User guide

IntroductIon
IntroductIon
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How Does CGM Work?
Glucose readings
Your BG meter measures glucose (sugar) levels in your blood, and your glucose sensor measures
glucose levels in the uid surrounding the cells in your tissue, which is called interstitial uid.
Most of the time, glucose travels rst to your blood and then to your interstitial uid.
Because of how glucose travels, your BG meter readings and sensor readings will rarely match exactly.
This is normal and should be expected because they are measuring glucose levels in 2 dierent uids
in your body.
Usually your BG meter readings and your sensor readings will be very close.
However, when glucose levels are rising or falling quickly, you should expect to see a larger dierence
between your BG meter value and the sensor glucose reading.
Examples of times when this may occur include:
• After meals or after administering a bolus
• When UP or DOWN arrows appear on your pump screen (more on this later!)
Important hints!
• Use CGM to understand your glucose trends
• Focus on what matters: the direction and the speed of the
sensor glucose change
• Pay less attention to each individual glucose number
• Always rely on BG meter readings for therapy adjustments
Calibration
Calibration is like buying a watch and setting it for the rst time and then checking the time during the
day to make sure it’s right. Calibrating is essential for your system to work.
Your CGM system uses meter BG readings to make sure the glucose sensor maintains its accuracy over
time. This is called calibration, and is essential for your system to work.
To calibrate you must check your BG on your meter and enter the value into the pump or monitor.
The methods available to calibrate your sensor are:
• On the insulin pumps, use the Bolus Wizard calculator
• Through the Sensor menu on the insulin pumps and Guardian REAL-Time monitor
• Through the Capture Event menu (only available on the Paradigm Veo insulin pump
or the Guardian REAL-Time monitor
The preferred method is to use the Bolus Wizard calculator, which may help prevent the stacking
of insulin. For details about how to calibrate, please go to STEP 5 (page 13) of the Starting up CGM
section.
When you calibrate is very important!
• On day one of a new sensor, a calibration is needed:
- approximately 2 hours after you connect the MiniLink transmitter to your
sensor (the system will notify you)
- again within 6 hours
- and again within 12 hours
• After day one, you need to calibrate 3–4 times a day for optimal sensor accuracy
• A minimum of 1 calibration every 12 hours is required to receive sensor glucose
readings
The best times to calibrate are when glucose levels are least likely to be changing rapidly, such as:
• Before meals
• Before insulin
• Before bedtime
Don’t calibrate when there are arrows on your insulin pump or monitor screen.
Key Points
• Calibration is essential for optimal sensor performance
• The glucose sensor performs best when calibrated 3-4 times per day
• CGM does not eliminate the need for BG meter readings (ngersticks)
• You do not need to wait 6 hours (day one) and 12 hours to calibrate.
You can calibrate early, as long as your glucose is stable