Radio Frequency Identification Readers Inducing Clinically Significant Electromagnetic Interference

Radio Frequency Identification Readers Inducing Clinically Significant Electromagnetic Interference

Although there is in vitro testing evidence for concern for implantable pacemaker and ICD EMI at LF and HF, no reactions were observed for pacemakers and ICD’s during exposure to UHF RFID or continuous-wave RFID. The FDA has not received any incident reports of pacemaker or ICD EMI caused by any RFID system. , therefore, we do not believe the current situation reveals an urgent public health risk.

In vitro tests reveal sample radio frequency identification readers inducing clinically significant electromagnetic interference to implantable pacemakers and implantable cardioverter-defibrillators

Percentage of pacemaker reactions graded for clinical significance. The percentage of tests with a reaction for pacemakers graded for clinical significance (there were no class II reactions). Pacemaker tests at nominal sensitivity during HF RFID exposure had 1% class I reactions and 1% class III reactions. HF = high frequency; LF = low frequency; RFID = radiofrequency identification; UHF = ultra high frequency; Max = maximum sensitivity; Nom = nominal sensitivity.

Abstract:

Background

The use of radiofrequency identification (RFID) systems is expanding and highlights the need to address electromagnetic interference (EMI) to implantable pacemakers and implantable cardioverter-defibrillators (ICDs).

Objective

This study sought to examine the electromagnetic compatibility (EMC) between RFID readers and implantable pacemakers or ICDs.

Methods

During in vitro testing, 15 implantable pacemakers and 15 ICDs were exposed to 13 passive RFID readers in 3 frequency bands: 134 kHz (low frequency [LF]), 13.56 MHz (high frequency [HF]), and 915 MHz (ultra high frequency [UHF]).

Results

While being exposed to LF RFID, a reaction was observed for 67% of all pacemaker tests (maximum distance 60 cm) and 47% of all ICD tests (maximum distance 40 cm). During HF RFID exposure, a reaction was observed for 6% of all pacemaker tests (maximum distance 22.5 cm) and 1% of all ICD tests (maximum distance 7.5 cm). For both pacemakers and ICDs, no reactions were observed during exposure to UHF RFID or continuous-wave RFID. Pacemakers and ICDs were most susceptible to modulated LF RFID readers.

Conclusion

Although there is in vitro testing evidence for concern for implantable pacemaker and ICD EMI at LF and HF, the FDA has not received any incident reports of pacemaker or ICD EMI caused by any RFID system. We do not believe the current situation reveals an urgent public health risk.

Relevant Excerpts

Relevant Excerpts below were taken from the Full Text Study, which can be found here:  http://www.heartrhythmjournal.com/article/S1547-5271(09)01146-1/fulltext  This was a very good study by HeartRhythm, the official journal of the Heart Rhythm Society, and I highly recommend you read it in its entirety if you plan on using RFID in a health care environment.    Lewis Kilby, eChain Technology

“Modulated LF RFID is a near-perfect source to cause EMI for implantable pacemakers and ICDs.  The majority of pacemakers and ICDs were susceptible to EMI while being exposed to modulated LF RFID readers.”

“The reactions caused by HF RFID readers were observed from 3 of 30 devices tested.”

“The RFID technologies that were most compatible with implantable pacemakers and ICDs in our testing were UHF RFID and continuous-wave RFID readers.”

“Maintaining a reasonable separation distance between RFID readers and implantable pacemakers and ICDs will also help mitigate EMI.”

“The separation distances where EMI was observed ranged from 2.5 to 60 cm.”

“Larger separation distances will help mitigate implantable pacemaker and ICD EMI, and RFID implementation should take this into consideration.”