MICROSTRIP DEFECTED GROUND STRUCTURE FOR DETERMINATION OF BLOOD GLUCOSE CONCENTRATION

This work reports the application of a microwave sensor in measuring human blood glucose concentration. The main contribution of this work lies on the blood glucose profile which is collected from 69 random patients regardless of their gender, age, and haematology properties, instead of using water as the base or focusing on a single person. Hence the blood glucose profile is more realistic. Blood is extracted from the participants and dropped at the centre of the dumbbells section of a microstrip defected ground structure to gather the notch frequency shifting data. On the other hand, the blood samples are measured using Omron Freestyle Glucometer to collect their associated blood glucose readings. Five predicting models have been proposed in this work. Based on the cross-validation, it is found that the blood glucose level can be correlated very well with shifted notch frequency by using a linear model. It introduces least root mean square error (RMSE) of 0.0592 and shows good correlation ([R.sup.2] = 0.9356) between the reading from commercial glucometer and microwave sensor in the range up to 12mmol/L. The reliability of this microwave sensor is proven once again when the predicted blood glucose data are all falling in Zone A of Clarke Error Grid. The outcome of this work shows the capability of this microwave sensor in measuring the blood glucose level. Since this microwave sensor can be reused under a proper cleaning procedure, it improves the sustainability of conventional blood glucose testing by reducing the disposal of testing strips and cost. It is believed that this sensor will be suitable for extensive blood glucose testing conducted in the laboratory.