Ultrasound medical instrument having a medical ultrasonic blade

Abstract

An ultrasound medical instrument includes a medical ultrasonic blade having a proximal blade portion and a distal blade portion. The distal blade portion bends more easily than does the proximal blade portion. A user-actuated articulated sheath surrounds a portion of the medical ultrasonic blade. The distal blade portion includes a distal end portion adapted to contact and ultrasonically treat patient tissue.

What is claimed is: 
     
         1 . An ultrasonic medical instrument comprising a medical ultrasonic blade having a length and including a proximal blade portion and a distal blade portion, wherein the proximal blade portion has a larger transverse area and the distal blade portion has a smaller transverse area, wherein the distal blade portion is more bendable than the proximal blade portion, wherein the distal blade portion includes a distal end portion adapted to contact and ultrasonically treat patient tissue; and
 a user-actuated articulated sheath surrounding at least a portion of the medical ultrasonic blade.   
     
     
         2 . The ultrasound medical instrument of  claim 1 , wherein the proximal blade portion transitions to the distal blade portion proximate a longitudinal vibration antinode. 
     
     
         3 . The ultrasound medical instrument of  claim 1 , wherein the medical ultrasonic blade further includes two longitudinal vibration nodes located on the distal blade portion. 
     
     
         4 . The ultrasound medical instrument of  claim 3 , wherein the sheath contacts the distal blade portion at least at one of the longitudinal vibration nodes. 
     
     
         5 . The ultrasound medical instrument of  claim 1 , wherein the sheath includes a rigid first sheath portion contacting a longitudinal vibration node of the proximal blade portion and a flexible second sheath portion contacting a longitudinal vibration node of the distal blade portion. 
     
     
         6 . The ultrasound medical instrument of  claim 3 , wherein the sheath contacts each of the longitudinal vibration nodes of the distal blade portion. 
     
     
         7 . The ultrasound medical instrument of  claim 1 , wherein the medical ultrasonic blade includes a first neck portion joining the proximal and distal blade portions, wherein the medical ultrasonic blade is substantially cylindrical from the proximal blade portion to the distal blade portion, wherein the proximal and distal blade portions each have a substantially constant diameter, and wherein the diameter of the distal blade portion is smaller than the diameter of the proximal blade portion. 
     
     
         8 . The ultrasonic medical instrument of  claim 1 , wherein the distal blade portion is joined to the proximal blade portion by a dowel press fit. 
     
     
         9 . The ultrasonic medical instrument of  claim 1 , wherein the distal blade portion is joined to the proximal blade portion by a ball-and-socket type attachment. 
     
     
         10 . The ultrasonic medical instrument of  claim 1 , wherein the proximal blade portion is essentially rigid. 
     
     
         11 . An ultrasound medical instrument comprising:
 a medical ultrasonic blade having a length and including first and second blade portions, each of the first and, second blade portions including at least one longitudinal vibration node, wherein the first blade portion is disposed proximal the second blade portion, wherein the first blade portion has a first transverse area and the second blade portion has a second transverse area, the first transverse area each being greater than the second transverse area, and wherein the second blade portion is more bendable than the first blade portion; and   a user-actuated articulated sheath received over the medical ultrasonic blade, the sheath including a rigid first sheath portion contacting the longitudinal vibration node of the first blade portion, a flexible second sheath portion contacting the longitudinal vibration node of the second portion.   
     
     
         12 . The ultrasonic medical instrument of  claim 11  wherein the second portion of the medical ultrasonic blade includes at least two longitudinal vibration nodes.