Extract tetrahedra out of 3d delaunay triangulation

Hi guys, 

I saw an example that showed how to have a 3d triangulation from the voronoi 3d: 

http://www.grasshopper3d.com/forum/topics/3d-delaunay-triangulation...

I would like to know how could it possible to extract all the tetrahedra from the triangulation as a set of 4 points. 

Thank you