aami tir18:2010, guidance on electromagnetic...

AAMI TIR18:2010

Association for the Advancementof Medical Instrumentation

Guidance on electromagnetic compatibility of medical devices in

healthcare facilities

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For a complete copy of this AAMI document, contact AAMI at (877) 249-8226

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AAMI Technical Information Report AAMI TIR18:2010 (Revision of AAMI TIR18:1997)

Guidance on electromagnetic compatibility of medical devices in healthcare facilities

Approved 8 March 2010 by Association for the Advancement of Medical Instrumentation

Abstract: This AAMI Technical Information Report (TIR) provides information, guidance, and general recommendations regarding electromagnetic compatibility (EMC) of medical devices and the use of RF wireless technology in healthcare facilities to promote patient safety. It is intended to provide a broad range of information about EMC of medical devices for clinical and biomedical engineers and other technical personnel; healthcare administrators, including heads of hospital departments; medical staff; and healthcare associations. The information herein will help healthcare organizations evaluate their electromagnetic (EM) environment and implement actions needed to minimize electromagnetic interference (EMI) problems and manage the EM environment, including wireless RF sources. Although this TIR focuses on healthcare facilities, the home environment is briefly addressed. Management of the electromagnetic environment and management of medical devices for EMC are discussed, as are the following subjects: assessment of the electromagnetic environment; investigation and reporting of EMI problems; selected case studies in EMI problems; site selection, design, and construction of new facilities; a model EMC and wireless policy and guidance for developing EMC and wireless policies; and principles of electromagnetic energy and interference mechanisms. Definitions of terms and a bibliography are also provided.

Keywords: ad hoc testing, cellular telephones, conducted immunity, electromagnetic compatibility, electromagnetic disturbance, electromagnetic interference, electrostatic discharge, EMC, EM disturbance, EMI, ESD, mobile communications, mobile telephones, radiated immunity, wireless local area network (LAN)

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AAMI Technical Information Report

A technical information report (TIR) is a publication of the Association for the Advancement of Medical Instrumentation (AAMI) Standards Board that addresses a particular aspect of medical technology.

Although the material presented in a TIR may need further evaluation by experts, releasing the information is valuable because the industry and the professions have an immediate need for it.

A TIR differs markedly from a standard or recommended practice, and readers should understand the differences between these documents.

Standards and recommended practices are subject to a formal process of committee approval, public review, and resolution of all comments. This process of consensus is supervised by the AAMI Standards Board and, in the case of American National Standards, by the American National Standards Institute.

A TIR is not subject to the same formal approval process as a standard. However, a TIR is approved for distribution by a technical committee and the AAMI Standards Board.

Another difference is that, although both standards and TIRs are periodically reviewed, a standard must be acted on—reaffirmed, revised, or withdrawn—and the action formally approved usually every five years but at least every 10 years. For a TIR, AAMI consults with a technical committee about five years after the publication date (and periodically thereafter) for guidance on whether the document is still useful—that is, to check that the information is relevant or of historical value. If the information is not useful, the TIR is removed from circulation.

A TIR may be developed because it is more responsive to underlying safety or performance issues than a standard or recommended practice, or because achieving consensus is extremely difficult or unlikely. Unlike a standard, a TIR permits the inclusion of differing viewpoints on technical issues.

CAUTION NOTICE: This AAMI TIR may be revised or withdrawn at any time. Because it addresses a rapidly evolving field or technology, readers are cautioned to ensure that they have also considered information that may be more recent than this document.

All standards, recommended practices, technical information reports, and other types of technical documents developed by AAMI are voluntary, and their application is solely within the discretion and professional judgment of the user of the document. Occasionally, voluntary technical documents are adopted by government regulatory agencies or procurement authorities, in which case the adopting agency is responsible for enforcement of its rules and regulations.

Comments on this technical information report are invited and should be sent to AAMI, Attn: Standards Department, 4301 N. Fairfax Drive, Suite 301, Arlington, VA 22203.

