Optically Controlled Microwave Sensor for Biomedical Applications

In this paper, a design of a microwave resonator is introduced for noninvasive blood glucose biomedical sensing. The proposed sensor is constructed from a printed transmission line of 50Ω characteristics impedance. The transmission line is loaded with a meander line of a sweep penny elegance chaos. The structure is splitted into two symmetric parts that are connected to each other through a light dependent resistor (LDR). The to maximize the field fringing through the sample under test, an interdigital capacitor is introduced in parallel to the meander line structure. The proposed sensor is found to provide multiple frequency resonances. However, the authors considered the frequency resonance at 3.46GHz to ensure the effective resonance of the detection with changing the blood glucose level. Therefore, the proposed sensor is fabricated and tested experimentally with 100 patients to realize the effects of varying the blood glucose level up on the proposed sensor transmission loss spectra in terms is of S11 magnitude. The proposed sensor performance is tested and optimized using circuit model theory. Next, the design performance is validated numerically using Computer Simulation Technology of Micro Wave Studio (CST MWS) commercial software package of finite integral technique algorithm. Finally, the experimental and theoretical results are found in good agreement to each other.