Apparatus and method for an ultrasonic medical device operating in torsional and transverse modes

Abstract

The present invention provides an apparatus and a method for an ultrasonic medical device operating in a torsional mode and a transverse mode. An ultrasonic probe of the ultrasonic medical device is placed in communication with a biological material. An ultrasonic energy source is activated to produce an electrical signal that drives a transducer to produce a torsional vibration of the ultrasonic probe. The torsional vibration produces a component of force in a transverse direction relative to a longitudinal axis of the ultrasonic probe, thereby exciting a transverse vibration along the longitudinal axis causing the ultrasonic probe to undergo both a torsional vibration and a transverse vibration. The torsional vibration and the transverse vibration cause cavitation in a medium surrounding the ultrasonic probe to ablate the biological material.

1 . An ultrasonic medical device comprising:
 an ultrasonic probe comprising a proximal end, a distal end and a longitudinal axis therebetween; and   a transducer coupled to the ultrasonic probe, the transducer being configured to create a torsional vibration along the ultrasonic probe, the ultrasonic probe and the transducer being adapted so that the torsional vibration induces a transverse vibration along a portion of the ultrasonic probe.   
     
     
         2 . The ultrasonic medical device of  claim 1  wherein the transverse vibration is tuned into coincidence with the torsional vibration along the portion of the ultrasonic probe in which the transverse vibration is induced. 
     
     
         3 . The ultrasonic medical device of  claim 1  wherein tension to the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration. 
     
     
         4 . The ultrasonic medical device of  claim 1  wherein bending the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration. 
     
     
         5 . The ultrasonic medical device of  claim 1  wherein the torsional vibration and the transverse vibration are segregated over the portion of the ultrasonic probe. 
     
     
         6 . The ultrasonic medical device of  claim 1  wherein the torsional vibration of the ultrasonic probe produces a plurality of torsional nodes and a plurality of torsional anti-nodes along the portion of the ultrasonic probe. 
     
     
         7 . The ultrasonic medical device of  claim 1  wherein the torsional vibration of the ultrasonic probe causes a rotation and counterrotation along at least the portion of the ultrasonic probe. 
     
     
         8 . A medical device comprising:
 an elongated, flexible probe comprising a proximal end, a distal end and a longitudinal axis between the proximal end and the distal end;   a transducer coupled to the elongated, flexible probe, the transducer being configured to create a torsional vibration along the longitudinal axis of the elongated, flexible probe when electrical energy is applied to the transducer, the elongate, flexible probe and the transducer being adapted so that the torsional vibration induces a transverse vibration along the longitudinal axis of the elongated, flexible probe.   
     
     
         9 . The medical device of  claim 8  wherein the transverse vibration is tuned into coincidence with the torsional vibration along at least a portion of the longitudinal axis of the elongated, flexible probe in which the transverse vibration is induced. 
     
     
         10 . The medical device of  claim 8  wherein tension to the elongated, flexible probe tunes the transverse vibration into coincidence with the torsional vibration. 
     
     
         11 . The medical device of  claim 8  wherein bending the elongated, flexible probe tunes the transverse vibration into coincidence with the torsional vibration. 
     
     
         12 . The medical device of  claim 8  wherein bending the elongated, flexible probe shifts a frequency of the elongated, flexible probe causing the transverse vibration to coincide with the torsional vibration. 
     
     
         13 . The medical device of  claim 8  wherein the torsional vibration and the transverse vibration are superimposed or segregated along the longitudinal axis of the elongated, flexible probe. 
     
     
         14 . The medical device of  claim 8  wherein the elongated, flexible probe comprises a varying diameter from the proximal end of the elongated, flexible probe to the distal end of the elongated, flexible probe. 
     
     
         15 . An ultrasonic probe comprising:
 a proximal end;   a distal end that terminates in a probe tip; and   a longitudinal axis between the proximal end and the distal end, wherein the ultrasonic probe supports a torsional vibration and a transverse vibration.   
     
     
         16 . The ultrasonic probe of  claim 15  wherein the transverse vibration is tuned into coincidence with the torsional vibration along at least a portion of the longitudinal axis of the ultrasonic probe in which the transverse vibration is induced. 
     
     
         17 . The ultrasonic probe of  claim 15  wherein tension to the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration. 
     
     
         18 . The ultrasonic probe of  claim 15  wherein bending the ultrasonic probe tunes the transverse vibration into coincidence with the torsional vibration. 
     
     
         19 . The ultrasonic probe of  claim 15  wherein bending the ultrasonic probe shifts a frequency of the ultrasonic probe causing the transverse vibration to coincide with the torsional vibration. 
     
     
         20 . The ultrasonic probe of  claim 15  wherein the ultrasonic probe comprises a varying cross section from the proximal end of the ultrasonic probe to the distal end of the ultrasonic probe.