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RFID EMI - Now what?

July 3, 2008
by anonymous
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The news of the JAMA article on electromagnetic interference (EMI) from radio frequency identification (RFID) made a big splash last week – hitting all of the leading industry newsletters and online news services, and citing specific numbers for EMI incidents. According to the study, 34 EMI incidents were found and reproducible; 22 were hazardous, 2 were significant and 10 were light with a median distance between reader and device of 30 cm (slightly less than one foot). When I read the news reports my first reaction was “why did it take two years to get published, especially with the technology changing so rapidly? Once I read the complete article several other questions came to mind --“What this means for hospitals using RFID or thinking about using RFID? What can hospitals do, what can vendors do, and what should the RFID technology community do?” From client work and research I have gained a decent amount of information about the technology and the vendors so I decided to do some sleuthing on vendor and industry reactions, and advice.

Reactions from the leading healthcare RTLS (real time location system) vendors were not surprising. Those that don’t use radio frequency but use another technology such as infrared or ultrasound were more than happy to cite the article’s statistics and encourage readers to eliminate the potential problem by using their product. Those using RFID technology that did post a response and gave quotes to the press cited that their technology was more advanced, not the same frequency or power usage as the ones in the article.

All of which did not give me the “warm fuzzies.” So I kept on digging. Checking the leading RFID journal – called RFID Journal – I found the article summary on the first page of its healthcare section with comments and advice. The advice was “you don’t know what will happen in your environment unless you test.” These were echoed by the read comments – putting the onus on the hospitals.

Searching further I landed on the website for the Association for Automatic Identification and Mobility (AIM Global) and read a great article called “RFID in Healthcare: Risk or Benefit by Bert Moore.” The article pointed out RFID systems do conform to FCC and ETSI for emissions but many of the medical devices were designed before this regulation was in effect and could remain in service for some time – a reality for every hospital. The article concludes with taking a much broader look at the problem of RFID and EMI and solutions. Members of AIM will be working with the FDA to retest medical devices. The group has also offered to work with the vendor community to develop more comprehensive testing and guidelines for best practices.

The net – net, the article did stir up a lot of attention. You can dismiss it as old, out of date with limited testing, as some did. Or use it as a catalyst to improve the way the technology is used in healthcare. In the immediate future, hospitals will need to test RFID in their own settings. Let’s hope the offer for the FDA, manufacturers and AIM global to work together bears fruit in the future. Please share your comments and ideas for dealing with the issue at your hospital.



Have you heard about this. If medical device tablet companies are adding FRID readers to their computers than change is coming sooner than later. Here's a quick excerpt.

Arbor has added cellular connectivity and GPS to its medical tablet PC. The M1256 has a 12.1-inch touchscreen, a 1.6GHz Atom N270 processor, a 60GB or 80GB hard disk drive, 802.11a/b/g/n wireless, a two megapixel camera, an RFID reader, and Bluetooth, says Arbor. vendors are hoping that health care reform in the U.S. will lead to an increase in IT spending, because this new new tablet is merely the latest in a recent series of devices employing the MCA (mobile clinical assistant) reference platform devised by Intel.

I've read the article as well, and here's my take on it.
I think the article took a long time to get published because most people who deal with EMI in the hospital/healthcare environment saw it as a poorly conducted study that accomplishes little of any real value. Why?

It sows a lot of unnecessary fear for the readers. While EMI is a real concern, active RFID is not a major concern, the power levels are simply too low for any accidental interference. Passive ID readers are the highest risk devices - the only incident where those are a risk are the portable ones used to track OR supplies during surgery, and the patient is heavily monitored there. Luckily, there will also be a lot of staff there that can handle a potential incident.

As to the solutions proposed. On site testing for interference is a waste of time in most hospitals. Hospitals generally do not have the expertise, equipment or environment to properly test for interference. Also, even the ANSI standard for hospital testing (ANSI C63.18) recognizes that testing will only provide a snapshot of the specific devices in that location at that time. It would be dangerous to generalize the results.

Modifying equipment to withstand EMI. Medical equipment is aleady built to standards for EMI (IEC 60601-2). While theoretically possible to build equipment to withstand all EMI, it would multiply the cost of the equipment to the point where the hospital couldn't afford it (or far fewer pieces). This reduces the hospital's ability to treat patients, decreasing safety.

The solution is ongoing assessment and mitigation of risk by hospitals. This will require training in the basics of EMI for some staff and more advanced for others (which requires a background in electronics).

I started in wireless electronics repair 33 years ago and have worked as a Clinical Engineer for 18 years in the hospital environment. This is nothing new, the proliferation of new technologies has finally captured the attention of those that were able to ignore it in the past.