Alignment features for ultrasonic surgical instrument

Abstract

An ultrasonic instrument comprises a body, a shaft assembly, an ultrasonic blade, and a pivoting member. The shaft assembly extends distally from the body. The ultrasonic blade is positioned distal to the shaft assembly. The pivoting member is pivotable with respect to the blade from an open position to a closed position to thereby clamp tissue between the pivoting member and the blade. One or both of the shaft assembly or the pivoting member comprise a guide feature. The guide feature is configured to provide lateral alignment of the distal portion of the pivoting member with the blade as the pivoting member is pivoted to the closed position.

I/We claim: 
     
     
         1 . An ultrasonic instrument comprising:
 (a) a body;   (b) a shaft assembly extending distally from the body;   (c) an ultrasonic blade positioned distal to the shaft assembly; and   (d) a pivoting member, wherein the pivoting member is pivotably coupled with the shaft assembly, wherein the pivoting member defines a distal portion and a proximal portion, wherein the pivoting member is pivotable with respect to the blade from an open position to a closed position to thereby clamp tissue between the pivoting member and the blade;   wherein one or both of the pivoting member or the shaft assembly comprise a guide feature configured to provide lateral alignment of the distal portion of the pivoting member with the blade as the pivoting member is pivoted to the closed position.   
     
     
         2 . The ultrasonic instrument of  claim 1 , wherein the guide feature comprises at least one projection extending transversely from one or both of the pivoting member or the shaft assembly. 
     
     
         3 . The ultrasonic instrument of  claim 2 , wherein guide feature further comprises a pocket formed in the other of the pivoting member or the shaft assembly, wherein the pocket is configured to receive the at least one projection when the the pivoting member is in the closed position. 
     
     
         4 . The ultrasonic instrument of  claim 2 , wherein the at least one projection is tapered. 
     
     
         5 . The ultrasonic instrument of  claim 2 , wherein the at least one projection comprises a pair of projections, wherein the pair of projections extend in transversely opposing directions in relation to a longitudinal axis defined by the shaft assembly. 
     
     
         6 . The ultrasonic instrument of  claim 1 , wherein the guide feature comprises at least one set screw, wherein the at least one set screw is configured to bear against an exterior surface of the shaft assembly. 
     
     
         7 . The ultrasonic instrument of  claim 1 , wherein the guide feature comprises at least one resilient member, wherein the at least one resilient member is configured to bear against an exterior surface of the shaft assembly. 
     
     
         8 . The ultrasonic instrument of  claim 1 , wherein the guide feature comprises at least one ramp, wherein the at least one ramp is configured to exert a progressively increasing force upon the exterior surface of the shaft assembly as the pivoting member is pivoted to the closed position. 
     
     
         9 . The ultrasonic instrument of  claim 1 , wherein the guide feature comprises at least one ball bearing configured to bear against an exterior surface of the shaft assembly. 
     
     
         10 . The ultrasonic instrument of  claim 1 , further comprising a cutting member, wherein the cutting member is pivotably coupled with the shaft assembly, wherein the cutting member is further pivotable relative to the pivoting member, wherein the cutting member is configured to slice tissue. 
     
     
         11 . The ultrasonic instrument of  claim 1 , wherein the distal portion of the pivoting member comprises a clamp arm, wherein the pivoting member is pivotable with respect to the blade from an open position to a closed position to thereby clamp tissue between the clamp arm and the blade, wherein the blade has a first transverse height, wherein the clamp arm has a second transverse height, wherein the ratio of the first height to the second height is between approximately 0.8 and approximately 1.0. 
     
     
         12 . The ultrasonic instrument of  claim 1 , wherein the distal portion of the pivoting member comprises a clamp arm, wherein the pivoting member is pivotable with respect to the blade from an open position to a closed position to thereby clamp tissue between the clamp arm and the blade, wherein the clamp arm has a transverse height of less than approximately 0.07 inches. 
     
