Mr. Lubecke has been working with James Lin of the University of Illinois in Chicago to test his ideas. The researchers used a radio with similar frequency and power to a typical mobile phone to demonstrate the effect in their lab. Now they are building a prototype detector. Today's cell phone networks treat the interference information as unwanted noise and discard it. For the new system to work, the network will have to be modified to retain and interpret the signals, Mr. Lubeck said.
Some experts say the technology faces major challenges.
Alan Preece, who investigates mobile phone health effects at the University of Bristol, said that the heartbeat signal would be so much weaker than the main signal that it risks being swamped. If the Bell Labs discovery can be reliably exploited, it could also help you get remote diagnoses just by phoning your doctor. So while the jury is still out on cell phone safety, pending the results of a five year study by the World Health Organization, it looks like cell phones may have at least some potential health benefits on the horizon. This article is excerpted from New Scientist, a weekly science and technology magazine based in London. Distributed by the New York Times Syndicate.