Marker delivery device for tissue marker placement

A marker delivery device configured for deploying a tissue marker, comprising:

• a handle including a housing having a front end and a back end, with a chamber located between the front end and the back end, and having a hole leading from the chamber to the exterior of the handle;
• a cannula having a proximal end, a distal end, and a lumen, the cannula being positioned in the handle such that the cannula retractably extends through the hole beyond the front end of the housing;
• and
• a retraction mechanism mounted to the housing, the retraction mechanism being coupled to the proximal end of the cannula, the retraction mechanism being configured to store a retraction force, and configured to facilitate a retraction of the cannula into the chamber of the housing of the handle upon an actuation of the retraction mechanism, the retraction mechanism including a shear member having a shear region of reduced cross section dimension, the shear member configured to be displaced by a user to expose the shear region to the retraction force to shear the shear member at the shear region to enable the retraction.

A marker delivery device configured for deploying a tissue marker, comprising:

• a handle including a housing having a front end and a back end, with a chamber located between the front end and the back end, and having a hole leading from the chamber to the exterior of the handle;
• a cannula having a proximal end, a distal end, and a lumen, the cannula being positioned in the handle such that the cannula retractably extends through the hole beyond the front end of the housing;
• a marker introducer rod coaxial with the cannula, the marker introducer rod having an actuation end;
• a first shear member having a first region of reduced cross section dimension;
• a second shear member having a second region of reduced cross section dimension;
• a deployment mechanism mounted to the housing, the deployment mechanism including:
• a marker deployment trigger accessible at an exterior of the housing;
• and
• an introducer rod guide block attached to the actuation end of the marker introducer rod, the introducer rod guide block being slidably disposed in the chamber of the housing, the introducer rod guide block being linked to the marker deployment trigger by the first shear member;
• and
• a retraction mechanism mounted to the housing, the retraction mechanism being configured to store a retraction force, and configured to facilitate a retraction of both the cannula and the marker introducer rod into the chamber of the housing of the handle upon an actuation of the retraction mechanism, the retraction mechanism including:
• a retraction trigger accessible at the exterior of the housing;
• and
• a cannula guide block attached to the proximal end of the cannula, the retraction force being applied to the cannula guide block, the cannula guide block being slidably disposed in the chamber of the housing, the retraction trigger being linked to the cannula guide block by the second shear member.