     
         13 . The ultrasonic instrument of  claim 1 , wherein the distal portion of the pivoting member comprises a clamp arm, wherein the pivoting member is pivotable with respect to the blade from an open position to a closed position to thereby clamp tissue between the clamp arm and the blade, wherein the blade has a first transverse width, wherein the clamp arm has a second transverse width, wherein the ratio of the first height to the second height is between approximately 0.65 and approximately 1.0. 
     
     
         14 . The ultrasonic instrument of  claim 1 , wherein the distal portion of the pivoting member comprises a clamp arm, wherein the pivoting member is pivotable with respect to the blade from an open position to a closed position to thereby clamp tissue between the clamp arm and the blade, wherein the clamp arm has a transverse width of less than approximately 0.065 inches. 
     
     
         15 . The ultrasonic instrument of  claim 1 , further comprising:
 (a) a waveguide extending longitudinally through the shaft assembly, wherein the ultrasonic blade is acoustically coupled with the waveguide; and   (b) a locking feature, wherein the locking feature is operable to move from an open position to a closed position, wherein the waveguide is operable to rotate within the body when the locking feature is in the open position, and wherein the locking feature is operable to lock the waveguide in a selected rotational position relative to the body when the locking feature is in the closed position.   
     
     
         16 . The ultrasonic instrument of  claim 1 , further comprising a waveguide extending longitudinally through the shaft assembly, wherein the ultrasonic blade is acoustically coupled with the waveguide, wherein the shaft assembly further comprises a distal shaft component and a proximal shaft component, wherein the proximal shaft component is rotatable relative to the distal shaft component to adjust the rotational position of the waveguide relative to the body, wherein the proximal shaft component is securable to the distal shaft component to lock the rotational position of the waveguide relative to the body. 
     
     
         17 . The ultrasonic instrument of  claim 1 , further comprising:
 (a) a waveguide extending longitudinally through the shaft assembly, wherein the ultrasonic blade is acoustically coupled with the waveguide; and   (b) an annular member secured to a nodal region of the waveguide, wherein the annular member is rotatable relative to the body to adjust the rotational position of the waveguide relative to the body, wherein the annular member is further securable relatively to the body to lock the rotational position of the waveguide relative to the body.   
     
     
         18 . An ultrasonic instrument comprising:
 (a) a body;   (b) a shaft assembly extending distally from the body, wherein the shaft assembly defines a longitudinal axis;   (c) an ultrasonic blade positioned distal to the shaft assembly; and   (d) a pivoting member, wherein the pivoting member is pivotably coupled with the shaft assembly, wherein the pivoting member is pivotable along a first plane aligned with the longitudinal axis of the shaft assembly to thereby clamp tissue between the pivoting member and the blade; and   (e) a resilient member configured to resiliently bias the pivoting member along a second plane aligned with the longitudinal axis of the shaft assembly, wherein the second plane is perpendicular to the first plane.   
     
     
         19 . An ultrasonic instrument comprising:
 (a) a body;   (b) a shaft assembly extending distally from the body;   (c) a first working element positioned at the distal end of the shaft assembly;   (d) a pivoting member, wherein the pivoting member is pivotably coupled with the shaft assembly, wherein at least a portion of the pivoting member is deformable;   (e) a second working element positioned at the distal end of the pivoting member, wherein the pivoting member is pivotable in a first direction to drive the second working element toward the first working element, wherein the pivoting member is pivotable in a second direction to drive the second working element away from the first working element; and   (f) a stiffening feature, wherein the stiffening feature is configured to provide variable stiffness to the deformable portion of the pivoting member, wherein the stiffening feature is configured to provide a first stiffness to the pivoting member when the pivoting member is pivoted in the first direction, wherein the stiffening feature is configured to provide a second stiffness to the pivoting member when the pivoting member is pivoted in the second direction, wherein the second stiffness is greater than the first stiffness.   
     
     
         20 . The ultrasonic instrument of  claim 19 , wherein the stiffening feature comprises a sliding member slidably disposed along the pivoting member, wherein the sliding member is configured to vary the stiffness of the pivoting member based on a selected longitudinal position of the sliding member relative to the pivoting member.