Published by

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© 2010 by the Association for the Advancement of Medical Instrumentation

All Rights Reserved Publication, reproduction, photocopying, storage, or transmission, electronically or otherwise, of all or any part of this document without the prior written permission of the Association for the Advancement of Medical Instrumentation is strictly prohibited by law. It is illegal under federal law (17 U.S.C. § 101, et seq.) to make copies of all or any part of this document (whether internally or externally) without the prior written permission of the Association for the Advancement of Medical Instrumentation. Violators risk legal action, including civil and criminal penalties, and damages of $100,000 per offense. For permission regarding the use of all or any part of this document, complete the reprint request form at www.aami.org or contact AAMI at 4301 N. Fairfax Drive, Suite 301, Arlington, VA 22203. Phone: (703) 525-4890; Fax: (703) 525-1067. Printed in the United States of America ISBN 1-57020-379-2

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Contents

NOTE—Following each section cited below is a code to indicate which of the following readers should pay particular attention to that section. An acronym/abbreviation will be used for convenience:

Healthcare administrators, including hospital heads (ADMIN) Patient safety/risk management personnel (PSRM) Clinical/biomedical engineers and other technical personnel (TECH) Medical staff (MED) Healthcare associations (HCA) All readers (ALL)

Page Glossary of equivalent standards ..............................................................................................................................vii

Committee representation .........................................................................................................................................ix

Foreword ...................................................................................................................................................................x

1 Introduction and scope (ALL) .............................................................................................................................1

2 Definitions and abbreviations (ALL) ...................................................................................................................1

3 General recommendations (ALL) .......................................................................................................................5

3.1 Overview.....................................................................................................................................................5 3.2 Focal point for EMC....................................................................................................................................5 3.3 EMC and wireless technology coordination ................................................................................................5

3.4 Policies and procedures..............................................................................................................................5 3.5 Resources ..................................................................................................................................................5 3.6 Ad hoc immunity testing..............................................................................................................................5

3.7 Ad hoc immunity testing (close distance) ....................................................................................................5 3.8 Coordination of equipment purchase, installation, servicing, and management..........................................6

3.9 Standards ...................................................................................................................................................6 3.10 Education..................................................................................................................................................6

3.11 EMI problems............................................................................................................................................6 3.12 RF transmitters .........................................................................................................................................6 3.13 List of RF sources.....................................................................................................................................6 3.14 RF spectrum usage...................................................................................................................................6 3.15 Electronic medical devices used near high-power RF sources .................................................................6 3.16 EMC test reports.......................................................................................................................................6 3.17 Facility considerations...............................................................................................................................6 3.18 "No problem found"...................................................................................................................................6 3.19 EMC professionals....................................................................................................................................6

4 Assessment of the electromagnetic environment in existing facilities (TECH) ...................................................7 4.1 Overview.....................................................................................................................................................7 4.2 Identification of RF sources ........................................................................................................................7

4.3 Identification of areas where critical medical devices are used...................................................................9 4.4 Ambient electromagnetic measurements....................................................................................................9

5 Management of the electromagnetic environment (TECH, ADMIN, PSRM, MED) ............................................10 5.1 Overview.....................................................................................................................................................10 5.2 RF spectrum management .........................................................................................................................10 5.3 On-site portable and mobile RF sources.....................................................................................................10

5.3.1 General considerations.................................................................................................................10 5.3.2 Categories of RF communications equipment users ....................................................................10 5.3.3 Portable and mobile RF source management strategies ..............................................................11

5.4 On-site fixed RF sources ............................................................................................................................16 5.4.1 General considerations.................................................................................................................16 5.4.2 Pager transmitters ........................................................................................................................16

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5.4.3 Commercial and safety service RF repeaters and cellular and PCS base stations ......................16 5.4.4 Outside RF sources......................................................................................................................16

5.5 Management of unintentional (incidental) sources of RF energy ................................................................19 5.6 Separation-distance considerations ............................................................................................................19 5.7 ESD mitigation ............................................................................................................................................22 5.8 AC power distribution system management................................................................................................22 5.9 Cable management.....................................................................................................................................22

6 Management of medical devices for EMC (TECH, ADMIN, PSRM)...................................................................22 6.1 Overview.....................................................................................................................................................22 6.2 New medical devices ..................................................................................................................................22 6.3 Existing medical devices.............................................................................................................................23

6.3.1 General considerations ......................................................................................................................23 6.3.2 System mitigation...............................................................................................................................23 6.3.3 Service and maintenance ..................................................................................................................24

6.4 Ad hoc RF immunity testing ........................................................................................................................24 6.5 Medical devices for home-care, mobile, and telemedicine use ...................................................................26 6.6 Implantable medical devices.......................................................................................................................27

