Abstract:
A device and a method for improved treatment of tissue by direct application thereto of desired therapeutic substances in the form of a stream of therapeutic droplets carried in a high velocity gas produced by accelerating a flow of gas through at least one gas discharge nozzle so as to provide a gas discharge flow at an elevated velocity, and introducing into the elevated velocity gas discharge flow at least one flow of therapeutic liquid, through at least one liquid discharge nozzle, thereby fragmenting the at least one flow of therapeutic liquid into a stream of therapeutic droplets, and accelerating the stream to an accelerated velocity similar to the velocity of the gas discharge flow, and then applying the accelerated therapeutic droplet stream to a tissue mass desired for therapeutic treatment thereby.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates, generally, to devices for administering therapeutic substances, and, more specifically, to devices for applying a high velocity therapeutic liquid-gas stream for administering such substances to the skin. 
       BACKGROUND OF THE INVENTION 
       [0002]    It is known in the art to provide apparatus for dermal abrasion and the cleansing of exposed in vivo tissue. There are a multiplicity of applications to both humans and animals during surgical procedures where the removal from the tissue surface of solid contaminants, such as fibers, dust, sand particles, and the like, as well as organic matter, such as puss, fats, and others, is necessary. 
         [0003]    In addition, such cleansing is necessary in preparation prior to and/or subsequent to treatment such as applying therapeutic substances to the tissue. In dental conditions such as gingivitis which is caused by the long-term effects of plaque deposits, unremoved plaque mineralizes into a hard deposit called calculus (tartar) that becomes trapped at the base of the tooth which often becomes a host for bacteria. After descaling or scraping away the accumulated calculus, it is necessary to cleanse the area at the base of the tooth and the surrounding gum tissue, thereby removing calculus debris and the toxins produced by the bacteria. 
         [0004]    When a fluid stream is employed to irrigate a tissue surface, a boundary layer is formed which is characterized by having a fluid velocity which decreases sharply adjacent to the flow surface, and which is virtually zero at the tissue surface. As a result, those particles which are smaller than the thickness of the boundary layer of the fluid stream are often difficult or impossible to remove thereby. The smallest particles located in the boundary layer exhibit a drag resistance of a magnitude sufficient for these particles to remain attached to the surface and to resist being swept away by the fluid stream, even if this has an overall very high velocity. 
         [0005]    International Patent Application Number PCT/IL2005/000017, “A High Velocity Liquid-Gas Mist Tissue Abrasion Device” to the present inventor, included herein by reference, provides a thorough overview of the prior art for tissue cleaning and abrasion. Disclosed therein is a device for tissue cleaning and abrasion employing a high-velocity liquid-gas streaming mist that produces a minimal to negligible thickness boundary layer. However, neither the device disclosed therein nor any of the prior art provides improved treatment by including the direct application of therapeutic substances to the tissue being treated. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention aims to provide a device and a method for improved treatment of tissue, in particular human scalp, by direct application thereto of desired therapeutic substances in the form of a stream of therapeutic droplets carried in a high velocity gas. 
         [0007]    There is thus provided, in accordance with a preferred embodiment of the invention, a method of administering a therapeutic substance to tissue including the steps of:
   a) accelerating a flow of gas, which is one of a group including at least one of air, oxygen, nitrogen, and carbon dioxide, through at least one gas discharge nozzle so as to provide a gas discharge flow at an elevated velocity;   b) introducing into the elevated velocity gas discharge flow at least one flow of therapeutic liquid, which is one of the group consisting of: saline solution and a solution comprising saline solution and at least one additional therapeutic substance, which may be a substance selected from a group which consists of: a medication, a nutrient, and a moisturizer, through at least one liquid discharge nozzle, thereby to fragment the at least one flow of therapeutic liquid into a stream of therapeutic droplets, and to accelerate the stream to an accelerated velocity similar to the velocity of the gas discharge flow; and   c) applying the accelerated therapeutic droplet stream to a tissue mass desired for therapeutic treatment thereby.   
 
         [0011]    Further in accordance with a preferred embodiment of the invention, the step of applying is applying the accelerated therapeutic droplet stream to a human scalp in which hair may be present, which is desired for therapeutic treatment by the accelerated therapeutic droplet stream. Additionally, the accelerated therapeutic droplet stream may be applied to the tissue mass topically or subcutaneously. The step of applying the accelerated therapeutic droplet stream to a tissue mass may include holding in one hand a device for applying the accelerated therapeutic droplet stream. Additionally, the step of applying the accelerated therapeutic droplet stream to a tissue mass further includes cleansing the tissue mass thereby to remove contaminants from the tissue mass and dispersing accumulated liquid from the tissue mass by the flow of high velocity gas. 
