The FreeStyle Libre system represents the new method of 'flash' glucose monitoring and is designed to help improve self-management of diabetes in people who use insulin, particularly those who struggle with fingerprick testing.
The system monitors glucose levels in interstitial fluid using a sensor worn on the upper arm. These levels reliably reflect blood glucose readings, although fingerprick testing may still be needed in certain circumstances such as when levels are changing rapidly.
The sensor, the size of a £2 coin, is applied to the upper arm using the applicator provided. When the sensor is attached, a thin, flexible and sterile sensing fibre is inserted 5mm under the skin. The fibre draws interstitial fluid from the muscle into the sensor, where glucose levels are automatically measured every minute and stored at 15-minute intervals.
The sensor is designed to stay in place for 14 days. Most people who used the system in clinical trials found application painless.
Patients scan the sensor using the handheld reader. The reader presents the patient with current glucose levels, trends and an overview of the data collected over an 8-hour period. Users must scan the sensor at least once every 8 hours in order to see a full 24-hour ambulatory glucose profile.
As an alternative to using the reader, the sensor can also be scanned using the free LibreLink app on an Android smartphone.
Flash glucose monitoring provides data on demand and differs from continuous glucose monitoring devices, which provide continuous insight into glucose levels throughout the day and alert patients if levels are too high or too low.
The FreeStyle Libre is intended to be used alongside routine blood glucose monitoring in adults and children over the age of 4 years who use insulin to control their type I or type II diabetes.
Patients will be able to receive the FreeStyle Libre sensors on prescription and healthcare professionals will be able to provide the reader free of charge, both subject to inclusion in local formularies.
Patients also have the option to purchase the system themselves.