Operation of ingestible antennas along the gastrointestinal tract: Detuning and performance

In this study, we numerically assess detuning issues for an ingestible antenna which is designed to operate in the Medical Device Radiocommunications Service (MedRadio, 401-406 MHz), as it travels along the gastrointestinal (GI) tract. For this purpose, we evaluate the antenna resonance performance within four canonical single-tissue models of the human esophagus, stomach, small and large intestine. The antenna is further placed at different locations within the aforementioned tissue models in order to assess detuning issues related to its relative positioning within each of them. Inherent detuning issues are observed and discussed in the four different simplified tissue models considering three specific locations of the antenna in each model, resulting in twelve different scenarios. The resonance, radiation and safety performance of the ingestible antenna is, finally, evaluated.