Ultrasonic trocar

Abstract

A trocar is provided having a needle unit. The needle unit has a paracentetic section, which is substantially pyramidal. The paracentetic section has two curved surfaces that diagonally oppose each other. The surfaces are formed by cutting the ridges of the section, which diagonally oppose each other. The remaining two ridges of the paracentetic section make, respectively, sharp cutting edges for cutting living tissues. The cutting edges are substantially symmetrical to each other with respect to the axis of the needle unit.

1 . An ultrasonic medical device comprising an ultrasonic oscillator, a horn for amplifying the ultrasonic waves generated by the ultrasonic oscillator, a vibration-transmitting member having a proximal part, a fastening part fastening the proximal part to the horn and a distal part to contact living tissues, for receiving ultrasonic waves from the ultrasonic oscillator through the horn, and a fastening member for removably coupling the distal part of the vibration-transmitting member to the horn, wherein the vibration-transmitting member has a torque-generating section which is to be held with fingers and to apply a torque to the vibration-transmitting member to couple and remove the vibration-transmitting member with and from the horn.  
     
     
         2 . An ultrasonic medical device comprising an ultrasonic oscillator, a horn and a vibration transmitting member, wherein the horn and the vibration-transmitting member are coupled in screw engagement, wherein the vibration-transmitting member has a fastening means which is operated with fingers to set the vibration-transmitting member into screw engagement with the horn.  
     
     
         3 . An ultrasonic medical device according to  claim 2 , wherein the fastening means is removably coupled to the vibration-transmitting member.  
     
     
         4 . An ultrasonic medical device according to  claim 2 , wherein the fastening means is provided independently of the vibration-transmitting member and has rotation-preventing means at a junction with the vibration-transmitting member.  
     
     
         5 . An ultrasonic medical device according to  claim 2 , wherein the fastening means is combined with the vibration-transmitting member, forming an integral member.  
     
     
         6 . An ultrasonic medical device according to  claim 4 , wherein the rotation-preventing means is constituted by a portion of the vibration-transmitting member and a hole made in an inner circumferential surface of the fastening means, said portion having a cross section of a special shape and having made by cutting a part of the vibration-transmitting member, forming two opposing flat surfaces substantially parallel to each other.  
     
     
         7 . An ultrasonic medical device according to  claim 4 , wherein the rotation-preventing means is constituted by projections provided on the vibration transmitting member and recesses made in an inner circumferential surface of the fastening means, for holding the projections of the vibration-transmitting member.  
     
     
         8 . An ultrasonic medical device comprising an ultrasonic oscillator, a horn, and a vibration transmitting member, wherein the horn and the vibration-transmitting member are coupled in screw engagement, wherein the vibration-transmitting member has a torque-generating means which is operated with fingers to apply a torque to the vibration-transmitting member, thereby to couple and disconnect the vibration-transmitting member to and from the horn, said torque-generating means having grooves to be operated easily with fingers.  
     
     
         9 . An ultrasonic medical device according to  claim 8 , wherein the torque-generating means has the grooves in a part which has a diameter larger, than a diameter of the vibration-transmitting member.  
     
     
         10 . An ultrasonic medical device according to  claim 8 , wherein the torque-generating means extends forwards from an antinode of an ultrasonic ware, which is located at a proximal end of the vibration transmitting member, to a node of the ultrasonic wave, for a quarter of a length of the ultrasonic wave.  
     
     
         11 . An, ultrasonic medical device comprising an ultrasonic oscillator, a horn for amplifying the ultrasonic waves generated by the ultrasonic oscillator, a vibration-transmitting member set in screw engagement with the horn, wherein the vibration-transmitting member has a torque-generating section which is to be held with fingers and to applying, when rotated, a torque to the vibration-transmitting member to couple and remove the vibration-transmitting member with and from the horn, and which has a constant-force mechanism for applying a predetermined fastening force to the vibration-transmitting member, thereby to set the vibration-transmitting member into screw engagement with the horn.  
     
     
         12 . An ultrasonic medical device comprising an ultrasonic oscillator, a horn for amplifying the ultrasonic waves generated by the ultrasonic oscillator, 
 a vibration-transmitting member set in screw engagement with the horn, wherein the vibration-transmitting member has a torque-generating section which is located at a node of ultrasonic vibration of the vibration-transmitting member, which is to be held with fingers and to applying, when rotated, a torque to the vibration-transmitting member to couple and remove the vibration-transmitting member with and from the horn, and which has a constant-force mechanism for applying a predetermined fastening force to the vibration-transmitting member, thereby to set the vibration-transmitting member into screw engagement with the horn.