Investigation on Dielectric Properties of Glucose Aqueous Solutions at 500 KHz-5MHz for Noninvasive Blood Glucose Monitoring

摘要

Noninvasive blood glucose monitoring (NBGM) provides patient with diabetes a prospective approach with the characteristics of painless and sustainable monitoring. In this study, the dielectric properties of glucose aqueous solutions, namely, deionized water solutions and saline solutions were studied. Specifically, the conductivity and the dielectric constant were measured by using impedance analyzer in the frequencies range of 500 KHz to 5MHz at 25°C. The results showed that both the dielectric constant and the conductivity for the two types of glucose aqueous solutions decreased with the increase of glucose concentration in the above frequency band. By comparing the two solutions with human blood, it was found that the dielectric properties of physiological saline are closer to that of human blood. In the study, saline solution was adopted as research object. In order to formulate the relationship between the dielectric properties of saline solutions and glucose concentration, the third-order Cole-Cole model for each glucose concentration was developed and the coefficient of determination R~2 was as higher as 0.99. In addition, a second-order polynomial is used to model the glucose concentration dependence for the Cole-Cole parameters. The result indicates that the NBGM at low frequencies has potentials in practical applications.