Surgical stapler with rotary cam drive and return

Abstract

A surgical circular stapler has a body, shaft, a stapling assembly, a motor, a cam assembly, and a firing assembly. The shaft extends distally from the body. The stapling assembly is secured to a distal end of the shaft. Longitudinal translation of the firing assembly causes the stapling assembly to drive a plurality of staples in a circular array to secure two lumens of tissue together. The stapling assembly may further drive a blade to sever any excess tissue interior of the circular array of staples. The motor is operable to rotate the cam assembly. Rotation of the cam assembly causes longitudinal translation of the firing assembly. A single rotation of the cam assembly is operable to drive the firing assembly from a proximal position to a distal position and back to a proximal position.

I/We claim: 
     
         1 . A surgical instrument comprising:
 (a) a body;   (b) a shaft extending distally from the body, wherein the shaft comprises a proximal end and a distal end;   (c) a stapling assembly, wherein the stapling assembly is disposed at the distal end of the shaft, wherein the stapling assembly is configured to selectively move from an open position to a closed position, and wherein the stapling assembly is operable to drive a plurality of staples into tissue;   (d) a motor;   (e) a cam assembly coupled with the motor, wherein the motor is configured to rotate the cam assembly; and   (f) a firing assembly coupled with the cam assembly, wherein the firing assembly is configured to longitudinally translate to thereby cause the stapling assembly to drive the plurality of staples, and wherein the cam assembly is rotatable to thereby longitudinally actuate the firing assembly.   
     
     
         2 . The instrument of  claim 1 , wherein the cam assembly comprises a radially inwardly presented cam surface and a radially outwardly presented cam surface, wherein the radially outwardly presented cam surface is configured to drive the firing assembly distally in response to rotation of the cam assembly through a first range of angular motion, wherein the radially inwardly presented cam surface is configured to drive the firing assembly proximally in response to rotation of the cam assembly through a second range of angular motion. 
     
     
         3 . The instrument of  claim 1 , wherein the firing assembly comprises an arm engaged with the cam assembly, wherein the arm is configured to longitudinally translate to cause longitudinal actuation of the firing assembly. 
     
     
         4 . The instrument of  claim 3 , wherein the cam assembly comprises a barrel cam. 
     
     
         5 . The instrument of  claim 4 , wherein barrel cam comprises a sloping cam face. 
     
     
         6 . The instrument of  claim 5 , wherein the firing assembly further comprises a roller in contact with the sloping cam face. 
     
     
         7 . The instrument of  claim 5 , wherein barrel cam comprises a sloping annular projection extending outwardly from an exterior of the barrel cam. 
     
     
         8 . The instrument of  claim 5 , wherein barrel cam comprises a sloping annular channel defined within an exterior of the barrel cam. 
     
     
         9 . The instrument of  claim 8 , wherein the arm is slidably disposed within the sloping annular channel. 
     
     
         10 . The instrument of  claim 1 , wherein the body comprises a handle assembly, wherein the motor is positioned in the handle assembly. 
     
     
         11 . The instrument of  claim 10 , wherein the handle assembly comprises a pistol grip, wherein the pistol grip is oriented obliquely in relation to a proximal portion of the firing assembly and in relation to the proximal end of the shaft, wherein the motor is positioned within the pistol grip such that the motor is oriented obliquely in relation to a proximal portion of the firing assembly and in relation to the proximal end of the shaft. 
     
     
         12 . The instrument of  claim 1 , further comprising a pivoting arm rotatably secured to the body, wherein a first portion of the pivoting arm is engaged with the cam assembly, wherein a second portion of the pivoting arm is engaged with the firing assembly, wherein the cam assembly is rotatable to cause rotation of the pivoting arm, and wherein the pivoting arm is rotatable to cause longitudinal actuation of the firing assembly. 
     
     
         13 . The instrument of  claim 12 , wherein the cam assembly comprises a cam having a channel formed in the exterior of the cam. 
     
     
         14 . The instrument of  claim 12 , wherein the cam assembly comprises a cam channel formed in a face of a rotating member. 
     
     
         15 . The instrument of  claim 14 , wherein the first portion of the pivoting arm is slidably disposed within the cam channel. 
     
     
         16 . The instrument of  claim 12 , wherein the cam assembly comprises a cam projection extending from a face of a rotating member, wherein the first portion of the pivoting arm is slidably coupled with the cam projection. 
     
     
         17 . The instrument of  claim 1 , wherein the cam assembly comprises at least a first cam and a second cam. 
     
     
         18 . The instrument of  claim 17 , wherein the firing assembly comprises a pivoting arm rotatably secured to the body, wherein a first portion of the pivoting arm is engaged with the first cam, wherein a second portion of the pivoting arm is engaged with the second cam, wherein a third portion of the pivoting arm is engaged with the firing assembly, wherein the cam assembly is rotatable to cause rotation of the pivoting arm, wherein the pivoting arm is rotatable to cause longitudinal translation of the firing assembly. 
     
     
         19 . A surgical instrument comprising:
 (a) a body;   (b) a shaft extending distally from the body, wherein the shaft comprises a proximal end and a distal end;   (c) a stapling assembly, wherein the stapling assembly is disposed at the distal end of the shaft, wherein the stapling assembly is configured to selectively move from an open position to a closed position, and wherein the stapling assembly is operable to drive a plurality of staples into tissue;   (d) a motor;   (e) a cam assembly coupled with the motor, wherein the motor is configured to rotate the cam assembly; and   (f) a firing assembly, wherein the firing assembly is configured to longitudinally translate to thereby cause the stapling assembly to drive the plurality of staples, wherein the cam assembly is rotatable to thereby longitudinally translate the firing assembly, wherein the cam assembly is configured to rotate through a single revolution to thereby drive the firing assembly from a proximal position to a distal position and back to either the proximal position or another position that is proximal to the distal position.   
     
     
         20 . A surgical instrument comprising:
 (a) a body;   (b) a shaft extending distally from the body, wherein the shaft comprises a proximal end and a distal end;   (c) a stapling assembly, wherein the stapling assembly is disposed at the distal end of the shaft, wherein the stapling assembly is configured to selectively move from an open position to a closed position, wherein the stapling assembly is operable to drive a plurality of staples into tissue;   (d) a motor;   (e) a cam assembly coupled with the motor, wherein the motor is configured to rotate the cam assembly; and   (f) a firing assembly, wherein the firing assembly comprises an engagement member, wherein the engagement member in engaged with the cam assembly, wherein the firing assembly is configured to longitudinally translate to thereby cause the stapling assembly to drive the plurality of staples, and wherein the cam assembly is configured to cause longitudinal translation of the firing assembly in two longitudinal directions in response to a single revolution of the cam assembly.