Design of unique simulators to evaluate medical device susceptibility to radio frequency identification exposure

Background: The use of radiofrequency identification (RFID) in healthcare is increasing, but one of the biggest obstacles for widespread adoption is electromagnetic compatibility (EMC). Numerous studies have documented that RFID can interfere with medical devices. No recognized standard test methods currently exist to address medical device EMC from RFID emitters. This study identifies a potential protocol to test the effect of RFID exposure on medical devices. Methods: We developed four separate simulators which cover four distinct RFID frequency bands: Low frequency (LF): 125 kHz; High frequency (HF):13.56 MHz; Ultra high frequency (UHF): 915 MHz; and 2.4 GHz. The RFID Test Library includes actual RFID input signals and recommended field strength values for each simulator. The simulators consist of Helmholtz coils for LF and HF and use IEC 61000 4-3 exposure methods for UHF and 2.4 GHz. Discussion: The protocol presented in this paper represents one way to test if your medical device could be affected from exposure to RFID readers. The antennas chosen are used to produce repeatable tests. The input signals and field strengths are chosen to represent a wide variety of actual RFID reader technologies. Summary: The protocol needs to be tested with actual medical devices to understand the effects of the varying RFID test signals and to determine if the RFID Test Library is adequately defined. These tests are currently being conducted independently by the Food and Drug Administration (FDA) and MET Laboratories. Suggested maximum field levels are calculated and presented as a reasonable worst case exposure. It is the intent that after test validation this protocol will be submitted to the Association for Automatic Identification and Mobility (AIM) for publication.