         [0012]    In further accordance with a preferred embodiment of the invention, in the step of introducing, the at least one flow of therapeutic liquid is one flow of saline solution, and the step of introducing further includes the step of supplying, possibly at preselected times for preselected time intervals, to the flow of saline solution a predetermined flow of at least one additional therapeutic substance from the above-mentioned group, thereby producing a mixed flow of therapeutic liquid having a predetermined concentration of the at least one additional therapeutic substance. 
         [0013]    In accordance with an alternative preferred embodiment of the invention, in the step of introducing, the at least one flow of therapeutic liquid is at least two flows of therapeutic liquids, wherein a first flow of therapeutic liquid is a flow of saline solution and at least one additional flow of therapeutic liquid, which is possibly introduced at preselected times for preselected time intervals, is a predetermined flow of at least one additional therapeutic substance from the above-mentioned group, thereby producing a stream of therapeutic droplets containing a predetermined concentration of the at least one additional therapeutic substance. 
         [0014]    Additionally in accordance with a preferred embodiment of the invention, the step of accelerating a flow of gas includes accelerating the flow of gas to a velocity either in the range of sub-sonic to supersonic velocity or the range of sonic to supersonic velocity. 
         [0015]    Further in accordance with a preferred embodiment of the invention, the step of introducing into the elevated velocity gas discharge flow at least one flow of therapeutic liquid, includes the flow of gas entering the at least one gas discharge nozzle being at a pressure of a first magnitude, and the at least one gas discharge nozzle being operative to cause a pressure drop in the gas flow therethrough such that the pressure of the gas discharged from the at least one gas discharge nozzle is of a second magnitude, wherein the first magnitude is at least twice the second magnitude, thereby causing a shock wave in the gas and the at least one flow of liquid downstream of the at least one gas discharge nozzle and the at least one liquid discharge nozzle so as to cause atomizing of the therapeutic liquid discharged from the at least one liquid discharge nozzle into a high velocity stream of therapeutic droplets, thereby forming a stream of therapeutic droplets suspended in the flow of discharged high velocity gas. 
         [0016]    Furthermore, there is provided, in accordance with an additional preferred embodiment of the invention, a device for administering a therapeutic substance to tissue, the device including:
   a) a gas inlet port connected to a pressurized gas source at a pressure in the range of 40 to 150 psi, and including at least one gas selected from: air, oxygen, carbon dioxide and nitrogen;   b) at least one therapeutic liquid inlet port, each connected to a pressurized therapeutic liquid source at a pressure in the range of 1 to 5 psi, and wherein the therapeutic liquid is one of the group which consists of: saline solution and a solution comprising saline solution and at least one additional therapeutic substance which is a substance selected from a group which consists of: a medication, a nutrient, and a moisturizer; and operative to supply therapeutic liquid at preselected times for preselected intervals; and   c) a stream jet delivery nozzle arrangement including;
       i) at least one gas discharge nozzle arranged to receive a flow of pressurized gas from the gas inlet port and configured to accelerate the flow of gas so as to discharge it at an elevated velocity in the range of sub-sonic to supersonic velocity; and   ii) at least one liquid discharge nozzle arranged to receive a flow of therapeutic liquid from the at least one therapeutic liquid inlet port and operative to discharge the flow of therapeutic liquid into the elevated velocity flow of gas, thereby to similarly accelerate the velocity of the discharged therapeutic liquid as a therapeutic stream of accelerated therapeutic droplets and to discharge the stream of accelerated therapeutic droplets towards a tissue mass desired for therapeutic treatment by the therapeutic droplets.   
       
 
         [0022]    Further in accordance with a preferred embodiment of the invention, the tissue mass desired for therapeutic treatment is a human scalp in which hair may be present. 
         [0023]    In accordance with an alternative preferred embodiment of the invention, the stream jet delivery nozzle arrangement may include at least two gas discharge nozzles and at least two liquid discharge nozzles. 
         [0024]    Additionally, in accordance with a preferred embodiment of the invention, the at least one liquid discharge nozzle is disposed substantially concentric and within the at least one gas discharge nozzle and the at least one gas discharge nozzle is a device configured to have a converging portion, a throat portion and a diverging portion. Further, the device is configured to be used while being held in one hand. 
