Abstract:
Apparatus and method for the treatment of tissue, such as hard and soft tissues, wounds, tumors, muscles, and cartilage, through the direct contact of ultrasound energy is disclosed. Ultrasound energy is delivered to a target area through direct contact with an ultrasound tip. Ultrasound energy is also delivered through direct contact with a coupling medium. The ultrasound tip is specially designed to comprise of a cavity area for controlled fragmentation and the simultaneous sonication of a target area. The specially designed ultrasound tip allows for ultrasound energy to focus on a target area. The ultrasound apparatus may be moved in a variety of different directions during the treatment of tissue.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to apparatus and method for the treatment of tissue, such as hard and soft tissue, wounds, tumors, muscles, and cartilage, with ultrasound energy by direct contact. 
     2. Description of the Related Art 
     There are a variety of known methods for the treatment of tissue. These methods include wound dressings, hyperbaric oxygen treatment, growth factor therapy, antibiotics, surgery, physical therapy, vacuum therapy, electrical simulation, bioengineered tissue, ultraviolet light therapy, and tissue ultrasound. There are also a variety of known methods for the treatment of wounds with ultrasound energy. 
     U.S. patents that disclose devices and methods for wound treatment using an ultrasound spray include: U.S. Pat. No. 6,478,754 to Babaev; U.S. Pat. No. 6,761,729 to Babaev; U.S. Pat. No. 6,533,803 to Babaev; U.S. Pat. No. 6,569,099 to Babaev; U.S. Pat. No. 6,663,554 to Babaev; and finally U.S. Pat. No. 6,960,173 to Babaev. These devices and methods can only achieve limited results because there is no sufficient delivery of ultrasound energy to the target because there is no direct contract with the target area. U.S. Pat. Nos. 7,025,735 to Soring and 6,916,296 also to Soring disclose a method and device for the treatment of septic wounds that uses both a liquid aerosol and direct contact. 
     U.S. Patent Application 2004/0030254 to Babaev discloses a device and method for ultrasound wound debridement. Babaev discloses a device that causes debridement through mechanical vibration in the ultrasound tip. This device is also limited in that it uses only mechanical vibration for debridement. 
     Therefore, there is a need for a device and method that can use both mechanical vibration and ultrasound cavitation for fragmentation. There is also a need for a device and method that can simultaneously treat tissue and remove unwanted tissue through fragmentation. 
     SUMMARY OF THE INVENTION 
     The present invention is directed towards an apparatus and method for the treatment of tissue, such as hard and soft tissues, wounds, tumors, muscles, and cartilage, through the direct contact of ultrasound energy. Apparatus and methods in accordance with the present invention may meet the above-mentioned needs and also provide additional advantages and improvements that will be recognized by those skilled in the art upon review of the present disclosure. 
     The present invention comprises an ultrasound transducer and a specially designed ultrasound tip, for the treatment of tissue, connected to the transducer by an ultrasound horn. The specially designed tip allows for controlled fragmentation and simultaneous sonication of a treatment area, such as a wound and/or a tissue to be treated such as, bone, unwanted tissue layers, and infected tissues, via direct contact. The specially designed tip also focuses ultrasound energy onto a treatment area. The tip comprises a cavity formed by its radial sides. An example combination of an ultrasound horn and tip with a cavity area is one forming a shape similar to a spoon utensil. The opening of the cavity may be orientated parallel to the longitudinal axis of the ultrasound horn. Alternatively, the opening of the cavity may be orientated at an angle, with respect to the longitudinal axis of the horn. The edges and surfaces of the ultrasound tip may be smooth, rough/jagged, or any combination thereof. During treatment, a channel running at least partially through the horn before opening into the tip&#39;s cavity deliver a coupling medium into the cavity. The channel may also be used to extract fragmented tissue. 
     During treatment ultrasound energy is generally delivered to the tissue being treated from the radial side of the ultrasound tip. The ultrasound energy may be delivered directly by contacting the target areas with the ultrasound tip. The ultrasound energy may also be delivered indirectly by contacting the target area with the coupling medium delivered into the cavity. Any medium through which ultrasound energy is capable of traveling, except for a mist, aerosol spray, or atomized liquid, may be used as a coupling medium. Both the mechanical vibrations induced in the tip by the transducer and the cavitations induced within the coupling medium by the ultrasound energy traveling through the tip may fragment the tissue being treated. Tissue may also be treated by dragging the various portions of the vibrating tip across it. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be shown and described with reference to the drawings of preferred embodiments and clearly understood in detail. Like elements of the various embodiments depicted within the figures are equivalently numbered. 
