Comprehensive System for Noninvasive Glucose Monitoring Utilizing a Rectangular Dielectric Resonator Microwave Sensor

Abstract

This study introduces a comprehensive system for glucose level measurement using a compact two-port rectangular dielectric resonator (RDR) to validate the system’s accuracy against traditional invasive glucometer measurements. The system features a voltage-controlled oscillator (VCO) that generates a 2.47-GHz frequency. A power detector converts the RF signal to dc voltage levels, and a multimeter facilitates the interpretation. The primary sensor component is energized via a rectangular aperture-coupling mechanism in the ground plane. The RDR acts as a sensor because of the varying dielectric permittivity linked to different glucose concentrations, leading to unique resonance frequencies and magnitude shifts. The bare sensor’s resonance frequency was designed to be at 3.28 GHz, shifting to 2.47 GHz when loaded with a human finger. The Cole-Cole method modeled the human thumb with the blood layer in simulation. An electrical prototype enhanced detection, providing a 39E−02 MHz/mg/dL resolution at 2.47 GHz. The RDR sensors’ S-parameters highly correlated with laboratory-based testing, achieving 92.68% accuracy. Compared to home-based invasive glucometer measurements, the proposed continuous glucose monitoring (CGM) system with a two-port RDR sensor measures diabetes value changes with 92.08% precision.