Methods and Systems for Removal of a Targeted Tissue from the Body

Abstract

Methods and systems for acoustic treatment of tissue are provided. Acoustic energy, for example ultrasound energy, under proper functional control can penetrate deeply and be controlled precisely in tissue. Some aspects provide a method configured for removal of at least a portion of targeted tissue, such as a scar, abscess, non-cancerous tumor, or fibrous knot, in a tissue of the body.

We claim: 
     
         1 . A non-invasive method of removing a targeted tissue from tissue, the targeted tissue having an acoustic impedance mismatch with the tissue, the method comprising:
 a) targeting the targeted tissue;   b) coupling an ultrasound energy source to the targeted tissue, the ultrasound energy source configured to produce a pulsed first ultrasound energy having a frequency of between 100 kHz and 200 MHz, a pulse duration of between 1 ps and 1 ms, and a power between 1 kW and 50 kW;   c) directing from 500 nJ to 5 J of the pulsed first ultrasound energy from the ultrasound energy source into the targeted tissue, thereby initiating an acousto-mechanical or acousto-elastic effect in the targeted tissue.   
     
     
         2 . The method of  claim 1 , wherein the pulse duration is between 1 ns and 10 μs. 
     
     
         3 . The method of  claim 1 , wherein the ultrasound frequency is between 1 MHz and 30 MHz. 
     
     
         4 . The method of  claim 1 , the method further comprising:
 d) subsequent to step c), directing a second ultrasound energy from the ultrasound energy source or a second ultrasound energy source having an ultrasound pulse duration of at least 100 μs into the targeted tissue or a portion thereof, thereby initiating a second effect in the targeted tissue or the portion thereof.   
     
     
         5 . The method of  claim 4 , wherein the second effect is a cavitation effect or a thermal effect. 
     
     
         6 . The method of  claim 1 , wherein the acousto-mechanical or acousto-elastic effect exceeds a fragmentation threshold of the targeted tissue. 
     
     
         7 . The method of  claim 1 , wherein the pulsed first ultrasound energy is a single ultrasound pulse. 
     
     
         8 . The method of  claim 1 , wherein the tissue is subcutaneous tissue. 
     
     
         9 . The method of  claim 1 , wherein the acousto-mechanical or acousto-elastic effect moves at least a portion of the targeted tissue in the tissue. 
     
     
         10 . The method of  claim 9 , wherein the acousto-mechanical or acousto-elastic effect moves at least a portion of the targeted tissue toward a surface of the tissue. 
     
     
         11 . The method of  claim 10 , wherein the acousto-mechanical or acousto-elastic effect expels at least a portion of the targeted tissue from the tissue. 
     
     
         12 . The method of  claim 9 , wherein the acousto-mechanical or acousto-elastic effect moves at least a portion of the targeted tissue away from a surface of the tissue. 
     
     
         13 . The method of  claim 12 , wherein the acousto-mechanical or acousto-elastic effect moves at least a portion of the targeted tissue to a depth where they are no longer visible through the epidermis. 
     
     
         14 . An ultrasound treatment system for targeted tissue removal comprising:
 an ultrasound source configured to emit a propagating ultrasound energy having a propagating ultrasound pulse duration between 100 ps and 1 ms, a propagating ultrasound pulse power ranging from 1 kW to 50 kW, and a propagating ultrasound frequency between 100 kHz and 200 MHz;   a control system configured to direct the ultrasound energy source to emit the propagating ultrasound energy to a targeted tissue located in a target zone within a medium at an intensity gain between 500 and 25,000, thereby initiating an acousto-mechanical or acousto-elastic effect within the targeted tissue.   
     
     
         15 . The system of  claim 14 , wherein the pulse duration is between 1 ns and 10 μs. 
     
     
         16 . The system of  claim 14 , wherein the ultrasound frequency is between 1 MHz and 30 MHz. 
     
     
         17 . The system of  claim 14 , the system optionally comprising a second ultrasound source, wherein the ultrasound source or the second ultrasound source is configured to emit a second propagating ultrasound energy having a second propagating ultrasound pulse duration of at least 100 us, the control system configured to direct the ultrasound energy source or the second ultrasound energy source to emit the second propagating ultrasound energy to the target zone. 
     
     
         18 . The system of  claim 14 , wherein the ultrasound energy source is configured to emit a single ultrasound pulse, the single ultrasound pulse initiating the acousto-mechanical or acousto-elastic effect within the targeted tissue. 
     
     
         19 . A non-invasive method of treating a targeted tissue embedded in a tissue, the method comprising:
 a) coupling an ultrasound energy source to the targeted tissue embedded in the tissue; and   b) initiating, using a single ultrasound energy pulse from the ultrasound energy source, an acousto-mechanical or acousto-elastic effect in the targeted tissue that exceeds a fragmentation threshold of the targeted tissue.   
     
     
         20 . The method of  claim 19  wherein the tissue is subcutaneous tissue.