It’s been years since someone raised the question of interference from wireless telecom base stations to pacemakers, so it was interesting a few weeks ago to check up on recent research. The conclusion? Interference from base station antennas is still not an issue, power levels from handsets have dropped, and the modern implanted medical devices are more resistant to interference.
Certainly, we’re not in a position to give medical advice. The physicians who prescribe such devices should provide information from the manufacturer on their immunity to radio frequency interference, and then it takes only a simple engineering assessment to compare the reported maximum field level to which the device is immune against with projected or measured level from a particular base station operation. The prevailing U.S. standard for the RF immunity of medical devices is the 2007 revision of the Association for the Advancement of Medical Instrumentation (AAMI) Standard 60601-1-2, which mirrors the International Electrotechnical Commission (IEC) Standard 601-1-2. Formally recognizing this standard, the Food and Drug Administration (FDA) says that it “will allow manufacturers to ensure that cardiac pacemakers and defibrillators are safe from cell phone EMI [electromagnetic interference].”
The manufacturers, though, can provide even greater protection. Medtronics, one of the principal producers of pacemakers, provided this RF immunity information in 2009 for its devices, and I would expect that other manufacturers have incorporated similar resilience into their own products:
“Medtronic pacemakers/defibrillators are designed to operate normally in electric fields measuring 100 volts per meter” (V/m) and “to operate normally within RF levels that meet the government Maximum Permissible Exposure (MPE) limits” for electric fields at “150 kHz and up,” including “[s]ources such as: radio transmitter antennas, television transmitter antennas, cellular telephone antennas, RF welding equipment, dielectric heaters, radar.”
The FCC’s MPE limits at mobile phone frequencies, all above 150 MHz, range from 42 to 61 V/m, so exposures from base station antennas that meet the FCC limits also fall within the acceptable range for Medtronic’s devices. Therefore, persons with implanted medical devices like these should not experience interference from base station operations where the transmitting antennas cannot be approached directly. Actual RF levels are probably higher in coffee shops and other “WiFi” locations, or even near certain devices in homes, such as wireless routers, microwave ovens, and cordless phones. Those levels should be compliant, too – it simply shows people with pacemakers are already living with higher levels of RF energy and so should not worry about the presence of base stations.