Low advance ratio, high reciprocation rate tissue removal device

Abstract

Disclosed is a tissue removal device having an outer tube with a resection window and an inner tube disposed within the outer tube. The inner tube is slidable and rotatable relative to the outer tube so that the distal end of the inner tube moves back and forth across the resection window to sever tissue extending therethrough. The inner tube may be driven to rotate at a speed of at least about 1100 rpm, to axially translate at a rate of at least about 1.5 cps, and with an advance ratio of no more than about 0.25. The drive system for controlling axial reciprocation and rotation of the inner tube may be totally mechanical.

1 . A tissue removal device comprising:
 a housing having a distal end and a proximal end;   an outer tube having a proximal end and a distal end, the proximal end of the outer tube being fixed to the distal end of the housing and extending distally therefrom, the distal end of the outer tube including a resection window; and   an inner tube disposed within the outer tube, the inner tube being slidable and rotatable relative to the outer tube so that the distal end of the inner tube moves back and forth across the resection window to sever tissue extending therethrough;   wherein the inner tube is driven to rotate at a speed of at least 1100 rotations per minute and to oscillate translationally at a rate of at least 1.5 cycles per second with an advance ratio of no more than 0.25, the advance ratio being the ratio of the speed at which the inner tube oscillates translationally to the speed at which the inner tube rotates.   
     
     
         2 . The tissue removal device of  claim 1 , wherein the inner tube comprises a lumen and is configured to operate under vacuum pressures in the range of 200 to about 800 mm Hg to withdraw tissue and liquid into the resection window and through the inner tube. 
     
     
         3 . The tissue removal device of  claim 1 , wherein the inner tube is driven to rotate at a speed of at least 5000 rotations per minute. 
     
     
         4 . The tissue removal device of  claim 1 , wherein the inner tube is driven to rotate at a speed of at least about 6000 rotations per minute. 
     
     
         5 . The tissue removal device of  claim 2  wherein the withdrawing of the liquid is no more than about 300 cubic centimeters per minute. 
     
     
         6 . The tissue removal device of  claim 1 , wherein the advance ratio is no more than 0.15. 
     
     
         7 . The tissue removal device of  claim 1 , wherein the inner tube is driven to oscillate translationally at about 2.5 to 4 cycles per second. 
     
     
         8 . The tissue removal device of  claim 1 , wherein the inner tube is configured to remove tissue at a rate of at least 1.5 gm/min. 
     
     
         9 . The tissue removal device of  claim 1 , wherein the outer tube comprises an outer diameter of no greater than about 3.0 mm.