In the first few hours of a new sensor

hourglass sand clock

Ever wonder what happens during those first few hours of your new sensor wear? What’s happening to the sensor, and why do you have to wait two hours before you start getting sensor readings? While it may be tempting to want a shorter initialization time frame, it’s important to follow the steps you learned in training to ensure your Enlite sensor performs at its best throughout the six days of wear. 

Let’s review what’s really happening during the start-up time…
 

Step 1: Wetting Period- Five minutes
 

Right after inserting your sensor, the first step is the “wetting period”,which is the time between sensor insertion and transmitter connection. During the wetting period, the interstitial fluid of your body tissue (that’s the fluid between your cells and under your skin) wets the sensor electrode. The transmitter requires a certain amount of wetting before it will turn on. 

With the Enlite sensor, the wetting period can take up to five minutes. However, you’ll want to connect your MiniLink transmitter as quickly as possible (within five minutes) after inserting the sensor to ensure optimal sensor performance. If the sensor sits under your skin longer than five minutes without the transmitter attached, a chemical reaction can occur and hydrogen peroxide can build up around the sensor site, causing performance issues. So avoid letting too much time go by between inserting your sensor and connecting your transmitter.

 

Step 2: Initialization Period- Two hours
 

Once the transmitter is properly connected, and if the sensor has had enough time to become “wet”, the green light on the transmitter will flash within 10 seconds, and the second step begins – the two hour “initialization period”. This is the two hour period where the device will begin to measure sensor signals. The initialization is built in to allow the device to create a stable signal from the sensor before attempting to calibrate and calculate sensor readings. 

You’ll also know you entered into the two-hour initialization period when your pump displays WARM-UP on the screen. This means you’ve started a new sensor or reconnected an old sensor. During this initialization period, the sensor is not ready to take glucose measurements, so avoid entering a BG meter reading until your pump alerts METER BG NOW, which notifies you that the initialization period had ended, and the sensor is ready for its first calibration. 

If the sensor is not wetting properly, you may receive Sensor Error and Lost Sensor alerts during the two-hour initialization period. If these alerts occur, don’t worry. If a Sensor Error occurs, simply clear it. If a Lost Sensor occurs within 20 minutes of a sensor start, select start NEW SENSOR. You do not need to replace your sensor or remove/reconnect your transmitter. Your pump will alert METER BG NOW about two hours after you connect the MiniLink transmitter to the sensor. You can read more about these errors here

It’s fascinating how much takes place during those first few hours, right? Happy Sensing! 

Want to learn more about other aspects of our CGM technologies? Let us know by posting a comment.

 

IMPORTANT SAFETY INFORMATION

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. MiniMed 530G with Enlite is intended for the delivery of insulin and continuous glucose monitoring for the management of diabetes mellitus by persons 16 years of age or older who require insulin. 

Pump therapy is not recommended for people who are unwilling or unable 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. 

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 making adjustments to diabetes therapy. MiniMed 530G with Enlite is not intended to be used directly for preventing or treating hypoglycemia but to suspend insulin delivery when the user is unable to respond to the Threshold Suspend alarm and take measures to prevent or treat hypoglycemia themselves. 

Please visit www.medtronicdiabetes.com/importantsafetyinformation for more details.

 

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Submitted by Matthew Boyle (not verified) on

In reply to by Commenter (not verified)

I often get wildly inaccurate readings from my sensor. Is this a bad batch of sensors? I have had times where it was more than 150 point off. I understand that if you take a finger stick while your BS is moving to rapidly in one direction it will be off, but this is not the case.

My cgm and metered blood sugars are not close at all sometimes as much as a 50% difference. I need suggestions or may discontinue the cgm because I can't trust the cgm . Your help would be appreciated.

Hi Matthew and G. I understand the difference between your sensor glucose and blood glucose can be frustrating. We do recommend calibrating 3 to 4 times a day for optimal sensor performance.

You may find this information on why sensor readings are different from BG readings helpful: http://www.medtronicdiabetes.com/customer-support/sensors-and-transmitt….

You may also find this article from one of our customer’s initial experience using the system helpful, too: http://www.loop-blog.com/blog/My-Initial-Thoughts-on-the-MiniMed-530G-w….

I will have one of our advanced specialists connect with the both of you to try and help. Please let me know if there’s anything else I can help you with.

Submitted by Mary (not verified) on

In reply to by Commenter (not verified)

I don't understand step #1. I take the transmitter off and charge for 20min, incert into a new site then hook up the charged transmitter. There is at least a 20 minute period it's not hooked up to my body. Step #1 says I shouldn't go longer than 5 minutes.

