An intravascular filter having a filament which expands a filter element. The filament is a coil which is stretched to reduce the diameter of the coil for introduction. The filter element is preferably biased toward the closed position and is opened by the coil when tension is released on the coil. The...http://www.google.ca/patents/US6890341?utm_source=gb-gplus-sharePatent US6890341 - Methods and devices for filtering fluid flow through a body structure
