US Patent 6951564 Site marker device

A site marker device and marker are provided. The site marker device includes a housing and a distally extending delivery tube. A pusher rod is movably positioned within the delivery tube to eject a marker from the distal end thereof. An elongated tubular body is positioned about the delivery tube. An actuator is provided to provide two stage advancement. During the first stage, the delivery tube and the pusher rod are advanced through the distal end of the elongated tubular body. During the second stage of advancement, the pusher rod is advanced independently of the delivery tube to eject a marker from the distal end thereof. The marker is formed from a shape memory material and has a circular or hoop configuration in the relaxed state.