7 Identification, investigation, and reporting of EMI problems (TECH, MED, ADMIN, PSRM) ..............................27 7.1 Overview.....................................................................................................................................................27 7.2 Identification and investigation ....................................................................................................................27 7.3 Reporting ....................................................................................................................................................28

8 Site selection, design, and construction of facilities (TECH, ADMIN, HCA) .......................................................29 8.1 Overview.....................................................................................................................................................29 8.2 New construction ........................................................................................................................................29 8.3 Modifications of existing facilities ................................................................................................................30 8.4 Floor planning .............................................................................................................................................30 8.5 EMC professional help................................................................................................................................30

9 Education and training (ALL)..............................................................................................................................30 9.1 Overview.....................................................................................................................................................30 9.2 Scope of education and training..................................................................................................................30 9.3 Resources...................................................................................................................................................30

Annexes

A Principles of electromagnetic energy and interference mechanisms (TECH).....................................................31 B Selected case studies in EMI problems (TECH, MED, PSRM) ..........................................................................37 C Model electromagnetic compatibility (EMC) and radiofrequency wireless technology policy and guidance

for developing EMC and wireless policies (ADMIN, PSRM, HCA) .....................................................................43 D Overview of surveys of electromagnetic environments associated with healthcare facilities (TECH).................52 E Example of manufacturer declaration of electrosurgical generator meeting IEC 60601-1-2 (TECH,

ADMIN, MED) .............................................................................................................................................54 F Bibliography (ALL)..............................................................................................................................................59

Tables

1 Groups requiring coordination and communication regarding medical device EMC and wireless technology for assurance of patient and staff safety ..........................................................................................5

2 Examples of rooftop transmitters at a hospital ...................................................................................................17 3 General description of common wireless technologies.......................................................................................20 4 Approximate minimum separations ....................................................................................................................21 A.1 Example solutions of equation 1 ........................................................................................................................33

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A.2 Typical portable and mobile transmitters, frequencies, output power, and estimated field strength at 1 meter...............................................................................................................................................................34

A.3 Fixed transmitters, frequencies, maximum licensed radiated power, and estimated field strength at 1 kilometer .........................................................................................................................................................35

A.4 Example solutions to equation 4 for k = 7 and E = 3 V/m...................................................................................36 E.1 Guidance and manufacturer’s declaration—electromagnetic emissions ............................................................55 E.2 Guidance and manufacturer’s declaration—electromagnetic immunity..............................................................56 E.3 Guidance and manufacturer’s declaration―electromagnetic immunity..............................................................57 E.4 Recommended separation distances between portable and mobile RF communications equipment and

the generator......................................................................................................................................................58 Figures

1 Example arrangement of antennas on 9th floor roof of a hospital .......................................................................18 2 Guidance on when to perform ad hoc RF immunity testing................................................................................25

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Glossary of equivalent standards

International Standards adopted in the United States may include normative references to other International Standards. For each International Standard that has been adopted by AAMI (and ANSI), the table below gives the corresponding U.S. designation and level of equivalency to the International Standard. NOTE: Documents are sorted by international designation. The code in the US column, “(R)20xx” indicates the year the document was officially reaffirmed by AAMI. E.g., ANSI/AAMI/ISO 10993-4:2002/(R)2009 indicates that 10993-4, originally approved and published in 2002, was reaffirmed without change in 2009.

Other normatively referenced International Standards may be under consideration for U.S. adoption by AAMI; therefore, this list should not be considered exhaustive.

International designation U.S. designation Equivalency IEC 60601-1:2005 Technical Corrigendum 1 and 2

ANSI/AAMI ES60601-1:2005 and ANSI/AAMI ES60601-1:2005/A2:2010

ANSI/AAMI ES60601-1:2005/C1:2009 (amdt)

Major technical variations C1 Identical to Corrigendum 1 & 2

IEC 60601-1-2:2007 ANSI/AAMI/IEC 60601-1-2:2007 Identical IEC 60601-2-2:2009 ANSI/AAMI/IEC 60601-2-2:2009 Identical IEC 60601-2-4:2002 ANSI/AAMI DF80:2003/(R)2010 Major technical variations IEC 60601-2-19:2009 ANSI/AAMI/IEC 60601-2-19:2009 Identical IEC 60601-2-20:2009 ANSI/AAMI/IEC 60601-2-20:2009 Identical IEC 60601-2-21:2009 ANSI/AAMI/IEC 60601-2-21:2009 Identical IEC 60601-2-24:1998 ANSI/AAMI ID26:2004/(R)2009 Major technical variations IEC 60601-2-47:2001 ANSI/AAMI EC38:2007 Major technical variations IEC 60601-2-50:2009 ANSI/AAMI/IEC 60601-2-50:2009 Identical IEC 80601-2-30:2009 and Technical Corrigendum 1

