Patent attributes
An implantable vessel filter device having a plurality of radially expandable legs with hooks, and a center-post configured to prevent entanglement of the radially expandable legs when they are compressed against the center-post. In one variation, the filter device includes a first set of legs, forming a first filter basket in the expanded position, and a second set of legs, forming a second filter basket distal to the first filter in the expanded position. Hooks may be provided on the second set of legs to prevent migration of the filter along the vessel after the filter is deployed. Grooves may be provided along the shaft of the center-post to receive the hooks and prevent the hooks from interlocking when the legs of the filter are compressed along the center-post.
