Medical Encyclopedia
Summary of the types of CGMS available in the U.S.
Real time systems display results for the user to see and sound alarms when blood sugars are too high or too low.
There are three real-time systems:
-- Two non-integrated, "real time" CGMS available: The Guardian RT and the DexCom STS CGMS; and
-- One integrated real-time system (MiniMed Paradigm REAL-Time System).
There is also one more CGMS, the MiniMed Gold CGMS, which is not a real-time system and is intended for diagnostic purposes as requested by a doctor.
Will my insurance cover the cost of a CGMS?
You will need to contact your insurance administrator to see if a CGMS is covered for you.
Things to consider before purchasing the DexCom STS
With CGMS technology you have to calibrate the system with each sensor change and in some cases daily. It will not do away with finger sticks. The FDA warning label on CGMS specifically states not to act (treat lows or take insulin) based on sensor readings but to do a finger stick before acting.
CGMS are valuable tools for learning trends, but they do not replace finger sticks and require you to wear to a separate cannula.
The cost of transmitters, sensors and other CGMS-related items can average as much as $400 per month (in addition to your test strips and insulin pump supplies).
Continuous Glucose Monitoring System (CGMS)
Definition of a Continuous Glucose Monitoring System (CGMS) - medical device that measures and logs blood sugar readings frequently during the day and night. It then averages the blood sugar readings. There are two non-integrated, "real time" CGMS available: The Guardian RT and the DexCom STS CGMS. Real time systems display results for the user to see and sound alarms when blood sugars are too high or too low.
The MiniMed REAL-Time system uses integrated technology that allows certain Paradigm insulin pumps to receive data from a CGMS device called MiniLink Transmitter. This allows the sensor data sent to the MiniLink Transmitter to then display on the insulin pump rather than a separate monitor.
The MiniMed Gold CGMS is not a real-time system and is intended for diagnostic purposes as request by a doctor.
About the Real-Time DexCom STS CGMS
DexCom, based in San Diego, CA, has developed a short-term continuous glucose monitoring system, the Seven™ System, which includes the Seven Sensor, the Seven Transmitter, and the Seven Receiver. On March 31, 2007 they announced final FDA approval of the system as is, which included approval for 7-day sensors.
How does it work?
The tiny probe-like sensor is inserted by the user under the skin, and is held in place by an adhesive. Once inserted, the sensor begins continuously monitoring blood sugar (glucose) levels.
The Seven Transmitter sends the glucose reading signal from the Seven Sensor and wirelessly transmits the data to the hand-held Seven Receiver. The Seven Receiver processes the glucose signal and with the push of a button, displays the user’s current glucose value, as well as 1-hour, 3-hour, and 9-hour trends. The Seven Receiver also sounds an alert when a high or low glucose excursion is detected.
The sensor does not administer insulin and a separate cannula must be worn to infuse insulin from an insulin pump or you will need to continue taking shots.
What the DexCom STS can do for you
The DexCom STS can pick up on trends that might otherwise go undetected. For example, CGMS technology can pick up low blood sugar readings during the nighttime when the patient is sleeping. It can also evaluate how a person's blood sugar reacts to exercise, food, illness, etc. Understanding these trends can help your doctor make adjustments in your diabetes care plan to keep you blood sugars under better control while reducing the risk of hypoglycemia (low blood sugar).
DexCom CGM Components
Seven Sensor
Seven Transmitter
Seven Receiver
Continuous glucose monitoring is not the same thing as a closed loop system.
A closed loop system, which is not yet available, would deliver insulin automatically based on readings taken by CGMS sensors. This would mimic the normal function of the pancreas by constantly making insulin adjustments based on current blood sugar readings and history of insulin already delivered.