         [0025]    Further in accordance with a preferred embodiment of the invention, the flow of gas entering the at least one gas discharge nozzle is at a pressure of a first magnitude, and the at least one gas discharge nozzle is operative to cause a pressure drop in the gas flow therethrough such that the pressure of the gas discharged from the at least one gas discharge nozzle is of a second magnitude, wherein the first magnitude is at least twice the second magnitude, so as to cause a shock wave in the gas and the at least one flow of liquid downstream of the at least one gas discharge nozzle and the at least one liquid discharge nozzle so as to cause atomizing of the therapeutic liquid discharged from the at least one liquid discharge nozzle into a high velocity stream of therapeutic droplets, thereby to form a stream of therapeutic droplets suspended in the flow of discharged high velocity gas. 
         [0026]    Still furthermore, there is provided, in accordance with an additional preferred embodiment of the invention, a system for administering a therapeutic substance to tissue, including:
       a) a pressurized gas source;   b) at least one pressurized therapeutic liquid source; and   c) a device as described hereinabove.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The present invention will be more fully understood and its features and advantages will become apparent to those skilled in the art by reference to the ensuing description, taken in conjunction with the accompanying drawings, in which: 
           [0031]      FIG. 1  is a perspective view of a device for administering therapeutic substances to tissue, constructed and operative in accordance with a preferred embodiment of the present invention; 
           [0032]      FIG. 2  is a schematic side view of the device of  FIG. 1 ; 
           [0033]      FIGS. 3 and 4  are enlarged schematic and graphical representations, respectively, of a delivery nozzle arrangement of the device seen in  FIGS. 1 and 2 ; 
           [0034]      FIG. 5  is a schematic view of a flow of stream droplets discharging from the delivery nozzle arrangement as seen in  FIG. 4  against a surface to which therapeutic substances are to be administered; 
           [0035]      FIG. 6  is a schematic view of a flow of stream droplets discharging from the delivery nozzle arrangement seen in  FIG. 4 , into a periodontal pocket; 
           [0036]      FIG. 7  is a schematic view of a nozzle arrangement, constructed and operative in accordance with an alternative embodiment of the present invention, having multiple gas and liquid discharge nozzles; and 
           [0037]      FIG. 8  is a block diagram of a system for administering therapeutic substances to tissue, in accordance with preferred embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]    The present invention relates to a device for administering therapeutic substances to tissue by directing thereat a liquid-gas stream of droplets consisting of one or more therapeutic liquids at a high velocity generally within the range of sub-sonic to super-sonic. To achieve this, gas is discharged from a converging-diverging gas nozzle configured to accelerate the flow of gas so as to discharge it at an elevated velocity. A low rate of flow of therapeutic liquid is discharged into the elevated velocity flow of gas, thereby to similarly accelerate the velocity of the discharged therapeutic liquid as a therapeutic stream of accelerated droplets. The volumetric rate of flow of therapeutic liquid from the device is relatively low, thereby essentially preventing the formation of a virtually stagnant liquid boundary layer on the surface of the tissue to which therapeutic substances are to be administered. 
         [0039]    When the therapeutic liquid administered by the present invention is saline solution, the invention can first be employed to clean a tissue surface, as described in International Patent Application Number PCT/IL2005/000017, “A High Velocity Liquid-Gas Mist Tissue Abrasion Device” to the present inventor, included herein by reference, prior to administering additional therapeutic substances, such as medications, nutrients, or moisturizers; or colorants, any of which may be in liquid or soluble powder form. This allows more efficient dosing of the subsequent therapeutic substances, since, as will be appreciated by persons skilled in the art, the substances removed by cleaning would be likely, if left in place, to impede application and/or absorption of the desired therapeutic substances to the tissue desired for therapeutic treatment thereby. Included in the present invention are fluid flow control mechanisms known in the art operative to introduce into the device of the present invention a mixed flow of saline solution and other therapeutic substances, which may be in liquid or emulsion form, of a desired concentration therein which can further be controlled to only produce the mixed flow at specified times and for specified intervals. The device of the present invention would then accordingly produce a mixed therapeutic stream as desired and needed. Thus, as described above a tissue surface could first be cleaned by saline solution and then dosed therapeutically by a medication solution when it is ready to optimally receive the dosage. In an alternative embodiment of the present invention, instead of one mixed flow as mentioned hereinabove, the present invention further includes fluid flow control mechanisms known in the art operative to produce a number of therapeutic liquid flows for discharge into the elevated velocity flow of gas, which also may be turned on and off at specified times and for specified intervals. This arrangement also produces a mixed therapeutic stream as desired and needed. 
