Abstract: A biopsy device includes coaxially disposed inner and outer needles in which the outer needle tip is configured for obtaining a tissue sample. The inner surface of the outer needle includes a tissue retention feature which may include a countersink and/or a feature formed in the inner surface. The device may be introduced to a biopsy site through an introducer in which the introducer is vented and/or a certain ratio of introducer inner diameter and biopsy device outer diameter is maintained. The full core devices also permit a tighter tolerance between the I.D. and O.D. of the outer cannula and stylet, respectively, which further permits the use of a smaller gage introducer. Full devices also include a sample trap assembly operable to enlarge the sample cavity after the full core sample has been obtained.

Abstract: A biopsy device includes coaxially disposed inner and outer needles in which the outer needle tip is configured for obtaining a tissue sample. The inner surface of the outer needle includes a tissue retention feature which may include a countersink and/or a feature formed in the inner surface. The device may be configured such that the inner needle does not extend past a certain point within the outer needle.