Patent ID: 7883526

Claim:
An embolic coil comprising: a wound coil including a plurality of turns defining an elongated lumen, the wound coil having a proximal end portion and a distal end portion; a stretch resistant member that is fixedly unattached to the wound coil while being at least partially received longitudinally within the elongated lumen and having a proximal end portion, a distal end portion, and a distally positioned enlarged portion; a headpiece formed from a hypotube that has an outer surface secured to the coil lumen at the proximal end portion of the wound coil, with the proximal end portion of the stretch resistant member having been plasma welded to the hypotube, whereby said headpiece comprises the hypotube and the proximal end portion of the stretch resistant member, with the proximal end portion of the wound coil being secured to the headpiece outer surface; a restrictor member at least partially received within and fixedly attached to the wound coil lumen, wherein the restrictor member defines an aperture smaller than the distally positioned enlarged portion of the stretch resistant member, a portion of the stretch resistant member is movable through the aperture to allow stretching of the wound coil, and the distally positioned enlarged portion is adapted to engage the restrictor member to resist stretching of the wound coil during use of the coil; and the wound coil lumen is larger than the distally positioned enlarged portion of the stretch resistant member whereby this enlarged portion is movable through the wound coil lumen and the wound coil extends beyond the enlarged portion of the stretch resistant member.