Accuracy and Functionality of Select Continuous Glucose Monitoring Systems Are Not Impacted by Implantable Cardioverter Defibrillator Devices.

BACKGROUND: Increasing numbers of individuals with diabetes are adopting use of continuous glucose monitoring (CGM) in their daily self-management. Many of these individuals have advanced heart disease. Implantable cardioverter defibrillator (ICD) devices can effectively reduce arrhythmic death and all-cause mortality in individuals with advanced heart disease. However, the potential impact of ICD devices on CGM system accuracy and functionality has not been well studied. METHODS: This evaluation assessed whether FreeStyle Libre (FL) CGM systems can coexist and function within the same patient in the presence of wireless interference devices, including current ICD devices. Interferer sources included Wi-Fi devices, Bluetooth devices, cellular mobile devices, implantable medical devices, Bluetooth Low-Energy (BLE) devices, BLE accessory devices and BLE mobile devices, and ICD-programmer interferers. Five testing methodologies were used to evaluate the accuracy and functionality of the CGM systems when exposed to ICD functions: high-energy emergency shocking, pacing modes, anti-tachycardia pacing mode (ATP), and DC Fibber mode. RESULTS: All acceptance criteria and testing requirements were met for the CGM and ICD system for wireless coexistence evaluation. CONCLUSIONS: Our findings demonstrated that coexisting ICD devices and FL CGM systems provide safe and effective wireless communications with functional and accurate transfer of data during scenarios expected in clinical use.

Safety and Functional Integrity of Continuous Glucose Monitoring Sensors When Used During Radiologic Procedures Under High Exposure Conditions.

BACKGROUND: We investigated wearable components of the Abbott Diabetes Care FreeStyle Libre® (continuous glucose monitoring [CGM 1), FreeStyle Libre® 2 (CGM 2), and FreeStyle Libre® 3 (CGM 3) systems in simulated diagnostic radiologic procedures. METHODS: Sensors were loaded with simulated glucose data and exposed to X-ray scanning, computed tomography (CT), and magnetic resonance imaging (MRI) to simulate radiotherapeutic procedures. The exposure settings were representative of maximum in clinical settings. After the simulations, bench tests were used to assess data integrity and responsiveness of sensors to various concentrations of aqueous glucose. RESULTS: All sensors passed all acceptance criteria following each session of X-ray, CT, and MRI exposures. During the 3 T MRI simulation, the displacement forces for the CGM 1, CGM 2, and CGM 3 sensors were 0.132, 0.109, and 0.063 N, respectively, which are more than 100× smaller than the force of 15.97 N required to dislodge the sensor from the body. Data stored in the sensors prior to the exposures remained intact. CONCLUSION: The sensors maintained functionality following a series of high exposure conditions in both X-ray and CT scanning systems, and the sensors were easily visible and identifiable when scanned using clinically relevant scanning parameters. Therefore, patients can continue to wear and use their sensors during and after imaging. The nonclinical MRI testing demonstrated that the sensors can be worn under the specified MRI conditions.