Ultrasonic Surgical Handpiece Having a Thermal Diffuser

Abstract

An ultrasonic surgical handpiece comprising a thermal diffuser that includes a thermal conductive layer and an electrical insulating layer. The thermal diffuser reduces hot spots that are objectionable to the user. The handpiece may also comprise an anti-rotation feature which distributes force of the metal horn applied to the polymer housing by increasing applied area under torque.

We claim: 
     
         1 . A surgical handpiece for an ultrasonic surgical apparatus, comprising:
 a housing having an elongated body along a longitudinal axis;   a thermal diffuser comprising a thermal conductive layer and an electrical insulating layer, wherein both the thermal conductive layer and the electrical insulating layer are disposed on the body of the housing, wherein the electrical insulating layer is closer to the longitudinal axis than the thermal conductive layer;   wherein the thermal conductive layer includes two or more thermal conductive material pieces combining to form a first inner circumference and a first outer circumference, wherein each one of the two or more thermal conductive material pieces includes a length, an inner radius, and an outer radius; and   wherein at least a portion of a circumference of the two or more thermal conductive material pieces includes an overlapping area therebetween.   
     
     
         2 . The surgical handpiece of  claim 1 , wherein the thermal diffuser is in a cylindrical or partially cylindrical form that fits in the elongated body of the housing around the longitudinal axis. 
     
     
         3 . The surgical handpiece of  claim 1 , wherein the thermal conductive layer is made of a material selected from the group consisting of copper, aluminum, nickel, silver, gold and alloys thereof. 
     
     
         4 . The surgical handpiece of  claim 1 , wherein the electrical insulating layer is made of a material selected from the group consisting of polytetrafluoroethylene, polycarbonate, polypropylene and combinations thereof. 
     
     
         5 . The surgical handpiece of  claim 1 , wherein the thermal conductive layer and the electrical insulating layer are bonded with an adhesive. 
     
     
         6 . The surgical handpiece of  claim 1 , wherein the housing is made of an electrical insulating material. 
     
     
         7 . A surgical handpiece for an ultrasonic surgical apparatus, comprising:
 a housing having an elongated body along a longitudinal axis;   a thermal diffuser comprising a thermal conductive layer and an electrical insulating layer, wherein both the thermal conductive layer and the electrical insulating layer are disposed on the body of the housing, wherein the electrical insulating layer is closer to the longitudinal axis than the thermal conductive layer;   wherein the thermal conductive layer includes two or more thermal conductive material pieces combining to form a first inner circumference and a first outer circumference, wherein each one of the two or more thermal conductive material pieces includes a length, an inner radius, and an outer radius; and   at least one of the two or more thermal conductive material pieces includes a second inner circumference and a second outer circumference and at least one of the two or more thermal conductive material pieces includes a third inner circumference and a third outer circumference, wherein at least a portion of the length of adjacent thermal conductive material pieces overlap the second inner circumference with the third outer circumference, and wherein the electrical insulating layer is disposed along the second inner circumference and the third inner circumference of the two or more thermal conductive material pieces forming the first inner circumference.   
     
     
         8 . The surgical handpiece of  claim 7 , wherein the full length of the adjacent thermal conductive material pieces overlap. 
     
     
         9 . The surgical handpiece of  claim 7 , wherein the second inner circumference abuts the third outer circumference of the overlapping adjacent thermal conductive material pieces. 
     
     
         10 . The surgical handpiece of  claim 7  wherein the thermal conductive layer is made of at least copper and the electrical insulating layer is made of at least polytetrafluoroethylene. 
     
     
         11 . The surgical handpiece of  claim 7 , wherein the thermal conductive layer and the electrical insulating layer are bonded with an adhesive. 
     
     
         12 . An ultrasonic surgical apparatus comprising:
 a housing;   an ultrasonically powered transducer within the housing;   a thermal diffuser comprising a thermal conductive layer and an electrical insulating layer, wherein both the thermal conductive layer and the electrical insulating layer are disposed between the housing and the transducer, wherein the thermal conductive layer is closer to the housing than the electrical insulating layer;   wherein the thermal conductive layer includes two or more thermal conductive material pieces combining to form a first inner circumference and a first outer circumference, wherein each one of the two or more thermal conductive material pieces includes a length, an inner radius, and an outer radius; and   wherein at least a portion of a circumference of the two or more thermal conductive material pieces includes an overlapping area therebetween.   
     
     
         13 . The apparatus of  claim 12 , wherein the housing has an elongated body and the thermal diffuser is in a cylindrical or partially cylindrical form that fits in the elongated body around the transducer. 
     
     
         14 . The apparatus of  claim 12 , wherein the thermal conductive layer is made of a material selected from the group consisting of copper, aluminum, nickel, silver, gold and alloys thereof. 
     
     
         15 . The apparatus of  claim 12 , wherein the electrical insulating layer is made of a material selected from the group consisting of polytetrafluoroethylene, polycarbonate, polypropylene and combinations thereof. 
     
     
         16 . The apparatus of  claim 12 , wherein the thermal conductive layer and the electrical insulating layer are bonded with an adhesive. 
     
     
         17 . The apparatus of  claim 12 , wherein the housing is made of an electrical insulating material. 
     
     
         18 . The apparatus of  claim 12 , further comprising an ultrasonic horn contained within the housing. 
     
     
         19 . The apparatus of  claim 18 , wherein the housing includes an inner surface, a longitudinal axis, and a housing engagement portion on the inner surface, the housing engagement portion having a transverse section that includes a central recess, a plurality of pointed recesses pointing radially outward from the central recess and spaced evenly about the longitudinal axis, and convex arcs joining adjacent pointed recesses;
 wherein the ultrasonic horn includes an outer surface and a horn engagement portion on the outer surface, the horn engagement portion having a transverse section that includes a central portion, a plurality of pointed protrusions extending radially outward and spaced evenly about the longitudinal axis, and concave arcs joining adjacent pointed protrusions; and   wherein each of the pointed protrusions corresponds in shape and is engageable with each of the pointed recesses.   
     
     
         20 . The apparatus of  claim 19 , wherein at least one pointed recess has a recess tip portion that is rounded or curved or constitutes a portion of a sphere. 
     
     
         21 . The apparatus of  claim 19 , wherein at least one pointed protrusion has a protrusion tip portion that is rounded or curved or constitutes a portion of a sphere.