Surgical tool with nested shaft tube

A surgical instrument includes a base, an outer tube having a proximal end operably coupled to the base, and an inner tube extending within the outer tube. The inner tube has a proximal end operably coupled to the base to allow the inner tube to slidably move relative to the outer tube in response to a force applied to a distal end of the inner tube and such that a frictional force applied to an outer surface of the outer tube is not applied to the inner member. 手术器械包括底座、具有可操作地耦接到底座的近端的外管以及在外管内延伸的内管。该内管具有可操作地耦接到底座的近端，以允许内管响应于施加到内管的远端的力而相对于外管可滑动的移动，并且使得施加到外管的外表面的摩擦力不被施加到内部构件。