Electromagnetic Interference May Irritate Equipment


“RFID applications in health care have received increasing attention because of the potentially positive effect on patient safety and also on tracking and tracing of medical equipment and devices”, the authors write. Possible applications include drug blister packs, which could be marked to prevent drug counterfeiting, or the quality of blood products being monitored with temperature-sensitive RFID tags.

The study was conducted in a controlled, non-clinical setting to assess and classify incidents of electromagnetic interference (EMI) by RFID on critical care equipment. The tests were performed in a one-bed patient room in an intensive care unit (ICU) with no patients present. Electromagnetic interference by two RFID systems - active (with batteries and ability to transmit information) and passive (without batteries, information retrieved by RFID reader) - was assessed in the proximity of 41 medical devices of 17 categories and 22 different manufacturers.

Incidents of EMI were classified according to a critical care adverse events scale as hazardous, significant, or light. All 41 medical devices were submitted three EMI tests resulting in 123 EMI tests. A total of 34 EMI incidents were found. 22 were classified as hazardous, two as significant, and ten as light. The passive signal induced a higher number of incidents (26 in 41 EMI tests; 63 percent), and hazardous incidents (17), compared with the active signal.

Hazardous incidents included the switch-off and change in set ventilation rate of mechanical ventilators, the stoppage of syringe pumps, the malfunction of external pacemakers, the stoppage of renal replacement devices, and interference in the atrial and ventricular electrogram curve read by the pacemaker programmer. The median (midpoint) distance between reader and device at which all types of incidents occurred was 11.8 inches.

The authors conclude: “Implementation of RFID in the ICU and other similar health care environments should require on-site EMI tests in addition to updated international standards.”

COMPAMED.de; Source: American Medical Association