         FIG. 1  is a perspective view of an ultrasound apparatus for the treatment of tissue according to the present invention. 
         FIG. 2  is a cross-sectional view of the ultrasound apparatus for the treatment of tissue shown in  FIG. 1 . 
         FIG. 3  is a cross-sectional view of an alternate embodiment of an ultrasound apparatus for the treatment of tissue. 
         FIG. 4  is a detailed cross-sectional schematic representation of the delivery of ultrasound energy. 
         FIGS. 5A-C  depict an example tissue treatment method using an embodiment of the ultrasound apparatus for the treatment of tissue. 
         FIGS. 6A-E  depict alternative embodiments of the ultrasound tip. 
         FIG. 7  is a cross-sectional view of an alternative embodiment of the ultrasound tip containing a polygonal cavity. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is a method and device for the treatment of tissue through the direct contact of ultrasound energy. Preferred embodiments of the present invention in the context of an apparatus and methods are illustrated in the figures and described in detail below. 
       FIG. 1  is a perspective view of an ultrasound apparatus for use according to the present invention that comprises an ultrasound generator  101 , a power cable  102 , an ultrasound transducer  103 , an ultrasound horn  104 , and a specially designed ultrasound tip  105 . The ultrasound generator  101  may be battery powered or powered through an electrical outlet. 
       FIG. 2  illustrates a cross-sectional view of the ultrasound apparatus for the treatment of tissue shown in  FIG. 1 . The ultrasound apparatus depicted in  FIG. 2  comprises an ultrasound transducer  103  that is mechanically connected to the proximal end  201  of an ultrasound horn  104  by threading  202  or other means. Opposite the proximal end  201  of horn  104  is a distal end  203 . Extending between the distal end  203  and the proximal end  201  of horn  104  is a radial surface  204 . A longitudinal axis  206  extends through horn  104  from its proximal end  201  to its distal end  203 . The distal end  203  of the ultrasound horn  104  is mechanically connected to an ultrasound tip  105  by threading  205  or other means. The preferred embodiment comprises an ultrasound transducer  103  that is connected to the ultrasound horn  104  by a mechanical interface; alternative embodiments could have the ultrasound transducer  103  directly connected to the ultrasound horn  104  to comprise a single piece without a mechanical interface. The preferred embodiment also comprises an ultrasound horn  104  that is connected to the ultrasound tip  105  by a mechanical interface; alternative embodiments could have the ultrasound  104  directly connected to the ultrasound tip  105  as to comprise a single piece without a mechanical interface. As can be seen in  FIG. 2 , the combination of the ultrasound horn  104  and tip  105  forms a shape similar to that of a spoon. 
     The tip  105  contains a back side  207 . Opposite the back side  207  of tip  105  is a radial side  208  forming a parabaloid cavity  209  with an opening  210  orientated parallel to the longitudinal axis  206  of horn  104 . At least partially encircling the opening  210  of cavity  209  is a jagged edge  211 . Tip  105  may also contain an orifice  215  extending from its radial side  208  to its back side  207 . 
     Channel  213 , containing an opening within radial surface  204  of horn  104  and an opening within radial side  208  of tip  105 , runs through at least a portion of horn  104  before opening into cavity  209 . Channel  213  permits the delivery of a coupling medium to cavity  209 . 
       FIG. 3  depicts a possible alternative embodiment of the ultrasound apparatus for the treatment of tissue. As illustrated in  FIG. 3 , channel  213  may also run through at least a portion transducer  103 . In such an embodiment, channel  213  could be thought of two channels in communication with one another. The first channel would be a channel originating in a surface of transducer  103 , other than its distal surface, and extending at least partially through transducer  103  before opening into the second channel. The second channel would be a channel originating within the proximal surface of horn  104  and running through horn  104  and into cavity  209 . 
     The ultrasound apparatus for the treatment of tissue that depicted in  FIG. 2  may further comprise an entry port  212  at the proximal end of channel  213 . The entry port  212  may be orientated perpendicular to or at any other angle to axis  206  of the ultrasound horn  104 . The preferred alignment for the entry port  212  is perpendicular to the ultrasound horn  104 . 