         [0040]    For example, the present invention can be used to treat a human scalp, even where hair is present. First, the device produces an accelerated saline stream used to clean the scalp of extraneous material, excess oils, and dead epidermal tissue such as is known to produce dandruff. Then, a moisturizing, nutrient, anti-dandruff, or anti-hair loss, or other desired therapeutic substance is included in the accelerated stream to apply the desired therapeutic treatment to the scalp. 
         [0041]    It should further be noted that the present invention is capable of applying the therapeutic substance to the desired tissue both topically and subcutaneously. Investigations employing prototype versions of the present invention have shown that the accelerated therapeutic stream produced thereby will, for suitable droplet flow velocities and length of time of exposure of the tissue to the droplet flow, penetrate the tissue surface. This capacity of non-invasive subcutaneous treatment and dosage is a further advantage of the present invention. 
         [0042]    Referring now to  FIG. 8 , there is shown a block diagram of a system, generally referred to as  500 , for applying a high velocity liquid-gas therapeutic stream to tissue for therapeutic treatment thereof. System  500  employs a stream generating device  510  similar to that disclosed in International Patent Application Number PCT/IL2005/000017, “A High Velocity Liquid-Gas Mist Tissue Abrasion Device” to the present inventor, included herein by reference, which is fed by high pressure gas supply  520  and high pressure liquid supply  530  and produces a high-velocity liquid-gas mist stream  550  suitable for tissue abrasion as described therein. The present invention further includes a supply of therapeutic substance  540 , which may be in liquid or soluble powder form, that is introduced to liquid supply  530  so that the resulting high-velocity liquid-gas stream  550  includes the therapeutic substance which is thus applied to the tissue mass exposed to stream  550 . Alternatively 575, the therapeutic substance is introduced directly into stream generating device  510  either in addition to (neutral) liquid supply  530  or when liquid supply  530  is turned off, thereby producing the desired high-velocity liquid-gas stream  550  which includes a predetermined concentration of the therapeutic substance. 
         [0043]    With reference to  FIGS. 1 and 2 , there is seen, according to a preferred embodiment of the present invention, a device referenced generally  100  for applying a high velocity liquid-gas therapeutic stream to tissue for therapeutic treatment thereof. Alternatively, the velocity of the stream may be regulated so as to merely provide cleansing of the tissue. Device  100  includes a housing portion referenced  102  having a generally tubular configuration, and having proximal and distal ends, referenced generally  104  and  106  respectively. A gas inlet port referenced  108  and a liquid inlet port referenced  110  are provided at proximal end  104 , and a stream jet delivery nozzle arrangement referenced generally  112 , is provided at distal end  106 . In  FIG. 2 , there is additionally shown, in schematic form, a therapeutic liquid inlet port  109  connecting pressurized therapeutic liquid source  107  liquid via flow control device  105  to liquid inlet port  110  to allow production of a mixed flow of therapeutic liquid. It should be noted that the present arrangement producing one mixed therapeutic liquid flow is only shown by way of example, and that multiple therapeutic liquid flows, as well as control of the time of application of different therapeutic liquid flows are also included in the present invention as discussed hereinabove. 
         [0044]    Referring now to  FIGS. 3 and 4  in conjunction with  FIG. 2 , there are seen schematic and graphical cross-sectional views of nozzle arrangement  112  of device  100 . Nozzle arrangement  112  includes a gas discharge nozzle referenced generally  114  and, disposed generally concentrically there-within, is a liquid discharge nozzle referenced  116 . Liquid inlet port  110  ( FIG. 2 ) is connected in fluid flow communication with liquid discharge nozzle  116  by means of a liquid communication tube referenced  118 , disposed generally concentrically within tubular housing portion  102  ( FIGS. 2 and 3 ). 
         [0045]    Pressurized gas supplied from a pressurized gas source (not shown) enters device  100  through gas inlet port  108  ( FIG. 2 ) and passes along and within tubular housing portion  102  as indicated by arrows  134 , so as to discharge through gas discharge nozzle  114 . Gas discharge nozzle  114  is generally configured having, in flow succession, a converging portion referenced  120 , a throat portion referenced  122  and a diverging discharge portion referenced  124 . The pressurized gas discharging from nozzle  114 , as indicated by arrows  126 , undergoes a rapid and substantial reduction in pressure to atmospheric pressure and a substantial acceleration to a high velocity, within the range of subsonic to supersonic velocity and specifically to a supersonic velocity. Gas discharge nozzle  114  is configured such that the discharging gas has an average cone angle of less than 10 degrees; that is, providing a substantially parallel gas flow. 
