After we had made the valves which fitted every heart that could be modelled we faced the next challenge: to print you need a solid. We could place the valves at the right place but the problem was that both the surface of the heart and the surface of the valve were intersecting with each other. When we tried to mesh Boolean in rhino the fan from your laptop creates such a lifting effect that your laptop actually begins to float or it spontaneously combusts. So we came to the conclusion that we needed to search for another solution that using Rhino.
Our friends from Autodesk had the ideal program which we could use to mix the meshes, join them, or Boolean difference them. This program helped us throughout the rest of the project and was our savior. Every patch that needed to be done, every Boolean difference or union, this program would fix everything for us.