Tissue cutter with differential hardness

Abstract

Disclosed is a tubular cutting element for axial reciprocal movement within an outer tubular sleeve. The cutting element has an elongate tubular body, having a proximal end, a distal end and a cutting tip. The tubular body is formed in a drawing operation and the cutting tip is formed in a milling operation. The tubular body may have a Rockwell C hardness of no more than about 40, and the cutting tip may have a Rockwell C hardness of at least about 50.

1 . A tissue removal device comprising:
 a housing having a distal end and a proximal end;   an outer tube having a distal end and a proximal end, the proximal end of the outer tube supported by the housing, the outer tube configured for transcervical insertion, the outer tube having an opening at the distal end of the outer tube;   an inner tube being hollow and comprising a first material, the inner tube being disposed within the outer tube and configured to be slidable and rotatable relative to the outer tube, wherein the inner tube is sufficiently flexible to bend in conformity with a bend in the outer tube while rotating within the outer tube;   a distal tip element comprising a second material, the distal tip element attached to a distal end of the inner tube so that distal tip element moves rotationally and translationally across the side opening to sever tissue extending therethrough;   wherein the second material comprises a hardness that exceeds the hardness of the first material by a Rockwell C hardness of at least about 10.   
     
     
         2 . The tissue removal device of  claim 1 , wherein the second material comprises a Rockwell C hardness of at least about 50. 
     
     
         3 . The tissue removal device of  claims 1 , wherein the second material comprises a Rockwell C hardness of at least about 60. 
     
     
         4 . The tissue removal device of  claims 1 , wherein the second material comprises a hardness that exceeds the hardness of the first material by a Rockwell C hardness of at least about 20. 
     
     
         5 . The tissue removal device of  claims 1 , further comprising an assembly configured to drive the inner tube. 
     
     
         6 . The tissue removal device of  claims 1 , wherein the distal tip element comprises a longitudinal length greater than the longitudinal length of the opening of the outer tube. 
     
     
         7 . The tissue removal device of  claim 6 , wherein the longitudinal length of the distal tip element is less than 2 inches. 
     
     
         8 . The tissue removal device of  claim 6 , wherein the longitudinal length of the distal tip element is about 1 inch. 
     
     
         9 . The tissue removal device of  claims 1 , wherein the distal tip element comprises a sharpened cutting edge. 
     
     
         10 . The tissue removal device of  claims 1 , the distal tip having a proximal end and a distal end, the proximal end of the distal tip having a diameter greater than the diameter of the distal end of the distal tip. 
     
     
         11 . A method for removing intrauterine tissue comprising:
 inserting transcervically into a uterus, an outer tube having a distal end and a proximal end, the proximal end of the outer tube supported by a distal end of a housing, the outer tube having a side opening at the distal end of the outer tube;   rotating and translating an inner tube disposed within the outer tube, the inner tube comprising a first material, the inner tube being hollow, the inner tube disposed within the outer tube, the inner tube configured to be slidable and rotatable relative to the outer tube, the inner tube being sufficiently flexible so as to bend in conformity with a bend in the outer tube while rotating within the outer tube;   severing with a sharpened distal tip element, tissue extending into the outer tube through the side opening, the distal tip element comprising a second material, the distal tip element attached to a distal end of the inner tube so that distal tip element moves rotationally and translationally across the side opening;   wherein the second material comprises a hardness that exceeds the hardness of the first material by a Rockwell C hardness of at least about 10.   
     
     
         12 . The method for removing intrauterine tissue of  claim 11 , wherein the second material comprises a Rockwell C hardness of at least about 50. 
     
     
         13 . The method for removing intrauterine tissue of  claim 11 , wherein the second material comprises a Rockwell C hardness of at least about 60. 
     
     
         14 . The method for removing intrauterine tissue of  claim 11 , wherein the second material comprises a hardness that exceeds the hardness of the first material by a Rockwell C hardness of at least about 20. 
     
     
         15 . The method for removing intrauterine tissue of  claim 11 , further comprising an assembly configured to drive the inner tube. 
     
     
         16 . The method for removing intrauterine tissue of  claim 11 , wherein the distal tip element comprises a longitudinal length greater than the longitudinal length of the side opening of the outer tube. 
     
     
         17 . The method for removing intrauterine tissue of  claim 16 , wherein the longitudinal length of the distal tip element is less than 2 inches. 
     
     
         18 . The method for removing intrauterine tissue of  claim 11 , wherein the longitudinal length of the distal tip element comprises a cutting edge. 
     
     
         19 . The method for removing intrauterine tissue of  claim 11 , the distal tip having a proximal end and a distal end, the proximal end of the distal tip having a diameter greater than the diameter of the distal end of the distal tip. 
     
     
         20 . The method for removing intrauterine tissue of  claim 11 , wherein the distal tip has a uniform diameter over an entire length of the distal tip.