Abstract:
The invention relates to a therapeutic device to promote the healing of a wound, comprising a cover around the wound to form an essentially airtight cover over the wound, whereby a liquid-permeable pad is preferably provided between the wound and cover, a drainage line connecting the cover with a suction pump so that the wound can be suctioned to draw the fluids from it, and a connector to connect the cover with the drainage line, whereby the connector is provided with an opening to connect the proximal end of the drainage line to the wound, with which a more solid connection is guaranteed between the cover and the drainage line, which however at the same time has sufficient elasticity to conform to the respective body form and/or shape of the wound. It is also proposed that the connection contain fastening sections which extend from an area radiating from the opening to the area near the outer edge of the cover and which are separated from each other by notches.

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application is the National Phase Application under 35 USC §371 of International Application No. PCT/EP2006/002794, filed Mar. 28, 2006, which claims priority to German Patent Application 10 2005 015 878.1, filed Apr. 6, 2005, which is incorporated by reference in its entirety. This application is related to U.S. patent application Ser. No. 11/909,596, entitled “Vacuum Therapy Device”, filed Sep. 24, 2007. 
     
    
     BACKGROUND 
       [0002]    A. Technical Field 
         [0003]    The present invention relates to a therapeutic device to promote the healing of a wound, comprising a cover around the wound to form an essentially airtight cover over the wound, whereby a liquid-permeable pad is preferably provided between the wound and cover, a drainage line connecting the cover with a suction pump, a drainage line connecting the cover with a suction pump so that the wound can be suctioned to draw fluids from it, and a connector to connect the cover with the drainage line, whereby the connector comprises an opening to connect the proximal end of the drainage line with the wound. 
         [0004]    B. Background of the Invention 
         [0005]    Such wound healing devices are used to treat secondary healing chronic or acute wounds, in particular in humans. Using the negative pressure present in the skin area around the wound is supposed to remove fluid, that is, in particular wound exudation, from the wound to thereby shorten the healing period. In many cases, the use of such a wound healing device makes wound healing possible in the first place. 
         [0006]    A class-appropriate wound healing device is described in EP 1 088 569 B1. For the wound healing device disclosed in this patent it is in particular provided that the connector comprises a disc-like shell whose lower surface is in contact with a porous pad. This connector is obviously meant to insure even pressure distribution. The connector of the aforementioned wound healing device is provided for use in conjunction with a porous pad which is pressed onto the wound. The porous pad is extendible. An even distribution of the pressure on the wound is therefore problematic because the cross-section area of the drainage tube is generally distinctly smaller than the size of the wound. 
         [0007]    It is therefore necessary to distribute the negative pressure applied by the drainage tube with or without use of a porous pad to the largest possible area so that pressure is applied as evenly as possible to the full dimension of the wound. To do so, the cited patent proposes that the connector be designed as a disk-like shell, whereby the lower surface of this shell is in contact with the porous pad. 
         [0008]    In may case of practical application, however, this known shape of the connector is still not sufficient to guarantee a solid connection between the cover and the drainage tube. Moreover, the known disk-like shell is not always suitable for the respective shape of the wound as the provided curvature of the disk is sometimes not appropriate. The shape of a disk-like shell is however extendible to only a limited degree. For example, bending a convexly-bent disk-like shell to the wound can lead to a type of bulging of the surface for reasons of topology. Also, the disk-like shape of the shell of the connector is relatively rigid and as such cannot be adapted to the specific wound shapes or even to body shapes. These disadvantages result in limitations in the applicability of the known wound healing device. 
       SUMMARY OF THE INVENTION 
       [0009]    It is therefore the task of this invention to indicate a class-appropriate wound healing device to promote the healing of a wound, in which a more solid connection between the cover and the drainage line is guaranteed which however at the same time has a sufficient elasticity to conform to the respective body shape and/or wound shape. This task is inventively solved by the connector having fastening sections which extend from an area surrounding the opening to the area near the outer edge and are separated from each other by notches. 
