US Patent 7959642 Medical instrument having a needle knife

A medical instrument includes a flexible sheath, a pivot base, a medical needle knife base, a medical needle knife, and a handpiece. The flexible sheath has a distal sheath portion insertable within a patient and has a proximal sheath portion. The pivot base is attached to the distal sheath portion. The needle knife base is pivotally connected to the pivot base and has a passageway. The medical needle knife is extendable from the passageway and is retractable within the passageway. The handpiece is connected to the proximal sheath portion and includes a manually-operated articulation control operatively connected to the needle knife base for pivoting the needle knife base with respect to the pivot base.