Change that pacemaker. Now!
Mobiles disrupt old models
Signals from GSM phones could interfere with heart pacemakers, according to a study published in the Institute of Physics journal, Physics in Medicine and Biology .
The study  (abstract) found that some pacemakers confuse the signals from mobile phones for the heart's own electrical signals, causing the pacemaker to go on the blink.
The report's authors, based in the US and Italy, say that newer pacemakers fitted with a ceramic filter are immune from the problem. They're now calling on all pacemaker makers to use these filters .
"Most manufacturers have started to equip their new models with ceramic filters," said Giovanni Calcagnini, biomedical engineer at the Italian Institute of Health in Rome.
"We recommend all new models be equipped with these filters, since it is difficult to change cellphone technology to avoid them producing low-frequency radio frequency signals, " he said.
Without the ceramic filter radio frequency signals from GSM phones passed straight through standard filters used pacemakers, the study found. In turn, some electrical components of the pacemakers act like an aerial, which pick up and transmit these "undesirable signals" to the pacemaker's sensitive electronic circuits.
"This phenomenon could pose a critical problem for people wearing pacemakers because digital mobile phones use extremely low-frequency signals, which can be mistaken for normal heartbeat," said Calcagnini.
"If a pacemaker detects a normal heartbeat it will not function properly and could be very dangerous for the wearer. The pacemaker equipped with the ceramic filter, however, was immune to mobile phone radio frequency signals," he said.
Scientists have been aware of the threat to pacemakers from mobile phone since 1994. At the time researchers suggested wearers should keep a safe distance from mobile phones - just in case.
The paper is published here (pdf). It costs £18. ®
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