Patent attributes
A biopsy apparatus including a housing having a distal end, an outer cannula, an inner cannula, at least one motor, a vacuum source, and a leak path is disclosed. The outer cannula defines a first inner lumen having an open proximal end and a longitudinal axis extending therethrough that communicates with a tissue receiving opening. The inner cannula is slidably disposed within the first inner lumen and defines a second inner lumen that is coaxial with the longitudinal axis of the first inner lumen. The motor moves the inner cannula within the outer cannula. The vacuum source in fluid communication with the second inner lumen, aspirates tissue through the second inner lumen. The leak path is in communication with the atmosphere and is positioned transverse to the longitudinal axis of the first and second inner lumens to relieve vacuum behind tissue that is being aspirated though the second inner lumen.
