ID Number		1757
Study Type		Engineering & Physics
Model		900 and 1800 MHz (GSM) and 2 GHz (UMTS) use in hospitals and evaluation of EMI events with medical devices
Details		Medical devices (n = 61) including ventilators, syringe pumps, dialysis machines, pacemakers, feeding pumps, and air humidifiers were tested against RF emissions from 900 MHz GPRS-1 (pulse duration 1113 usec) and GPRS-2 (pulse duration 556.5 usec), both at 2 watts peak pulse power, as well as a 2 GHz UMTS transmitter at 200 mW transmit power. The authors report almost 80% of the medical devices showed some kind of interference, with 33% classified as hazardous. GPRS contributed to the most EMI incidents (80%) and UMTS accounted for 17%. The authors further advocate maintaining a 1 meter separation distance, although do not specify how such a management strategy would be enforced. In a related study, the authors looked at the effects of RFID from active (125 kHz, 2 uW transmit) and passive (868 MHz) tags on various medical devices (n = 41). The authors used the ANSI C63.18 ad hoc test method at distances as close as 0.1 cm. The RFID tags were attached to the medical device (not clear where) and the readers were brought in proximity of the medical device (activating the tags). The readers for the 125 kHz active system was listed at 3 uT at 1 meter and for the 868 MHz passive system was 2-4 watts (normally these transmit a few very short usec pulses). Distances associated with interference ranged from 0.1 to 600 cm, with a median distance of ~30 cm. "Hazardous" interference occured in ~27% of the devices tested, with more from the 868 passive reader than with the 125 kHz active reader
Findings		Not Applicable to Bioeffects
Status		Completed With Publication
Principal Investigator		University of Amsterdam, Netherlands
Funding Agency		Private/Instit.
Country		NETHERLANDS
References		van der Togt, R et al. JAMA, (2008) 299:2884-2890 van Lieshout, EJ et al. Critical Care, (2007) 11:R98-
Comments		No explanation of field levels in close proximity. For 125 kHz active reader, not known if it was a loop (higher order function with distance), what the modulation was, what the E-field was, etc