Biopsy device having a ratchet drive mechanism for driving a biopsy probe assembly

Abstract

A biopsy device includes a first cannula and a second cannula disposed co-axially with the first cannula. A first gear is fixedly attached to the first cannula. A second gear is fixedly attached to the second cannula. A torsion spring is interposed between the first gear and the second gear. The torsion spring is connected to each of the first gear and the second gear. A ratchet drive mechanism is configured to wind the torsion spring to store energy during a cocking operation, and is configured to release the energy stored by the torsion spring during a firing operation to drivably rotate the first gear to rotate the first cannula relative to the second cannula.

Dependencies are inferred from the claim text.