     The ultrasound apparatus for the treatment of tissue may contain more than one channel extending at least partially through the horn, and possibly through the at least a portion of the transducer, before opening into the cavity of the tip. Including multiple channels opening into the cavity of the tip enables coupling medium to be extracted from the cavity and simultaneously delivered to the cavity in order to continually supply the cavity with fresh coupling medium. When multiple channels are used, the channel delivering coupling medium to the cavity may be smaller than the channel through which the coupling medium is extracted. Fragmented tissue may also be extracted along with the coupling medium. The preferred embodiment of an ultrasound apparatus for the treatment of tissue comprises a channel running through the transducer and the horn before opening into the cavity of the tip, utilized to delivery coupling medium to the cavity, and a channel originating in a radial surface of the horn and extending partially through the horn before opening into the cavity of the tip, that is utilized for extracting coupling medium from the cavity. If two channels originating in radial surfaces of the horn and extending partially through the horn before opening into the cavity of the tip are utilized, it is preferred that each channel originates on a opposite side of the ultrasound horn. 
       FIG. 4  details the delivery of ultrasound energy  401  from the radial side  208  of tip  105 , through a coupling medium  402 . The specific embodiment depicted comprises a delivery channel  404  for delivering coupling medium  402  into cavity  209  and an extraction channel  405  for extracting coupling medium  402  from cavity  209 . Forming a paraboloid cavity  209 , the radial side  208  focuses the ultrasound energy  401  emanating from the tip  105  towards focus  406  of the paraboloid cavity  209 . Focus  406  of the paraboloid cavity  209  need not lay outside cavity  209 , as depicted in  FIG. 4 . It may be beneficial to simultaneously deliver and extract coupling medium  402  from cavity  209 . When simultaneously delivered and extracted from cavity  209 , coupling medium  402  would enter cavity  209  from channel  404  and then strike the radial side  208  and circle back around before exiting cavity  209  through channel  405 , possibly creating a vortex motion. 
       FIGS. 5A-C  illustrate a possible method of using an embodiment of the ultrasound apparatus to treat tissue. As depicted in  FIG. 5A , an edge adjacent to opening  210  of the cavity  209  formed by the radial side  208  of tip  105  is dragged across the tissue  501  to be treated. As an edge adjacent to opening  210  is dragged across tissue  501 , tip  105  is ultrasonically vibrated. The mechanical motion of the vibration of tip  105  fragments unwanted tissue  502  from the tissue  501  being treated. If a coupling medium is simultaneously delivered to cavity  209 , the fragmentation of tissue  501  may be enhanced by cavitations created within the coupling medium. In addition to possible enhancing fragmentation, delivering a coupling medium to cavity  209  may enhance the transmission of ultrasonic energy  401  from the radial side  208  to tissue  501 . Holding tip  105  at an angle, as depicted in  FIG. 5A , permits the ultrasonic energy  401  emanating from radial  208  to be focused onto tissue  501 . 
     Back side  207  of tip  105  may also be dragged across tissue  501 , as depicted in  FIGS. 5B  and C. Dragging back side  207  across tissue  501  permits the ultrasound energy emanating from back side  207  to be directly delivered to tissue  501 . It is important to note that ultrasound energy delivered to the tissue  501  by dragging the back side  207  of vibrating tip  105  across tissue  501  is mostly carried by radial waves released from tip  105 . However, ultrasound energy carried by shear and longitudinal waves released from tip  105  may also reach tissue  501 . 
     If tip  105  includes an orifice  215  extending from radial side  208  to back side  207 , then dragging back side  207  across tissue  501 , while tip  105  is ultrasonically vibrated, may simultaneously directly deliver ultrasound energy to tissue  501  and fragment unwanted tissue  502 . Such a method of treating tissue  501  is depicted in  FIG. 5C . 
     Furthermore, tip  105  may be rotated along the longitudinal axis  206  of horn  104  as back side  207  is dragged across tissue  501 . Rotating a vibrating tip  105 , while its back side  207  is dragged across tissue  501 , permits ultrasonic energy carried by ultrasonic waves emanating from the various portions of back side  207  to be directly delivered to tissue  501 . This may also occur when the angle of the ultrasound apparatus with respect to tissue  501  is increased and decreased. 
       FIGS. 6A-E  depict different embodiments of an ultrasound tip  105  with a cavity connected to a horn  104 . In all the embodiments depicted in  FIGS. 6A-E  the combination of horn  104  and ultrasound tip  105 , with its radial sides forming a cavity, forms a shape similar to a spoon. The opening  210  of the cavity in the embodiment depicted in  FIG. 6A  is parallel to the longitudinal axis  206  of the ultrasound horn  104 . This is the preferred embodiment. Alternatively, the opening  210  of the cavity, as depicted in  FIGS. 6B to 6D , may be at an angle with respect to the axis  206  of the ultrasound horn  104 . Other comparable shapes of combination of shapes, in addition to those depicted in  FIGS. 6A-E , may be similarly effective as long as the opening  210  of the cavity is not oriented orthogonal to the axis  206  of horn  104 . 
