Abstract:
A wound dressing includes a chamber ( 12 ) defining a treatment space ( 14 ) and at least one opening ( 20 ) communicating with the treatment space. In one embodiment, a plurality of channels are defined on an inner wall of the chamber. In another embodiment, a tube ( 31 ) extends through the chamber and into the treatment space and defines a plurality of openings ( 35 ) in a portion of the tube extending into the treatment space. In yet another embodiment, a tube extends through the chamber and into the treatment space and comprises a plurality of branches ( 37 ) extending to different regions of the treatment space.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/694,849, filed Jun. 29, 2005, incorporated herein by reference as if set forth in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The invention relates generally to the field of wound treatment, and more particularly to a wound chamber for treating wounds on a limb of the body. 
     Various techniques are employed to treat open wounds. In some cases, open wounds may be treated with moist or dry gauze. However, such treatment may result in excessive pain, dehydration of the wound, loss of fluids and proteins, loss of heat or delayed healing. To delay the appearance of infection, burn wounds may be additionally treated with antibacterial creams and the like. 
     Open wounds appear to heal faster in an environment that is somewhere between moist and dry. Partial thickness wounds heal faster when covered with a polyethylene film than when exposed to air. Conventionally, dressings with some water permeability provide the optimal conditions for healing. 
     Wound chambers for protecting open wounds and providing environmental control of the treatment site have been developed. For example, an exemplary wound chambers and methods for use are described in U.S. Pat. No. 5,152,757, entitled “System for Diagnosis and Treatment of Wounds,” by Elof Eriksson, and U.S. patent application Ser. No. 11/130,490, entitled “Wound Chamber With Remote Access Portal,” by Eriksson et al., each of which is incorporated herein by reference as if set forth in its entirety. 
     A wound chamber typically includes a chamber for enclosing a predetermined surface area about a wound on a patient. The wound chamber is sealed to the skin immediately adjacent to the wound. However, certain wounds on and around a limb may not be treatable by a wound chamber that is intended for use on relatively flat skin surfaces. Instead, it may be necessary to enclose all or a portion of a limb in a chamber in order to create a chamber environment around the wound. In addition to other features, the wound chamber may have a portal for introducing treatment fluid and treatment additives into the wound chamber and extracting wound fluid and/or air from the wound chamber. Such operations are typically performed using a syringe or similar delivery/extraction device. For example, the portal may be an injection portal made of a self-sealing material through which a hollow steel needle can be passed. The use of a steel needle in close proximity to the patient creates a risk of injury to the patient and also to the health care provider. An additional risk of the needle damaging the wound chamber is also present. In some clinical applications, the wound chamber itself may be covered by a secondary dressing or covering, such as gauze or an elastic bandage. In such circumstances, a portal located directly on the chamber would be covered by the secondary dressing and would be inaccessible. 
     The present invention is directed to providing a chamber to treat wounds on limbs, and to overcoming, or at least reducing the effects of, one or more of the problems set forth above. 
     BRIEF SUMMARY OF THE INVENTION 
     A wound dressing includes a chamber defining a treatment space and at least one opening communicating with the treatment space. 
     In aspect of the invention a plurality of channels are defined on an inner wall of the chamber. 
     In another aspect of the invention, a tube extends through the chamber and into the treatment space and defines a plurality of openings in a portion of the tube extending into the treatment space. 
     In yet another aspect of the invention, a tube extends through the chamber and into the treatment space and comprises a plurality of branches extending to different regions of the treatment space. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which: 
         FIG. 1  is perspective view of a limb dressing in accordance with one embodiment of the present invention; 
         FIG. 2  is a perspective view of the limb dressing with an attached strip of adhesive backed tape; 
         FIG. 3  is a perspective view of the limb dressing with an internal adhesive surface closure; 
         FIG. 4  is a perspective view of the limb dressing with a cuff and drawstring closure; 
         FIG. 5  is a perspective view of the limb dressing with a closing strap; 
         FIG. 6  is a perspective view of the limb dressing with a seam that may be opened and resealed; 
         FIG. 7  is a perspective view of the limb dressing with straps for gathering and retaining loose portions of the dressing; 
         FIG. 8  is a sectional view of a tube extending into the treatment space of a wound chamber in the limb dressing; 
         FIGS. 9 and 10  are sectional views of a branched tube extending into the treatment space; 
         FIG. 11  is a sectional view of the wall of a wound chamber with raised ridges defined in the interior side of such wall; 
         FIG. 12  is a sectional view of the wall of a wound chamber with grooves defined in the interior side of such wall; 
         FIGS. 13-16  are perspective views of the limb dressing with varying channel patterns defined in the interior walls of the chamber; 
         FIG. 17  is a perspective view of a portal with a valve fitted to the tube of a wound chamber; 
         FIG. 18  is a sectional view of a portal with a valve for exhausting air withdrawn from the interior of a wound chamber; 
         FIG. 19  is a perspective view of a collapsible tube that may be used with a wound chamber; 
         FIG. 20  is a perspective view of a syringe with a flexible delivery tip inserted into the collapsible tube of  FIG. 19 ; and 
         FIG. 21  is a perspective view of the delivery tube equipped with a fitting and an auxiliary port. 
     
    
    
     While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE INVENTION 
     While the present invention may be embodied in any of several different forms, the present invention is described here with the understanding that the present disclosure is to be considered as setting forth an exemplification of the present invention that is not intended to limit the invention to the specific embodiment(s) illustrated. Nothing in this application is considered critical or essential to the present invention unless explicitly indicated as being “critical” or “essential.” 
