Polarimetric glucose sensing utilizing a digital closed-loop control system

Abstract

The condition known as diabetes mellitus afflicts millions of people worldwide. The primary cause of this disease is a decreased secretion of insulin into the bloodstream. This reduced insulin circulation can result in abnormally high blood glucose levels, known as hyperglycemia. This condition can cause long-term complications such as cardiovascular disease, hypertension, retinopathy, nephropathy, and neuropathy. Research indicates that the risk of these complications can be reduced with frequent blood glucose monitoring so appropriate actions can be taken. Currently, only invasive techniques are commercially available to monitor blood glucose levels. However, a noninvasive method utilizing polarimetry is being researched as an alternative method for the indirect determination of blood glucose levels. These measurements would eventually be obtained by determining the amount of rotation in polarization of a laser beam which passes through the aqueous humor of the eye. In this study, a polarimeter utilizing a digital closed-loop control was designed, implemented, and tested. Its potential as a non-invasive glucose sensor was evaluated in vitro in both glucose doped water and aqueous humor mediums. Overall, the obtained results in this research are promising and show a considerable improvement over previously published work.