Bloodless glucometers work by measuring glucose levels in teardrops, using fluorescent beads that glow different colors, shining an infrared light beam on the skin, or using ultrasound, says WebMD. All of these devices are in the development stage.
One device uses a contact lens with a special sensor embedded in it to measure glucose levels in tears, explains WebMD. The sensor then turns different colors to indicate high or low blood sugar levels. Another monitoring system uses beads contained in a thin sheath inserted below the skin. Shining a light on the patch of skin causes the beads to glow, and their color reflects glucose levels.
Some bloodless glucometers require one finger prick each day to calibrate readings, says WebMD. One of these aims infrared light at the skin, and the light that is reflected back to a receiver provides information on blood glucose levels. Another device uses a patch applied to the skin every morning. The patch transmits ultrasound to body fluids and gives a constant glucose reading.
Bloodless glucometers are innovative alternatives to traditional meters that require a drop of blood on a test strip, but as of 2005, they are not available to the general public, notes WebMD. Some of the devices are being tested in clinical trials, but none have been approved by the Food and Drug Administration.