RFID tags could cause medical device malfunction
29 June 2008
Radio frequency identification devices have the potential to cause
critical care medical equipment to malfunction, according to a study of
the effects on medical devices that included, external pacemakers,
mechanical ventilators, infusion/syringe pumps, dialysis devices,
defibrillators, monitors and anaesthesia devices.
The study was conducted by Vrije University, Amsterdam and published
in the June 25 issue of JAMA.
“Applications of autoidentification technologies such as radio
frequency identification (RFID) in everyday life include security access
cards, electronic toll collection, and antitheft clips in retail
clothing. RFID applications in healthcare 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
current expenditure levels on RFID systems within healthcare in the
United States are estimated to be approximately $90 million per year
with 10-year growth projections to $2 billion,” the authors write.
Possible applications of RFID include drug blister packs, which could
be marked to prevent drug counterfeiting; and the quality of blood
products being monitored with temperature-sensitive RFID tags. The
decreasing size and cost of RFID tags also permits use in surgical
sponges, endoscopic capsules and endotracheal tubes, according to
background information in the article. The potential for harmful
electromagnetic interference (EMI) by electronic anti-theft surveillance
systems on implantable pacemakers and defibrillators is known, but the
effect on critical care devices in not certain.
Remko van der Togt of Vrije University, Amsterdam, the Netherlands,
and colleagues conducted a study in a controlled, non-clinical setting
to assess and classify incidents of electromagnetic interference by RFID
on critical care equipment. The tests were performed in a one-bed
patient room in an intensive care unit (ICU) and 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 (in 17 categories, 22 different
manufacturers). The devices included items such as external pacemakers,
mechanical ventilators, infusion/syringe pumps, dialysis devices,
defibrillators, monitors and anaesthesia devices. Incidents of EMI were
classified according to a critical care adverse events scale as
hazardous, significant, or light.
All 41 medical devices were submitted to 3 EMI tests resulting in 123
EMI tests. A total of 34 EMI incidents were found; 22 were classified as
hazardous, 2 as significant, and 10 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: total switch-off and change in set
ventilation rate of mechanical ventilators; complete stoppage of syringe
pumps; malfunction of external pacemakers; complete 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. Hazardous incidents
occurred at a median distance of 9.8 inches.
"The lack of standardization of RFID in healthcare permits RFID
systems originally designed for logistics to enter the medical arena on
the basis of requirements such as the range at which medical tagged
items or individuals are to be detected.
"However, the economic benefits of optimal healthcare logistics,
including a supply chain of RFID-tagged disposables or pharmaceuticals,
could face barriers in the critical care environment. The intensity of
electronic life-supporting medical devices in this area requires careful
management of the introduction of new wireless communications such as
RFID,” the authors say.
“Implementation of RFID in the ICU and other similar healthcare
environments should require on-site EMI tests in addition to updated
international standards.”