Ingestible RFID bio-capsule tag design for medical monitoring

Medicine monitoring is a very difficult and crucial task to accomplish. It is critical to monitor the ingestion of medication as sometimes patients forget to take their medication or take the wrong medication. This can lead to drug overdose and other fatal consequences. Recently, Eastman Kodak™ Company has proposed a system to monitor medicine ingestion by tagging each pill with an RFID Tag. The medical monitoring system can consist of RFID pill tag, a small reader in the form of a necklace and a main receiver for data storage. As soon the patient swallows the RFID pill tag, the necklace reader reads the tag and the information is sent to the main receiver for data storing and cataloging. Thus, the patient can keep track of his medicine intake. This paper presents the design of an ingestible RFID tag antenna which can be attached to any capsule pill and used in this medicine monitoring process. This RFID tag is complex conjugate matched to the Aliens Higgs-2 microchip impedance (for initial prototyping). The tag operates from 860MHz to 960MHz covering the entire UHF RFID band. The design is based on a space filling conformal planar meandered dipole concept. The antenna is mismatched in free space and it is tuned to the human body, so that when the pill is ingested, the tag will send the back-scattered signal to the reader. Potential batch fabrication of the tag antenna by depositing thin metal films on flexible polymers is discussed.