| CPC A61B 17/00 (2013.01) [A61B 34/30 (2016.02); A61B 34/71 (2016.02); A61B 2034/715 (2016.02)] | 20 Claims | 

| 
               1. A medical instrument comprising: 
            an instrument shaft; 
                an actuated structure at a distal end of the instrument shaft; 
                a backend mechanism at a proximal end of the instrument shaft, comprising: 
                a backend shaft rotatable in a first direction and a second direction that is opposite of the first direction; 
                  a first one-way clutch coupled to the backend shaft, the first one-way clutch configured to slip when the backend shaft is rotated in the second direction; 
                  a second one-way clutch coupled to the backend shaft, the second one-way clutch configured to slip when the backend shaft is rotated in the first direction; 
                a first length of tendon connected to the actuated structure and extending down the instrument shaft, the first length of tendon wound around the first one-way clutch in the first direction; and 
                a second length of tendon connected to the actuated structure and extending down the instrument shaft, the second length of tendon wound around the second one-way clutch in the second direction; and 
                a drive element operably coupled to the backend shaft and configured to drive the first length of tendon by rotating the backend shaft in the first direction and drive the second length of tendon by rotating the backend shaft in the second direction to drive the actuated structure. 
               |