Patent ID: 8317818

Claim:
A removable filter to be placed in a flow of blood through a blood vessel having a wall, the filter comprising: a) a head having proximal and distal end portions and a central longitudinal axis; b) a plurality of filter members extending from the head in generally one direction that is distally of the head, at least some of the filter members having a first larger diameter and a distal end, a tapered portion affixed to said distal end and a hook attached to said tapered portion opposite said distal end, each hook including a curved section extending distally away from said tapered portion and laterally away from said central longitudinal axis, said curved portion having a radius of curvature larger than said first diameter, said hook terminating at a hook free end that is spaced away from the distal end of the filter member with a gap in between said filter member distal end and said hook free end, said hook defining a plane; c) wherein said hook is of a second smaller diameter when compared to the first larger diameter of said filter member; and d) a sharp edge spanning at least a portion of at least one of the filter members and extending to said tapered portion, said sharp edge extending from said tapered portion toward said curved portion but terminating before extending over a majority of the curved portion of the hook so that the hook curved portion is able to straighten during removal from the wall of the blood vessel, said sharp edge being in said plane.