A pause in microbolus and basal delivery after meal bolusing makes spike control diffucult for Auto Mode in the Medtronic MiniMed 670G pump.
Tegaderm Film to the Rescue When I run out of the oval tape that comes with the Guardian 3 Sensors for the MiniMed 670G, the Tegaderm Film by 3M comes…
According to Medtronic, Auto Mode does not learn an individual’s time of day patterns or diurnal variations (i.e., dawn phenomenon) for the Medtronic MiniMed 670G. Medtronic recommends the following for…
Since Auto Mode is adaptive and conservative in nature, patience must be exercised and expectations curtailed to reasonable levels. I can say it took me about a year to get…
If you still have the first generation transmitter and are still fighting with the BG required loop issue contact your Medtronic educator to get the enhanced transmitter as soon as you can. It will save you a lot of grief.
Exactly a year ago on this day, I met with my diabetes educator for my Medtronic MiniMed 670G training. Two weeks later I started using Auto Mode. Along the way,…
Lesson I learned: At the beginning of sensor life, it might not be a good idea to only depend on sensor readings only. Also, probably not a good idea to change the Guardian sensor, infusion set and eat pizza close together!
Last night, I had what I would call a perfect storm where I replaced my sensor and infusion set and then ate pizza. Unfortunately, my sensor did not catch up with a sharp rise in blood sugar since it had not stabilized. I only caught the high sugar readings when I checked my meter Blood Glucose (BG) reading.
From the onset let me say I think the Medtronic MiniMed 670G and the Auto Mode setting are a big leap forward in glucose control for Type 1 diabetes. Closed loop insulin pump technology is the technology of the future. Personally I foresee the insulin pump becoming an install-and-forget type of medical device in the near-future. While in no way perfect, the first iteration of the MiniMed 670G was a great step forward in this direction.
Some people using the Minimed 670G pump and Guardian sensor have recommended inserting a new sensor a couple hours beforehand prior to the expiry of their sensor they are using…
Double arrows pointing down on your pump is never a good thing especially if the number is 65. But towards the end of life the guardian CGM sensor, it is…
Link to the Article abstract for this article titled Optimizing Hybrid Closed-Loop Therapy in Adolescents and Emerging Adults Using the MiniMed 670G System by Messer Et al. that was published on Diabetes Care in April 2018. Inbox me to see how we can get you a copy of this paper. Disclaimer.
Bottom line: Your Endo might need to really get aggressive in adjusting your carb-ratios for Auto Mode.
This article is probably the most detailed of any publicly available Medtronic sanctioned studies that actually discusses the MiniMed 670G pump and gives guidelines on how to optimize Auto Mode. It delves a little and provides references on how the HCL algorithm used in Auto Mode works and the inputs that can be adjusted when it comes to Auto Mode.
In their trials, the authors worked on optimizing Auto Mode inputs for 31 adolescent and young adult participants (14-26 years old) over a period of 3 months.
The study provides three settings that can be used to tune Auto Mode, namely: carb to insulin ratio, Active Insulin Time (AIT) and Bolus Speed (although this setting is not used or explained for the trial).
The main takeaways from this paper can be summarized as follows:
UPDATE 09/10/19 – A new enhanced transmitter to resolve the BG loop issue is being issued to Medtronic MiniMed 670G owners. This has worked beautifully for me since receiving it about 3 months ago.
To request for the new enhanced transmitter follow this link.
Or you can contact your Medtronic Diabetes Educator or call Medtronic directly for one.
Couple weeks ago, I could not enter Auto Mode on my 670G for three days due to the dreaded “BG Required Loop.” As a solution, I eventually had to change the sensor to be able to re-enter AutoMode.
God knows I have tried to resolve the issue using every advise given online in forums (including trying to “fake” the system by entering a number just above or below your last entry) but these have only worked only a couple times.
What I think Causes the BG Required Loop
At issue I think is the way that the 670G calibrates the Guardian sensor. It seems to be programmed to validate the BG you’ve entered into the system probably based on the ISIG history and its predictive model of where your BG readings are trending towards.
I recently set out to compare the two meters since I like to have a back up meter to the Contour Next meter supplied by Medtronic. It is only until recently that AETNA started to approve the Contour Next glucose test strips through my insurance coverage.
So I have been using the ONETOUCH UltraMini for the last 5 years or so since it was the only meter that was fully covered by my insurance without a co-pay on my part.
The difference in readings was all over the place, but the only discernible pattern was that the Contour next Link 2.4 meter read consistently higher than the ONETOUCH UltraMini.
I personally think that the Contour Next is a more accurate meter (closer to the real blood glucose number) but the ONETOUCH UltraMini is more precise (multiple readings from one site are closer).
And this is important since the ONETOUCH UltraMini and ONETOUCH Verio’s superior precision is key to reducing Auto Mode and sensor errors and especially eliminating the “BG Required Loop” that occurs in Auto Mode.
Guardian Sensor Stability and Auto Mode
I have been trying to get back to Auto Mode for the better part of the day today.
As you can see my readings in manual mode were not so bad and I would say those were stable sensor readings. I am not sure what reading variance the Auto Mode algorithm considers acceptable to enter Auto Mode.
There is a lot to like about the Auto Mode feature for the Medtronic MiniMed 670G. This feature is analogous to self-driving technology where a car employing this technology drives along fine until the camera hits a blind spot. The same happens for Auto Mode, it works fine until an unexpected situation arises and the Auto Mode algorithm cannot handle this sudden change.
The closed-loop hybrid system is ground-breaking technology that as a research scientist I really appreciate. Yes, it is a work in progress. But its current intricacies and potential to give people with Diabetes better control of their glucose numbers and more freedom to pursue other important things in their lives is really laudable.
UPDATE - I have certainly found out that dialing the Carb Ratio and Active Insulin time up and down do not necessarily mean that you will get better control. That is why it is important to work with your endo or educator to tune these settings.
When it comes to Auto Mode for the MiniMed 670G, tuning the settings to get as close to your sugar targets feels a little more complicated as compared to the manual mode. This is because the closed loop system has a feedback mechanism which will likely throw-off one setting when you change another.
In the course of your day, the system is performing a balancing act between bolus and basal to keep you as close to Auto Mode’s fixed and preset BG target of 120mg/dL by introducing a third input – the micro bolus.
When it is all said and done, the user has control of two settings only, namely Carb Ratio (CR) and Active Insulin time (AIT).
When moving to pump therapy, the idea of basal and bolus and how you use them in tandem does not make a lot of sense at first. There's little to…
Every now and then you will get this dreaded message on your Medtronic MiniMed 670G: "Do not Calibrate. Sensor Updating. Do not Calibrate. Sensor Updating. This could take up to…
As you can see my morning fasting glucose numbers are running higher than I would like them. I feel well rested in the morning if my numbers are below 120.…
Bottom-line: For accuracy and fewer calibration errors I have found upper thigh sensor insertion sites better than belly sites. These sites take longer to stabilize (about 12-24 hours) but always…
I never had luck using AAA rechargeable batteries with the MiniMed 530G. For some reason, the 530G found the batteries not to have enough charge even after I had recharged…