InVivo and ExVivo Measurements of Blood Glucose Using Whispering Gallery Modes The permittivity of blood glucose is not a strong function of its concentration in microwave or millimeterwave frequencies. Measuring glucose concentrations remains a challenge, particularly in the presence of interference caused by the ambient leaky waves. In this paper, however, we demonstrate that a nearlinear correlation between the glucose concentration and the blood permittivity was noticeably observed at a whispering gallery mode resonance. Method: the proposed sensor was a vacuum suction aspirator partially wounded with a turn of the Goubau line. This arrangement enabled a fixed cylindrical volume of a skin tissue bump or glucosewater solution to be formed and used as a whispering gallery resonator for invivo and exvivo measurements. Results: in the invivo study, a nearlinear correlation between the glucose levels and the S21 parameters was noticeably observed at the fundamental whispering gallery resonance (i.e., at 2.18 GHz). In the exvivo study, a similar correlation was observed between the concentration of a glucosewater solution and the S21 parameters 56.6 GHz. Conclusion: the results of both investigations were consistent not only with the invasive measurements using the AccucheckTM, but also with the conclusion drawn by some other research groups who have successfully measured blood glucose concentrations at millimeterwave frequencies.

Food Security Sensing System Using a Waveguide Antenna Microwave Imaging through an Example of an Egg In this paper, we present a form of food security sensing using a waveguide antenna microwave imaging system through an example of an egg. A waveguide antenna system with a frequency range of 7xe2x80x9313 GHz and a maximum gain of 17.37 dBi was proposed. The maximum scanning area of the waveguide antenna microwave imaging sensing system is 30 xc3x97 30 cm2. In order to study the resolution and sensitivity of the waveguide antenna microwave imaging sensing system, the circular and triangular highk materials (with the same thickness but with different dielectric constants of the materials) were used as the testing sample for observing the microwave images. By using the proposed waveguide antenna microwave imaging sensing system, the highk materials with different dielectric constants and shapes could be easily sensed. Therefore, the waveguide antenna microwave imaging sensing system could be potentially used for applications in rapid, nondestructive food security sensing. Regarding the example of an egg, the proposed waveguide antenna microwave imaging sensing system could effectively identify the health status of many eggs very quickly. The proposed waveguide antenna microwave imaging sensing system provides a simple, nondestructive, effective, and rapid method for food security applications.