Press Release
PR48-(03)
28 May 2003
Keeping pace of mobile phone safety
A new study in the Institute of
Physics journal Physics in Medicine and Biology, reveals that the new
generation of digital mobile phones can interfere with many types of heart
pacemaker. The pacemakers can confuse the signals generated by mobile phones
for the heart's own electrical signals, causing the pacemaker to
malfunction. The authors of the paper, based in the US and Italy, say that
newer pacemakers fitted with a ceramic filter are immune and recommend that
all manufacturers use these filters.
Electromagnetic
interference between mobile phones and cardiac pacemakers has caused concern
among physicians since 1994, when it was reported that mobile phones could
cause the life-saving implants to malfunction. Early studies found various
pacemakers susceptible to interference and the researchers suggested wearers
should keep a safe distance from mobile phones. The studies did not look at
the cause of the interference, however, so it was not known which pacemaker
wearers were most at risk.
Biomedical engineer
Giovanni Calcagnini of the Italian Institute of
Health in Rome explains that some electrical components of the
pacemakers act like an aerial. They can pick up undesirable radio frequency
signals and transmit them to the pacemaker's sensitive electronic circuits.
He and his colleagues at the Center for Devices and Radiological Health of
the Food and Drug Administration, in
Rockville, Maryland, USA, have investigated exactly how radio frequency
signals of the kind used by modern mobile phones are transmitted to the
pacemaker's internal components.
The researchers tested
three versions of the same pacemaker model. The first was equipped with a
conventional filter, used to block high-frequency radio signals. The second
used the newer ceramic filters connected directly to the internal circuits.
The third pacemaker was fitted with both devices.
For each pacemaker, the
researchers monitored the pacemaker's output signal, which usually helps
control the patient's heart beat, while exposing the device to the radio
signals from mobile phones, including the GSM (Global System for Mobile)
phones used throughout Europe.
They report in Physics in
Medicine and Biology that the radio frequency signals from GSM phones passed
straight through the standard filter device. "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," explains 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.
"Most manufacturers
have started to equip their new models with ceramic filters," explains
Giovanni Calcagnini. "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."
Notes for editors
1. The reference for the
article “On the mechanisms of interference between mobile phones and
pacemakers: parasitic demodulation of GSM signal by the sensing amplifier”
is Phys. Med. Biol. 48 (7 June 2003) 1661-1671, and it can be found at
stacks.iop.org/0031-9155/48/1661. The Physics in Medicine and Biology web
site is at http://www.iop.org/EJ/PMB
.
2. For more information
about the research, please contact author Giovanni Calcagnini, tel.
+39-06-49902862, email gcalc@iss.it .
3. For more information
about this press release and the Institute of Physics, please contact
Michelle Cain, Corporate Communications Officer, tel. +44 (0) 20 7470 4869,
email michele.cain@iop.org. For more Institute of Physics press releases,
see http://physics.iop.org/IOP/Press/prlist.html
.
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This press release was
researched and written for the Institute of Physics by David Bradley,
freelance science writer, website: www.sciencebase.com
Copyright (c) Institute of
Physics and IOP Publishing Ltd. 2000- 2003
http://physics.iop.org/IOP/Press/PR4803.html
