Microwave substrate integrated waveguide resonator sensor for non-invasive monitoring of blood glucose concentration: Low cost and painless tool for diabetics

[Display omitted] •Microwave sensor for non-invasive blood glucose monitoring in fingertips.•BGC changing changes the resonant frequency of the sensor.•Easy integration capability with other parts of circuit.•Low cost and painless tool for diabetic patients.•Portability of the proposed microwave biosensor. In this study, a microwave resonant sensor with an operation frequency of 9 GHz and a quality factor of 240 has been designed, fabricated and tested by fingertips of the users to control blood glucose levels. The proposed method includes the implementation of a band-pass filter in the substrate integrated waveguide cavity, which has been carried out using a modified split ring resonator. In this research, 4 volunteers with glucose level changes ranging from 92 to 141 mg dL−1 have been tested invasive (by a glucometer) and non-invasive (by the designed sensor). For this range of glucose level changes, the frequency detection resolution is 7.67 MHz (mg dL−1)−1.