Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players

<p>Abstract</p> <p>Background</p> <p>Recently, malfunctioning of a cardiac pacemaker electromagnetic, caused by electromagnetic interference (EMI) by fields emitted by personal portable music players was highly publicized around the world. A clinical study of one patien...

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Main Author: Bassen Howard
Format: Article
Language:English
Published: BMC 2008-02-01
Series:BioMedical Engineering OnLine
Online Access:http://www.biomedical-engineering-online.com/content/7/1/7
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author Bassen Howard
author_facet Bassen Howard
author_sort Bassen Howard
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Recently, malfunctioning of a cardiac pacemaker electromagnetic, caused by electromagnetic interference (EMI) by fields emitted by personal portable music players was highly publicized around the world. A clinical study of one patient was performed and two types of interference were observed when the clinicians placed a pacemaker programming head and an iPod were placed adjacent to the patient's implanted pacemaker. The authors concluded that "Warning labels may be needed to avoid close contact between pacemakers and iPods". We performed an in-vitro study to evaluate these claims of EMI and present our findings of no-effects" in this paper.</p> <p>Methods</p> <p>We performed in-vitro evaluations of the low frequency magnetic field emissions from various models of the Apple Inc. iPod music player. We measured magnetic field emissions with a 3-coil sensor (diameter of 3.5 cm) placed within 1 cm of the surface of the player. Highly localized fields were observed (only existing in a one square cm area). We also measured the voltages induced inside an 'instrumented-can' pacemaker with two standard unipolar leads. Each iPod was placed in the air, 2.7 cm above the pacemaker case. The pacemaker case and leads were placed in a saline filled torso simulator per pacemaker electromagnetic compatibility standard ANSI/AAMI PC69:2000. Voltages inside the can were measured.</p> <p>Results</p> <p>Emissions were strongest (≈ 0.2 μT pp) near a few localized points on the cases of the two iPods with hard drives. Emissions consisted of 100 kHz sinusoidal signal with lower frequency (20 msec wide) pulsed amplitude modulation. Voltages induced in the iPods were below the noise level of our instruments (0.5 mV pp in the 0 – 1 kHz band or 2 mV pp in the 0 – 5 MHz bandwidth.</p> <p>Conclusion</p> <p>Our measurements of the magnitude and the spatial distribution of low frequency magnetic flux density emissions by 4 different models of iPod portable music players. Levels of less than 0.2 μT exist very close (1 cm) from the case. The measured voltages induced inside an 'instrumented-can' pacemaker were below the noise level of our instruments. Based on the observations of our in-vitro study we conclude that no interference effects can occur in pacemakers exposed to the iPod devices we tested.</p>
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spelling doaj.art-a569a339d951487e923819a02f2a640b2022-12-22T00:57:21ZengBMCBioMedical Engineering OnLine1475-925X2008-02-0171710.1186/1475-925X-7-7Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music playersBassen Howard<p>Abstract</p> <p>Background</p> <p>Recently, malfunctioning of a cardiac pacemaker electromagnetic, caused by electromagnetic interference (EMI) by fields emitted by personal portable music players was highly publicized around the world. A clinical study of one patient was performed and two types of interference were observed when the clinicians placed a pacemaker programming head and an iPod were placed adjacent to the patient's implanted pacemaker. The authors concluded that "Warning labels may be needed to avoid close contact between pacemakers and iPods". We performed an in-vitro study to evaluate these claims of EMI and present our findings of no-effects" in this paper.</p> <p>Methods</p> <p>We performed in-vitro evaluations of the low frequency magnetic field emissions from various models of the Apple Inc. iPod music player. We measured magnetic field emissions with a 3-coil sensor (diameter of 3.5 cm) placed within 1 cm of the surface of the player. Highly localized fields were observed (only existing in a one square cm area). We also measured the voltages induced inside an 'instrumented-can' pacemaker with two standard unipolar leads. Each iPod was placed in the air, 2.7 cm above the pacemaker case. The pacemaker case and leads were placed in a saline filled torso simulator per pacemaker electromagnetic compatibility standard ANSI/AAMI PC69:2000. Voltages inside the can were measured.</p> <p>Results</p> <p>Emissions were strongest (≈ 0.2 μT pp) near a few localized points on the cases of the two iPods with hard drives. Emissions consisted of 100 kHz sinusoidal signal with lower frequency (20 msec wide) pulsed amplitude modulation. Voltages induced in the iPods were below the noise level of our instruments (0.5 mV pp in the 0 – 1 kHz band or 2 mV pp in the 0 – 5 MHz bandwidth.</p> <p>Conclusion</p> <p>Our measurements of the magnitude and the spatial distribution of low frequency magnetic flux density emissions by 4 different models of iPod portable music players. Levels of less than 0.2 μT exist very close (1 cm) from the case. The measured voltages induced inside an 'instrumented-can' pacemaker were below the noise level of our instruments. Based on the observations of our in-vitro study we conclude that no interference effects can occur in pacemakers exposed to the iPod devices we tested.</p>http://www.biomedical-engineering-online.com/content/7/1/7
spellingShingle Bassen Howard
Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players
BioMedical Engineering OnLine
title Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players
title_full Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players
title_fullStr Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players
title_full_unstemmed Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players
title_short Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players
title_sort low frequency magnetic emissions and resulting induced voltages in a pacemaker by ipod portable music players
url http://www.biomedical-engineering-online.com/content/7/1/7
work_keys_str_mv AT bassenhoward lowfrequencymagneticemissionsandresultinginducedvoltagesinapacemakerbyipodportablemusicplayers