Filter and filter insertion instrument

An insertion instrument for positioning a filter in a blood vessel of the body, said instrument comprising:

• a hollow, bullet-shaped carrier body;
• a piston mounted in the hollow carrier body;
• an elongated ejector shaft projecting from the piston through the carrier body for ejecting from the carrier body, a filter mounted externally thereon;
• means resiliently resisting movement of the piston and ejector shaft relative to said carrier body;
• a tubular member connected to said bullet-shaped carrier body for conveying a fluid to the hollow interior of the body for actuating said piston against said means resiliently resisting said movement of the piston and ejector shaft relative to the carrier body;
• and
• means for injecting a fluid into said tubular member at the end thereof opposite the end connected to said bullet-shaped body.

An insertion instrument for positioning a filter in a blood vessel in the body, said instrument comprising:

• a bullet-shaped carrier body;
• a neck portion secured to one end of the carrier body;
• an ejector assembly mounted in the carrier body for ejecting the filter from the carrier;
• ejector assembly actuating means connected to the carrier body;
• a threaded connector secured to the neck portion;
• and
• a locking collar detachably securing said ejector assembly actuating means to said threaded connector, said locking collar including an axially extending peripheral flange spaced from said neck portion.

An insertion instrument for positioning a filter in a blood vessel of the body, said instrument comprising:

• a solid carrier for carrying the filter;
• an ejector assembly mounted in the carrier for ejecting the filter from the carrier;
• an elongated catheter having one of its ends connected to said carrier;
• and
• a syringe connected to the opposite end of said catheter from the end thereof connected to said carrier for injecting an ejector assembly actuating fluid into the catheter.

Apparatus for entrapping emboli entrained in circulating blood, said apparatus comprising:

• a bullet-shaped carrier body having bore means extending therethrough from one end thereof to the other;
• a filter demountably carried on the carrier body, said filter comprising:
• a hub positioned ata at end of said carrier body in alignment with said bore means;
• and
• a plurality of resilient legs each having one end secured to said hub, said legs extending along said body in peripherally spaced relation therearound;
• collar means secured to said carrier body at the opposite end thereof from said hub and encircling the ends of said legs opposite the ends secured to the hub for sheathing the encircled ends of said legs and biasing the legs into a retracted, folded position along the body;
• and
• demounting means movably positioned in said bore means in the body for demounting said filter from the carrier body.