New catheters for user-friendly infusion kits for patients with diabetes

Many diabetics must use a small pump every day to inject insulin (popularly known as a drop). Connecting the drop is not always easy and there is a risk that the patient incorrectly inserts it, hitting muscle tissue instead of fatty tissue.

Incorrect insertion ruins the device’s functionality
If a patient incorrectly injects needle into muscle tissue instead of fatty tissue as instructed, this can cause the thin, small catheter (0.7 mm diameter) that is supposed to inject the insulin to become blocked.

New user-friendly infusion kit
This is why Unomedical has developed an infusion kit where the infusion device and kit are assembled in one sterile unit. Unomedical wanted a catheter specially designed for the kit that could make allowances for the patient making an incorrect injection.

The collaboration with FRECON was excellent. Their work is high-quality and, together, we created a useful solution that has now completed its final tests and is ready for the market.

Tobias Stumpe
Design & Development Engineer, Unomedical

Task: Comprehensive calculations

In collaboration with Unomedical, FRECON was responsible for carrying out the task, which was to challenge the traditional design of a catheter with a hole in the end.

“Unomedical wanted to insert slits in the catheter, which is made of soft plastic. Therefore, we calculated different configurations of these slits and found the one that gave the best opening of the catheter. We’re talking about something as small as just 0.7 mm in diameter,” explains Rasmus Lundby Høyer, Design Specialist (FEM/FEA), FRECON.

Development of an information film

This task required us to develop and code a small animated film, which illustrates simply and precisely when and how the catheter becomes deformed in different situations. The film has subsequently been used as marketing material by the customer, e.g. at trade fairs.

New marketing possibilities
With the newly designed solution, the customer now has a product that provides them with completely new marketing possibilities.

Watch the video at the bottom of this page.

As part of the comprehensive calculations to find the ideal position of the small slits in the catheter and their size, we developed a transient calculation model in ANSYS, made from a small block, which would simulate a “muscle” and which could be moved up and down to find out when and how the catheter would deform or kink. We did this by measuring the volume and the area that “opens” when the catheter bends or is compressed.