Biopsy needle sample retention system

1. A biopsy needle assembly configured for use with a tissue biopsy device, the biopsy needle assembly comprising:

an outer tubular member comprising a distal end portion configured to sever a first portion of a tissue sample; and

a cutting member slidably disposed within the outer tubular member, wherein the cutting member comprises a distal end portion, and wherein the distal end portion of the cutting member is configured to displace toward a central axis of the outer tubular member to sever a second portion of the tissue sample;

wherein the distal end portion is configured to extend through an opening in the outer tubular member, the opening extending between an outside surface of the outer tubular member and a lumen of the outer tubular member.

2. The biopsy needle assembly of claim 1 , wherein the distal end portion of the cutting member further comprises a tab, and wherein displacement of a portion of the tab into the lumen of the outer tubular member is configured to sever the second portion of the tissue sample.

3. The biopsy needle assembly of claim 2 , wherein the at least one opening is configured to direct the portion of the tab into the lumen of the outer tubular member in response to relative displacement of the cutting member in relation to the outer tubular member.

4. The biopsy needle assembly of claim 3 , wherein the portion of the tab is bent such that the tab is configured to enter the lumen of the outer tubular member through the opening.

5. The biopsy needle assembly of claim 2 , wherein the tab is configured to sever the second portion of the tissue sample at or adjacent a distal-most point of the distal end portion of the outer tubular member.

6. The biopsy needle assembly of claim 1 wherein the cutting member is configured to sever the second portion of the tissue sample at an optimized position from a distal-most point of the distal end portion of the outer tubular member.

7. The biopsy needle assembly of claim 1 , further comprising a trocar disposed within the cutting member, wherein the trocar comprises a distal end portion configured to facilitate advancement of the biopsy needle assembly through a body tissue.

8. A tissue biopsy device configured to obtain a tissue sample, comprising:

a first elongate member configured to be advanced into a body tissue;

a second elongate member movably disposed around the first elongate member and configured to sever a first portion of the tissue sample;

a third elongate member movably disposed within the second elongate member and configured to sever a second portion of the tissue sample at or adjacent a distal-most point of a distal end portion of the second elongate member; and

an actuator configured to actuate at least the second elongate member and the third elongate member such that the tissue sample is severed

wherein a distal end portion of the third elongate member is partially disposed in an opening extending through a wall of the second elongate member prior to actuation, such that the distal end portion does not catch on tissue as the tissue biopsy device is advanced through tissue.

9. The device of claim 8 , wherein the distal end portion of the third elongate member is configured to be displaced toward a central axis of the second elongate member to sever the second portion of the tissue sample.

10. The device of claim 9 , wherein the distal end portion of the second elongate member is configured to direct the displacement of the distal end portion of the third elongate member.

11. The device of claim 8 , wherein the third elongate member is further configured to extract the severed tissue sample from the body tissue.