         [0010]    The fact that the fastening sections extend up to the proximity of the outer edge of the cover guarantees that the pressure is distributed from the relatively small outlet cross-section of the drainage tube to the broadest possible area of the wound. However, to avoid at such a large extension of the connector that it ceases to conform evenly to certain unfavorable body shapes and/or wound shapes, but rather maintains a certain distance from the wound and or the porous pad, notches are provided between individual fastening sections. These sections between individual fastening sections advantageously insure a certain elasticity of the connector even if, for example, the connector is produced from an essentially rigid material. 
         [0011]    The advantage then consists of the combination of an increased application area of the connector compared to known connectors, on the one hand, with a simultaneous guarantee of a certain elasticity of the widened connector by notches, on the other. 
         [0012]    The invention is further improved if the notches run in an essentially radial direction with respect to the axis of the opening. In particular, in the typical situation that a porous pad, such as an absorbent sponge, is placed on the wound, more or less convex surfaces are created on which the drainage tube has to be placed. 
         [0013]    The bending of this surface can however vary depending on the part of the body on which the wound is located and the extent of the wound. If then according to the invention, the connector is to be widened compared to known connectors so that inventively it extends to the edge of the cover, this variability of the bending of the surface to be covered will increasingly become a problem, as explained below. 
         [0014]    The inventive solution of this problem by distributing the connector into fastening sections is therefore especially effective if according to this design the notches run radially to the axis of the opening. For topological reasons, the deviation of a curved surface from a smooth surface becomes increasingly greater with increasing distance from a contact point of these two surfaces. 
         [0015]    If therefore the notches also run radially to the axis of the opening, this deviation which is expressed in a separation/distance of the curved connector from the differently curved porous pad can therefore be most effectively avoided. By using radial notches it is possible for the fastening sections of the inventive connector to achieve a certain elasticity which would not exist without the notches, as unlike known connectors the inventive connector extends to the outer edge of the cover. 
         [0016]    The effect of the inventive connector is further improved if the notches are designed as interruptions of an outer edge. The outer edge of the connector is found in the largest radial distance to the axis of the connector opening. As explained, the result of this is that a possible deviation of the connector&#39;s curve is at its maximum at that point from the curve of the porous pad. For this reason it is advantageous to interrupt these border areas in the form of notches. 
         [0017]    If in a further embodiment of the invention, the notches are designed in a tapered fashion in the direction of the opening, the described radial enlargement of the curvature difference between the connector and the porous pad is considered in a particularly effective way. It is known that according to the state of the art the pressing together of the outer edge of a flexible disk-like shell topologically results in the bulging in the form of radially running folds. This problem is solved in a surprising simple way by the invention by the widening the notches with greater distance from the axis. 
         [0018]    In a special embodiment of the invention, the connector is designed in an essentially star-shaped fashion. The symmetry of the star shape advantageously results in an especially even distribution of pressure across the wound. 
         [0019]    An alternative embodiment of the inventive therapeutic device provides the notches in a spiral shape. In this case, a random number of spiral-like notches can be provided from the outer# edge of the connector in the direction of the axis of the opening. The already known problems are also solved in this case. 
         [0020]    According to a variant of the present invention, the fastening sections form a cavity with respect to the wound. This results not only in a distribution of the pressure on the wound introduced by the drainage tube but also additionally an increase in the suction area. The suction of wound exudation can therefore occur additionally through the cavities under the fastening sections. An undesirable excessive remaining # of wound exudation in the wound or in a porous pad place thereon is thereby advantageously avoided. 
         [0021]    The suction of wound exudation over a larger surface area is further optimized in a further development of the invention if the fastening sections are designed as tubes cut in an axial direction, whereby preferably a diameter of approximately ⅔ is cut away. The transport of wound exudation by tubes inventively cut open facing downwards works especially well since due to their edge-free interior contours the tubes are particularly well-suited for transporting fluids. 
         [0022]    In order for the cavity between the open tubes and the wound and/or the porous wound dressing to not be excessively high and to still provide a sufficiently large cross section for suction, it has been shown to be especially favorable if approximately ⅔ of the diameter of the tubes is cut away. It goes without saying that the expression “cut away” does not necessarily refer to a production process for the inventive connection, but refers instead to the obtained result of a “third tube.” The third tube can for example also be produced by a casting process without requiring the removal of material. 