ANSI/AAMI/IEC 80601-2-30:2009 and ANSI/AAMI/IEC 80601-2-30:2009/ C1:2009 (amdt) – consolidated text

Identical (with inclusion) C1 Identical to Corrigendum 1

IEC 80601-2-58:2008 ANSI/AAMI/IEC 80601-2-58:2008 Identical IEC/TR 60878:2009 ANSI/AAMI/IEC TIR60878:2003 Identical IEC/TR 62296:2009 ANSI/AAMI/IEC TIR62296:2009 Identical IEC 62304:2006 ANSI/AAMI/IEC 62304:2006 Identical IEC/TR 62348:2006 ANSI/AAMI/IEC TIR62348:2006 Identical IEC/TR 62354:2009 ANSI/AAMI/IEC TIR62354:2009 Identical IEC/TR 80002-1:2009 ANSI/IEC/TR 80002-1:2009 Identical ISO 5840:2005 ANSI/AAMI/ISO 5840:2005/(R)2010 Identical ISO 7198:1998 ANSI/AAMI/ISO 7198:1998/2001/(R)2010 Identical ISO 7199:2009 ANSI/AAMI/ISO 7199:2009 Identical ISO 8637:2004 ANSI/AAMI RD16:2007 Major technical variations ISO 8638:2004 ANSI/AAMI RD17:2007 Major technical variations ISO 10993-1:2009 ANSI/AAMI/ISO 10993-1:2009 Identical ISO 10993-2:2006 ANSI/AAMI/ISO 10993-2:2006 Identical ISO 10993-3:2003 ANSI/AAMI/ISO 10993-3:2003/(R)2009 Identical ISO 10993-4:2002 and Amendment 1:2006

ANSI/AAMI/ISO 10993-4:2002/(R)2009 and Amendment 1:2006/(R)2009

Identical

ISO 10993-5:2009 ANSI/AAMI/ISO 10993-5:2009 Identical ISO 10993-6:2007 ANSI/AAMI/ISO 10993-6:2007 Identical ISO 10993-7:2008 ANSI/AAMI/ISO 10993-7:2008 Identical ISO 10993-9:1999 ANSI/AAMI/ISO 10993-9:1999/(R)2005 Identical ISO 10993-10:2002 and Amendment 1:2006

ANSI/AAMI BE78:2002/(R)2008 ANSI/AAMI BE78:2002/A1:2006/(R)2008

Minor technical variations Identical

ISO 10993-11:2006 ANSI/AAMI/ISO 10993-11:2006 Identical ISO 10993-12:2007 ANSI/AAMI/ISO 10993-12:2007 Identical ISO 10993-13:1998 ANSI/AAMI/ISO 10993-13:1999/(R)2004 Identical ISO 10993-14:2001 ANSI/AAMI/ISO 10993-14:2001/(R)2006 Identical ISO 10993-15:2000 ANSI/AAMI/ISO 10993-15:2000/(R)2006 Identical ISO 10993-16:2010 ANSI/AAMI/ISO 10993-16:2010 Identical ISO 10993-17:2002 ANSI/AAMI/ISO 10993-17:2002/(R)2008 Identical ISO 10993-18:2005 ANSI/AAMI BE83:2006 Major technical variations ISO/TS 10993-19:2006 ANSI/AAMI/ISO TIR10993-19:2006 Identical

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International designation U.S. designation Equivalency ISO/TS 10993-20:2006 ANSI/AAMI/ISO TIR10993-20:2006 Identical ISO 11135-1:2007 ANSI/AAMI/ISO 11135-1:2007 Identical ISO/TS 11135-2:2008 ANSI/AAMI/ISO TIR11135-2:2008 Identical ISO 11137-1:2006 ANSI/AAMI/ISO 11137-1:2006/(R)2010 Identical ISO 11137-2:2006 (2006-08-01 corrected version)

