RFID, GPS Technology and Electronic Surveillance

University Team Sees Ingestible RFID Tag as a Boon to Clinical Trials

The tag, attached to a small capsule, would enable drug developers to track when individuals take their medication.

April 27, 2010

RFID Journal - In 2005, Rizwan Bashirullah, an assistant professor at the University of Florida's Department of Electrical and Computer Engineering, faced an unusual challenge: to develop a technology for tracking when medications were taken, thereby ensuring patients or clinical trial participants stay on their drug regimen. Jose Principe, a University of Florida professor of electrical and computer engineering, had asked Bashirullah to develop transmission technology as part of a team he was organizing to create a system to aid in the detection of medication regimen compliance ...

Bashirullah tried to conceive an RFID-based solution to the problem.

"Initially, I thought it couldn't be done," he says. For one thing, although RFID could transmit information that would confirm the swallowing of a pill, he was uncertain if it was possible for a tag to transmit a passive RF signal through the human body from the digestive tract.

After several years' worth of research, however, Bashirullah and his colleagues and students have developed a tiny RFID tag—adhered to a pill capsule—that could transmit sensor data indicating the pill was in an individual's digestive system.

The system, including a microchip, a digestible antenna and software, was designed by a team of researchers from Florida University, as well as Florida biomedical research and engineering firm Convergent Engineering. In October 2009, Bashirullah and several of the researchers launched a company known as eTect, to develop and market the solution, which they dubbed an ID-Cap.

The system employs low-frequency (LF) signals and the human body's natural electrical conductivity to carry the signals from an RFID interrogator to the tag, and from the tag back to the reader. To date, the system has been tested only on devices that mimic the human body, as well as on cadavers.

The passive LF silicon microchip, approximately the size of a grain of sand, is encoded with a unique ID number. The chip is joined to a digestible antenna that dissolves in the stomach, and is made with conductive ink composed of silver nanoparticles. The tag remains operational within the digestive tract until it dissolves. Because the human body can conduct electricity, Bashirullah says, the researchers were able to use a relatively small tag antenna—covering slightly more than half of a capsule that measures 20 millimeters (0.8 inch) in length and 10 millimeters (0.4 inch) in width.

The system works like this:

A patient wears a battery-powered RFID interrogator, which could be embedded in a patch worn on an arm or against the abdomen, so that the reader's input and output terminals make electrical contact with the skin. "In this way," Bashirullah states, "we can use the body as a communication medium."

Once a person swallows the capsule, the interrogator emits an LF signal that travels through the body to the stomach, powering up the tag, says Eric Buffkin, eTect's president. The tag then transmits its unique ID number through the body so that it can be received by the reader, which then forwards that information to a mobile device, such as an iPhone or other handheld unit, via a Bluetooth connection. The handheld could then, in turn, send the data to a facility's back-end system via a SIM or cellular connection.

Users of the system could receive a reminder on their mobile device when they need to take a pill, either as an automated reminder programmed into the phone's software, or via a text message from the pharmaceutical trial manager. The phone would send a Bluetooth message to the interrogator to read the tag affixed to the pill, which would then respond with its own unique ID number and verify that the pill has been swallowed. According to Buffkin, the researchers developed a proprietary sensor, built into the tag's chip, that can detect if the pill is in the stomach.

The next step for researchers, Buffkin says, is to gain approval from the U.S. Food and Drug Administration (FDA) to begin laboratory trials of the pill on animals and humans, though the group has not yet submitted such a request to the FDA. ETect has already been in dialogue with drug manufacturers, however.

"They are keenly interested in this product," says Buffkin, who envisions the system being sold as a package, including readers, tags or tagged capsules, and software to store data and transmission instructions.

Several years ago, Eastman Kodak Co. filed an application with the U.S. Patent and Trademark Office for a "system to monitor the ingestion of medicines," featuring a digestible RFID tag (see Kodak's RFID Moment). That patent application was later resubmitted by Carestream Health, which was formed in May 2007 when private equity firm Onex Corp. purchased Eastman Kodak's health group. To date, no commercial product has yet been introduced by either Kodak or Carestream Health based on that patent.