Cylindrical Dielectric Resonator Antenna Sensor for Non-Invasive Glucose Sensing Application

Abstract

A compact cylindrical dielectric resonator antenna is presented for non-invasive glucose sensing. The proposed antenna sensor consists of an Alumina ceramic dielectric resonator fed by a 50 Ω microstrip line. For sensing the glucose, the thumb of the subject is placed on the dielectric resonator. The permittivity of the blood inside the thumb depends on the glucose concentration. Therefore, the change of the input impedance of the proposed sensor is proportional to change of blood permittivity caused by variable glucose concentration, translating in a shift of resonance frequency. The concept is validated by simulated results obtained in full-wave electromagnetic simulator CST Microwave Studio. Moreover, a 3D electromagnetic model of human thumb is also proposed. The blood layer is modeled by Cole-Cole model. Additionally, the variations in the thumb placement is also evaluated and it is shown that the resonance frequency (4.725 GHz) of the proposed sensor is not altered much by variations in thumb placement. The sensitivity of the proposed sensor is 2.81 kHz/mgdL <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . The size of the proposed sensor is 60×60×1.52 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> that makes it suitable for hand-held use.