BIOPSY APPARATUS HAVING MULTIPLE AIR PATHS FOR VENTING

A biopsy apparatus, including a biopsy probe assembly having a cutter cannula, a vacuum cannula, and a stylet cannula coaxially arranged. The vacuum cannula is positioned inside the stylet cannula to define a first intermediate lumen. The stylet cannula is positioned within the cutter cannula to define a second intermediate lumen. The stylet cannula is movable relative to the vacuum cannula and the cutter cannula between an extended position and a retracted position. The stylet cannula has a longitudinal vent slot. A seal has a proximal seal portion. When the stylet cannula is moved from the extended position toward the retracted position, the longitudinal vent slot is longitudinally positioned under the proximal seal portion to open a seal bypass path across the proximal seal portion to establish a first air path at the first intermediate lumen and a second air path at the second intermediate lumen.