A Noninvasive Method for Measuring the Blood Glucose Level Using a Narrow Band Microstrip Antenna

In this paper, a narrowband and compact antenna resonating at 6.1 GHz with a peak realized gain of 3.3 dBi is proposed to monitor the glucose concentra-tion in the blood without taking invasive blood samples. The proposed antenna is fabricated using a low-cost FR -4 substrate with compact dimensions of 30 mm x 30 mm x 1.6 mm. The impedance bandwidth of this antenna ranges from 5.2 to 7.1 GHz. For measuring blood glu-cose levels, a human finger phantom model with dimen-sions of 15 mm x 12 mm x 10 mm is constructed using the EM simulation (HFSS) environment. The fin-ger phantom consists of different layers such as skin, fat, muscle, blood, and bone modeled at 6.1 GHz using var-ious dielectric materials for various glucose concentra-tions. The finger phantom model is placed at different locations around the antenna to measure the frequency shift for monitoring glucose concentration in blood sam-ples. The proposed finger phantom model is validated by conducting an experimental study by placing a real human finger around the fabricated antenna and measur-ing the frequency shift. This study shows a very good agreement with the results obtained by the simulated phantom model. The advantages and outperformance of the proposed sensor are highlighted in terms of the sensi-tivity obtained and compared with other techniques given in the literature.