Patent ID: 8579931

Claim:
A marking apparatus for the percutaneous placement of an imaging marker at a location in a tissue mass to facilitate subsequent determination of the location of the tissue mass, the marking apparatus comprising: a handle having a proximal handle end and a hollow interior that extends distally from the proximal handle end; a cannula mounted to the handle and configured to extend from the handle, the cannula being configured to define a lumen open to the hollow interior of the handle, a distal end of the cannula forming an insertion tip with an axial opening at the insertion tip; a stylet having a proximal end with a proximal tip and a distal end, slidably received within the lumen for movement between a ready position and an extended position, where, in the ready position, the distal end of the stylet is spaced inwardly from the insertion tip to define a marker recess between the distal end of the stylet and the axial opening, and in the extended position the distal end of the stylet extends at least into the marker recess; an imaging marker disposed completely within the marker recess to be expelled through the axial opening by movement of the stylet from the ready position to the extended position, wherein the imaging marker has no lead long enough to extend from the interior of the tissue mass to the exterior of the tissue mass when the imaging marker has been placed in the tissue mass; and an actuator having a plunger connected to the proximal end of the stylet, and configured to move the stylet from the ready position to the extended position to expel the imaging marker, the plunger configured to project proximally from the hollow interior at the proximal handle end, the plunger in its entirety having an exterior surface that is of uniform diameter and has an outer perimeter that is smaller than an outer perimeter of the handle, whereby the marking apparatus has the handle, the cannula, the stylet, and the actuator combined as a single unitary self-contained device, and is configured to be grasped and operated by a single hand of a user, and wherein the actuator comprises the plunger slidably and rotatably mounted to the handle, and further includes a safety that comprises a channel provided on one of the handle and the plunger and a catch provided on the other of the handle and the plunger and configured such that when the catch and channel are rotationally aligned, the plunger can move the stylet from the ready position to the extended position, and configured such that when the catch and the channel are rotationally mis-aligned, the plunger cannot move the stylet from the ready position to the extended position.