ANSI/AAMI/ISO 11137-2:2006 Identical

ISO 11137-3:2006 ANSI/AAMI/ISO 11137-3:2006/(R)2010 Identical ISO 11138-1: 2006 ANSI/AAMI/ISO 11138-1:2006/(R)2010 Identical ISO 11138-2: 2006 ANSI/AAMI/ISO 11138-2:2006/(R)2010 Identical ISO 11138-3: 2006 ANSI/AAMI/ISO 11138-3:2006/(R)2010 Identical ISO 11138-4: 2006 ANSI/AAMI/ISO 11138-4:2006/(R)2010 Identical ISO 11138-5: 2006 ANSI/AAMI/ISO 11138-5:2006/(R)2010 Identical ISO/TS 11139:2006 ANSI/AAMI/ISO 11139:2006 Identical ISO 11140-1:2005 ANSI/AAMI/ISO 11140-1:2005 Identical ISO 11140-3:2007 ANSI/AAMI/ISO 11140-3:2007 Identical ISO 11140-4:2007 ANSI/AAMI/ISO 11140-4:2007 Identical ISO 11140-5:2007 ANSI/AAMI/ISO 11140-5:2007 Identical ISO 11607-1:2006 ANSI/AAMI/ISO 11607-1:2006 Identical ISO 11607-2:2006 ANSI/AAMI/ISO 11607-2:2006 Identical ISO 11737-1: 2006 ANSI/AAMI/ISO 11737-1:2006 Identical ISO 11737-2:2009 ANSI/AAMI/ISO 11737-2:2009 Identical ISO 13408-1:2008 ANSI/AAMI/ISO 13408-1:2008 Identical ISO 13408-2:2003 ANSI/AAMI/ISO 13408-2:2003 Identical ISO 13408-3:2006 ANSI/AAMI/ISO 13408-3:2006 Identical ISO 13408-4:2005 ANSI/AAMI/ISO 13408-4:2005 Identical ISO 13408-5:2006 ANSI/AAMI/ISO 13408-5:2006 Identical ISO 13408-6:2006 ANSI/AAMI/ISO 13408-6:2006 Identical ISO 13485:2003 ANSI/AAMI/ISO 13485:2003/(R)2009 Identical ISO 14155-1:2003 ANSI/AAMI/ISO 14155-1:2003/(R)2008 Identical ISO 14155-2:2003 ANSI/AAMI/ISO 14155-2:2003/(R)2008 Identical ISO 14160:1998 ANSI/AAMI/ISO 14160:1998/(R)2008 Identical ISO 14161:2009 ANSI/AAMI/ISO 14161:2009 Identical ISO 14708-3:2008 ANSI/AAMI/ISO 14708-3:2008 Identical ISO 14708-4:2008 ANSI/AAMI/ISO 14708-4:2008 Identical ISO 14708-5:2010 ANSI/AAMI /ISO 14708-5:2010 Identical ISO 14937:2009 ANSI/AAMI/ISO 14937:2009 Identical ISO/TR 14969:2004 ANSI/AAMI/ISO TIR14969:2004 Identical ISO 14971:2007 ANSI/AAMI/ISO 14971:2007 Identical ISO 15223-1:2007 and A1:2008 ANSI/AAMI/ISO 15223-1:2007 and A1:2008 Identical ISO 15223-2:2010 ANSI/AAMI/ISO 15223-2:2010 Identical ISO 15225:2010 ANSI/AAMI/ISO 15225:2010 Identical ISO 15674:2009 ANSI/AAMI/ISO 15674:2009 Identical ISO 15675:2009 ANSI/AAMI/ISO 15675:2009 Identical ISO 15882:2008 ANSI/AAMI/ISO 15882:2008 Identical ISO 15883-1:2006 ANSI/AAMI ST15883-1:2009 Major technical variations ISO/TR 16142:2006 ANSI/AAMI/ISO TIR16142:2005 Identical ISO 17664:2004 ANSI/AAMI ST81:2004 Major technical variations ISO 17665-1:2006 ANSI/AAMI/ISO 17665-1:2006 Identical (with inclusions) ISO/TS 17665-2:2009 ANSI/AAMI/ISO TIR17665-2:2009 Identical ISO 18472:2006 ANSI/AAMI/ISO 18472:2006 Identical ISO/TS 19218:2005 ANSI/AAMI/ISO 19218:2005 Identical ISO 22442-1:2007 ANSI/AAMI/ISO 22442-1:2007 Identical ISO 22442-2:2007 ANSI/AAMI/ISO 22442-2:2007 Identical ISO 22442-3:2007 ANSI/AAMI/ISO 22442-3:2007 Identical ISO 25539-1:2003 and A1:2005 ANSI/AAMI/ISO 25539-1:2003/(R)2009 and

