Discussion Forum

Hi,

For my graduation project I am currently modeling the lymphatic primary valve. The model consists of two overlapping lymphatic endothelial cells, poroelastic extracellular matrix on the left (poro) and vessel lumen on the right (fsi). In order to function as a valve, the lymphatic endothelial cells are connected to their environment at certain points via anchoring filament (rope like structures). They 'pull' on the cells as the poroelastic extracellular matrix swells on incoming pressure, holding the cells into place under the pressure gradient and allowing the fluid to flow through the valve at the overlapping parts (see attached GIF). In this example I kept parts of the endothelial cells out of my model, fixing them in place. The ECM boundary on the left uniformly moves from left to right, expanding and contracting.

In order to model the mentioned anchoring filaments I introduced six points (see my attached model) on the ECM boundary at the left (poro) and used integration coupling at each of those points to get their displacement. Then I made variables out of this and prescribed these to each of the six points of attachment on the endothelial cells (fsi). However the displacement of the ECM boundary is now distorted compared to my previous model (GIF).

Why is this the case and is there anything I can do about this? Thank you in advance!

Best regards,
Jibbe Soetens