Full core biopsy needle with secondary cutting cannula

摘要

There is shown and described embodiments of a biopsy needle that is simpler to make and use than existing devices. An inner and outer cannula are provided, with the outer cannula having a superelastic finger that lies along the length of the inner cannula in a retracted position and partially covers the lumen of the inner cannula in an extended position. The finger is pointed and in the form of a triangle in a particular embodiment, and does not extend beyond the outer extent of the inner cannula in the extended position.

主权项

1. A full-core biopsy needle comprising:
an inner cannula having a sharpened distal end, defining a central lumen through said cannula and said distal end, said distal end including a substantially planar surface that is oblique to the longitudinal axis of said central lumen and around said central lumen; and a monolithic outer cannula having a body with a substantially uniform outer diameter and defining a central lumen, with a distal end having a finger extending distally, at least said finger having superelastic properties, said inner cannula being received within said central lumen of said outer cannula, said inner cannula and outer cannula being configured so that they are easily slidable with respect to each other and have a close fit at least at said distal ends, wherein said outer cannula and inner cannula have a first respective position in which said finger lies substantially over said oblique planar surface of said inner cannula but does not cover all of said oblique planar surface of said inner cannula and does not extend beyond the circumference at a distal-most point of the distal end of said inner cannula, and a second respective position in which said finger lies along the outer surface of said inner cannula and does not extend over said oblique surface, wherein said finger does not extend beyond said outer diameter of said outer cannula and remains exterior to the distal end.