Continuous Glucose Monitoring: 40 Years, What We′ve Learned and What’s Next

Abstract

After 40 years of research and development, today continuous glucose monitoring (CGM) is demonstrating the benefit it provides for millions with diabetes. To provide in vivo accuracy, new permselective membranes and mediated systems have been developed to prevent enzyme saturation and to minimize interference signals. Early in vivo implanted sensor research clearly showed that the foreign body response was a more difficult issue to overcome. Understanding the biological interface and circumventing the inflammatory response continue to drive development of a CGM sensor with accuracy and reliability performance suitable in a closed-loop artificial pancreas. Along with biocompatible polymer development, other complimentary algorithm and data analysis techniques have improved the performance of commercial systems significantly. For example, the mean average relative difference of Dexcom's CGM system improved from 26 to 14% and its use-life was extended from 3 to 7 d. Significant gains in usability, including size, flexibility, insertion, calibration, and data interface, have been incorporated into new generations of commercial CGM systems. Besides Medtronic, Dexcom, and Abbott, other major players are also investing in CGM. Becton Dickinson is conducting clinical trials with an optical galactose glucose binding system. Development of fully implanted sensor systems fulfills the desire for a discreet, reliable CGM system. Research continues to find innovative ways to help make living with diabetes easier and more normal, and new segments are being pursued (intensive care unit, surgery, behavior modification) in which CGM is being utilized.

Electrochemical Glucose Biosensors for Diabetes Care

“…Consequently, there are many reviews which allow for a very good overview of employed techniques, results, trends of development, and challenges which remain to be mastered [222][223][224][225][226][227][228][229][230][231][232]. The emphasis of this review is the description of sensor technology which is currently used in CGM systems.…”

Wearable Continuous Glucose Monitoring Sensors: A Revolution in Diabetes Treatment

“…In recent years, various glucose-sensing mechanisms for non-invasive, or at least minimally invasive, CGM have been tested [18][19][20][21][22][23][24][25][26], in an attempt to match all fundamental requirements for an extended in vivo use, e.g., sensitivity, specificity, linearity within biological relevant range, biocompatibility, and lifetime [13]. Among all the proposed techniques, i.e., electrochemical, optical, and piezoelectric, the one that is today exploited by most of the commercialized CGM systems is the glucose-oxidase electrochemical principle [8].…”

Preclinical Performance Evaluation of Percutaneous Glucose Biosensors

“…While widely available and easy to use, the inherent error associated with BG measurement for most handheld glucometers (MARD 5-10%) 48 approaches that of several commercially available CGMs (12-19%). 49 This drawback has significant implications for the utility of nonstatistical clinical accuracy metrics (eg, C-EGA), as imprecision of the reference method will propagate into the EGA and suggest inadequate CGM performance, especially in the region of 50-100 mg dL -1 BG where accuracy requirements are most demanding. Statistical measures of CGM accuracy (ie, mean and median absolute and relative deviation) are thus more suitable for the initial evaluation of in vivo glucose sensor performance, as these descriptors are less sensitive to error in the reference method.…”