iPods cleared of interfering with cardiac pacemakers
1 February 2008
A study by the US Food and Drug Administration has
refuted claims that portable music players, such as Apple's iPod, interfere
with cardiac pacemakers. The study is reported in the open access journal
BioMedical Engineering OnLine.
Howard Bassen, a researcher with the US
FDA led a research team that measured the magnetic fields produced by four
different iPod models: a fourth-generation iPod, an iPod with video, an iPod
nano and an iPod shuffle. They also measured the voltages delivered inside
the pacemaker by the magnetic fields from the iPods. All measurements
indicated there would be no effects on users with cardiac pacemakers.
year there were reports of a patient with a cardiac pacemaker suffering
dizziness while using an iPod. Cardiologists operated an iPod during the
patient’s examination and noted interference with the pacemaker. The
cardiologists published their results in the medical journal, Heart
After publication, there was talk of warning labels for
portable music and video players, although a subsequent clinical study
failed to show any dangerous connection between the music devices and
patients with pacemakers.
Now, Bassen’s more detailed study demonstrates
that iPods are not capable of producing electromagnetic interference in
Using a 3-coil sensor, the team measured the
magnetic field produced by the iPod at a distance of around 5 to 10mm. They
obtained readings for the magnetic field at various specific and small
regions 10mm from an iPod. The peak magnetic field strength was 0.2
millionths of a Tesla, a value hundreds of times lower than the levels
capable of interfering with a pacemaker.
In addition, Bassen’s team
attempted to detect any voltages these fields might produce within the
protective "can" of a pacemaker. The can was placed inside a simulated human
torso used by pacemaker manufacturers for interference testing. Bassen and
his team found that the voltage levels within the pacemaker can were well
below the detection limits of their highly sensitive equipment.
the observations of our in-vitro study we conclude that no interference
effects can occur in pacemakers exposed to the iPods we tested," Bassen
Bassen H. Low frequency magnetic
emissions and resulting induced voltages in a pacemaker by iPod portable
music players. BioMedical Engineering OnLine 2008, 7:7
Link to preliminary version of article (downloads PDF file; accessed 1 Feb,
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