Innovative Non-Invasive Blood Glucose Monitoring by Using Multiband Split Ring Resonator Monopole Antenna (MSRRMA)

This paper presents a multiband, compact monopole antenna based on an irregular curved shape of split ring resonator design MSRRMA to enable continuous monitoring of human blood glucose concentration level without requiring invasive blood samples. The proposed sensor resonates at frequencies of 0.94, 1.5, 3, 4.6, 6.3 and 7.2 GHz, with reflection coefficient impedance bandwidths ≤-10 dB at 4%, 3.5%, 65%, and 50%, respectively. Two cells of SRR metamaterial shape are used to create notches at 1.7 GHz and 4.4 GHz. The proposed monopole antenna is constructed using a cost-effective FR4 substrate with dimensions of 35 × 50 × 1.6 mm³. The 3D electromagnetic simulation using computer simulation technology (CST) software is employed to simulate the proposed antenna sensor with a human finger phantom model, measuring the sensor's sensitivity to blood glucose concentrations. The finger phantom model is positioned at various angles around the antenna to detect frequency changes relevant to blood glucose content monitoring. In experimental research, a real human finger is placed around the proposed sensor to measure resonant frequency, magnitude, and phase changes. The proposed sensor is fabricated to validate the results, highlighting its benefits and superiority in sensitivity compared to alternative methods in the literature.