Feasibility of Continuous Ketone Monitoring in Subcutaneous Tissue using a Ketone Sensor

Background:The feasibility of measuring ?-hydroxybutyrate in ISF using a continuous ketone monitoring (CKM) sensor using a single calibration without further adjustments over 14?days is described.Methods:A CKM sensor was developed using wired enzyme technology with ?-hydroxybutyrate dehydrogenase chemistry. In vitro characterization of the sensor was performed in phosphate buffered saline at 37°C. In vivo performance was evaluated in 12 healthy participants on low carbohydrate diets, who wore 3 ketone sensors on the back of their upper arms to continuously measure ketone levels over 14?days. Reference capillary ketone measurements were performed using Precision Xtra? test strips at least 8 times a day.Results:The sensor is stable over 14?days and has a linear response over the 0-8?mM range. The operational stability of the sensor is very good with a 2.1% signal change over 14?days. The first human study of the CKM sensor demonstrated that the sensor can continuously track ketones well through the entire 14?days of wear. The performance with a single retrospective calibration of the sensor showed 82.4% of data pairs within 0.225?mM/20% and 91.4% within 0.3?mM/30% of the capillary ketone reference (presented as mM at