Feb 28, 2007RFID tags might someday be affixed to pills and then used to monitor the medicine once it is swallowed, according to a patent filed by Eastman Kodak Co. and posted last month on the Web site of the U.S. Patent and Trademark Office. The patent describes how such RFID tags would be useful for verifying proper drug usage, monitoring drug interactions, controlling dosage and even maintaining inventory control. However, it's not clear whether such RFID-tagged pills will ever show up at your local pharmacy or hospital.
Eastman Kodak officials declined to comment on the patent, citing a corporate policy of not publicly discussing technology that has not been commercialized. According to the patent filing, Kodak employees John Spoonhower and Edward Covannon coinvented the ingestible tag technology. The tag system outlined in the patent includes a tag comprised of at least one antenna—which could be made of digestible material such as encapsulated metallic liquids, clays, or even liquids or gases—and an external transceiver that communicates with the tag to read the RF signals. The tag would document when a pill was digested because its antenna would also have been broken down at the same time, thus destroying the tag's ability to receive and transmit an RF signal.
The patent also describes a similar application for tags that could signal when an artificial body part is due for replacement. According to the patent, the tag could be engineered "to break down under mechanical stresses rather than by chemical reaction. Such a tag may be affixed to an artificial or natural body part. It is then implanted and can be remotely queried. When wear on the body part—for example, an artificial hip—has proceeded to a predetermined level, the tag is rendered useless, thus alerting the remote query that the body part has achieved an unsatisfactory level of wear."
Such tags are not yet available on the market, but Eric Newmark, senior research analyst with Health Industry Insights says they do have value.
For example, an ingestible tag could replace current RFID mechanisms to monitor patient compliance of dosing schedules. Drug-monitoring applications have already appeared in the clinical environment and for the elderly in home-care situations, according to Newmark. "Until now it has been built into packaging that tracks each pill as it is popped out [of a pill dispenser]," Newmark says. "Kodak's current patent filing for an ingestible tag could certainly reduce the costs surrounding this process, but more importantly, it opens the door for other potential medical uses, such as a cheaper and easier way to monitor internal bodily functions, track wear and tear on implants, and examine the absorption of drugs. However, this type of tag is a longer-term play, since use of this type of technology still needs to undergo extensive safety and efficacy testing to gain FDA approval."
Kodak currently offers a variety of health-care imaging technologies as part of its Health Group, which in mid-January Kodak announced is being sold to Onex Healthcare Holdings Inc., a subsidiary of Onex Corp., for up to $2.55 billion. In its patent, Kodak suggests that the ingestible tag could be a less-invasive alternative to "traditional methods of obtaining internal physiological information" such as "physically probing the body via an orifice or incision with tools such as endoscopes or laparoscopes; imaging the body with modalities such as X-ray, computed tomography or magnetic resonance imaging; or collecting biological samples such as blood, saliva, bodily secretions or biopsy tissue."
"It would be appealing," the patent continues, "to probe the living body without the effort, expense, inconvenience and risk of injury or infection involved with the above methods."
In particular, the company suggests a digestible RFID tag could be an improvement over ingestible cameras, such as the PillCam, a video capsule developed by Given Imaging, which is specifically designed to view the inner lining of the esophagus. The PillCam, about the size of a multivitamin, has a miniature camera on each end. Sensors are placed on the patient's chest and connected to a data recorder. According to Kodak's patent, PillCams are "relatively complex, expensive, unpleasant to swallow and are limited in their ability to collect physiological information."
