A Non-Invasive Honey-Cell CSRR Glucose Sensor: Design Considerations and Modelling

Objective

Over the years, microwave techniques have demonstrated their ability to characterise biological tissues. This study aimed to employ this approach to investigate the changes in the finger's glucose levels and to develop a sensitive sensor that people with diabetes can use.

Materials and methods

A simplified four-layer tissue model of the human fingertip was developed to validate the sensor's ability to detect variations in glucose levels. 3D electromagnetic simulations of the sensor with human fingertips inserted in the sensing region while varying the pressure were performed and compared to obtained experimental results using a VNA (vector network analyser).

Results

When varying the finger layers thicknesses independently, it was observed that the change in the skin layer thickness influences the frequency the most. It was also noticed that the higher the finger pressure, the more the resonance shifted towards low frequencies with a decreasing magnitude.

Conclusion

The achieved results show the impact of the finger's pressure on the sensor. Further investigations are in progress to obtain a good reproducibility of experimental results using a best-fitted pressure protocol on diabetic subjects.