Microwave Hydration Monitoring Using Wearable Antennas

Dehydration, even at a mild stage, can disrupt physiological processes in both humans and animals. Early diagnosis and continuous monitoring are essential to prevent dehydration from damaging vital systems. However, measuring dehydration remains a challenge, as there is no single gold-standard method, and current approaches are expensive, invasive, and unsuitable for continuous assessment. Microwave techniques offer a promising alternative to address these issues. This study explores wearable antennas designed for microwave-based localized tissue assessment at the extremities to detect hydration changes. A conformal printed monopole antenna, operating over a wide frequency range, is developed on denim fabric, and its performance is analyzed both in air and in contact with lossy dielectrics. Due to mismatches at the air-tissue interface and unstable radiation behavior in the target frequency band, enhancement approaches are studied, resulting in a compact design with improved performance when in contact with tissue, called a ”body-matched antenna.” This design is then evaluated through simulations using a realistic multilayer arm model, as well as through measurements with ground beef phantoms and a human pilot study. The results suggest the potential of the system to detect changes in hydration. As a proof of concept, a portable monitoring system is developed using body-matched antennas, enabling remote assessment of permittivity changes. The outcomes of this study represent a step toward continuous hydration monitoring.

Name thesis:degree_name

Master of Science (MSc)

Discipline thesis:degree_discipline

Engineering – Electrical & Computer

Grantor

Schulich School of Engineering

Year dc:date.issued

2025

Author dc:creator

• Khalili, Mehdi

Advisor dc:contributor.advisor

• Fear, Elise Carolyn

Committee members dc:contributor.committeemember

• Okoniewski, Michal
• Nielsen, Jorgen

• Microwaves
• Antennas
• Hydration monitoring
• Applied Electromagnetics

Statement dc:rights

• Unless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

en

DOI

https://dx.doi.org/10.11575/PRISM/50234

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:1880/122641