         [0023]    An especially symmetrical pressure distribution is created in a special embodiment of the inventive therapeutic device if four fastening sections are provided. 
         [0024]    Especially cost effective and also highly stable is an embodiment of the invention in which the connector is produced from a continuous injection-molded part. In this case, the fastening sections, the opening and an optionally provided connector piece for the drainage tube can all be produced as a continuous injection-molded part. This eliminates the need to assemble the individual components of the connector, which advantageously results in reducing costs. 
         [0025]    Also, the embodiment as a continuous injection-molded part has the advantage of virtually eliminating leaks in the connector. 
         [0026]    If a special embodiment of the invention provides an end of the opening turned away from the wound bent connecting sleeve, the forces between the tube and the connector created by the patient&#39;s movement artifacts are effectively absorbed. 
         [0027]    In particular, the bending of the connecting sleeve makes it possible to run the drainage tube parallel to the patient&#39;s body so that the leverage at the connection site can be avoided which would be created if the drainage tube were connected vertically to the connector. Overall, the connection is advantageously more secure and robust. 
         [0028]    A distribution of the pressure over the wound is achieved by the invention in a particularly effective manner if the connector is produced from an essentially rigid material. For example, the connector can be made of PVC or other plastics. Compared to the wound dressing and the cover and other components, these materials are rigid and can therefore be used as pressure distributors. On the other hand, these materials do exhibit a certain elasticity. This elasticity is particularly present at the ends of the fastening sections so that to a limited degree a “nestling” of the fastening sections of the inventive connector to the wound or the porous pad is achieved. 
         [0029]    It is provided in a further development of the invention that a pressure sensor is supplied on at least one fastening section. As the connector is inventively provided in the negative pressure area of the wound, the fastening section is very well suited as a pressure measuring point. For example, a strain gage can be provided to measure pressure. The pressure measured in this way corresponds precisely to the local pressure on the wound which is crucial for vacuum therapy. 
         [0030]    This measurement is particularly suited as influencing variable for a pressure adjustment of the vacuum therapy device. In this case it is especially advantageous if as a further development of the invention the pressure sensor is sealed in the fastening section. 
         [0031]    This advantageously insures that the pressure sensor cannot detach from the connector and penetrate the wound. Also, the sealing of the pressure sensor rules out all contact of same with the wound itself or with the wound exudation. For a direct contact between the wound or the porous wound dressing it is advantageous in the embodiment of the invention if the connection is provided under the cover. 
         [0032]    Alternatively, it is also conceivable to arrange the connector above the cover though this means that there is not direct contact between the connector and the wound and or porous pad, while on the other the fastening sections can no longer be used as pressure measuring points. Also, the suctioning through the fastening sections is no longer possible if the connector is provided under the cover. 
         [0033]    According to a variant of the inventive therapeutic device, the pad comprises a natural sponge on which the connector is supported. Compared to the previously known use of synthetic materials as for example open-cell polymer plastics as a porous pad for vacuum therapy devices, natural sponges provide a number of advantages. 
         [0034]    First of all, there is an increased demand by patients for natural or near-natural products. In addition, natural sponges have hemostatic properties in the form of compresses. Further, there are indications of biologically active ingredients, which have antibacterial, anti-inflammatory, cytotoxic or microstatic properties. 
         [0035]    These many advantageous properties of natural sponges are also advantageous for vacuum healing therapy. Also, natural sponges are sufficiently available on the market in the desired quality for the use in a mass-produced commercial therapy device. The combination of a natural sponge with the inventive connectors for the even distribution of the fed pressure results in optimal care for the wound. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0036]    The invention is described in a preferred embodiment using a drawing, whereby other advantageous details can be found in the drawing figures. 
           [0037]    Parts having the same function are labeled with the same reference numbers. 
