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Tips and Tricks for New CGM Users

By Karrie Hawbaker

Public Relations Manager

Posted:  11/8/2011 12:00 AM


Today we hear from Celeste Cooper, who offers up some helpful sensor tips – whether you’re just starting out or nearly CGM pro! For even more resources, visit the Help and Support section of our Website.

My name is Celeste Cooper and I am a 15 year pump user and now have 6 years of sensing experience. I’ll admit, I have never written a blog and have read very few. My brain works better when there is no cell phone, internet or TV, so I see the bright side of power failures. My brain often feels bombarded with too much information. But still, I love my sensor....... how can that be? Because it gives me critical information that is immediately helpful, like getting the weather instead of the stock report. But loving it came slowly, after learning when I should believe it and what to do so that I could believe it most of the time.

If you are new to CGM you likely have had lots of questions and maybe some moments of frustration trying to find answers to those questions. The truth is, some things you can learn from books and websites, some from your trainer, and some only from experience. (Remember learning how insulin worked in your body when you were first diagnosed?) So, some of the most useful information about CGM, I have learned for myself and from talking to other sensor users.

The most important factor in sensor accuracy (in my humble opinion) is when you calibrate, and I think the first calibration after placing a sensor carries the most weight.

I am sure your trainer has taught you when not to calibrate; you’ve also learned it from the product workbooks:
Don’t calibrate when your BG is rapidly changing (i.e. after eating, exercise, etc.)
Don’t calibrate when you have up or down arrows. (That’s fine, but before the first calibration, there are no arrows to guide you!)

There is another extremely important factor to consider in that first calibration and that is “is the sensor wet enough”? I find making sure it’s in a part of my body that has sufficient fat for it to settle in and become thoroughly bathed in interstitial fluid is key. So is waiting the full 2 hours until after you get the “Enter BG” alert to do that first calibration.

Making sure the sensor stays fully inserted is also important, I think. If it comes out even partially, that can affect sensor accuracy. Putting a Band-Aid across the transmitter to secure it works for me, but I know of others who like the clear IV3000 tape.

So there’s my opinions and tips – what are yours?

Stay healthy and may you be happy with your readings!


- Medtronic Diabetes insulin infusion pumps, continuous glucose monitoring systems and associated components are limited to sale by or on the order of a physician and should only be used under the direction of a healthcare professional familiar with the risks associated with the use of these systems.
- Successful operation of the insulin infusion pumps and/or continuous glucose monitoring systems requires adequate vision and hearing to recognize alerts and alarms.

Medtronic Diabetes Insulin Infusion Pumps
- Insulin pump therapy is not recommended for individuals who are unable or unwilling to perform a minimum of four blood glucose tests per day.
- Insulin pumps use rapid-acting insulin. If your insulin delivery is interrupted for any reason, you must be prepared to replace the missed insulin immediately.

Medtronic Diabetes Continuous Glucose Monitoring (CGM) Systems
- The information provided by CGM systems is intended to supplement, not replace, blood glucose information obtained using a home glucose meter. A confirmatory fingerstick is required prior to treatment.
- Insertion of a glucose sensor may cause bleeding or irritation at the insertion site. Consult a physician immediately if you experience significant pain or if you suspect that the site is infected.

Please visit for complete safety information.


thomas brannan

Posted on Fri Nov 11 01:32:39 GMT 2011

I figure getting a waterproof band aid would cost about half as much as the iv3000 tape. I found on First Option Medical web site the 67361-0001 Smith & Nephew OpSite Flexifix Transparent Dressing 4 Inch X 11 Yard - Box at $27.95 plus $9.95 for shipping for a total cost of $37.90 about half of the iv3000. It comes on a roll that you cut and I figure of getting about 120 cut per roll. And boy does it stick.

Salvatore Di Domizio Jr

Posted on Tue Nov 15 15:21:55 GMT 2011

Well, this is my first blog, very interesting and informative to be here. It's great to be blogging with people who have the same situations as I do.
I have had my pump for 5 months and the CMG device for 3 months, and my A1C has gone from 6.7 down to 5.7, and I feel much, much better having the insulin delivered in small doses rather then a shot in the AM and PM. Thank God for my Onocologist and Metronics, not to forget Univera, Independent Health and Medicare for allowing me to acquire the pump and sensor.
I have a sugesstion for Metronics to make the Sensor more user friendly. The current SENSOR END is just what it says, an abrupt end to the sensor life. As with the pump reservoir, we are given an alert that the reservoir is low. It would be great if we were given an alert adjustable as the reservoir alert, for the sensor end, say 1-5 hours before the sensor end. I don't know how many times that I have looked at the count-up hour sensor life indicator, and then gone out and been caught not at home to change the sensor when I should. This adjustable SENSOR LIFE ENDING SOON alarm would be a great reminder of the need to change your sensor soon. I hope that the engineers can just add it to the program in conjunction with the sensor life day/hour calculations. This revision would really help us out so that we would have less interruptions in our sensor readings, because every minute counts in the time lapse when a sensor's lifespan ends. Thank you!


Posted on Tue Nov 15 22:41:50 GMT 2011

@Salvatore - Glad to hear you’re doing so well and thanks for the great feedback about the SENSOR END! I’ll be sure to pass that on to the CGM team. In the meantime, it may be helpful to know that the SENSOR END will always alert you 72 hours after the first METER BG NOW alert. Also, if you ever want to check to see how much time is left on the sensor, you can see that on the Sensor Status screen.

