Non-Invasive Real-Time Monitoring of Glucose Level Using Novel Microwave Biosensor Based on Triple-Pole CSRR

• Published in: IEEE transactions on biomedical circuits and systems Vol. 14; no. 6; pp. 1407 - 1420
• Main Authors: Omer, Ala Eldin, Shaker, George, Safavi-Naeini, Safieddin, Alquie, Georges, Deshours, Frederique, Kokabi, Hamid, Shubair, Raed M.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.12.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); Institute of Electrical and Electronics Engineers
• Subjects: Biosensors; Blood; Centimeter waves; Complementary split-ring resonators; Debye model; Diabetes; Diabetes mellitus; dielectric characterization; Dielectric properties; Dielectric substrates; Electrical properties; Electromagnetic fields; Engineering Sciences; Fabrication; Frequency dependence; Frequency response; Glucose; Glucose sensors; Health risks; Microstrip; microstrip technology; microwave sensing; Microwave sensors; Mimicry; Monitoring; Network analysers; non-invasive glucose detection; Real time; Sensitivity; Sensors; Split ring resonators; Substrates; Tissues; Transmission lines; Debye model; Non-invasive glucose detection; Dielectric characterization; Complementary split-ring resonators; Microwave sensing; Microstrip technology
• ISSN: 1932-4545; 1940-9990; 1940-9990
• DOI: 10.1109/TBCAS.2020.3038589

Planar microwave sensors are considered an attractive choice to noninvasively probe the dielectric attributes of biological tissues due to their low cost, simple fabrication, miniature scale, and minimum risk to human health. This paper develops and measures a novel microwave biosensor for non-invasive real-time monitoring of glucose level. The design comprises a rectangular plexiglass channel integrated on a triple-pole complementary split ring resonator (TP-CSRR). The proposed sensor operates in the centimeter-wave range 1-6 GHz and is manufactured using PCB on top of an FR4 dielectric substrate. The sensor elements are excited via a coupled microstrip transmission-line etched on the bottom side of the substrate. The integrated CSRR-based sensor is used as a near-field probe to non-invasively monitor the glucose level changes in the blood mimicking solutions of clinically relevant concentrations to Type-2 normal diabetes (70-120 mg/dL), by recording the frequency response of the harmonic reflection and transmission resonances. This indicates the sensor's capability of detecting small variations in the dielectric properties of the blood samples that are responsive to the electromagnetic fields. The proposed sensor is verified through practical measurements of the fabricated design. Experimental results obtained using a Vector Network Analyzer (VNA) demonstrate a sensitivity performance of about 6.2 dB/(mg/ml) for the developed triple-pole sensor that significantly outperforms the conventional single-pole and other proposed sensors in the literature in terms of the resonance amplitude resolution.