The sensor is inserted through the skin using an applicator with a needle. The needle is then removed, leaving a small sensing element under the skin. It measures the glucose level of the interstitial fluid. The transmitter is located on or attached to the sensor. The transmitter transmits the glucose levels from the sensor wirelessly to the receiver, i.e. a separate reader. The reader can also be a smartphone, smartwatch or insulin pump.
A single sensor will work in the subcutaneous fatty tissue for 1–2 weeks, after which it is replaced. The nurse teaches how to insert and replace the sensor by oneself. There are also longer-lasting sensors implanted into the subcutaneous tissue, which are implanted at the treatment centre. Some of the sensor systems have been calibrated at the factory, while others need to be calibrated with blood test from a fingertip 2–4 times a day.
The reader shows the glucose level, glucose graph and arrow indicating the direction of the changes in glucose levels. The insulin doses, amounts of carbohydrates, exercise and different events or observations can be entered in it. Some of the devices also allow sending the glucose levels to another person via a smartphone app.
In Finland, there are several glucose sensor systems in use. Their availability varies depending on the wellbeing services county. You can talk to your nurse or doctor about the different options and their availability for either temporary or continuous monitoring.
You can get more information of the different glucose sensor systems available in Finland from the importers’ websites that you can find from the section "Related to the topic".