Joint optical-electrical technique for noninvasive glucose monitoring

Abstract

In Diabetes mellitus, self monitoring of blood glucose is crucial for effective treatment since it can help identify and prevent unwanted periods of hypo- and hyperglycemia; this monitoring procedure usually involves finger-stick testing which is painful to the patient and carries the risk of infection. Non-invasive techniques, including impedance and near infrared spectroscopy, have been developed to predict glucose concentration; however, these techniques have not reached the accuracy needed for glucose monitoring. In this work a new concept which involves the combination of two spectroscopic measurements, electrical impedance spectroscopy and near infrared spectroscopy, is developed to decrease the prediction error of single-measurement non-invasive glucose monitoring systems. Electrical impedance and near infrared spectroscopy measurements were performed under controlled temperature and humidity conditions on ten non-diabetic volunteers (age 26.1 $\pm $ 3.7 years, BMI 25.24 $\pm $ 3.67 kg/m$^{2})$. The results show that all of the values predicted by the joint optical-electrical technique were clinically acceptable and the root mean squared error of prediction, which in this study was compared to a commercial glucose meter, is lower than previously published values for near infrared spectroscopy and impedance spectroscopy done separately.