A novel approach to non-invasive blood glucose sensing based on a single-slot defected ground structure

Abstract

In this study, we explore a novel approach to measure blood glucose concentration in a non-invasive way using a compact defected ground structure (DGS) filter. The proposed sensor is promising because it is cost-effective, compact, non-ionizing in nature, and convenient for diabetics. Therefore, a portable microwave biosensor can be utilized using these features. In this study, we present a single DGS sensor which is designed on a Rogers RO4003C substrate and fed by a 50 Ω microstrip line, and operating in the industrial, scientific, and medical radio bands (2.4–2.5 GHz). The changes in dielectric properties in blood are mainly relying on glucose concentrations. The main concept of using a sensor is by placing a finger on the sensing area (the slot). The filter is demonstrated by simulations using CST Microwave Studio. Additionally, the blood layer with different glucose concentrations from 250 to 16 000 mg/dl is presented by the Cole–Cole model. The sensor can achieve a relatively good sensitivity of 7.8285 kHz/mg/dl. The size of the fabricated sensor is 40 × 40 × 0.883 mm3, which is suitable for hand-held use.

Non-Invasive Glucose Sensing Technologies and Products: A Comprehensive Review for Researchers and Clinicians

“…PPG absorbance and reflectance signal can vary depending on blood circulation, blood viscosity, peripheral vascular resistance, vascular elasticity, and movement [37]. To increase the accuracy of this technique, machine learning or other paired sensor techniques would be needed to adjust for these variables [40].…”

“…Research has shown promise for glucose monitoring handheld devices for in vivo mmW measurements through the earlobe or finger web between 3 and 5 mm thick using silicon-loaded probes [105], through a compact finger slot reader or fingertip [40,96], and through the forearm [using bioheat transfer models;] [106], [using a near-field probe;] [107]. The studies reported that skin, fat, and blood have the most significant impact on the reflected signal, while muscle and bone have a negligible effect [107].…”

Improving Sensitivity of Noninvasive Blood Glucose Microwave Sensor Via Substrate Selection

“…Several studies have investigated the impact of dielectric constant on the sensitivity of noninvasive blood glucose detection. In a comparative study 1 , researchers evaluated different substrates and discovered a positive correlation between higher dielectric constants and improved sensitivity and accuracy in glucose detection. Similarly, in related research 2 , experiments using diverse substrates demonstrated that higher dielectric constants contributed to enhanced glucose detection capabilities.…”

A symmetric bar chart-shape microwave sensor with high Q-factor for permittivity determination of fluidics

“…The sensors with high sensitivity can be used for adjustable cancellation [57]. The important issue is what methods and techniques are needed to increase the sensitivity of sensors [58][59][60][61].…”