Continuous Glucose Monitoring Medtronic
Anyone who has encountered type 1 diabetes knows that the main gadget of a diabetic in the modern world is a continuous glucose monitoring device (CGM).
After our daughter was diagnosed in 2015, we thought we could live using syringes and a glucometer. That's how we lived, our daughter is 2 years old and when she felt ill, we urgently gave her juice and measured her glucose using a glucometer. It was a terrible time.
In 2016, an endocrinologist at our clinic suggested installing an insulin pump without CGM – Medtronic 722. For us, this was a step forward – fewer injections and hope for CGM in the future. Six months later, with the help of the foundation, we were able to purchase a Minilink (a transmitter from CGM, compatible with the Medtronic 722 pump). Together with the endocrinologist, we installed the first Enlite sensor. Now the glucose value was read from the Minilink every 5 minutes and displayed on the Medtronic 722 pump screen. It was cool. But we did not enjoy this device for long. The main drawback of CGM in the Medtronic 722 + Minilink + Enlite Sensor is that data is displayed with a 20-minute delay. This is due to the fact that the glucose value in the subcutaneous fluid is delayed by 20 minutes relative to the glucose determined in the blood.
Thus, if the pump shows a value of 9 mM/l and decreases by about 1.5 mM/l in 5 minutes, then the real glucose value may be around 9 – 1.5*4 = 3 mM/l. And this is already hypoglycemia. With relatively smooth sugars, everything is normal, but for children who are now running around, have not eaten enough, and a bunch of other factors… I still see ads for the Medtronic 722 pump and am surprised that the price tag on Avito is quite high.
At the same time, there was no supply of consumables for the pump and NMG. It was very expensive. Then a law was passed on supplying consumables for insulin pumps and it became easier, but they only gave out infusion sets and reservoirs. Sensors were still bought in an online store.
Medtronic 722 solemnly lived 4 years and in Moscow we were offered to install Medtronic 640 with NMG included. At the same time, all consumables were the same, which is very convenient. The Medtronic 640 pump itself calculates sugar after 20 minutes, which makes life much easier. At the same time, this system can turn off the base when approaching the lower limit, which is very helpful at night to keep sugar within the norm. The only disadvantage of this option, compared to modern systems, is the impossibility of transferring data to the phone and to the Kaber Link cloud.
The second daughter's diabetes did not finish us off, as it did with the first. And by the time she was discharged from the hospital, the Medtronic Connect system was purchased, displaying sugar values on the phone. This was the fastest and cheapest option for implementing NMG. The downside of this system was that the phone would periodically run out of battery, was left in another room, and a normal Internet connection was needed for calibration.
In April 2024, we had two Medtronic 740 pumps installed, complete with NMG, with the ability to output data to a phone and to the Kaber Link cloud. By this time, we were no longer afraid to buy consumables on Avito (for about a year and a half, they were not available in online stores at all). And then an unexpected surprise awaited us in the form of new consumables for NMG – Sensor 3.
Externally, this sensor is very similar to Enlite, but its price on Avito starts from 4,000 rubles, while Enlite can be found for 400 rubles per sensor. It's a shame when a sensor for 4,000 rubles does not start and you have to replace it with a new one. A couple of months of buying Sensor 3 brought horror, up to 40,000 rubles were spent on servicing two pumps. At the same time, the sensors are very similar in appearance. A little delving into the problematic allowed me to find out that they differ only in the connector, and an idea arose about the possibility of upgrading the Enlite sensor to fit the Sensor 3 connector. The figure schematically shows the features of the connectors and an option for upgrading (I do this with a file) Enlite to Sensor 3. This modification has already been done 10 times, everything is fine.
At the same time, there are craftsmen on Avito who modify the transmitter itself.
This article tells about personal experience of using NMG from Medtronic and does not encourage you to do any independent modifications to the sensors. Everything is at your own risk.