A1:2005/(R)2009 Identical

ISO 25539-2:2008 ANSI/AAMI/ISO 25539-2:2008 Identical ISO 81060-1:2007 ANSI/AAMI/ISO 81060-1:2007 Identical ISO 81060-2:2009 ANSI/AAMI/ISO 81060-2:2009 Identical

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Committee representation

Association for the Advancement of Medical Instrumentation AAMI Electromagnetic Compatibility Committee

This technical information report (TIR) was developed by the AAMI Electromagnetic Compatibility Committee. Approval of this TIR does not necessarily mean that all committee members voted for its approval.

At the time this document was published, the AAMI Electromagnetic Compatibility Committee had the following members: Cochairs: Donald N. Heirman Curtus L. Sponberg Members: Eric V. Anderson, Philips Healthcare Art Augustine, ECRI Institute Alan S. Berson, PhD, U.S. National Institutes of Health Steve Cantwell, Spacelabs Medical, Inc. Lyle Cookson, Mindray DS USA, Inc. Yadin David, EdD, CCE, PE, HCSP, Independent Expert, Houston, TX Joseph F. Dyro, CCE, PhD, Independent Expert, East Setaucket, NY Rich Eaton, Medical Imaging & Technology Alliance Jeffrey L. Eggleston, MS, PE, Covidien Wallace R. Elliott, CCE, University of Vermont Technical Service Program James J. Greco, Medapprove, Inc. Rickey L. Hampton, Premier, Inc. Donald N. Heirman, University of Oklahoma Center for the Study of Wireless EMC Robert S. Jenkins, Welcy Allyn Inc. Bernie Liebler, Advanced Medical Technology Association John Manarik, Baxter Healthcare Corporation Bernard N. Segal, PhD, Independent Expert, Montreal, Canada Jeffrey L. Silberberg, U.S. Food and Drug Administration Ray P. Silkaitis, PhD, Hospira Worldwide Inc. James Spicer, Abbott Laboratories Curtis L. Sponberg, Medtronic, Inc. James D. Stewardson, Independent Expert, Brighton, CO Jerry Trepanier, GE Healthcare Joshua E. Tsitlik, PhD, Washington Hospital Center Dave Tyler, CaridianBCT Sterilization Services Inc. John Jack Wyar, Steris Corporation Alternates: David A. Hite, Steris Corporation Jamie Jones, Abbott Laboratories Joshua Kim, Welcy Allyn Inc. Gopal Mohanty, PhD, Baxter Healthcare Corporation Ashwin A. Patel, Hospira Worldwide Inc. Bruce Qualey, Spacelabs Medical, Inc. Donald Sherratt, CaridianBCT Sterilization Services, Inc. Barry F. Waltman, Medtronic, Inc. Donald M. Witters, Jr., U.S. Food and Drug Administration

NOTE—Participation by federal agency representatives in the development of this technical information report does not constitute endorsement by the federal government or any of its agencies.

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Foreword

The electromagnetic (EM) environment in modern healthcare facilities can be extremely variable, particularly as a result of the tremendous growth in radiofrequency (RF) wireless communications such as cellular telephones, wireless personal digital assistants (PDAs), and wireless local area networks (LANs). Electromagnetic compatibility (EMC) is the ability of a system or medical device to function satisfactorily in its electromagnetic environment without introducing intolerable EM disturbance to anything in that environment. Thus, EMC of medical devices must be an integral part of all health care wherever active medical devices and systems are deployed. Healthcare organizations must actively manage their equipment and RF wireless technology to ensure EMC and mitigate the risks of electromagnetic interference (EMI).

This edition of the TIR reflects the continuous efforts of concerned medical device users, healthcare professionals, regulators, and medical device manufacturers to disseminate information and recommendations for control of EMI caused by EM disturbance from a variety of sources. The first edition was developed by the AAMI Electromagnetic Compatibility Committee in response to interest and inquiries from clinical and biomedical engineers regarding the risks of radiated EMI that might be caused by RF transmitters (e.g., portable cellular telephones) and what could be done to mitigate those risks. It was inspired in part by Paperman, et al. (1994). This new edition focuses on updating the original information and recommendations and on distinguishing important points for consideration by both engineering/technical and nontechnical personnel who use and manage electrical and electronic systems in healthcare facilities.

