Characterisation and Modelling of Microwave Open-Ended Coaxial Sensor for In Vivo Non-invasive Glucose Content Measurements

Diabetes is one of the world-leading lethal diseases that have no cure, but it is manageable to prevent further deterioration. The in vivo non-invasive glucose monitoring method can be a key to aid the diabetes patient in monitoring the glucose level effectively in the future with the features of cost-effectiveness, painless and minimum infection. In this paper, the dielectric measurement technique has been applied to obtain the relationship between dielectric properties and the in vivo blood glucose concentration on a human subject. An open-ended coaxial sensor is used to measure the EM parameters at various blood glucose concentrations by placing them on Pulse, Thumb and Finger. The measurement data have been collected and compared to the commercial invasive glucose meter. The characterisation and modelling have been performed with a few selected frequencies at 1GHz, 2GHz and 4GHz. Based on the analysis, the dielectric constant drops and the loss factor rises as the glucose level increases. The models have been validated, and the performance has been analysed. It was showed that the Pulse is the optimal position to apply for the non-invasive blood glucose measurement.