Mechanisms for controlling rotation of outer cannula for use in endoscopic tool

Abstract

A surgical instrument includes a cutting assembly, an outer tubing, and a flexible torque component. The cutting assembly extends from a first proximal end to a first distal end. The cutting assembly includes an outer cannula defining a cutting window and an inner cannula disposed within the outer cannula. The outer tubing extends from a proximal tubing end to a distal tubing end. The distal tubing end is coupled to the outer cannula. The outer tubing is configured to receive a torque at the proximal tubing end and transmit the torque to the outer cannula to rotate the outer cannula. The outer tubing includes a plurality of first wires and a plurality of second wires each including more than eight wires and less than twenty four wires. The flexible torque component is coupled to a third proximal end of the inner cannula to rotate the inner cannula.

What is claimed is: 
     
         1 . A method comprising:
 positioning a cutting assembly, the cutting assembly comprising an outer cannula and an inner cannula disposed within the outer cannula;   rotating the outer cannula to position a cutting window of the outer cannula adjacent a region from which to resect material by rotating a flexible outer tubing coupled to the outer cannula, wherein the flexible outer tubing includes a plurality of first wires and a plurality of second wires oriented at an angle relative to the plurality of first wires, the plurality of first wires and the plurality of second wires each including more than eight wires and less than twenty four wires; and   rotating, by a drive assembly, a flexible torque component coupled to the inner cannula to rotate the inner cannula relative to the outer cannula to resect the material.   
     
     
         2 . The method of  claim 1 , wherein rotating the flexible outer tubing comprises rotating the flexible outer tubing with a first rate of rotation, the first rate of rotation having a difference of less than or equal to thirty percent compared to a second rate of rotation of the cutting window, the difference based on a first number of the plurality of first wires and a second number of the plurality of second wires. 
     
     
         3 . The method of  claim 2 , wherein the first number and the second number is twelve. 
     
     
         4 . The method of  claim 2 , wherein a spacing between at least two adjacent first wires of the plurality of first wires inversely corresponds to a sum of the first number and the second number. 
     
     
         5 . The method of  claim 1 , wherein the flexible outer tubing includes a base layer adjacent to the plurality of second wires, the base layer comprising an elastomer and a friction reducing additive, and a top layer adjacent to the plurality of first wires, the top layer comprising the elastomer and the friction reducing additive. 
     
     
         6 . The method of  claim 1 , wherein the cutting window includes a material entry opening through which the material to be resected enters the cutting assembly, and the method further comprising actuating a vacuum source coupled to a material exit port of an aspiration channel, the aspiration channel extending from the material exit port to the material entry opening, the vacuum source suctioning the material into the material entry opening and removing the material from the aspiration channel at the material exit port. 
     
     
         7 . The method of  claim 1 , further comprising providing fluid at a proximal irrigation end of an irrigation channel extending between the flexible outer tubing and the flexible torque component to output the fluid adjacent to the outer cannula. 
     
     
         8 . The method of  claim 1 , wherein rotating the flexible outer tubing comprises rotating, by a manual rotational actuator, the flexible outer tubing. 
     
     
         9 . A cutting tool comprising:
 a cutting assembly configured to resect material, the cutting assembly comprising an inner cannula disposed within an outer cannula, the inner cannula configured to rotate relative to the outer cannula, the outer cannula defining a cutting window; and   a flexible outer tubing configured to rotate the outer cannula, the flexible outer tubing including a plurality of first wires and a plurality of second wires oriented at an angle relative to the plurality of first wires, the plurality of first wires and the plurality of second wires each including more than eight wires and less than twenty four wires.   
     
     
         10 . The cutting tool of  claim 9 , wherein the flexible outer tubing rotating the outer cannula comprises the flexible outer tubing rotating is further configured to rotate the outer cannula with a first rate of rotation, the first rate of rotation having a difference of less than or equal to thirty percent compared to a second rate of rotation of the cutting window, the difference based on a first number of the plurality of first wires and a second number of the plurality of second wires. 
     
     
         11 . The cutting tool of  claim 10 , wherein the difference is less than or equal to ten percent. 
     
     
         12 . The cutting tool of  claim 10 , wherein the first number and the second number is twelve. 
     
     
         13 . The cutting tool of  claim 10 , wherein a spacing between at least two adjacent first wires of the plurality of first wires inversely corresponds to a sum of the first number and the second number. 
     
     
         14 . The cutting tool of  claim 9 , wherein the flexible outer tubing includes a base layer adjacent to the plurality of second wires, the base layer comprising an elastomer and a friction reducing additive, and a top layer adjacent to the plurality of first wires, the top layer comprising the elastomer and the friction reducing additive. 
     
     
         15 . The cutting tool of  claim 9 , wherein the cutting window includes a material entry opening through which the material to be resected enters the cutting assembly, and the cutting tool further comprising an aspiration channel that extends from the material entry opening to a material exit opening coupled to a vacuum source, the aspiration channel configured to receive the resected material via the material entry opening and configured to remove the resected material from the aspiration channel at the material exit opening. 
     
     
         16 . The cutting tool of  claim 9 , further comprising an irrigation channel that extends inside the flexible outer tubing, the irrigation channel configured to receive fluid at a proximal irrigation end and outputting output the fluid adjacent to the outer cannula. 
     
     
         17 . The cutting tool of  claim 9 , further comprising a manual rotational actuator configured to rotate the flexible outer tubing. 
     
     
         18 . The cutting tool of  claim 17 , further comprising a drive assembly separate from the manual rotational actuator configured to rotate the flexible outer tubing. 
     
     
         19 . The cutting tool of  claim 9 , wherein the flexible outer tubing includes an outer diameter less than 0.5 inches. 
     
     
         20 . The cutting tool of  claim 9 , wherein the flexible outer tubing includes an inner diameter of the flexible outer tubing having a ratio to an outer diameter of the flexible outer tubing greater than or equal to 0.5 and less than or equal to 0.95.