From Medtronic's Press Release:
The Guardian® RT System records as many as 864 glucose readings during a three-day period using a disposable glucose sensor that connects to a transmitter and communicates to a monitor using radio frequency. The sensor measures glucose in the interstitial fluid found between the body’s cells, and is typically discarded and replaced by the patient after three days of use. Glucose measurements are relayed every five minutes from the transmitter to the monitor, which displays the glucose values on its screen.
The monitor described above is actually a small screen on a portable pager-like device. The glucose sensor is a tiny electrode that must be inserted under the skin but is good for up to 288 glucose readings a day, for three days. Fingersticks are still needed twice a day to calibrate the glucose sensor, and to verify a possible hypoglycemic or hyperglycemic condition. The System is intended for management of either type 1 or type 2 diabetes, for those over 18 years of age.
For Medtronic's press release:
Medtronic Announces FDA Approval Of Real-Time Continuous Glucose Monitoring System
For Medtronic's product information:
Guardian® RT Continuous Glucose Monitoring System