Submitted by LOOP Blog Editorial on

In reply to by Mary (not verified)

That’s a great question, Mary. After charging your transmitter, insert your new sensor and connect your charged MiniLink transmitter as quickly as possible (within 5 minutes). Don’t insert your new sensor until your transmitter is ready to be connected. Please let me know if you’d like me to connect you with someone for further explanation.

Submitted by Debbie McCormick (not verified) on

In reply to by Commenter (not verified)

Many times when I attach a new sensor and push New Sensor I will get a message within 15 minutes to Enter BG now. It doesn't wait the 2 hours. Should I be concerned?

Submitted by LOOP Blog Editorial on

In reply to by Debbie McCormick (not verified)

Hi Debbie. I will have a member of my team connect with you to help answer your questions. Please let me know if there’s anything else I can help you with.

Submitted by Dalton Baugess (not verified) on

In reply to by Commenter (not verified)

I know the Enlite 2 was in clinical trials and the Enlite 3 is getting ready to go to clinical trials. At what point will these be on the market? When will a better taping method be introduced like was used in the clinical trials?

Submitted by LOOP Blog Editorial on

In reply to by Dalton Baugess (not verified)

That’s a great question, Dalton! Unfortunately, I cannot comment on when these products will be available, and am not allowed to talk about future products due to FDA rules. Please know that Medtronic does everything we can to get new products to the market as soon as possible.

Submitted by Pieter Joubert (not verified) on

In reply to by Commenter (not verified)

Am I correct to say the transmitter's only job is to transmit the readings of the sensor to my pump? As long as it does that, it works. Therefore the age of the transmitter itself does not have an impact on the accuracy of the sensor readings. If the transmitter fails, it will no longer send a reading to my pump. It will not start sending wrong readings to my pump?

Submitted by LOOP Blog Editorial on

In reply to by Pieter Joubert (not verified)

Hi Pieter, the transmitter sends readings from your glucose sensor to your insulin pump using radio frequency, so if the transmitter no longer works, it will not send sensor readings to your pump. Any radio frequency interference or the age of your transmitter will not cause any incorrect sensor data to be sent to your pump. Please let me know if you’re having issues with your sensor glucose readings, and I’ll connect you with someone from my team to help.

Submitted by Michele (not verified) on

In reply to by Commenter (not verified)

I am absolutely loving my new pump, sensor and the new app on my phone! The first 2 times using the sensor was definitely a learning process. But I stuck with it, made adjustments and now NEVER want to be "sensor-less":). Feeling like I have a new lease on life !

Submitted by LOOP Blog Editorial on

In reply to by Michele (not verified)

Michele, it makes me so happy to hear you stuck with using the sensor, and are now loving your new integrated system and MiniMed Connect! Patience really does pay off  I wish you the best of luck. We’re always here if you need anything.

Submitted by Nicole Searle (not verified) on

In reply to by Michele (not verified)

Which pump do you have?? any suggestions on calibrating when doing a new sensor??

Submitted by Lisa (not verified) on

In reply to by Commenter (not verified)

Where do I change the warm up time for a new sensor? It normally says 2 hours but for some reason it now says 3?

Submitted by LOOP Blog Editorial on

In reply to by Lisa (not verified)

Lisa, the two hour sensor initialization is not a setting that can be adjusted. I will have a member from our HelpLine team reach out to you to talk through the graphs on your pump.

Submitted by Lisa (not verified) on

In reply to by LOOP Blog Editorial

Thank you! Resolved!
Lisa

Submitted by Gary C (not verified) on

In reply to by Commenter (not verified)

I seldom get 6 days out of an Enlite sensor before I get a CAL ERR alert. The first couple of days the calibration seems to be working fine (my trainer said "go for quality, not quantity in calibrations--which seems to work.) I try to time the calibration for times when I seem to be pretty steady--early morning, periods without eating, etc. But at some point--usually around the 3d or 4th day, the readings start going off--80 points, 100-150 points, one way or the other. I've tried to turn the sensor off when it seems way off and wait for a quiet time (waking up), to turn it on again and recalibrate. Sometimes it works, sometimes not. Anyway, it is frustrating and I've actually given up on CGM for literally months at a time because the CGM is just too "needy" and not trustworthy. When it is off that much my Carelink reports for the doctor are also off. But now I'm back trying CGM again and it seems to still be happening (4 days 5 hours on the last sensor--maybe I should just accept that 4-5 days is my normal usage). I'm just a little frustrated and wondering if there is anything to do. I use the 530g with Enlite; 70-yr old late onset diabetic.