         [0046]    Liquid, including a desired concentration of therapeutic substances, from one or more pressurized therapeutic liquid sources (not shown) enters device  100  through liquid inlet port  110  ( FIG. 2 ) and passes, as indicated by arrow  132 , through liquid communication tube  118  ( FIGS. 2 and 4 ). In turn, at distal end  106 , therapeutic liquid is discharged through an opening referenced  128  in the distal end of liquid discharge nozzle  116  into the discharging flow  126  of gas, the therapeutic liquid flow being indicated by arrow  130 . 
         [0047]    It will be appreciated by persons skilled in the art that, as the pressurized discharging gas emerges  126  from gas discharge nozzle  114  into the atmosphere, it undergoes a rapid drop in pressure to atmospheric pressure. The sudden pressure drop results in a substantial acceleration of the velocity of the discharging gas flow that approximates or even exceeds the velocity of sound and results in the production of a shock wave. The effect of the shock wave is to atomize the therapeutic liquid discharging from liquid discharge nozzle  116  into the flow of gas as a stream of therapeutic liquid droplets  130 , such that there is obtained a relatively narrow jet of therapeutic liquid droplets in a high velocity gas flow  126 . 
         [0048]    Further, by way of example, the proportion of liquid flow to gas flow is extremely low due to the relatively high gas pressure of about 100 psi and low liquid pressure of about 2 psi, as well as the relatively large internal diameter of gas discharge nozzle  114  (about 0.5 mm) compared to a small internal diameter (about 0.09 mm) of liquid discharge nozzle  116 . Consequently, little liquid tends to accumulate at the site to be cleaned or treated. Furthermore, the relatively high gas flow has the effect of dispersing any accumulated liquid. When using a jet utilizing only liquid for cleansing, the liquid tends to accumulate on the tissue surface resulting in formation of a virtually stagnant liquid boundary layer close to and in contact with the surface, thereby reducing the effectiveness of cleansing. The very thin to negligible layer of liquid produced on the tissue surface by the present invention allows more efficient dosage of additional therapeutic substances to the tissue surface, including the possibility of subcutaneous application of the therapeutic substances, as discussed hereinabove. 
         [0049]    Referring now to  FIG. 5 , there is seen a high velocity flow of therapeutic liquid droplets referenced  140  discharging, in a high velocity gas flow  126 , from nozzle arrangement  112  against a tissue surface referenced  142  to be cleaned or treated. Device  100  is held in the hand of a user by housing portion  102 . 
         [0050]    Referring now to  FIG. 6 , there is seen a flow of therapeutic liquid droplets  140  discharging, in a high velocity gas flow  126 , from nozzle arrangement  112  of device  100  into a periodontal pocket referenced  144  disposed between a gum referenced  146  and a tooth wall referenced  148 . Device  100  is held in the hand of a user by housing portion  102 . This procedure is especially effective for cleansing periodontal pockets, subsequent to a dental descaling treatment, so as to remove plaque and calculus debris as well as bacteria and the toxins produced by the bacteria, which otherwise lead to mechanical irritation and inflammation of the gingiva. Device  100  can further be used to apply desired dental therapeutic substances, such as antibiotics or anesthetics to the dental pocket. 
         [0051]    Referring now to  FIG. 7 , there is seen, according to an alternative embodiment of the present invention, a cross-sectional view of a device (not shown) having a housing portion  102  and a multiple nozzle arrangement referenced generally  150 . Nozzle arrangement  150  is configured having multiple gas discharge nozzles referenced  152  and multiple therapeutic liquid discharge nozzles referenced  154  disposed generally concentrically within each gas nozzle  152  and projecting there-beyond. Such a multiple nozzle arrangement  150  facilitates expanding the rate of tissue cleaning, in the event that the system is used for this purpose. Additionally, the present configuration supports multiple therapeutic liquid flows, which may be individually controlled, as described hereinabove. 
         [0052]    It will be appreciated by persons skilled in the art that the present invention is not limited by the drawings and description hereinabove presented. Rather, the invention is defined solely by the claims that follow.