I've been diabetic for 25 years and have always had a fear and phobia of needles and although I did my own injections this could at times take minutes to do and were often painful.
So when my DSN finally convinced me to go on the pump and I saw the different cannulas available I went for insertion device based on the fact of "how hard can it be to press a button?!"
However, I've had various different degrees of success with my cannula changes. When I first went on the pump it was done and dusted in 5-10 minutes, but after a succession of really painfull insertions each cannual change turned into an extremely traumatic experience, often leading to not changing the cannula for days (obvioulsy not a good thing to do as the insulin absorbtion decreases).
In the end I came off the pump because I had such a mental barrier with the cannula change it was counta productive. However, after much support and help from my family, I have gone back on the pump, had my parents changing the cannula for me to start with but have now just started doing it again for myself
It can still take up to half and hour to change but it's a start.
I tend to do my changes early evening, just because it's more convenient, but I was told not to do it just before bed incase you're sugars spike. Sometimes I'll be good and keep the old cannula in for the evening/next morning just to make sure the new one is in properly. I have had a few occasions where after changing a cannula my sugars have run in the high teens all day so I know it's not working.
My cannula is changed every 2-3 days and the whole infusion set every 5-6 days. The insulin cartridge is changed when it's empty, the insulin is kept in the fridge until I get my warning alarm telling my cartridge is running low, and then I draw up the new cartridge and leave it out until needed. It was suggested by my rep that keeping a full/fill cartridge in the fridge is fine, so it's already set for when you need to change it.
I'm on the Accu-Chek Spirt Combo, from Roche