ID Number		968
Study Type		Engineering & Physics
Model		450, 900, 1800 MHz (NMT/CW, GSM) mobile phone and radio exposure to medical devices and analysis of electromagnetic interference
Details		Medical devices (n=224) in hospitals were tested for electromagnetic interference due to mobile phone systems operating on C-net (450 MHz NMT operating at 0.5 watts max power), D-net (900 MHz GSM operating at 2 watts peak power), and E-net (1800 MHz GSM operating at 1 watt peak power) systems. A 435 MHz radio operating at 2.5 watts of power was also tested. The medical devices were largely used in intensive care areas and included apnea monitors, respirators, blood pressure monitors, dialysis machines, heart lung machines, ECG monitors, and external pacemakers. A total of 1,350 tests were performed. At 1 meter, only 4 devices showed EMI with mobile phones (2 apnea monitors and 2 respirators). At 10 cm (field strength of ~100 V/m), 76-92% of the devices were unaffected. When the mobile phone antennas were made to transmit while in direct contact with the medical devices, half the devices showed no effect. The 435 MHz radio showed EMI with some devices from distances greater than 1 meter away. Much of the reported EMI was not a disruption of critical device function. There were also differences between the effects of CW transmissions from the 435 MHz radio and the 450 MHz NMT devices and the 900 & 1800 MHz GSM mobile phones. The authors concluded that prohibiting mobile phones in patients' rooms was not warranted as the coincidence of events that could result in a fatal accident from EMI is extremely unlikely. They did, however, recommend a minimal separation distance of 1.5 meters. The authors also recommended that medical devices used outside the hospital settings (in an uncontrolled environment) be made resistant to RF emissions that would be produced by mobile phones.
Findings		Not Applicable to Bioeffects
Status		Completed With Publication
Principal Investigator		Federal Office of Drugs and Medical Products, FRG
Funding Agency		Private/Instit.
Country		GERMANY
References		Irnich, WE et al. Biomed Instrum Technol, (1999) 33:28-34
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