Shape memory marker deployment device
A marker delivery device includes an outer cannula, an inner cannula assembly, and a push rod. The outer cannula defines a longitudinal axis and includes an outer lumen. The outer lumen extends distally along the longitudinal axis from a handle to an open outer cannula distal end. The inner cannula assembly includes an inner cannula and a grip. The inner cannula is disposed within the outer lumen and extends distally along the longitudinal axis from the grip to an open distal end. The inner cannula has a resilient portion located proximate the open distal end. The resilient portion is configured to move between a stressed configuration when engaged with the outer cannula and a relaxed configuration when disengaged with the outer cannula. The push rod is disposed within an inner lumen of the inner cannula and is configured to deploy a marker through the open distal end.
1 . A marker delivery device comprising:
(a) an outer cannula, the outer cannula defining a longitudinal axis and including an outer lumen, the outer lumen extending distally along the longitudinal axis from a handle to an open outer cannula distal end;
(b) an inner cannula assembly including an inner cannula and a grip, the inner cannula including a first inner cannula and a second inner cannula, the first inner cannula being removably coupled to the second inner cannula, the first inner cannula being disposed within the outer lumen and extending distally along the longitudinal axis from the grip to a first inner cannula open distal end, the second inner cannula having an open distal end and a resilient portion located proximate the open distal end and a straight portion located between the open distal end and the resilient portion, the straight portion and the resilient portion each including a closed tubular portion and having an outer diameter that is the same, the resilient portion being configured to move between a stressed configuration when engaged with the outer cannula and a relaxed configuration when disengaged with the outer cannula, the resilient portion being configured to be more parallel with the longitudinal axis when in the stressed configuration than the relaxed configuration, the resilient portion being configured to extend laterally from the outer cannula when in the relaxed configuration; and
(c) a push rod, the push rod being disposed within an inner lumen of the inner cannula, the push rod being configured to deploy a marker through the open distal end.
2 . The marker delivery device of claim 1 , the push rod being configured to move within the inner lumen to deploy the marker through a needle.
3 . The marker delivery device of claim 2 , the needle having a closed distal end including a piercing tip, a distal portion of the needle being configured to translate a marker therethrough.
4 . The marker delivery device of claim 1 , the inner cannula being of a shape memory alloy.
5 . The marker delivery device of claim 4 , the shape memory alloy including nitinol or copper.
6 . The marker delivery device of claim 5 , the shape memory alloy including at least a one-way shape memory alloy.
7 . The marker delivery device of claim 1 , further comprising a plunger attached to the push rod, and a guard having a first position and a second position, the guard being configured to block access to the plunger in the first position, the guard being further configured to permit access to the plunger in the second position, the plunger being operable to deploy the marker when the guard is in the second position.
8 . The marker delivery device of claim 7 , the guard having a retaining feature including a detent or a locking pin.
9 . The marker delivery device of claim 1 , the push rod including a shape memory alloy.
10 . The marker delivery device of claim 1 , the push rod being rigid.
11 . The marker delivery device of claim 1 , the handle including a locking feature.
12 . The marker delivery device of claim 11 , the locking feature being configured to slidably couple the inner cannula within the outer cannula.
13 . The marker delivery device of claim 11 , the locking feature including a detent, a collet, or threads configured to engage a compressible member.
14 . The marker delivery device of claim 1 , the outer cannula being movably coupled to the inner cannula to translate the inner cannula between a plurality of positions.
15 . The marker delivery device of claim 1 , the second inner cannula including an attachment end and a deployment end, the resilient portion being between the attachment end and the deployment end.
16 . A biopsy system configured to position a marker within soft tissue, comprising:
(a) a push rod;
(b) an inner cannula assembly including a grip and an inner cannula, the inner cannula extending distally along a longitudinal axis from the grip to an open distal end, the inner cannula having a resilient portion located proximate to the open distal end, the resilient portion defining a channel extending to the open distal end, the resilient portion having a natural configuration and a stressed configuration, the natural configuration corresponding to the resilient portion being deflected from the longitudinal axis, the stressed configuration corresponding to the resilient portion extending generally along the longitudinal axis, the channel being sized to translate the marker through the channel while in the stressed configuration, the push rod being configured to deploy the marker through the open distal end of the inner cannula and through the channel of the resilient portion;
(c) an outer cannula disposed entirely around the inner cannula and configured to transition the resilient portion of the inner cannula between the natural configuration and the stressed configuration; and
(d) a needle configured to receive the inner cannula and the outer cannula, the needle including a side aperture, the resilient portion being configured to position the open distal end thereof proximate the side aperture when the inner cannula and outer cannula are fully inserted into the needle, the outer cannula including a length to thereby extend a portion of the outer cannula to the side aperture to thereby expose the portion of the outer cannula through the side aperture.
17 . The biopsy system of claim 16 , the outer cannula being configured to transition the resilient portion of the inner cannula from the stressed configuration to the natural configuration when the inner cannula is fully inserted into the outer cannula.
18 . The biopsy system of claim 16 , the outer cannula further including an open distal end, the resilient portion of the inner cannula being configured to protrude from the open distal end of the outer cannula when the inner cannula is fully inserted into the outer cannula.
19 . The biopsy system of claim 16 , the resilient portion of the inner cannula being configured to protrude from the side aperture of the needle when the resilient portion is in the natural configuration.
20 . A method of deploying a biopsy marker into soft tissue, the method comprising:
positioning an outer cannula into a first position relative to an inner cannula; and
moving the inner cannula or the outer cannula to position the outer cannula in a second position relative to the inner cannula such that a resilient portion and a straight portion of the inner cannula protrudes from a distal end of the outer cannula to transition the resilient portion from a stressed straight position to a relaxed curved position;
loading the biopsy marker into a proximal end of the inner cannula and then actuating a push rod disposed within the inner cannula to deploy the biopsy marker from an open distal end of the inner cannula;
advancing each of the outer cannula and the inner cannula into a needle having a lateral opening, and
deploying the biopsy marker through the lateral opening of the needle to thereby position the biopsy marker lateral to each of the inner cannula, the outer cannula, and the needle and into the soft tissue.