While different devices use different types of light (some use infrared waves, others radio frequency waves), the basic
principle is the same.A monitor shines a beam of light through your skin, which is then reflected and scattered by the
glucose in your blood.
The sensor then detects signals from the light that is reflected back. Glucose exhibits a unique
reflection pattern that differs from the other components of blood; the difference in signals is how the sensor
determines your glucose level.