A mm-wave Antenna Array for Non-Invasive Glucose Monitoring

Abstract

Body-adapted radio frequency systems and antennas offer a bundle of possibilities in enabling lightweight, low-cost, accurate, reliable, and portable wireless sensing devices. The integration of these devices into wearable apparel added a line of complexities and design challenges to radio frequency engineers. In a glucose sensing device, the millimeter-wave band is particularly attractive due to its high sensitivity while satisfying size constraints and penetration depth restrictions. Furthermore, designing antennas to be worn by the users must take into account their possible movements as well as it must take into consideration maintaining efficient communication between the front-end systems and the human body. Efficient sensing is achieved when the penetration of the electromagnetic waves into the blood vessels is not hindered by various propagation effects. Hence, circularly polarized antennas are desired. Previous work in the literature presented various solutions for glucose monitoring that range from implantable sensors to minimally invasive devices to wearable apparel. However, none of the available work has demonstrated a wearable system at millimeter-wave that can offer continuous non-invasive glucose monitoring ability.

In this work, we intend to address a newly designed mm-wave aperture coupled, series-fed, multilayer structure array antenna with circular polarization for continuous non-invasive glucose monitoring. The proposed novel, miniaturized, highly directive, and circularly polarized mm-wave array antenna can be worn by patients with diabetes to continuously and non-invasively monitor their blood glucose variations. Electromagnetic wave propagation principles merged with data analytics algorithms are implemented to extract glucose concentrations from the interaction between electromagnetic wave propagation and the blood vessels. Ex-vivo on serum solutions and in-vivo experiments on animal models were executed to verify the accuracy and sensitivity of the proposed system.