The objective of this TIR is to convey important information about the potential risks of EMI and RF wireless technology and what can be done to reduce those risks while deploying increasingly sophisticated medical systems. A primary objective is to help clinical and biomedical engineers and other technical personnel assess the electromagnetic environment in individual healthcare facilities, implement actions needed to minimize EMI problems, promote EMC, and, thus, promote the safety of patients and staff. In addition, this TIR is intended to raise awareness about the risks and concerns surrounding EMC and RF wireless technology in healthcare facilities. To this end, the new edition of the TIR has been rearranged to make it easier for non-engineers to find and understand the recommendations for EMC and RF wireless technology. These recommendations are aimed at promoting understanding and communication among the vital components of the healthcare organization, including administrators, medical staff, risk managers, security personnel, physical plant staff, and patients.

This TIR includes specific recommendations regarding how to assess and manage the electromagnetic environment for EMC, recognize and report EMI incidents, and promote communication about EMC and RF wireless technology deployment and use. In addition, the TIR

a) describes a model EMC and wireless policy that can be tailored to meet the needs of an individual healthcare facility;

b) provides background information on electromagnetic energy and interference mechanisms;

c) discusses what might be done to promote EMC for existing equipment and facilities as well as for new equipment and facilities; and

d) includes case studies to illustrate the types of EMI problems that can occur.

Readers should pay particular attention to the sections noted in the table of contents as being of interest according to their role in the healthcare organization.

As used within the context of this document, “should” indicates that among several possibilities, one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required, or that (in the negative form) a certain possibility or course of action should be avoided but is not prohibited. “May” is used to indicate that a course of action is permissible within the limits of the technical information report. “Can” is used as a statement of possibility and capability. Finally, “must” is used only to describe “unavoidable” situations, including those mandated by government regulation.

Suggestions for improving this TIR are invited. Comments and suggested revisions should be sent to Standards Department, AAMI, 4301 N. Fairfax Drive, Suite 301, Arlington, VA 22203.

NOTE—This foreword does not contain provisions of the AAMI Technical Information Report, Guidance on electromagnetic compatibility of medical devices in healthcare facilities (AAMI TIR18:2010), but it does provide important information about the development and intended use of the document.

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AAMI Technical Information Report AAMI TIR18:2010

Guidance on electromagnetic compatibility of medical devices in healthcare facilities 1 Introduction and scope

Because the performance of electronic medical devices can be disrupted by electromagnetic (EM) energy, patient safety can potentially be put at increased risk because of the effects of electromagnetic interference (EMI). EMI is caused by an EM disturbance, which can be in the form of radiated disturbance (radio waves propagating through the air); conducted disturbance (radio waves induced on power or signal wires); AC power-line transients, surges, sags, and dropouts; and electrostatic discharge (ESD). Radiofrequency (RF) sources that emit various EM disturbances have proliferated in modern society, including healthcare facilities, creating the potential for EMI with electronic medical devices. Sources of EM disturbance include any product or device that uses electricity or can carry an electrical charge. Systems that can emit EM disturbances include, but are not limited to, the following:

a) Cellular telephones and other wireless communication devices

b) Two-way radios

c) Wireless barcode systems

d) Radiofrequency identification (RFID) systems

e) Security systems

f) Fire alarm systems

g) Nurse call systems

h) Heating, ventilation and air-conditioning (HVAC) systems

i) Motor controllers, including elevators and copiers

j) Medical devices

Concerns arise because the EM disturbance exposure might exceed the immunity designed into medical devices and systems and because some electronic medical devices currently in use have not been tested for immunity to EM disturbances. The risks faced by even those devices that comply with EMC standards seem to be increasing as the number of radio transmitter sources, including RF wireless technology, is dramatically increasing within and outside healthcare facilities. Numerous EMI incidents have been reported in the literature.

2 Definitions and abbreviations

For purposes of this TIR, the following definitions and abbreviations apply.

NOTE 1—Throughout this TIR, “cell phone” is used interchangeably with “mobile phone.” The preferable usage is “mobile phone” because “mobile phone” is the term commonly used internationally.

NOTE 2—References in brackets are the source of the definition.

2.1 ANSI: American National Standards Institute.

2.2 ASHE: American Society for Healthcare Engineering.

2.3 BP: Blood pressure.

2.4 CCU: Critical care unit.

2.5 CDMA: Code division multiple access.

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