Review of Communication Systems for Ingestible Miniaturized Integrated Sensor Microsystems

Recently, there is a growing interest for miniaturized telemetry systems for a variety of biomedical applications such as the development of wireless sensor systems that can be integrated into a noninvasive capsule format to perform endoscopic functions within the gastrointestinal tract. An important issue in such systems is the real time transmission of the data out of body wirelessly. Developments in system-on-chip and wireless technologies have led to complex electronic systems to be miniaturized to size of ingestible capsule and implantable microsystems. Inevitably such miniaturized complex systems impose some constraints on the case of an ingestible diagnostic capsule. It is desirable that system be wireless, programmable, and reusable. In this paper, we review some possible wireless interface methods and describe a programmable wireless direct sequence spread spectrum link developed for such an ingestible microsystem.