US Patent 6989021 Retrievable medical filter

The present invention relates to a retrievable medical filter which can be placed in a blood vessel or other body passage. The filter has improved structural features for enhancing its performance, including deployment, filtration and position stability at the desired site, as well as retrievability. The filter may preferably have a hook structure that provides multiple retrieval surfaces, or may be provided with anchors for removably retaining the filter in position. A filter may be designed with one end being customized for retrieval and the other end being customized for position retention, in which case a cartridge may be provided to ensure proper orientation of the filter during delivery.