1. A medical device comprising: a flexible shaft comprising a pulling member movable therein; an actuating mechanism operatively associated with a proximal end of the flexible shaft; an end effector associated with the distal end of the flexible shaft, wherein the end effector is operatively associated with a distal end of the pulling member; and wherein the actuator mechanism has a first configuration in which the actuator mechanism is decoupled from the pulling member, and a second configuraton wherein the actuator mechanism becomes operatively coupled to the pulling member to operate the end effector.