摘要 |
An instrument (10, 210) for removing tissue samples from a tissue mass (11). The instrument (10, 210) is motor (18) powered, preferably by self-contained rechargeable batteries (16), and employs electrically actuated stops (45, 50) to control the action of penetration and retraction. An inner notched (14a) stylet (14) penetrates the tissue mass (11) and a hollow outer tube or cannula (13) which surrounds the stylet (14) and serves to sever a sample of tissue (11). The tissue penetrating (14) and severing means (13) are operably connected to a motor (18) powered rotary cam (55) assembly by means of cam followers (60) and the rotary motion of the cam (55) is converted to sequential, linear motion in the tissue penetrating means (14) and severing means (13). The stylet mount (74, 274) and the cannula mount (75, 275) each have a recess (222, 223) in the backside thereof to receive a respective drive rod (62, 262a, 262b). A locking mechanism is optionally provided, such as annular grooves (231, 235) on the drive rods (262a, 262b) engage radially inward projections (228, 232) in the recess (222, 223) of the mounts (274, 275) to secure them to the drive rods (262a, 262b). |