We compared the sensor performance of 3 commercially available GM systems. A total of 12 patients with type 1 diabetes were included in a single-centre, open-label study in which the sensor performance of the Abbott FreeStyle libre (Abbott), Dexcom G4 Platinum (Dexcom) and Medtronic MiniMed 640G (Medtronic) systems over 12 hours was compared during mimicked real-life conditions (meals, exercise, hypo-and hyperglycaemia). Sensor performance was determined by fulfilment of ISO 15197:2013 criteria, calculating mean absolute relative difference (MARD), and was also illustrated using Parkes error grid and Bland-Altman plots. Sensor performance during changes in metabolic variables (lactate, betahydroxybutyrate, glucagon, non-esterified-fatty-acids) was determined by Spearman's rank correlation coefficient testing. The systems fulfilled ISO 15197:2013 criteria by 73.2% (Abbott), 56.1% (Dexcom) and 52.0% (Medtronic). The MARDs AE standard deviation in the entire glycaemic range were 13.2% AE 10.9% (Abbott), 16.8% AE 12.3% (Dexcom) and 21.4% AE 17.6% (Medtronic), respectively. All sensors performed less accurately during hypoglycaemia and best during hyperglycaemia. We did not observe an influence of metabolic variables on sensor performance.

Roll-to-roll UV nanoimprint lithography has superior advantages for high-throughput manufacturing of micro- or nano-structures on flexible polymer foils with various geometries and configurations.

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The purpose of this study was to characterize the heterogeneity of oxygen partial pressure in different adipose tissue zones and to assess the possibility of compensating these heterogeneities during optical glucose measurements. In this proof of concept study, the heterogeneity of oxygen partial pressure was determined in the adipose tissue of a pig by using 48 oxygen sensors in 3 zones of the abdominal region at two different blood oxygen levels. Sensor oxygen values correlated well with reference blood oxygen values and we identified heterogeneities in oxygen partial pressure among the defined zones of the abdominal region. Significant differences in the mean oxygen partial pressure were found when comparing the three abdominal zones but no significant differences were found when comparing two sensors located in close proximity (on one cannula). The low heterogeneity on one cannula allows the compensation of physiological oxygen variations for optical glucose measurements by using an additional oxygen sensor in close proximity to the glucose sensor. In addition, this setup can be used to continuously monitor tissue oxygenation e.g. in patients with adipose tissue dysfunction or serve limb ischemia.