Needle biopsy device

1. A device for needle biopsy, comprising:

a handle member having proximal and distal portions;

a proximal handle member disposed at the proximal portion of the handle member the proximal handle member being configured for slideable engagement with the proximal portion of the handle member, the proximal handle member includes a friction member that engages at least one indentation of a first series of indentations along the proximal portion of the handle member to limit slideable movement of the proximal handle member relative to the proximal portion of the handle member;

a distal handle member disposed at the distal portion of the handle member and configured to mate with another medical device including a channel, the distal handle member being configured for slideable engagement with the distal portion of the handle member, the distal handle member includes a friction member that engages at least one indentation of a second series of indentations along the distal portion of the handle member to limit slideable movement of the distal handle member relative to the distal portion of the handle member;

a sheath, having a lumen, the sheath being disposed within the handle member and extending from the distal portion of the handle member;

an exchangeable needle housing member, coupled to a flexible needle disposed within the sheath, the exchangeable needle housing member being releasably coupled to the proximal portion of the handle member and adapted to allow the needle housing member and needle to be removed from the device and exchanged with a different needle housing member and a different needle while the sheath remains disposed in the channel of the another medical device to which the distal handle member is mated, wherein the needle includes a plurality of protrusions disposed thereon, the protrusions centering the needle in the lumen of the sheath as the needle moves axially within the lumen, and at least a portion of the needle is surrounded by a polymer.

2. The device of claim 1 , wherein the plurality of protrusions are distributed along the length of the needle.

3. The device of claim 1 , wherein the plurality of protrusions are located at a consistent increment over the length of the needle.

4. The device of claim 1 , wherein at least a portion of the needle includes a tapered region for increasing the overall dimension of the needle, wherein the tapered region and the sheath lumen provide an interference therebetween for creating stability for the needle as the needle passes through the sheath lumen and is removed from the sheath lumen.

5. The device of claim 4 , wherein the interference is a drag force creating frictional resistance between an outer diameter of the needle and an inner diameter of the sheath lumen.

6. The device of claim 1 , wherein at least a portion of the needle includes materials or design features to enhance echogenicity and ultrasonic visibility.

7. The device of claim 1 , wherein the flexible needle additionally includes a stylet disposed therein.

8. The device of claim 1 , wherein the polymer is comprised of lubricous materials.

9. The device of claim 1 , wherein the polymer increases the overall dimension of the needle to create stability for the needle as the needle passes through the sheath lumen and is removed from the sheath lumen.