Abstract: A system for retrieving material from a biological vessel comprises an outer tube, advanceable through the biological vessel toward the material. At a distal part of the system, the system comprises a sleeve formed from wires that are arranged in a braid and covered with a polymer. A shaft is positioned within the outer tube, and attached to the sleeve such that the shaft is adapted to transition the sleeve between a collapsed state by drawing the sleeve proximally into the outer tube and an expanded state by advancing the sleeve distally out of the outer tube. A portion of a distal end of the sleeve includes leaflets formed by wires, the leaflets extending circumferentially around 25-75 percent of the distal end of the sleeve and protruding distally by 1-3 mm. Other embodiments are also described.

Abstract: A catheter system including an inner tube movable within an outer tube and a funnel-shaped sleeve attached to the inner tube and configured for transitioning between a collapsed state when sequestered within the outer tube and an expanded state when advanced out of the outer tube.

Abstract: An apparatus for removing an obstruction from a blood vessel of a subject comprises a flexible catheter and a trap. The trap is formed from a set of braided wires covered in a covering, and, at a distal end of the trap, has an oval opening that is beveled such that the oval opening has a distal portion, and a proximal portion proximal from the distal portion. The trap has a beak, defined by wires of the set, that extends over the proximal portion of the oval opening. The trap is biased to assume an expanded state in which the oval opening is wider than a rim of the catheter, and is compressible into a compressed state within the catheter such that the oval opening is narrower than in the expanded state. Other embodiments are also described.

Abstract: A catheter system including an inner tube movable within an outer tube and a funnel-shaped sleeve attached to the inner tube and configured for transitioning between a collapsed state when sequestered within the outer tube and an expanded state when advanced out of the outer tube.