What does it mean by "functionally closed system"?

Question

In automated blood component collection system, it seems some use "functionally closed system" while others don't. I don't really understand what is mean by it. Could someone explain? THanks!!

Answer 1

it means blood continuous flow inside the system and not anywhere else. It means it stays in the collection system and does not move out and is "functionally" because it is continuously flowing without any stops.

hope this helps^_^