Xochitl Ortiz

Posted on Fri Dec 09 04:01:51 GMT 2011

I'm new to insulin pump (i started 8/31/11) and am loving my pump, but a quick question that I have been thing about. When is it a good time to add cgm? Any ideas and/or suggestions would be greatly appreciated.


Posted on Sat Dec 10 01:51:44 GMT 2011

Thank you asking, Xochitl. You can really add CGM to your insulin pump at any time you feel you are ready. You may want to schedule a visit with your healthcare provider to discuss adding CGM therapy for your diabetes management as a prescription is required. You can also give our team a call at 800-646-4633 and they can help answer any questions you may have and/or look into your insurance coverage for the device.


Posted on Tue Jan 03 18:46:56 GMT 2012

I am new to the sensor. What is the usual lag time between your finger stick and the sensor reading? Also, I was reading on my sensor "above 400" and my finger stick was reading 298. This worried me. Any advice? I have been a pump user for 2 1/2 years and just started the sensor last week.


Posted on Wed Jan 04 16:10:43 GMT 2012

@Becca Welcome to CGM! J As with all CGM systems, the sensor lag time is determined both by your body (how glucose moves between the blood and fluid around your cells) and the sensor technology, and can vary. Our VP of Research and Development, John Mastrototaro, gives a nice explanation here:

In regards to the differences between your sensor and fingerstick reading, remember proper calibration is important to sensor accuracy. Remember to calibrate your CGM when glucose levels are least likely to be changing rapidly, for example: before meals, before insulin, before bedtime and when there are no arrows on your monitor screen. It is also important to remember proper fingerstick techniques to ensure the BG meter readings are accurate as well. You can find more information on calibration here: And, of course, our 24-Hour HelpLine at 1-800-646-4633 is always here to help.


Posted on Thu Jan 05 16:19:54 GMT 2012

Is there a way to cancel a calibration of the sensor. When I was bolusing for lunch, I mistakenly selected yes to calibrate the sensor. My doctor told me not to eat or bolus within 15mins of a calibration to keep my sugar steady. I couldn't find a way to cancel it and I was really hungry lol.


Posted on Fri Jan 06 01:17:51 GMT 2012

@Trent You can’t take back a calibration after it’s been entered. But, there are several other things to consider because the sensor value displayed is actually taking into account your last 4 calibrations, with an emphasis on the most recent calibration. Feel free to give the 24-Hour HelpLine a call if you want to discuss your specific situation - 1-800-866-4633. We also have some calibration tips here:

MaryFairweather Dexter

Posted on Thu Jun 28 13:38:08 GMT 2012

I've been pumping for 6 years, on the CGM for a year and am still not any better at getting it consistently calibrated, even though I am doing everything by the book. Instead I am spending my life trying to figure out the perfect place to insert this (most places don't) and the perfect time to calibrate. I get numerous false alarms (8 between midnight and 5am last night), which I would tolerate better if it would warn me when I truly was going high or low: then it's too often silent, or it tells me after I've already treated the low. Also, it's very well to say not to calibrate with arrows, but what if I'm having one of those days when my blood sugar is ricocheting and that's all I see. I'm LADA; some days are like that and those would be the best days to have a CGM. I don't use the data to calculate changes in bolus/basal rates because I can't remember which data is fact and which is fiction. Could I get a trainer who could actually get this device to work for ME?


Posted on Thu Jun 28 14:58:56 GMT 2012

Hi Mary - I'm sorry to hear this. I've passed your comment on to someone from our team who will be in touch with you shortly to help.


Posted on Tue Sep 18 20:23:15 GMT 2012

I have used the CGM successfully for a little over 2 years, until last month. For the last few weeks I get 'sensor error' after about 2 days of use. In fact, I inserted a sensor yesterday at 8AM and today at 3PM I got 'sensor error'. I thought I had a bad batch of sensors but Medtronic customer support says it is probably a transmitter problem, even though the transmitter charges normally. Has anyone else experienced this sensor error problem?


Posted on Tue Sep 18 22:35:08 GMT 2012

Virginia, I'm sorry to hear you're experiencing these sensor issues. I have passed along your comment and someone should be reaching out to you shortly.


Posted on Thu Nov 08 01:15:13 GMT 2012

Do I have go wait 2 hours before callibrating?


Posted on Sun Jul 21 12:26:39 GMT 2013

I am having a difficult time keeping the CGM stuck on me. I'm not sure why I have never had any problem keeping the pump infusion to stay on. It was not a problem in the cooler temp., but as soon as it got warm, I kept losing it. What should I do differently?


Posted on Mon Jul 22 20:05:56 GMT 2013

Hi Diane, I’m sorry to hear you’re having this problem. Please feel free to call the 24-Hour HelpLine if you want to discuss your specific situation at 1-800-866-4633. In the meantime, you can visit our website for tips at


Posted on Sun Jul 28 15:24:36 GMT 2013

I've been pumping for 4 years, on cgm for 8 months. Find this blog helpful, esp. since I think I'm the only one driven nuts by "sensor error". My problems seem to be weak sensor....which I don't understand since my pump and sensor are never more than 6 inches apart. I also get sensor error at odd times...the sensor might appear to be fine but then all of a sudden I get sensor error. Am I callibrating too soon, too often, not enough?

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