MULTI-FACETED BIOPSY NEEDLE TIPS AND NEEDLES, NEEDLE SETS, AND DEVICES INCORPORATING THE SAME
A multi-faceted soft tissue piercing element includes three distal planar cutting edges converging to form a sharp, distal point of the tissue piercing element. Each distal cutting edge forms a first angle with respect to a central longitudinal axis of the tissue piercing element. The tissue piercing element also includes three proximal planar cutting edges. Each proximal cutting edge extends proximally from a respective one of the three distal planar cutting edges. Each proximal cutting edge forms a second angle relative to the central longitudinal axis of the tissue piercing element. The second angle is larger than the first angle.
1 . A biopsy needle for penetrating soft tissue, comprising:
an elongate body extending between a proximal end and a distal end, the elongate body having a central longitudinal axis; and
a tissue piercing tip at the distal end of the elongate body, the tissue piercing tip comprising:
a first set of facets defined by three first faces and three first cutting edges, wherein each first cutting edge is formed by adjacent faces of the three first faces, and wherein each first cutting edge forms a first angle relative to the central longitudinal axis, and
a second set of facets positioned distal to the first set of facets, the second set of facets being defined by three second faces and three second cutting edges, wherein each second cutting edge is formed by adjacent faces of the three second faces, and wherein each second cutting edge forms a second angle relative to the central longitudinal axis, the second angle being smaller than the first angle, the three second cutting edges converging to form a distal end point of the biopsy needle.
2 . The biopsy needle of claim 1 , wherein the biopsy needle is a nine-gage (9-G) needle.
3 . The biopsy needle of claim 1 , wherein the biopsy needle is a seven-gauge (7-G) needle.
4 . The biopsy needle of claim 3 , wherein the first angle ranges between about 17 degrees and about 23 degrees relative to the central longitudinal axis.
5 . The biopsy needle of claim 3 , wherein the second angle ranges between about 9 degrees and about 15 degrees relative to the central longitudinal axis.
6 . The biopsy needle of claim 1 wherein a diameter of the elongate body is greater than a diameter of the tissue piercing tip.
7 . The biopsy needle of claim 1 , wherein the elongate body includes a sidewall defining a lumen.
8 . The biopsy needle of claim 7 , wherein the elongate body includes a tissue receiving aperture in the sidewall, the tissue receiving aperture being positioned adjacent to the tissue piercing tip in the distal end of the elongate body.
9 . The biopsy needle of claim 8 , wherein a distance between the distal end point and the tissue receiving aperture defines a dead space, the dead space ranging from about 8 mm to about 11 mm.
10 . The biopsy needle of claim 9 , wherein the first angle is about 20 degrees, the second angle is about 9 degrees, and the dead space is about 8.4 mm.
11 . The biopsy needle of claim 9 , wherein the first angle is about 20 degrees, the second angle is about 12 degrees, and the dead space is about 8.4 mm.
12 . The biopsy needle of claim 9 , wherein the first angle is about 20 degrees, the second angle is about 15 degrees, and the dead space is about 8.4 mm.
13 . The biopsy needle of claim 1 , wherein the three first faces are all symmetrical to each other and the three first cutting edges are all symmetrical to each other.
14 . The biopsy needle of claim 1 , wherein the three second faces are all symmetrical to each other and the three second cutting edges are all symmetrical to each other.
15 . The biopsy needle of claim 1 , wherein the tissue piercing tip comprises one or more reliefs.
16 . The biopsy needle of claim 15 , wherein the tissue piercing tip comprises three reliefs extending along the central longitudinal axis, each of the reliefs extending along a respective facet surface of the tissue piercing tip that is formed by a respective pair of first and second facets.
17 . The biopsy needle of claim 16 , wherein each of the reliefs forms a concave surface extending along the facet surface between the cutting edges, the concave surface being defined by a radius of curvature and a lateral span.
18 . The biopsy needle of claim 17 , wherein the radius of curvature is between about 1.9 mm to about 3.7 mm and the lateral span is between about 6.4 mm and about 8.3 mm.