Biopsy device with aspiration valve

A biopsy system, comprising:

• (a) an instrument set, the instrument set comprising
• an instrument set housing,
• an elongate outer cannula having an axial lumen, a proximal portion coupled to the instrument set housing, and a distal portion having a tissue receiving aperture in a side wall thereof in communication with the lumen,
• an elongate inner cannula disposed within the outer cannula lumen, an aspiration vent disposed within the instrument set housing, wherein the aspiration vent fluidly couples the outer cannula lumen to atmosphere through an aspiration vent opening,
• an aspirate valve assembly interposed in the aspiration vent, the aspirate valve assembly including a sealing member configured to seal the aspiration vent opening, and
• an interference member that may be selectively moved at least partially into the aspiration vent opening to thereby contact the sealing member and prevent the sealing member from sealing the aspiration vent opening:
• and
• (b) an instrument drive removably coupled to the instrument set, the instrument drive comprising
• an instrument drive housing removably coupled to the instrument set housing,
• a motorized inner cannula driver disposed within the instrument drive housing and configured to axially oscillate the inner cannula relative to the outer cannula during operation of the biopsy system, such that an open distal end of the inner cannula moves back and forth across the tissue receiving aperture to sever tissue extending therethrough, and
• an actuating member disposed within the instrument drive housing, wherein the actuating member is configured to selectively move the interference member at least partially into the vent opening to thereby prevent the sealing member from sealing the aspiration vent opening.