Submitted by Karrie Hawbaker (not verified) on

In reply to by Gary C (not verified)

Hi Gary - I'm sorry to hear that you're having problems with your CGM. I'd like to connect you with a member of my team. I've shared your information with them and you should hear soon.

Submitted by Dave (not verified) on

In reply to by Gary C (not verified)

I have the same issue. The first day is misery in that my calibration numbers are 100-150 points off. I get constant alarms to recalibrate and check blood sugar. After about a day of being a slave to recalibrating, checking, turning the sensor on and off it will finally even out with the numbers. The last 48 hours of the sensors life is a wild ride as well. Numbers again do not match. Constant alarms to recalibrate. Just not reliable. I often get failed Bolus delivery forcing me to do manual deliveries to make up the Bolus wizard’s original Bolus amount. I’m so tired of being a slave to this incompetent technology. Seems like pharmaceutical or medical boards need to be made aware of these issues.

Submitted by Jen (not verified) on

In reply to by Commenter (not verified)

I get one or two sensors out of a box of Enlite sensors that actually work accurately. The others are wildly inaccurate. I'm up at all hours of the night with false lows and worried throughout the day with false highs. Using the CGM forces me to test upwards of 20 plus times per day. I've contacted Medtronic and did troubleshooting so often- nothing has helped and I'm running out of sensors, patience, and trust in the system.

Submitted by Karrie Hawbaker (not verified) on

In reply to by Jen (not verified)

Hi Jen - I do apologize that you're having problems with the sensors. I have asked that someone from our Advanced Troubleshooting team reach out to you to discuss.

Submitted by Amber (not verified) on

In reply to by Jen (not verified)

I've experienced the same problem and I'm exhausted. It's really frustrating. My transmitter sends lows to my pump, and this will suspend delivery in the middle of the night and I wake up off and on all night with warnings of low, but in the morning, my blood sugar is really high because it stopped insulin delivery.

Submitted by Karrie Hawbaker (not verified) on

In reply to by Amber (not verified)

Amber, I'm sorry this has been your experience. I would like to see if there is anything we can do to help. If you're interested in connecting with a teammate to discuss this in more detail, please send me an email with your contact information to dhelp@medtronic.com and I will have a member of our advanced troubleshooting team give you a call.

Submitted by diane (not verified) on

In reply to by Commenter (not verified)

I am about to give up. The elite sensor works sometimes but is inaccurate often. It wakes me up with false lows at night and today I was treating high 200 blood sugars over 2-hours and then realized that I felt very low. Sensor was reading 247 and 2 different glucometers Said 72 and 69. So had I bolused again I would have been in trouble. I have done all the trouble shooting . Could it be the site?

Submitted by Karrie Hawbaker (not verified) on

In reply to by diane (not verified)

Thanks for reaching out Diane. This is a great conversation to have with someone from our Advanced Troubleshooting team. I have shared your comment with my team and you should be hearing from someone in the next few days.

Submitted by Shaun (not verified) on

In reply to by Commenter (not verified)

To the poster above (diane) and anyone reading it, you should never dose off of CGM, that is silly. Always do a finger stick before injecting insulin, insulin is too dangerous and it takes only seconds to do a finger stick before making that decision.

Submitted by Mark Dunn (not verified) on

In reply to by Shaun (not verified)

I will tell you what is "silly" , Dr. Shaun--using a cgm system which is inaccurate. Yes, I am using the enlite cgm system, and yes, with the 630G pump, its accuracy seems better than with the 530G. So, Diane, do not give up, find a medtronic trainer willing to work with you to obtain the right combination of practices, pump, and sensor cgm system. Come on 670G and guardian sensors; I have battled type 1 for 50 years and i am actually almost hopeful the 670G will take away a little of the mental wear and tear of the battle. Don't give up, Diane, you arent doing anything "silly".

Submitted by Patty (not verified) on

In reply to by Commenter (not verified)

I started to use my Medtronic Elite CGS again after having many alarms last year that made me give up on it. Now within 30 min of inserting it, it says "LOST SENSOR"!! I get the signal on my insulin pump that looks like headphones each time I reconnect to this sensor which is only an hour old now. Help!!! I am ready to stop using it again. I feel I need it for I have hypoglycemia unawareness where I have episodes of passing out and convulsing.

