ID Number		1021
Study Type		Engineering & Physics
Model		900, 1800 MHz (GSM, CDMA) exposure to medical devices and analysis of electromagnetic interference
Details		Researchers at Tuen Mun Hospital in Hong Kong, China tested 11 medical devices using 1800 MHz GSM signals and found interference effects in 2 of these, a CO2 airway adapter and the haemoglucostix meter. EMI was observed only in close proximity, although the power level of the phone transmitter during testing was not provided. Both susceptible medical devices were small pieces of equipment with lightweight design and a thin plastic casing. The 1800 MHz GSM data were compared to an earlier study performed in 1997 that used 900 MHz GSM signals. The authors conclude that the 1800 MHz GSM signal showed less interference effects. The authors suggest that their study "provides additional evidence to support the relaxation of concern over the impact of cellular phone EMF on medical equipment”, and recommend a minimal separation distance of 1 meter from electronic medical devices as a tentative hospital policy.
Findings		Not Applicable to Bioeffects
Status		Completed With Publication
Principal Investigator		Tuen Mun Hospital, Hong Kong, China
Funding Agency		Private/Instit.
Country		CHINA
References		Tat, FH et al. Emerg Med., (2002) 14:315-319
Comments		It is not clear what transmission level the phones were placed at in the study, or whether they were simply hooked-up to the network at variable transmit power level. The increased interference observed with the 900 MHz GSM signal may have been frequency dependent, although it may also have reflected the standard transmission at 2 watts peak vs 1 watt peak power with 1800 MHz GSM phones. The use of 3 different phone models all transmitting the 1800 MHz GSM signal was unnecessary, and although these were also used in combination, since they all transmitted the same signal, I am not sure what additional information this provided.