| 摘要 |
<p>A soft tissue biopsy device (10) provided with a piston retraction mechanism designed as a pistol-grip handle (15) for developing a suction chamber (54) within a housing (12) as the piston (28) slides therein. The suction reaches the cannula tip (22) as it is withdrawn, drawing tissue into a depression (26) on an exposed stylet (24). When the piston retraction mechanism (36) reaches a preset cam limit point, it automatically releases the piston (28), which is shot forward and restored to its position in the housing (12) by vacuum-spring action. Thus, the cannula (22) slides quickly over the stylet (24), cutting the tissue and retaining it in the depression (26). The entire procedure is performed by a single-handed operation. The biopsy device is designed with a piston (28) and housing (12) which are relatively large in comparison to the cannula diameter. Thus, with initial retraction of the piston (28), a relatively large suction is developed in the cannula (22), drawing tissue therein and firmly seating it in the stylet depression (26). <IMAGE></p> |
