A blood sugar monitor that can stay in the body for up to five months is being tested on NHS patients.
It is hoped the device, which continuously monitors the blood and beams the information to a smartphone, will help control type 1 diabetes.
Patients in London, Cambridge and Swansea are taking part in the trial to assess the safety and accuracy of the monitor.
Current blood-sugar sensors need to be replaced every week.
'Tightrope'
People with type 1 diabetes have to prick their finger regularly to test sugar levels, calculate the amount of sugar in their meals, and use this information to inject themselves with the right amount of insulin.
If levels are too high, there may be damage to the body's organs, but if levels fall too low, it can be fatal.
Dr Pratik Choudhary, a consultant at King's College Hospital and a lecturer at King's College London, told the BBC News website: "Living with type 1 diabetes is a bit like being a blind tightrope-walker.
"You're on this tightrope between high and low blood glucose levels and you're only allowed to open your blindfold four or five times a day.
"Continuous glucose monitoring allows you to open your eyes and see where you're going."
The monitor, built by US company Senseonics, is implanted under the skin in the upper arm.
More info here http://www.bbc.co.uk/news/health-34077192
It is hoped the device, which continuously monitors the blood and beams the information to a smartphone, will help control type 1 diabetes.
Patients in London, Cambridge and Swansea are taking part in the trial to assess the safety and accuracy of the monitor.
Current blood-sugar sensors need to be replaced every week.
'Tightrope'
People with type 1 diabetes have to prick their finger regularly to test sugar levels, calculate the amount of sugar in their meals, and use this information to inject themselves with the right amount of insulin.
If levels are too high, there may be damage to the body's organs, but if levels fall too low, it can be fatal.
Dr Pratik Choudhary, a consultant at King's College Hospital and a lecturer at King's College London, told the BBC News website: "Living with type 1 diabetes is a bit like being a blind tightrope-walker.
"You're on this tightrope between high and low blood glucose levels and you're only allowed to open your blindfold four or five times a day.
"Continuous glucose monitoring allows you to open your eyes and see where you're going."
The monitor, built by US company Senseonics, is implanted under the skin in the upper arm.
More info here http://www.bbc.co.uk/news/health-34077192