Yesterday on day 1, I laid out what I am doing and the rules.

Today I will go over inserting CGMs.

Each sensor comes in a box suited for one month of use. Minimed’s Sof-Sensor has 10 in a box and Dexcom’s 7+ and G4 each have 4 per box.

Of the three, Medtronic’s looks the scariest so let’s start there. The sof-sensor comes in 2 parts. The sensor itself and the spring loaded inserter (“Sen-Serter”) shown below.

It looks like a big needle but as you will see later, there is no reason to be scared (even if you hate needles).

To insert the needle you load it in the Sen-serter and pull it to the loaded postion. The arms at the bottom are angled to match the angle at the insertion point. When you are ready, press the white button on top and in a snap the needle is in. You then remove the Sen-serter by pulling it away from the site and remove the needle.

If you are brave enough you can also manually insert the needle. I decided against that.

Dexcom’s 7+ and G4 inserters are nearly identical as far as how they work and what they look like. In this post I will only be showing the 7+ as I don’t have any expired G4′s.

The Dexcom version only has a manual option. You never see the needle which makes it less scary though it is about the same length.

To put a Dexcom in you start by sticking the site to your abdomen and removing the safety as shown.

Then you press the plunger to insert the needle and pull back on the cuff to remove it, leaving the cgm.

Which one hurts less?

There is no clear anser to that question. It really depends on the spot you hit. When I inserted the 7+ I didn’t feel it at all but the G4 was a little pinch. When inserting the Medtronic all I felt was the plastic hitting my skin, though it did bleed a little bit.

The Needles:

The way the Medtronic and Dexcom CGMs work are a little different. When you insert the Medtronic, it has a solid needle and the CGM sensor is hollow. The Dexcom is opposite with a hollow needle and a solid sensor. The part left in your skin is about the same length from both companies. Dexcom’s is round. Medtronic’s is more of an oval shape.

The way it has been explained to me, Dexcom’s sensors work in 360 degrees. Medtronic’s acts more like a straw. It reads as your interstitial fluid travels inside. You would think that slows down the readings but Medtronic’s algorithms account for this and they include predictive alerts. Their unit tells you as much as 20 minutes before a high or low.

Share your insertion stories below. What does it feel like when you insert yours?