Evaluation of the GlucoPred hardware for glucose measurements in a liquid medium

Abstract

The goal of this study is to assess the suitability of the GlucoPred hardware platform, designed for non-invasive glucose measurements through the skin, in terms of glucose detection in liquid samples. This evaluation is based on the use of the first generation GlucoPred prototype, which is utilising near infrared LEDs with discrete values in the 590-2350nm range. Also on the prototype is three infrared detectors, covering individual and somewhat overlapping ranges in the 300-2600nm segment. Due to the prototype not being designed to perform measurements on liquids, a set of specialised sample cells utilising transflectance have been constructed. These cells have then been used to perform the measurements in an iterative process consisting of data gathering, multivariate analysis and subsequent improvements to the process. During these analyses it was discovered that the shorter wavelengths showed indications of saturating the detectors, and the data from the 590-1330nm range was therefore ignored in the later analyses. The final results provided by the remaining wavelengths verify the theoretical expectations that the 1450-1850nm and 2020-2350nm ranges exhibit absorptions directly related to the glucose content of the sample. These results also verify that this subset of wavelengths together with the detector covering the broadest range is capable of delivering measurements of liquid samples that can be used to build significantly accurate predictive models. Therefore, in spite of the subset of wavelengths which experienced indications of saturation, there is no evidence that the technology implemented on the GlucoPred should not be suitable for further adaptation towards a system for peritoneal glucose measurement.