A Conformal Ingestible Ultra-Wideband Capsule Antenna for Biotelemetry Communication

This work presents an ingestible wireless capsule endoscopy (WCE) antenna in conformal arrangements. The performance of ingestible antennas can be hindered (detuned) by several factors within the body, including the diverse electrical properties of tissues in the digestive system, the presence of electronic components within the capsule itself, variations in the thickness of the biocompatible coating, and the flexible nature of the device. The proposed meandered loop antenna enables miniaturization, low profile, cost-effectiveness, and wide bandwidth, reducing susceptibility to detuning effects in WCE. Based on simulations, the proposed antenna mounted with electronic components exhibits wide impedance bandwidths, from 0.4 –10.6 GHz, which covers the medical implants communication services (MICS) (401−406 MHz), wireless medical telemetry services (WMTS) (1.4 GHz), industrial, scientific, medical (ISM) (0.433, 0.915, and 2.45 GHz) and ultra-wideband (UWB) (3.1 –10.6 GHz) frequency bands. The proposed antenna (22.6 × 8.9 × 0.068 mm
³
) conformed on a compact capsule (17×7 mm
²
) has a gain of -37.0, - 35.3, - 29.1, - 32.3, and - 26.2 for 0.413, 0.433, 0.915, 1.4, and 2.45 GHz (central frequencies) respectively. In addition, the antenna is validated for robustness using different homogeneous phantoms (colon, muscle, small intestine, and stomach), and performance metrics such as far-field and SAR have been evaluated for central frequencies considering muscle phantom.