and
an operating frequency of 156 MHz, it should only be operated at distances
greater than 1.2 m (3.9 ft) from the system. Likewise, a 0.01-W Bluetooth wire-
less LAN device operating at 2.4 GHz should be placed no closer than 0.24 m
(10 in) from any part of the system.
Avoiding Electromagnetic Interference
A medical device can either generate or receive electromagnetic interference.
The EMC standards describe tests for both emitted and received interference.
Emission tests deal with interference generated by the device being tested. Philips
ultrasound systems do not generate interference based on the tests described in
the referenced standards.
An ultrasound system is designed to receive signals at radio frequencies and is
therefore susceptible to interference generated by RF energy sources. Examples
of other sources of interference are medical devices, information technology
products, and radio and television transmission towers. Tracing the source of
radiated interference can be a difficult task. Customers should consider the fol-
lowing in an attempt to locate the source:
• Is the interference intermittent or constant?
• Does the interference show up only with one transducer or with several
transducers?
• Do two different transducers operating at the same frequency have the same
problem?
• Is the interference present if the system is moved to a different location in the
facility?
• Can the EMC coupling path be attenuated? Moving the ECG leads too close to
the UP-D895MD printer could cause electromagnetic interference. For exam-
ple, placement of a transducer or printer close to an ECG cable can increase
electromagnetic interference. Moving the cable or other medical equipment
away from the location of the transducer or printer can result in reduced
electromagnetic interference.
The answers to these questions will help determine if the problem resides with
the system or the scanning environment. After you answer the questions, contact
your Philips service representative.
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