Abstract: A component for use as or for incorporation within a medical instrument navigable through body vessels of a human subject is provided. The component includes a tubular portion with an interrupted spiral defined by alternating cut and uncut sections. The sum of the arcuate extents of each bridge section and a cut section adjacent to the bridge section in end-to-end fashion is neither a whole number factor of 360 degrees nor a multiple of 90 degrees; this provides uniform rigidity, flexibility, and stretch resistance in all bending planes. The device further includes multiple sections, the pitch of the spiral varying from section to section in order to vary the sections' flexibilities.

Abstract: A medical device for placing an embolic device at a predetermined site within a vessel of the body including a delivery catheter and a flexible pusher member slidably disposed within the lumen of the catheter. An embolic device is retained within the delivery catheter by a mechanical interlocking mechanism which includes an engagement member attached to the distal end of the pusher member and extends through a retaining ring at the proximal end of the embolic device. A detachment member extends through an aperture at the distal end of the engagement member thereby locking the embolic device onto the pusher member. A kicker member extends from the distal end of the pusher member and is comprised of a shape memory material adapted to lift the retaining ring off of the engagement member at human body temperature when the detachment member is withdrawn from the aperture of the engagement member.