No. They use interstitial fluid, which corresponds to your blood glucose readings. Understanding something about the way your sensor works can help you get the best from Limbo.
A Continuous Glucose Monitor (CGM) is a sophisticated device designed to provide ongoing and precise information about blood glucose levels. It was originally designed to help diabetics understand their blood glucose. As they can’t use insulin to store glucose efficiently, having high or low blood sugar can be dangerous for type 1 diabetics.
They were developed as an alternative to finger stick testing - which meant pricking fingers to test blood, which is a real pain and can cause infections.
Limbo sensors (CGMs) are equipped with a filament that is gently inserted in the tissue under the skin. This filament interacts with your interstitial fluid – the fluid surrounding your body's cells and detects glucose concentrations.
The filament, typically composed of enzymes that react with glucose, initiates a chemical process that generates an electrical current proportional to the glucose levels in the interstitial fluid.
The sensor then measures this current and converts it into a corresponding glucose concentration. Using the bluetooth transmitter on top of your sensor, this data is transmitted in real-time to your phone and displayed as your Limbo line.
Be careful when applying the sensor
If you want your sensor to read well and work properly for two weeks, you need to apply it properly and care for it.
Have a look at Limbo’s instructions for putting on a sensor. We’ve analysed hundreds of real people using this equipment to work out what can go wrong and improved on the manufacturer’s instructions.
The glue on the sensor pad is there to hold the filament in place for 2 weeks, so do what you can to give it the best chance to succeed - cover with a patch, protect it from knocks and be careful when the unit is wet as the glue works better dry.
Your readings can change with pressure
When pressure is applied to the sensor site, it can compress the tissue and impede the flow of interstitial fluid. You’re most likely to do this while you’re resting. A temporary reduction in blood flow to the sensor site affects the availability of interstitial fluid. This alteration in fluid dynamics can result in a delay in the sensor's ability to accurately read changes in glucose levels.
You may see a sudden drop in your Limbo Line while the sensor’s not performing at its best. In this situation, you’re not getting the most reliable readings, so don’t worry if you suddenly seemed to have very low glucose at night once - it was likely you were lying on the sensor for a bit.