Submitted by Karrie Hawbaker (not verified) on

In reply to by Patty (not verified)

Patty, I'm very sorry to hear this. I've asked that someone from our 24 HelpLine reach out to help you. If you'd like immediate assistance, please give us a call at 800.646.4633, option 1.

Submitted by Karen Krautwurst (not verified) on

In reply to by Commenter (not verified)

I have consistent problems with my sensor reading too low. It usually happens within the first two days of the new sensor ( though if I manage to get past the first 72 hours without a calibration error, the sensor seems to last the whole six days). I get a calibration error on the first or second day. I have learned to wait almost a day before trying to calibrate again after the first error or it will definitely fail. I have tried troubleshooting with customer service, but I am following all the advice and the issue does not seem to be dissipating. The last customer service rep taught me about the calibration factor, so I now watch the ISIG to see when it is in range of my blood stick. As of today, my ISIG has been below 5 for almost 30 hours, and my tested blood sugar has not dropped below 100. It's very frustrating, and I'm close to giving up on these sensors as they don't seem accurate enough to help manage my sugars.

Submitted by Karrie Hawbaker (not verified) on

In reply to by Karen Krautwurst (not verified)

Karen, I'm sorry to hear this! I have asked that someone from our Advanced Troubleshooting team reach out to see about helping.

Submitted by Melissa (not verified) on

In reply to by Karen Krautwurst (not verified)

Karen - I know the recommended ISIG range is between 1.50 -20 - did they tell you on the phone an ideal range within that range?

Submitted by Adrienne Liander (not verified) on

In reply to by Commenter (not verified)

I've spoken with customer support twice in two weeks regarding the disparity in data the transmitter data sends to my pump from interstitial fluid vs blood glucose measurement from the meter. Today I was told my concern is attributable to the sensor "still getting situated".
What does "sill getting situated" mean? The Minilink was inserted at 10am, calibrated at noon, and giving erroneous data that resulted in Low Alerts & a Thresh Suspend 8 hours later, after dinner when meter glucose was 180.
I see a Wetting Period of 5 mins & Warm up of 2 hours. I cannot find anything on "still getting situated". What does that mean?

Submitted by Anna.Bjorlin on

In reply to by Adrienne Liander (not verified)

Adrienne, I am sorry for any confusion. I’d like to connect you with an advanced troubleshooting teammate to answer your questions. Please send your contact information to dhelp@medtronic.com and I will have a teammate give you a call.

Submitted by Robin Summers (not verified) on

In reply to by Commenter (not verified)

I am so frustrated with trying to use the enlight sensor CGM system. I started a new sensor 2 days ago and after the initial 2 hour calibration period , my iSig number was was very much out of range for my 220 blood sugar reading, I knew better than to calibrate!
I turned off my sensor, took a bonus to bring my blood sugar back down to 120 , then I turned the sensor back on and chose connect new sensor once I got the alert to check my blood glucose. It happened again , iSig out of range so I left my sensor on for several hours hoping the iSig and meter would correct and no luck: is there any possible way to get the sensor to start all over again without having to change it out. It gets very expensive to manage my diabetes if I keep having to change out the enlisted sensors,
Robin summers

Submitted by Karrie Hawbaker (not verified) on

In reply to by Robin Summers (not verified)

I’m sorry to hear you are having trouble. This is a good conversation to have with our 24-Hour HelpLine. Please give them a call at 800.646.4633, option 1 and a teammate will be happy to help.

Submitted by Erica Long (not verified) on

In reply to by Commenter (not verified)

Why does my insulin pump keep asking for a BG? I keep taking it and entering it and then it asks for it again in less than an hour. Very frustrated at all the alarms.

Submitted by LOOP Blog Editorial on

In reply to by Erica Long (not verified)

Erica, I recommend discussing this with the 24-Hour HelpLine team. Please give them a call when you can.

Submitted by Danielle Rasico (not verified) on

In reply to by Commenter (not verified)

I am wearing a guardian sensor with the670G and im reading to quit!! My pump is telling me to change sensor every couple days saying sensor error change and Or i never get a full nights rest because it's constantly beeping with some kind of error or blood sugar is going up or down please help!

Danielle

Submitted by Karrie Hawbaker (not verified) on

In reply to by Danielle Rasico (not verified)

I'm sorry to hear this, Danielle. This is certainly not the experience we've come to expect based on feedback from our customers. If you haven't already, please reach out to our 24-Hour HelpLine at 800.646.4633, option 1. They can troubleshoot as needed, and review your CareLink data and see what we can do to help.

