Linear ultrasonic shear stress cutting blade

Abstract

An ultrasonic horn for use with an ultrasonic surgical handpiece including a resonator comprises a linear cutting blade at the distal end of a horn body. The linear cutting blade includes adjacent side-by-side rows of teeth each of which includes a land through which ultrasonic waves are propagated outwardly from the distal end. The lands of the rows of teeth are angled so that the propagated ultrasonic waves of one plurality of lands intersects the propagated ultrasonic waves from the other row of lands. Shear stress fields are developed at the intersections of the ultrasonic waves that will perform the cutting function on target tissue. An irrigation arrangement is also disclosed.

1 . An ultrasonic horn configured for use with an ultrasonic surgical handpiece having a resonator that generates ultrasonic waves, the ultrasonic horn comprising:
 a body member having a proximal end, a distal end, and a longitudinal axis, the proximal end being adapted to connect to the handpiece and receive ultrasonic waves from the handpiece, and the body member configured to conduct the received ultrasonic waves to the distal end; and   an ultrasonic blade located at the distal end, the ultrasonic blade being non-annular and having a linear cutting surface on which are located a first row of a plurality of teeth and a second row of a plurality of teeth, the cutting surface configured so that the first row and the second row of teeth are located side by side one another and both first and second rows are parallel to the longitudinal axis, each tooth of the pluralities of teeth in the first and second rows having a root located at the cutting surface, a peak, and a land located outward from the cutting surface, each land configured to propagate ultrasonic waves outwardly from the distal end;   wherein the teeth in the first row are located and oriented in relation to the teeth in the second row on the cutting surface so that ultrasonic waves propagated outwardly by lands of teeth of the first row intersect ultrasonic waves propagated outwardly by lands of teeth of the second row to create shear stress fields;   wherein roots of the first row of teeth are located transverse to the longitudinal axis to roots of the second row of teeth and peaks of the first row of teeth are offset from peaks of the second row of teeth transverse to the longitudinal axis.   
     
     
         2 . The ultrasonic horn of  claim 1  wherein the linear cutting surface has a first width on which adjacent teeth are located, and wherein the blade has material under the linear cutting surface that is undercut wherein a width of the blade at the undercut is less than the first width of the blade at the linear cutting surface. 
     
     
         3 . The ultrasonic horn of  claim 1  wherein the first row of a plurality of teeth is located on the cutting surface with lands extending in the distal direction. 
     
     
         4 . The ultrasonic horn of  claim 1  wherein roots of the first row of a plurality of teeth are transversely aligned with roots of the second row of a plurality of teeth across the longitudinal axis at the cutting surface. 
     
     
         5 . The ultrasonic horn of  claim 4  wherein an angle of the lands of the first row of a plurality of teeth is different from an angle of the lands of the second row of a plurality of teeth. 
     
     
         6 . The ultrasonic horn of  claim 1  wherein roots of the first row of a plurality of teeth are offset from roots of the second row of a plurality of teeth across the longitudinal axis at the cutting surface. 
     
     
         7 . The ultrasonic horn of  claim 6  wherein an angle of the lands of the first row of a plurality of teeth is different from an angle of the lands of the second row of a plurality of teeth. 
     
     
         8 . The ultrasonic horn of  claim 7  wherein an angle of the lands of the first row of a plurality of teeth is opposite an angle of the lands of the second row of a plurality of teeth. 
     
     
         9 . The ultrasonic horn of  claim 1  wherein the first row of a plurality of teeth is located at the cutting surface and oriented at an angle to the longitudinal axis so that ultrasonic waves propagating from lands of the first row of a plurality of teeth intersect ultrasonic waves propagating from lands of the second row of a plurality of teeth wherein a shear field is located transverse to the longitudinal axis. 
     
     
         10 . (canceled) 
     
     
         11 . The ultrasonic horn of  claim 1  wherein the lands of the teeth in the first row of a plurality of teeth extend in the distal direction and the lands of the teeth in the second row of a plurality of teeth extend in the proximal direction. 
     
