Modeling and Characterization of Intra-Body Links for a Smart Contact Lens

• Published in: IEEE International Symposium on Circuits and Systems proceedings pp. 1 - 5
• Main Authors: Cuevas, Nestor, Roa, Elkim, Stanzione, Stefano, Van Helleputte, Nick, Raducanu, Bogdan C.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2021
• Subjects: Circuits and systems; Coils; Estimation; Head; Integrated circuit modeling; Lenses; Wearable computers
• ISBN: 9781728192017; 1728192013
• ISSN: 2158-1525
• DOI: 10.1109/ISCAS51556.2021.9401610

Modern and miniaturized ASICs enable the development of anatomically constrained applications within the biomedical framework, such as smart contact lenses. Recent works report lenses receiving power and communicating through inductive coupled links. However, the efficiency of an inductive link depends highly on alignment and distance between coils, thus encouraging the exploration of other techniques to power and communicate a smart contact lens. Intra-body links emerge as an alternative to inductive ones for wearable devices, with promising path-loss results reported in previous works. Here, we evaluate the feasibility of powering a smart contact lens through an intra-body link. We propose a simplified 3D-FEM human-head model to estimate channel losses in a real contact lens situation. Then, we validate the pathloss estimations on the head through a human arm experiment, and comparison against a simplified 3D-FEM human-arm model. Based on our analysis, we estimate retrieved power of μW level, demonstrating the feasibility of using an intra-body link to power a smart contact lens.