Recently, I switched from an Animas pump to the Minimed 720. Having been completely happy with Insets, I was hesitant to switch to anything else. I stumbled upon these Fifty50 reservoirs for Minimed Paradigm paradigm pump and naturally they caught my attention. Hoping the luer lock reservoirs would make for a smoother transition, I purchased some at the same time I ordered the new pump.
A new Fifty50 reservoir
It’s a great concept, but the reservoirs leave much to be desired as far as removing air bubbles. I never had problems with air bubbles when using my Animas pump, so I had no idea what I was in for. The plunger lacks the pointed tip that is found on the Animas cartridges so there is nothing to push air out of the connector portion of the reservoir. This means that in order to expel the bubbles, the bubbles must be positioned perfectly under the luer lock connector. Once I had a clean reservoir with no bubbles, priming the pump was another challenge. When priming, bubbles tended to get stuck in the area circled in the image below. I’m not sure what is different about the Fifty50 reservoirs that caused this, but it happened very consistently and took lots of patience and insulin to overcome.
Animas reservoir's pointed plunger tip
Bubbles tend to get stuck in the circled area when the tubing is attached.
Once I managed to get rid of all bubbles (took around 15 minutes for each fill), I had no problems with the reservoir. While I don’t recommend these reservoirs to someone new to a Minimed pump like me, they may be an OK alternative for someone with patience and extra luer lock infusion sets. They do work, and they do give consumers more choice, so despite some flaws, credit must be given to the company that created and manufactures these.