The adoption of RFID, by both health care providers and many industries outside of health care, has created concerns about potential RF interference. The Georgia Tech EAS/Medical Device E3 Test Center works with manufacturers to improve RF coexistence between wireless implants and the electronic article surveillance (EAS) systems that help retailers,
libraries and other establishments prevent theft and track inventory (press release).

“EAS systems may cause medical devices to do anything from shutting
down to invoking therapy at the wrong time – not a good thing if you’re
wearing a defibrillator, which is supposed to shock the heart when
needed,” explained Ralph Herkert, manager of the Center, which is part
of the Georgia Tech Research Institute (GTRI).

Typically, manufacturers use filters to reduce electromagnetic
interference, but medical devices pose special challenges. The
operating frequencies and modulation characteristics of EAS systems and
tag deactivators can fall in the same frequency band as biological
signals, such as the heartbeat. Filters would not only eliminate the
EAS signals but also the very signals that medical devices are designed
to detect.

“Instead of filters, medical device manufacturers must deal with
the interference in other ways, such as refining their firmware
algorithms,” Herkert said.

Testing is done by creating test environments in which to subject wireless medical devices to RF radiation from EAS systems and new types of security and logistics systems - including RFID. The variety of medical devices tested is quite diverse.

Although the Center initially tested pacemakers and defibrillators,
today it conducts research on a variety of medical devices including
implantable hearing devices, drug-infusion pumps, neurostimulators,
cardiac monitors and glucose monitors. And because today’s patients may
use more than one medical device, the center has been evaluating
possible interactions between different types of devices, such as
bone-healing stimulators and implanted cardiac devices.

Very cool. Do any RFID or wireless sensor vendors want to comment on the risks or potential mitigations?

Pictured right is Ralph Herkert in the lab - the implant is in a tank of saline solution to simulate the patient's body.

[Hat tip: DOTmed News]