Performance characterization of an abiotic and fluorescent-based continuous glucose monitoring system in patients with type 1 diabetes

Abstract

A continuous glucose monitoring (CGM) system consisting of a wireless, subcutaneously implantable glucose sensor and a body-worn transmitter is described and clinical performance over a 28 day implant period in 12 type 1 diabetic patients is reported. The implantable sensor is constructed of a fluorescent, boronic-acid based glucose indicating polymer coated onto a miniaturized, polymer-encased optical detection system. The external transmitter wirelessly communicates with and powers the sensor and contains Bluetooth capability for interfacing with a Smartphone application. The accuracy of 19 implanted sensors were evaluated over 28 days during 6 in-clinic sessions by comparing the CGM glucose values to venous blood glucose measurements taken every 15 min. Mean absolute relative difference (MARD) for all sensors was 11.6 ± 0.7%, and Clarke error grid analysis showed that 99% of paired data points were in the combined A and B zones.

Wearable Continuous Glucose Monitoring Sensors: A Revolution in Diabetes Treatment

“…Several optical detection methods have been proposed in the literature, both for noninvasive detection, e.g., near infrared detection and Raman spectroscopy, and for implanted systems, which are instead fluorescence-based sensors [18,26]. This last category of optical sensing technique has been recently successfully applied by Senseonics (Senseonics, Inc., Germantown, MD, USA) to develop a fully implanted CGM system [22,53], the Eversense sensor, which provides real-time glucose measurements through the external coupled transmitter for an expected lifetime of six months [54]. Currently, the Eversense CGM is approved to be used in European countries only (CE mark received in 2016) with a lifetime of 90 days and an accuracy of 11.4% MARD [55].…”

“…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].…”

Multisite Study of an Implanted Continuous Glucose Sensor Over 90 Days in Patients With Diabetes Mellitus

“…18,19 Briefly, the system includes a small, fully subcutaneously insertable sensor that measures glucose concentrations between 40 and 400 mg/dl in interstitial fluid. Glucose concentration is measured by means of fluorescence from the glucose-indicating hydrogel, which is polymerized onto the sensor capsule surface over the optical cavity.…”

“…18,19 Consequently, this technology can be configured to enable more stability over time and has enhanced in vivo longevity when compared with other CGM devices. In a single-site study of an earlier configuration of the Senseonics CGM system in patients with type 1 diabetes mellitus, we reported that the system was associated with a mean absolute relative difference (MARD) between sensor glucose values and laboratory reference glucose values of 11.6% over the 28-day study period.…”

“…In a single-site study of an earlier configuration of the Senseonics CGM system in patients with type 1 diabetes mellitus, we reported that the system was associated with a mean absolute relative difference (MARD) between sensor glucose values and laboratory reference glucose values of 11.6% over the 28-day study period. 19 The present multisite study analyzes sensor performance throughout a 90-day analysis. This work represents the next step in the characterization of the accuracy and safety of this system for clinical use in patients with diabetes mellitus.…”