Rotating full-core biopsy needle

Abstract

There is disclosed, among other things, embodiments of a biopsy needle for taking a full core sample through soft tissue. In the illustrated embodiments, the needle includes a single monolithic tubular member having a notch cut part-way through a distal portion of the tubular member to form an arch-shaped finger. At least a portion of the finger is bent toward the notch and into the lumen of the tubular member. Methods for using these embodiments are also described.

1 - 9 . (canceled) 
     
     
         10 . A biopsy needle, comprising:
 an elongated tubular member adapted for insertion into a patient to obtain a tissue sample, said tubular member having a proximal portion, a distal portion having a distal end, and a central longitudinal lumen along a longitudinal axis from said proximal portion through said distal portion and said distal end,   wherein said distal end includes a finger separated from the rest of the tubular member by a notch, a portion of said finger being bent toward said notch so that a portion of said finger extends into said lumen, wherein when a tissue sample enters the lumen it contacts said portion of said finger and extends beyond the finger within the lumen, and   wherein said tubular member is configured so that rotation around said axis causes at least a portion of tissue within said lumen to be separated from adjacent tissue.   
     
     
         11 . The needle of  claim 10 , wherein said finger is adapted to elastically flex outward away from said lumen by pressure from a tissue sample moving through said lumen when said tubular member is forced through tissue. 
     
     
         12 . The needle of  claim 10 , wherein said portion of said finger extending into said lumen includes at least one tooth having a sharp edge. 
     
     
         13 . The needle of  claim 12 , wherein said tubular member has a leading edge, and wherein said tooth and sharp edge are in a portion of said tubular member diametrically opposite to said leading edge. 
     
     
         14 . The needle of  claim 12 , wherein said tubular member has a leading edge, and wherein said tooth and sharp edge are in a portion of said tubular member lateral of said leading edge. 
     
     
         15 . The needle of  claim 14 , wherein said distal end includes a distal-facing surface, and wherein said notch extends through said distal-facing surface at a first location, said tooth being a portion of said finger adjacent said first location. 
     
     
         16 . The needle of  claim 10 , further comprising a longitudinal protrusion fixed to said tubular member within said lumen. 
     
     
         17 . The needle of  claim 16 , wherein said protrusion substantially faces said notch. 
     
     
         18 . The needle of  claim 16 , further comprising a mandrel having a first portion movable through said lumen, said first portion having a surface configured to face said tooth so that said mandrel can move without substantial interference with said tooth. 
     
     
         19 . The needle of  claim 18 , wherein said surface of said mandrel includes a surface that is at least one of flat and longitudinally grooved. 
     
     
         20 . A method of taking a biopsy, comprising:
 providing a needle having a tubular member with a notch defining a distal finger and a lumen, a portion of said finger being bent with respect to the rest of the tubular member into said lumen;   inserting said tubular member into tissue of a patient that is to be sampled, so that tissue to be sampled enters said lumen to a position proximal of said finger;   rotating said needle with respect to the tissue, said rotating reducing the area of connection between the tissue within said lumen and adjoining tissue;   withdrawing said needle from said patient, said portion of said finger bent into said lumen blocking the tissue proximal of said finger within said lumen from exiting said needle.   
     
     
         21 . The method of  claim 20 , wherein said rotating causes said portion of said finger to cut a profile through tissue within said lumen. 
     
     
         22 . The method of  claim 20 , wherein said rotating generates twisting strain between tissue within said lumen and adjoining tissue, resulting in a separation between tissue within said lumen and adjoining tissue or weakening of the join between tissue within said lumen and adjoining tissue.