     
         12 . (canceled) 
     
     
         13 . The ultrasonic horn of  claim 1  wherein the first and second rows of pluralities of teeth are parallel with the longitudinal axis and are positioned on either side of the longitudinal axis in forming the linear cutting surface of the blade. 
     
     
         14 . The ultrasonic horn of  claim 1  wherein the roots of the teeth in the first row of a plurality of teeth are offset from the roots of the teeth in the second row of a plurality of teeth and the lands of the first row of a plurality of teeth have the same but opposite angle in respect to the lands in the second row of a plurality of teeth. 
     
     
         15 . An ultrasonic horn configured for use with an ultrasonic surgical handpiece having a resonator that generates ultrasonic waves, the ultrasonic horn comprising:
 a body member having a proximal end, a distal end, and a longitudinal axis, the proximal end being adapted to connect to the handpiece and receive ultrasonic waves from the handpiece, and the body member configured to conduct the received ultrasonic waves to the distal end; and   an ultrasonic blade located at the distal end along the longitudinal axis of the body member, the ultrasonic blade being non-annular and having a linear cutting surface on which are located first and second parallel linear rows of teeth, each row having a plurality of teeth, the first and second rows being positioned on either side of the longitudinal axis adjacent each other, each tooth having a root located at the cutting surface and a land located outward from the cutting surface, each land configured to propagate an ultrasonic wave outwardly;   wherein the lands of the first row of teeth and the lands of the second row of teeth are located and oriented in relation to each other so that the respective ultrasonic waves propagated outwardly by the lands of one row intersect with the ultrasonic energy propagated outwardly by the lands of the other row to create shear stress fields.   
     
     
         16 . The ultrasonic horn of  claim 15  wherein:
 the locations of the roots in the first linear row of teeth are offset from the locations of the roots in the second linear row of teeth transverse to the longitudinal axis. 
 
     
     
         17 . The ultrasonic horn of  claim 15  wherein:
 the locations of the roots in the first linear row of teeth are aligned with the locations of the roots in the second linear row of teeth transverse to the longitudinal axis. 
 
     
     
         18 . A method of creating a shear stress field with ultrasonic waves, comprising:
 conducting ultrasonic waves through a body member from a proximal end of the body member to a distal end of the body member, the body member having a longitudinal axis; and   propagating the conducted ultrasonic waves outwardly from the distal end of the body member through a first row of teeth and a second row of teeth with the first and second rows of teeth both mounted to a cutting surface of a non-annular blade located at the distal end and are positioned adjacent each other, each tooth having a root located at the cutting surface and a land located outward from the cutting surface;   wherein the step of propagating comprises propagating ultrasonic waves outwardly by lands in a direction that intersects propagated ultrasonic waves from other lands to thereby form shear stress fields.   
     
     
         19 . The method of creating a shear stress field of  claim 18  wherein the propagating step further includes propagating the conducted ultrasonic waves outwardly from the distal end of the body member through lands of the first row of teeth and through lands of the second row of teeth, wherein the first and second rows of teeth are located separately at the non-annular cutting surface and are positioned adjacent each other in a side-by-side arrangement across the longitudinal axis. 
     
     
         20 . The method of creating a shear stress field of  claim 19  wherein the lands of one row of teeth have a first angle and the lands in the other row of teeth have a second angle that is opposite the first angle. 
     
     
         21 . The ultrasonic horn of  claim 15  wherein the linear cutting surface has a first width on which the adjacent first and second parallel linear rows of teeth are located, and wherein the blade has material under the linear cutting surface that is undercut;
 whereby a width of the blade at the undercut is less than the width of the blade at the cutting surface. 
 
     
     
         22 . The ultrasonic horn of  claim 17  wherein the lands of the first parallel linear row of teeth have a different angle from the lands in the second parallel linear row of teeth.