           [0038]    The figures of the drawings show: 
           [0039]      FIG. 1  schematic representation of the inventive wound healing device and its operating mode 
           [0040]      FIG. 2  perspective representation of one of the inventive connectors applied to the wound between the drainage tube and the wound cover 
           [0041]      FIG. 3  individual representation of the inventive connector from a top view 
           [0042]      FIG. 4   a  side view along the line A-A of the connector from  FIG. 3   
           [0043]      FIG. 4   b  perspective representation of a connector from  FIG. 3  view from below 
           [0044]      FIG. 5  principal representations of the shape of two variations of the inventive connector 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0045]    The present invention also relates to a procedure for operating a class-appropriate therapy device. 
         [0046]      FIG. 1  schematically shows an embodiment of an inventive wound healing device  1 . The wound healing device  1  comprises a base unit  2  and a wound dressing unit  3 . The base unit  2  contains a replaceable collecting container  4 , a suction pump  5  and a control device  6 . The base unit  2  is enclosed by a housing  7 . A carrying strap  8  is attached to the housing  7 . The collecting container  4  contains a mixture  9  consisting of wound exudation and gelling agent. 
         [0047]    The collecting container  4  comprises a suction opening  11  on one of the inner walls  10  facing the housing  7 . The suction opening  11  is connected to the suction pump  5  by the filter  12  and a suction tube  13 . A pump-side probe tube  14  branches off from the suction tube  13 . The pump-side probe tube  14  carries the prevailing pressure p 2  contained in the suction tube  13  to a suction-pump-side pressure sensor  15  which is located in the control device  6 . 
         [0048]    The control device  6  also contains the distal pressure sensor  16 , which interconnects the prevailing pressure p 1  prevailing on the distal end of the suction tube  17  via the probe tube  17  and the distal probe tube  36 . A 3/2-way valve  35  is installed in both the probe tube  17  and in the probe tube  14 . The distal probe tube  36  runs along the replaceable collecting container  4  inside the housing  7  to a suction opening  19  located in the outer wall  18  of the collecting container  4  in the housing  7  of the base unit  2 . Also, the distal probe tube  36  can optionally be run through a black box  33 . 
         [0049]    The wound dressing unit  3  comprises the wound exudation suction tube  20 , a sponge  21  and a film foil  23  through which the wound exudation suction tube  20  and the sponge  21  are fastened to skin  24  surrounding the wound  22  in such a way that an airtight connection is created. 
         [0050]    The sponge  21  is able to absorb and store fluids. Using the stretched film foil  23 , the sponge  21  is introduced with a certain contact pressure to the wound  22 . 
         [0051]    A connector  31  is provided between the sponge  21  and film foil  23 . The drainage tube  20  is connected to the connector  31 . The connector touches the side of the sponge  21  facing the wound  22 . 
         [0052]    Also, a strain gage  30  is fastened in the wound dressing  3  between the film foil  23  and the sponge  21  near the tube connector  31 . The strain gage  30  is used to measure the wound pressure on the wound  22 . The strain gage  30  is connected to an electrical cable  29 . 
         [0053]    The electrical cable  29  is connected to the outer edge of the suction tube  20  and in this way connected to the evaluation device  32  for the wound pressure P 3  by means of a plug-type connector  34  in the housing  7  of the base unit  2 . The evaluation device  32  is part of the control device  6 . 
         [0054]    The collecting container  4 , the wound exudation suction tube  20 , the sponge  21  and the film foil  23  are respectively sterile and replaceable for disposable use. 
         [0055]    The wound exudation is located in the wound  22 . To use the inventive wound healing device  1 , the sponge  21  is introduced into the wound  22 . Using the sponge  21 , one end of the wound exudation suction tube  20  is connected via the connector  31 , and then both the wound exudation suction tube  20 , the connector  31  and the sponge  21  are affixed to the skin area  24  around the wound  22  with the help of the film foil  23  in such a way that the system is made airtight. 
