Future
One noninvasive glucose meter has been approved by the U.S. FDA: The GlucoWatch G2 Biographer made by Cygnus Inc. The device was designed to be worn on the wrist and used electric fields to draw out body fluid for testing. The device did not replace conventional blood glucose monitoring. One limitation was that the GlucoWatch was not able to cope with perspiration at the measurement site. Sweat must be allowed to dry before measurement can resume. Due to this limitation and others, the product is no longer on the market.
The market introduction of noninvasive blood glucose measurement by spectroscopic measurement methods, in the field of near-infrared (NIR), by extracorporal measuring devices, has not been successful because the devices measure tissue sugar in body tissues and not the blood sugar in blood fluid. To determine blood glucose, the measuring beam of infrared light, for example, has to penetrate the tissue for measurement of blood glucose.
There are currently three CGMS (continuous glucose monitoring system) available. The first is Medtronic's Minimed Paradigm RTS with a sub-cutaneous probe attached to a small transmitter (roughly the size of a quarter) that sends interstitial glucose levels to a small pager sized receiver every five minutes. The Dexcom System is another system, available in two different generations in the US, the G4 and the G5. (1Q 2016). It is a hypodermic probe with a small transmitter. The receiver is about the size of a cell phone and can operate up to twenty feet from the transmitter. The Dexcom G4 transmits via radio frequency and requires a dedicated receiver.[25] The G5 version utilizes Bluetooth low energy for data transmission, and can transmit data directly to a compatible cellular telephone. Currently, Apple's iPhone and Android devices can be used as a receiver.[26] Aside from a two-hour calibration period, monitoring is logged at five-minute intervals for up to 1 week. The user can set the high and low glucose alarms. The third CGMS available is the FreeStyle Navigator from Abbott Laboratories.
There is currently an effort to develop an integrated treatment system with a glucose meter, insulin pump, and wristop controller, as well as an effort to integrate the glucose meter and a cell phone. Testing strips are proprietary and available only through the manufacturer (no insurance availability). These "Glugophones" are currently offered in three forms: as a dongle for the iPhone, an add-on pack for LG model UX5000, VX5200, and LX350 cell phones, as well as an add-on pack for the Motorola Razr cell phone. In US, this limits providers to AT&T and Verizon. Similar systems have been tested for a longer time in Finland.
Recent advances in cellular data communications technology have enabled the development of glucose meters that directly integrate cellular data transmission capability, enabling the user to both transmit glucose data to the medical caregiver and receive direct guidance from the caregiver on the screen of the glucose meter. The first such device, from Telcare, Inc., was exhibited at the 2010 CTIA International Wireless Expo,[27] where it won an E-Tech award. This device then underwent clinical testing in the US and internationally.
In early 2014 Google reported testing prototypes of contact lenses that monitor glucose levels and alert users when glucose levels cross certain thresholds.[28][29][30] Apple has patented methods for determining blood sugar levels by absorption spectroscopy, as well as by analyzing exhaled air in its electronic devices.