Submitted by Dave Williams (not verified) on

In reply to by Commenter (not verified)

12:02 am insulin flow blocked. What does that mean?
12:09 am bg required
12:10 am calibration required
12:10 am calibration not accepted
12:26 am calibrate now
12:29 am insulin flow blocked
12:29 am change sensor (Sensor is 6 hours old). Wtf?

This happens nearly every time I change my sensor. So frustrated!!! Not only is my control a wreck but this pump makes me an insomniac.

My endo last week told me I’m not letting my pump work enough for me. How can I trust it when it doesn’t calibrate?????? POS.

Submitted by Karrie Hawbaker (not verified) on

In reply to by Dave Williams (not verified)

Hi, Dave. I'm sorry you're having trouble, but our technical support team would like to see if there is anything we can do to help. Please give them a call at your convenience at 800.646.4633, option 1.

Submitted by `Tim Hackney (not verified) on

In reply to by Karrie Hawbaker (not verified)

I cant stand the insincere statement made by all minimed support employees. " I’m sorry you’re having trouble," its like they read it from the computer screen. along with all the other garbage you get from the level 1 call center people. Minimed would do better with a website for support. it would be easy... just go there and select what is happening to you from the drop down menu list.... not sure if that sounds like a good idea so just add a person who at best seems like they watched a movie about an insulin pump once and doesn't speak English selecting this for you with no understanding of why...
not sure why minimed cant just say "sorry, we put a bad product out"
oh that is because they are more concerned with the stock value and growing internationally
# minimed made me an insomniac too

Submitted by Nicole (not verified) on

In reply to by `Tim Hackney (not verified)

I'm sorry to hear this, Tim and this certainly isn't our intent. We stand behind our products and it's disappointing to hear you haven't had a good experience. Please know we do have several options for self-service, including our support section of our website, our social media channels, including videos on YouTube. In the meantime, if you require assistance, please send your contact information and a brief recap of your concerns to dhelp@medtronic.com and we'll be happy to get you connected with a senior teammate from our technical support team.

Usually when I call the 24 hour helpline they want me to remove the transmitter, connect it to the charger for a few minutes then reconnect it to the sensor to see if this corrects the problem on not receiving the BG my meter sent to the pump. The problem with this is the sensor has been in for a a few days and there is tape on it which is used to secure the sensor and transmitter in place. The tape is a pain in the butt to remove especially the first few days and it pulling on it can cause the sensor to pull out as well, wasting a sensor. Do you think they will design a system that will be easier to remove the transmitter in cases like this, since removing the transmitter and connecting it back seems to be the solution to almost every problem?

This is a great suggestion, William. I'm happy to share your thoughts with our team for review for the future.

Submitted by Michael O'Mahony (not verified) on

In reply to by Commenter (not verified)

I am using the Enlite sensors with a pump. I have found that a new sensor takes much longer to warm up and give steady readings than 2 hours. I monitor the ISIG value for a further few hours (2 - 3 hours anyway) and wait to do the first calibration until the ISIG values have reduced and stabilised. Previously, when I calibrated the sensor when prompted after the 2 hour warm up, the sensor readings would nose-dive and incorrectly suspend my basal. I have found that the sensors are more reliable by waiting to do the first calibration until the ISIG values stabilise, even though it is using some of the sensor life. The ratio of ISIG to blood glucose also changes (reduces) over the life of a sensor. Is this supposed to happen?

Submitted by Nicole (not verified) on

In reply to by Michael O'Mahony (not verified)

Thanks for reaching out, Michael. We are the US team and this particular model of pump is not available for US customers. I encourage you to check here http://bit.ly/1ce3pEc for local contacts who'd be happy to discuss this in more detail and confirm your pump is functioning as designed.

Submitted by Liesl Wilson (not verified) on

In reply to by Commenter (not verified)

I have not been able to keep a Guardian sensor on for more than 2 days. I get the message Updating Sensor. The ISIG number bounces around from 33 to .98.and then fails. I'm ready to give up. I use a 670G. I have been through 6 sensors in 7 days. The Helpline just sends me more. My last sensor, placed tonight in a spot never used before, failed before the first 2 hour stabilization. I have used Medtronic sensors for almost 10 years. The last 2 months have been terrible. Could I be having a reaction and inflammation at the insertion site that is clotting off the interstitial fluid?


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