Patent ID: 7611474

Claim:
A biopsy device, comprising: a. an outer piercing tube having an aperture proximate to a distal end thereof for receiving prolapsed tissue, wherein the outer piercing tube has a sharpened closed tip configured to penetrate a patient's skin; b. a cutter tube longitudinally translatable within the piercing tube; c. a cutter drive assembly comprising: (i) a translation drive shaft operable to translate the cutter tube, (ii) a rotation drive shaft operable to rotate the cutter tube, and (iii) a single-input to dual-output gearbox assembly coupled with the translation drive shaft and the rotation drive shaft, wherein the single-input to dual-output gearbox assembly comprises a translation gear coupled with the translation drive shaft, a rotation gear coupled with the rotation drive shaft, and a common input gear coupled with both the translation gear and the rotation gear, wherein the gearbox assembly is configured to rotate the translation gear and the rotation gear simultaneously in response to rotation of the common input gear; wherein the cutter drive assembly is operatively configured to: (v) distally translate the cutter tube at a rate of translation and rotate the cutter tube at a rate of rotation, wherein the rate of translation is in constant proportion to the rate of rotation, (vi) rotate the cutter tube through a predetermined number of rotations of the cutter tube across the aperture severing received prolapsed tissue, (vii) maintain the predetermined number of rotations despite axial resistance encountered by the cutter tube from tissues of varying density, and (viii) translate the cutter tube at a variable rate, wherein the predetermined number of rotations remains constant despite variations in the cutter tube rate of translation; and d. a rotary motor coupled to the common input gear, such that the rotary motor is operable to rotate the common input gear of the cutter drive assembly.