"Think of the jamming signal that we are creating as a secret key," Katabi said. "Everyone who doesn't know the secret key just sees a garbage signal."

In part, the technology works because it's a "full-duplex radio," able to simultaneously transmit and receive wireless signals. In this case, it can jam the signal and receive it from the device at the same time.


Usually, this technology results in larger devices, because they require the antennas to be spaced at specific distances from each other. But the team uses two antennas -- one for jamming and the other for receiving -- and special configurations to get around the usual size requirements.

So far, the team has successfully tested it with used implantable defibrillators they picked up in the Boston-area.

However, the researchers say they're not yet sure whether medical device companies would invest in such a security system. But the researchers said a Federal Communications Commission decision which moved implantable medical devices to a new frequency band makes it possible to communicate across greater distances, hence making the need for protection more urgent.

Around 300,000 implantable medical devices are implanted every year.

The scientists' research will be presented in August at Sigcomm 2011 in Toronto, Canada. To learn more, visit: http://groups.csail.mit.edu/netmit/IMDShield/index.html

Back to HCB News

More Industry Headlines