Scientific American recently published a feature on wireless enabled and needle-free, continuous blood glucose monitoring company Echo Therapeutics, which was one of the few startups in wireless health that announced venture capital investment last year. Echo is currently seeking NDA clearance from the FDA. According to Scientific American, Echo's offering, Symphony tCGM, has three distinct components:

> Prelude SkinPrep System shaves away the dead outermost surface of the skin and creates a dime-sized spot for the biosensor. Prelude also passes tiny electric pulses into the skin to determine whether it has reached live skin cells.

> A glucose biosensor that is applied to that dime-sized spot, usually on the chest or back. The biosensor detects glucose as it diffuses out of the body's capillaries. The sensor includes an enzyme that reacts with glucose and transmits a signal that passes to the wireless device. The sensor can be used for up to two days.

> A wireless handheld device that reads glucose levels from the biosensor, records the information and monitors the readings.

Of course, Symphony is not without precedent. As SA reports, the only FDA approved, non-invasive continuous blood glucose monitor is no longer on the market: GlucoWatch.

"The only 'noninvasive' glucose meter to have received U.S. Food and Drug Administration (FDA) approval is no longer on the market. In 2001 Cygnus, Inc., won FDA approval for its GlucoWatch, which was worn like a wristwatch and designed to be used in conjunction with conventional blood testing to track trends and patterns in a patient's glucose levels. The GlucoWatch administered a small electrical charge into the wrist to bring glucose to the skin surface where it could be measured every 10 minutes. The device, however, was discontinued in 2007 after complaints about its accuracy and that it caused skin irritation in some users."

For more, read the Scientific American article here