Researchers from Princeton University, NJ, have developed a laser device that measures blood sugar level using quantum cascade laser. This was designed with the thought to make painless blood sugar monitor. Currently the size of the device is quite big and the team is working on shrinking it to make it portable. Laser was an experimental setup that filled up a moderate-sized workbench. It also needed an elaborate cooling system to work. Gmachl said the researchers have solved the cooling problem, so the laser works at room temperature. The next step is to shrink it.
How it works:
The key to the system is the infrared laser’s frequency. What our eyes perceive as color is created by light’s frequency (the number of light waves that pass a point in a certain time). Red is the lowest frequency of light that humans normally can see, and infrared’s frequency is below that level. Current medical devices often use the “near-infrared,” this is just beyond what the eye can see. This frequency is not blocked by water, so it can be used in the body, which is largely made up of water. But it does interact with many acids and chemicals in the skin, so it makes it impractical to use for detecting blood sugar.
Mid-infrared light, however, is not as much affected by these other chemicals, so it works well for blood sugar. But mid-infrared light is difficult to harness with standard lasers. It also requires relatively high power and stability to penetrate the skin and scatter off bodily fluid. (The target is not the blood but fluid called dermal interstitial fluid, which has a strong correlation with blood sugar). The breakthrough came from the use of a new type of device that is particularly adept at producing mid-infrared frequencies — a quantum cascade laser.
To check its efficiency researchers used this laser to measure blood sugar of three healthy people before and after each of them ate 20 jellybeans. Same test was performed with using finger prick method. The researchers said their results indicated that the laser measurements readings produced average errors somewhat larger than the standard blood sugar monitors, but remained within the clinical requirement for accuracy.