         [0056]    The other end of the wound exudation suction tube  20  is also connected to the suction opening  19  contained in the outer wall  18  of the collecting container  4  in an airtight fashion. Due to the property of the sponge  21  to absorb and store fluids, the wound exudation  25  is removed from the wound  22  into the sponge  21 . The wound exudation quantity that exceeds the storage capacity of the sponge  21  is suctioned into the collecting container  4  through the wound exudation suction tube  20 . The negative pressure needed for the suction is produced by the suction pump  5 . For this purpose the suction tube  13  of the suction pump  5  interconnects the collecting container  4 . 
         [0057]    The filter  12  arranged between the collecting container  4  prevents the wound exudation  25  from entering the suction tube  13 , the suction pump  5 , the suction-pump-side probe tube  14  or even the suction-pump-side pressure sensor  15 . The excess wound exudation  25  collected in the collecting container  4  in the manner described above is thickened by a gelling agent. This effectively prevents the moistening of the filter  12  even when the base unit  2  is moved. As a result, for example, the filter  12  is prevented from being moistened and germs are prevented from getting into the control device  6 . Also, it is possible to dispose of the potentially contaminating wound fluid in the solid aggregate state in a more hygienic fashion. 
         [0058]    The negative pressure produced by the suction pump  5  is continuously received on the one hand by the suction-pump-side pressure sensor  15  and by the wound-side strain gage  30  on the other and also via the distal pressure sensor  16 , which measures the distal pressure p 1 . Then, the pressure p 3  taken from the wound-side strain gage  30 , the pressure p 2  taken from the suction-pump-side pressure sensor  15  and the pressure p 1  taken from the distal end of the suction tube  20  are used in the microprocessor of the control device  6  as input data for control. 
         [0059]    In order to maintain a moist wound environment, the pressure level in the wound dressing unit  3  is set according to the individual needs of the patient, the properties of the wound  22  and according to the criteria of compatibility (pain by the patient). 
         [0060]      FIG. 2  shows the connector  31  in detail. The connector  31  is placed on the sponge  21 . In turn, the sponge  21  completely covers the wound  22 . The edge of the wound  22  is shown with a dotted line to indicate that the wound  22  is completely covered by the sponge  21  and therefore cannot be seen in this view. 
         [0061]    The transparent film foil  23  is placed over the connector  31  and fastened to the skin  24  around the wound  22  in such a way that an essentially airtight seal is created. The connector  31  is designed as a continuous injection-molded part. For example, PVC (polyvinylchloride) is particularly suited as a material. However every other plastic or other material is suited that is used in medical therapy equipment and which is essentially rigid, with a certain elasticity. 
         [0062]    The connector  31  is provided with an opening  37  on its upper end. A connecting sleeve  38  is placed on the opening  37 . The connecting sleeve  38  is bent. An unspecified connection for the drainage tube  30  is located at the end of the connecting sleeve  38 . The opening  37  of the connector  31  flows into four suction arms  39 . 
         [0063]    In  FIG. 2  one of the suction arms  38  is hidden and can therefore not be seen. In addition, four fastening arms  40  are connected on the wound side to the opening  37  in the connector  31 . The suction arms  39  are approximately three times as long as the suction arms  39 . The double-star-like design of the connector  31  can also be seen in the top view in  FIG. 3 . 
         [0064]    The suctions arms  39  have, as seen in  FIG. 4 , in cross section the shape of a tube cut open lengthwise. Each suction arm  39  therefore defines with its wall  42  a channel, which is turned toward the wound  22 . 
         [0065]    In the embodiment, both of the fastening arms  40  run toward the pointed end. The suction arms  39  extend to close to the edge of the film foil  23 . The front area  43  of the suction arms  39  are closed. In this way the channel  41  is bordered upward by the wall  42  and at the end by the front area  43 . However, the channel is open toward the bottom, i.e. toward the wound  22 . 
         [0066]    In the interest of improved clarity, the connecting sleeve  38  for the drainage tube  20  is not represented in  FIG. 3 . Unlike the suction arms  39 , the fastening arms  40  are not convex and as such do not form a channel. Instead, the lower sides of the fastening arms  40  form a flat support surface which can be placed on the sponge  21 . 
