Abbott Laboratories announced Thursday its over-the-counter continuous glucose monitor Lingo is available in the U.S. starting at $49. Lingo is part of an emerging class of consumer-friendly biosensors that people can use to learn how their bodies respond to food, exercise, sleep and stress. These devices, called continuous glucose monitors, are small sensors that stick through the skin to measure real-time glucose levels. Glucose is a sugar molecule that comes from food, and it's the body's main energy sou ...