how to create a curve or polyline where mesh and surface intersect

Hi,

I have an open mesh and have created a series of surfaces that intersect the mesh at equal equal distances.

I am trying to create a polyline or curve where the surfaces and mesh intersect, can any one help?

So far I have achieved this using mesh intersect and joining the free edges of the interested meshes to create a polyline, this sort of works but I end up with a perimeter as well as my intersecting polyline which is not desirable.

Ideas?

Thanks

Dave

PS I have added two images that show you kind of what I want, just without the perimeter. The green outline/perimeter that you can see is the open mesh that I am working with, which is also another intersection between the other two larger meshes.