Surgical instrument deflection system

A surgical instrument comprises a housing (1), and a shaft (2) including a proximal end, a deflectable portion and a distal tip (3). A handle (5) is movable between a first position and a second position, and an actuator (7) is movably coupled to the handle (5) such that movement of the handle between its first and second position causes a corresponding movement of the actuator between a first and second position. A deflection wire (10) includes a proximal portion and a distal portion, the distal portion being fixed to the shaft (2), and the proximal portion being affixed to the housing (1) so as to provide a path length for the deflection wire within the housing. The movement of the handle (5) causes the actuator (7) to move to its second position, the second position of the actuator causing an increase in the path length for the deflection wire (10) so as cause a deflection of the distal tip (3). The path length may go through the actuator (7).