Lysis method and apparatus

Abstract

An apparatus a method for the application of ultrasound to a location within the body is provided. The apparatus can advantageously operate at a pulse duration below about 100 milliseconds and in the range 0.1 milliseconds to 100 milliseconds and a pulse repetition period below about 1 second and in the range of 1 millisecond to 1 second. Duty ratios over 5 and preferably over 8 are also advantageous. Therapeutic applications of ultrasound such as for assisting in the treatment of medical conditions such as cancer and/or other ailments are also provided.

What is claimed is:  
     
         1 . A method of applying therapeutic ultrasound to a location within a body, comprising: activating a transducer to produce ultrasound at a pulse repetition period of T≦1000 milliseconds and directing this ultrasound to a location within a body.  
     
     
         2 . The method of  claim 1 , wherein the ultrasound is directed to a location within the body in an invasive manner, with an ultrasound device which is inserted into the body.  
     
     
         3 . The method of  claim 1 , wherein the ultrasound is directed to a location within the body with a non-invasive ultrasound producing device.  
     
     
         4 . The method of  claim 2 , wherein T= about 1 millisecond to 1000 milliseconds.  
     
     
         5 . The method of  claim 3 , the transducer is operated to produce ultrasound at a frequency of about 100 to 1000 KHz.  
     
     
         6 . The method of  claim 5  wherein T= about 1 to 100 milliseconds.  
     
     
         7 . The method of  claim 3  wherein T= about 2.5 to 90 milliseconds.  
     
     
         8 . The method of  claim 5  wherein T=2.5 to 75 milliseconds.  
     
     
         9 . The method of  claim 3 , wherein τ= about 0.01 to 2.0 milliseconds.  
     
     
         10 . The method of  claim 3 , wherein τ= about 0.02 to 1.1 milliseconds.  
     
     
         11 . The method of  claim 3 , wherein τ=0.1 to 0.3 milliseconds.  
     
     
         12 . The method of  claim 9 , wherein the transducer is producing ultrasound at a frequency of about 100 to 1000 KHz.  
     
     
         13 . The method of  claim 3 , wherein the intensity of the ultrasound applied is I≧ about 750 W/cm 2 .  
     
     
         14 . The method of  claim 6 , wherein the intensity of the ultrasound applied is I≧ about 750 W/cm 2 .  
     
     
         15 . The method of  claim 9 , wherein the intensity of the ultrasound applied is I≧ about 750 W/cm 2 .  
     
     
         16 . The method of  claim 12 , wherein the intensity of the ultrasound applied is I≧ about 750 W/cm 2 .  
     
     
         17 . The method of  claim 13 , wherein the transducer produces ultrasound at a pulse duration of τ≦100 milliseconds.  
     
     
         18 . The method of  claim 1 , including the steps of initiating cavitation within the body by applying a first amount of power to the transducer, initiating cavitation at the location within the body, then reducing the power supplied, while maintaining cavitation.  
     
     
         19 . A method of applying therapeutic ultrasound to a location within a body, comprising: producing ultrasound with a pulse duration of τ≦100 milliseconds and transmitting the ultrasound to a location within a body via a transmission member which is at least partially inserted into the body.  
     
     
         20 . The method of  claim 19 , wherein the frequency of the ultrasound produced in about 20 to 100 KHz.  
     
     
         21 . The method of  claim 19 , wherein the pulse repetition period T≦about 1000 milliseconds.  
     
     
         22 . The method of  claim 21 , wherein T is about 100 to 500 milliseconds.  
     
     
         23 . The method of  claim 19 , wherein τ is about 20-60 milliseconds.  
     
     
         24 . The method of  claim 20 , wherein τ is about 10-100 milliseconds.  
     
     
         25 . The method of  claim 22 , wherein τ is about 10-100 milliseconds.  
     
     
         26 . The method of  claim 25 , wherein the frequency of the ultrasound produced is about 20 100 KHz.  
     
     
         27 . The method of  claim 19 , wherein the ultrasound is produced with a transducer operated at a peak power output of 10 to 40 watts.  
     
     
         28 . The method of  claim 22 , wherein the ultrasound is produced with a transducer operated at a peak power output of 10 to 40 watts.  
     
     
         29 . The method of  claim 25 , wherein the ultrasound is produced with a transducer operated at a peak power output of 10 to 40 watts.  
     
     
         30 . The method of  claim 27 , wherein the peak power output is about 15 to 30 watts.  
     
     
         31 . The method of  claim 23 , wherein the peak power output is about 15 to 30 watts.  
     
     
         32 . The method of  claim 23 , wherein substantially no cooling fluid is pumped around the transmission member.  
     
     
         33 . The method of  claim 19 , wherein the device is operated at a duty ratio T/τ about ≧5.  
     
     
         34 . The method of  claim 19 , wherein the device is operated at a duty ratio T/τ about ≧8.  
     
     
         35 . The method of  claim 3 , wherein the device is operated at a duty ratio of about ≧5.  
     
     
         36 . The method of  claim 3 , wherein the device is operated at a duty ratio of about ≧8.  
     
     
         37 . The method of  claim 19 , wherein the transmission member is located within a guide catheter and is substantially unsheathed within the guide catheter.  
     
     
         38 . A system for delivering ultrasound energy into a body, comprising: 
 a signal generator, a transducer coupled to the signal generator and a transmission member coupled to the transducer;    the signal generator, transducer and transmission member constructed and arranged to transmit ultrasound produced by the transducer to a location within the body by inserting at least a first portion of the transmission member into the body, the transmission member including substantially no sheathing for the transportation of cooling fluid around the first portion of the transmission member.    
     
     
         39 . The system of  claim 38 , wherein the signal generator, transducer and transmission members are constructed and arranged to deliver ultrasound energy to the coronary artery at a peak power output of over 10 watts.  
     
     
         40 . The system of  claim 38  including a sound detection device capable of detecting cavitation within the body caused by energy transmitted via the transmission member and displaying the presence of the detected cavitation.  
     
     
         41 . A system for delivering ultrasound energy into a body, comprising: 
 a signal generator, a transducer coupled to the signal generator and a transmission member coupled to the transducer; the signal generator, transducer and transmission member constructed and arranged to transmit ultrasound to a location within the body by inserting at least a portion of the transmission member into the body; and    a sound detection device and a display therefore capable of detecting the sound caused by cavitation within the body generated by ultrasound transmitted via the transmission member and displaying the presence of sound caused by the presence of cavitation.