         [0067]    As can be seen in  FIG. 4 , the suction arms  39  are bent around the wound at an angle  45 . The fastening arms  40  are bent at the same angle  45  to the wound. The lower surfaces of the fastening arms  40  and the end surfaces  46  of the suction arms  39  therefore lie on an intentionally common curved surface of a cone. 
         [0068]    When operating the wound dressing unit  3 , the negative pressure applied to the drainage tube  20  by the suction pump  5  is applied to the wound with the assistance of the inventive connector  31 . In this way the suction effect on the proximal end of the drainage tube  20  is distributed to the opening  37  of the connector  31  to the channels  41  of the four suction arms  39 . As a result, the connector  31  is evenly pressed by the surrounding atmospheric pressure on the sponge  21 . A shifting of the connector  31  on the sponge  21  is primarily prevented by the fastening arms  40  because the fastening arms  40  have a large contact surface on the sponge  21 . 
         [0069]    The connector  31  acts on the wound as a pressure distributor. The fastening arms  40  and in particular the suction arms  39  are somewhat elastic and can therefore adjust to a curvature of the sponge  21 . The pressure is transmitted to near the edges of the film foil  23 . The fastening arms  40  and in particular the suction arms  39  are somewhat elastic, and therefore can adjust to the bulge of the sponge  21 . This insures a constant contact between the connector  31  and the sponge  21 . 
         [0070]    In addition to the pressure distributing effect, the efficiency of the suction of the wound exudation  25  which is stored in the sponge  21 , is significantly improved. The improvement is achieved by a larger area, that is the opening area of the channels  41 , being suctioned. The suction situation can be seen particularly well in  FIG. 4   b . It shows that the connector is provided with six outputs  47 , specifically the upper outlet  47   a , to which the drainage tube  20  is connected, which is opposite the outlet  47   a , the lower outlet  47   b  which faces the wound, and the four outputs  47   c  which flow into the channels  41  of the respective suction arms  39 . 
         [0071]      FIG. 5  shows alternative embodiments of the connector  31 . The representations show the top view from  FIG. 3  of the embodiment described above. 
         [0072]      FIG. 5  shows an embodiment of the connector  31  according to the invention in which the suction arms  39  have a spiral shape. Part b of  FIG. 5  shows another alternative embodiment of the connector according to the present invention in which only one spiral-shaped suction arm  39  is provided. 
         [0073]    This suction arm winds a number of times around the opening  37 . Although the task of the invention is also solved by a connector having the general shape according to  FIG. 5   b , this variant is not preferred for practical reasons. Instead, the preferred embodiment is the star-shaped construction depicted in  FIGS. 2 through 4   a/b.    
       LIST OF DRAWING REFERENCES 
       [0000]    
       
         
           
               1  Wound healing device 
               2  Base unit 
               3  Wound dressing unit 
               4  Collecting container 
               5  Suction pump 
               6  Control device 
               7  Housing 
               8  Carrying strap 
               9  Mixture 
               10  Inside wall 
               11  Suction opening 
               12  Filter 
               13  Suction tube 
               14  Suction-pump-side probe tube 
               15  Suction-pump-side pressure sensor 
               16  Wound-side pressure sensor 
               17  Wound-side probe tube 
               18  Outer wall 
               19  Suction opening 
               20  Wound exudation suction tube 
               20   a  Interior tube wall 
               20   b  Exterior tube wall 
               20   c  Cavity 
               21  Sponge 
               22  Wound 
               23  Film foil 
               24  Skin 
               25  Wound exudation 
               26  Display unit 
               27  Control valve 
               28  Computer interface 
               29  Electrical cable 
               30  Strain gage 
               31  Tube connector 
               32  P 3  evaluation device 
               33  Black box 
               34  Plug-type connector 
               35  3/2-way valve 
               36  Distal probe tube 
               37  Opening 
               38  Connecting sleeve 
               39  Suction arm 
               40  Fastening arm 
               41  Channel 
               42  Wall 
               43  Front area 
               44  Horizontal 
               45  Angle 
               46  End surface 
               47   a  Outlet 
               47   b  Outlet 
               47   c  Outlet 
               47   d  Outlet 
               48  Notches