The Pump

This is the pump from Bartels-Mikrotechnik (www.bartels-mikrotechnik.de). Obviously it's the black square on the right; the other things are matches, but they give you the idea of the size of the pump.

When I experimented with this I found that it only worked effectively (with water or insulin) when powered by 240V. But then I discovered that even when the pump was off it would leak insulin. This is actually a know issue with pumps and the way to deal with it is to use something called a check valve. Bartels-Mikrotechnik have got this covered as well so they supply the check valve shown below. The image makes it look large but it's only 5mm diameter and 10mm long. The check valve is also needed to stop air from being sucked back into the system when the pump relaxes after a pumping pulse. However I wonder if this will be an issue when connected to the infusion set, attached to the patient.

Together in my initial packaged version of the i-Pump they will look like this. You can see some tubing here as well. This gives a better idea of the relative sizes of these components.

Click here for the datasheet on these and other components supplied by Bartels.

NOTE (8 July 2009) - Bartels now do an MP6 pump and driver/controller module. I may begin experiementing with these if any problems occur with the present design. However so far the MP5 with my own driver circuit works very well and may be more accurate as I think the MP5 delivers a smaller volume per single pump-action than the MP6.