NORMAN, Okla.-Follow-up research examining the interaction between cardiac pacemakers and certain wireless phones found that an adverse interaction only occurred when the devices were less than three inches apart from each other. This is half the previously recommended distance.
Researchers at the University of Oklahoma’s Wireless Electromagnetic Compatibility Center focused on the planar, or vertical, separation distance between pacemaker models and wireless phones that experienced interaction in the original study. Six pacemakers were tested in different combinations with the following technologies: Code Division Multiple Access, Personal Communications Service 1900 MHz, and Time Division Multiple Access at various frequencies.
Results of the Phase I study, reported in October 1996, found interactions between a small percentage of pacemakers and digital TDMA 11 hertz technology. There were not any interactions reported between pacemakers and analog handsets.
During the Phase II testing, pacemakers were submerged in a saline solution to emulate characteristics of the chest, while the planar separation was in the air, to represent a phone positioned above the skin. For interaction to occur under those conditions, the phone and pacemaker had to be closer than three inches.
The findings reaffirm recent Food and Drug Administration research findings, the university `s EMC center said.
