| 主权项 |
1. A vessel filter comprising a first region and a second region, the filter movable between a collapsed position for delivery to the vessel and an expanded position for placement within the vessel, the first region having a filter portion having a converging region to direct particles toward the center of the filter, the filter portion converging into a tubular portion, the tubular portion having an internal surface, the filter terminating at a cranial end, the second region being flared in the expanded position to have a transverse dimension increasing in a direction away from the filter portion toward a caudal end, the second region including a vessel engaging portion, the first region having a spacer to keep the filter more toward a center of a vessel upon placement of the filter within the vessel, wherein in the collapsed position of the filter the spacer extends axially in an elongated position cranially of the cranial end of the filter and in the expanded position of the filter the spacer forms a looped region extending radially with respect to a longitudinal axis of the filter, the spacer having a first end attached to the internal surface of the tubular portion and extending within the tubular portion and emerging cranially from the tubular portion to form the looped region. |
