Instrument for obtaining a biopsy specimen

Claim 1

An instrument for obtaining a specimen from a membrane body, comprising a housing, a hollow tube extending from said housing, tip means positioned on one end of said tube, said tip having an opening in a wall thereof, cutting means positioned in said tip and movable past the opening in said tip, vacuum-producing means mounted in said housing and having a movable portion for producing the vacuum, a vacuum conduit between said tube and said vacuum-producing means, means for actuating said vacuum-producing means to draw a portion of the membrane body into the tip and move said cutting means past said tip opening to sever a specimen from said membrane body drawn into said tip; said actuating means including a trigger, a first member for moving the vacuumproducing means'' movable portion coupled to said trigger, a wire extending through the tube and connected to the severing means at one end and supported by said first member at its other end, a block responsive to movement of said wire, means connected between said block and said first member for resiliently biasing said block, a cam follower positioned to prevent movement of the block while said first member is being moved over a portion of its travel, and an abutment member positioned on said cam follower in the line of travel of said first member such that upon contact of said first member and said abutment member, said cam follower is moved to release said block, whereby said cutting means is moved.