       FIGS. 6D  &amp; E also depict different possible embodiments of back surface  207  of ultrasound tip  105 . As depicted in  FIGS. 6D and 6E , back surface  207  may comprise a series of protrusions  601 . The back surface  207  of the ultrasound tip  105  may be completely covered by such protrusions, as depicted in  FIG. 6E . In the alternative, back surface  207  may contain an area including protrusions, as to create a jagged portion, and an area lacking protrusion, as to create smooth portion, as depicted in  FIG. 6D . 
       FIG. 7  is an alternative embodiment of cavity  209  formed by the radial sides  208  of tip  105 . In this embodiment a collection of radial sides  208  forms a polygonal-shaped paraboloid cavity  209 . Alternative embodiments of an open cavity may be similarly effective in delivering ultrasound energy. 
     The ultrasound apparatus shown in  FIG. 1  delivers ultrasound energy to a target area for the treatment of tissue, including the treatment of wounds and the removal of tumors. The tip is specially designed for controlled fragmentation and the simultaneous sonication of a target area via direct contact. The tip is also specially designed to focus ultrasound energy on a target area. The use of ultrasound may have multiple beneficial effects that include, but are not limited to, destroying bacteria, disinfecting a wound, stimulating cell growth, increasing blood flow, exerting less pressure on a wound, treating fistula and cavities, and removing unwanted tissue. These effects may aid in the healing process. 
     There are multiple methods that may be used to deliver ultrasound energy to a target area. Ultrasound energy may be delivered by contacting the target area with various portions of the ultrasound tip  105  such as the edge encircling cavity  209  or back surface  207 . Ultrasound energy may also be delivered by contacting the target area with a coupling medium. The ultrasound energy is generally delivered from the radial side  208  of the ultrasound tip  105 . Therefore, the ultrasound energy that is mainly delivered is radial waves. The use of radial waves, as compared to longitudinal waves, may allow the ultrasound tip  105  to vibrate horizontally on the target area rather than in a vertical motion. 
     The preferred coupling medium to use is a fluid, and the preferred fluid to use is saline. Other fluids such as drugs, antibiotics, antiseptics, etc may also be used. Both micro and macro cavitation may occur from the delivery of ultrasound energy through the coupling medium. Macro cavitation occurs in the coupling medium and results in sterilization of the target surface, fragmentation of tissue, and mechanical cleansing. Micro cavitation creates microstreaming inside the tissue, which is beneficial for tissue granulation. Fragmentation of unwanted tissue may result from the cavitation that occurs and the mechanical vibration of the ultrasound tip  105  on the tissue being treated. 
     The intensity of the ultrasound energy can be controlled through a variation in the parameters such as the frequency and amplitude at which the transducer induces the horn  104  and tip  105  to vibrate, as wells as the treatment time. The frequency at which the transducer induces the horn  104  and tip  105  to vibrate should be between 15 kHz to 20 MHz. The preferred low-frequency ultrasound range is 20 kHz-100 kHz. The more preferred low-frequency range is 25 kHz-50 kHz. The recommended low-frequency ultrasound is 30 kHz. The preferred high-frequency ultrasound range is 0.7 MHz-3 MHz. The recommended high-frequency ultrasound is 0.7 MHz. The amplitude of the low-frequency ultrasound vibrations induced within the horn  104  and tip  105  can be 5 microns or greater. The preferred low-frequency amplitude is in the range of 30 microns to 100 microns. The recommended low-frequency amplitude is 100 microns. The amplitude of the high-frequency ultrasound vibrations induced within the horn  104  and tip  105  can be 1 microns or greater. The preferred high-frequency amplitude is at least 5 microns. The recommended high-frequency amplitude is 10 microns. 
     There are a variety of factors that may influence treatment time. These factors may include the type of tissue being treated, the condition of a wound, the state of a wound, and the location of a wound. 
     Although specific embodiments and methods of use have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may substituted for the specific embodiments and methods shown. It is to be understood that the above description is intended to be illustrative and not restrictive. Combinations of the above embodiments and other embodiments as well as combinations of the above methods of use and other methods of use will be apparent to those having skill in the art upon review of the present disclosure. The scope of the present invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.