Does anyone know a doctor without a mobile phone? In the United States, according to a recent Harris Interactive poll, approximately 74 percent of the adult population subscribe to mobile phone service, and various sources estimate the average individual talk time per month is about 7 hours. Thus it is only logical that people bringing mobile phones and other transmitting personal electronic devices such as Blackberries, iPhones, and wireless laptops into hospitals have an expectation of using them. For doctors, these devices have evolved from a mere convenience to an essential part of medical practice. Patients and visitors are also increasingly dependent upon wireless communication, especially during times of happiness or crisis. But is the use of mobile phones and other transmitting devices in hospitals safe?
As the wireless revolution gathered steam at the end of the last century, many hospitals reacted to concern over electromagnetic interference with critical medical equipment by implementing precautionary bans on mobile phones throughout the facility. As policing of bans has become increasingly impractical and the benefits of wireless communication argue for a better solution, a growing number of hospitals have relaxed enforcement or adopted more liberal policies. Without an appropriate management strategy, however, the unrestricted use of mobile phones may make hospitals vulnerable to potentially dangerous, albeit uncommon, electromagnetic interference risks.
The situation becomes even more complex as hospitals enthusiastically deploy Wi-Fi networks to wirelessly shuttle medical information within their facilities (for example, electrocardiograms from ambulatory cardiac patient telemetry units to monitors at nurse’s stations, drug library updates to infusion pumps, patient lab test results to a doctor’s PDA, and server information to wireless laptops). The hospital’s wireless repertoire may soon include additional low-power, short-range wireless links, like Bluetooth and ZigBee, to support patient monitoring devices, as well as broadband wireless links, like WiMax, to transport large or real-time data streams.
Although accreditation groups, such as the Joint Commission, require hospitals to present a strategy for management of mobile phones, and the U.S. Food and Drug Administration is preparing guidance on wireless medical telemetry, there previously existed no comprehensive set of recommendations to manage wireless in hospitals. As a result, individual policies crafted by hospitals are inconsistent and often do not fully address issues such as electromagnetic interference, the need for different wireless systems to interoperate, and the need for medical data to be transported with necessary speed, accuracy, reliability, and priority.
To bridge this gap, engineers representing mobile phone manufacturers, medical device manufacturers, hospitals, and government regulatory agencies have collectively developed a set of internationally recognized guidance documents including the International Standards Organization ISO TR #21730 (2006), Association for the Advancement of Medical Instrumentation AAMI TIR 18 (1997, revision ongoing), and the IEEE 11073-00101 (2007). These guidance documents outline a consistent strategy to identify and mitigate electromagnetic interference risks, and facilitate more reliable and robust wireless transport across existing wireless networks. The Bluetooth special interest group, IEEE 802.15, and the ZigBee Alliance are working to further optimize available wireless technology for the transport of medical data. Following the simple strategies outlined in these organizations’ guidance documents will enable hospitals to more smoothly and safely integrate into the wireless world.
About the Author
Joseph J. Morrissey received his Ph.D. from Stanford Medical School in the biological sciences in 1993, and subsequently took a job with Motorola where he has worked for the past decade. Initially focusing on health research involving chronic low-level RF exposure, he has expanded into several areas of electromagnetic compatibility research.
To Probe Further
For information on the ISO guidance document, Health Informatics—Use of Mobile Wireless Communication and Computing Technology in Healthcare Facilities—Recommendations for Electromagnetic Compatibility (Management of Unintentional Electromagnetic Interference) With Medical Devices see http://www.iso.org.
For the Association for the Advancement of Medical Instrumentation report, Technical Information Report (TIR) 18, Guidance on Electromagnetic Compatibility Of Medical Devices For Clinical/Biomedical Engineers—Part 1: Radiated Radio-Frequency Electromagnetic Energy , see http://www.aami.org.
For IEEE’s 2007 report, Health informatics—Point-of-Care Medical Device Communication—Guidelines for the Use of RF Wireless Technology , see http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=1377858&isnumber=30075.
For the FDA’s Draft Guidance for Industry and FDA Staff-Radio-Frequency Wireless Technology in Medical Devices , see http://www.fda.gov/cdrh/osel/guidance/1618.html.