     Referring first to  FIG. 1 , a sectional view of a limb dressing  10  is provided. The limb dressing  10  includes a chamber  12  defining a treatment space  14 . A limb  16  with a wound  18  is shown within the treatment space  14 . The limb dressing  10  includes an opening  20  that communicates with the treatment space  14  and may be sealed about the limb  16  of a patient so that the wound  18  to be treated is enclosed within the treatment space  14 . 
     Referring next to  FIGS. 2-5 , various techniques may be used to secure the limb dressing  10  to the limb  16 . In the embodiment of  FIG. 2 , the opening  20  has no integrated system for sealing. Adhesive tape  25  may be applied by a user employing the limb dressing  10 . In the embodiment of  FIG. 3 , an adhesive material  24  is provided on the inside of the chamber wall near the opening  20 .  FIG. 4  shows a cuff  26  and cooperating drawstring  27 .  FIG. 5  shows connecting straps  28 . 
     Turning to  FIG. 6  a seam  29  may be opened to facilitate the installation of the chamber  12  around the limb  16 . The seam  29  may be unsealed and resealed by numerous methods known to those of ordinary skill in the art, such as with an adhesive tape. The seam  29  allows the limb dressing  10  to be applied in a manner that reduces the likelihood of contact between the chamber  12  and the wound  18  as the limb  16  is passed through the opening  20 . 
     As shown in  FIG. 7 , tabs  30  may be used to reduce the cross-sectional area of the chamber  21  to gather the chamber  12  around the limb after the chamber has been installed. The tabs  30  may be used to gather any loose material around the limb after the chamber has been installed. The tabs  30  may be constructed of Velcro® or other self-sticking material. The tabs  30  may also be simple drawstrings that are tied to one another. In general, the tabs  30  can be joined to one another to gather any loose material of the chamber  12 , particularly in the case of a patient with a small limb  16 . 
     Returning to  FIG. 1 , a tube  31  is attached to the chamber  12  and communicates with the treatment space  14 . The tube  31  may be permanently fixed to the chamber  12 , or a fitting  39  may be provided to allow removal of the tube  31 . The tube  31  is constructed so that it will maintain its shape, and will not collapse. A distal end of the tube  31  terminates in a portal  34 . In one embodiment, the portal  34  may be a female Luer fitting. As used herein the terms portal and fitting may be used interchangeably, depending on the particular implementation. A fitting generally refers to a device that mates with a complementary, interfacing device, while a portal may relate to a device into which something is inserted, such as a needle. The tube  31  is sealed to the chamber  12  in such a manner as to prevent the escape of liquid or air from the treatment space  14 . The juncture of the tube  31  and the chamber  12  may be reinforced with a flange  32 . Although only one tube  31  and portal  34  are illustrated, the invention is not so limited, and multiple tubes  31  and associated portals  34  may be provided for accessing the treatment space  14 . One tube  31  and portal  34  may be used as an inlet for providing treatment substances to the treatment space  14 , while another tube  31  and portal  34  may be used as an outlet for removing substances from the treatment space  14 . Such an inlet and outlet arrangement may be useful for administering a continuous treatment stream. 
     The tube  31  may terminate at a wall of the chamber  12 , or it may extend through the wall a distance and terminate within the treatment space  14  as shown in  FIGS. 8-10 . The composition of the chamber  12  may be strengthened in area  33  as shown in  FIG. 8  by increasing the thickness of the walls of chamber  12  to provide further protection for the portion  38  of the tube  31  within treatment space  14 . 
     As seen in  FIGS. 8 and 9 , the portion  38  of the tube  31  within the treatment space  14  may be perforated with one or more holes  35  to facilitate the flow of liquid or air through the tube  31 . The tube  31  may extend further into treatment space  14  in branches  37  as shown in  FIGS. 9 and 10 . 
     Turning to  FIGS. 11-16 , walls  40  of chamber  12  may be configured on the interior side with ridges  41  that define channels, as in  FIG. 11 , or with grooves  42 , as in  FIG. 12 , or by a combination of both. When the interior surfaces of the chamber wall  40  are pressed upon the skin of the patient, or against one another, the channels or grooves admit the flow of liquid or air. As a result, the movement of liquid and air throughout the treatment space  14  and in and out of the chamber  12  is facilitated. The channels or grooves may be disposed as a pattern of short nubs or depressions  43  as seen in  FIG. 13 , as an irregular grid  44  as shown in  FIG. 14 , as a series of branches  45  as shown in  FIG. 15 , as a series of narrow bands  46  as shown in  FIG. 16 , or in other configurations achieving a similar result. 
     Turning now to  FIGS. 17 and 18 , a delivery/extraction device  51 , such as a syringe, may be engaged with the portal  34  to allow delivery of treatment fluid and/or treatment additives to the treatment space  14  or removal of liquid or gases from the treatment space  14 . For example, the delivery/extraction device  51  may include a fitting  53 , such as a male Luer fitting, complementary to a female Luer fitting used as the portal  34 . In the case of complementary female and male Luer fittings, the rotation of the male fitting  53  on the delivery/extraction device  51  opens a valve in the female portal  34  extending from the tube  31 . The delivery/extraction device  51  may include devices other than the syringe illustrated. For example, the delivery/extraction device  51  may include a rigid or flexible container for holding one or more liquid or powdered treatment substances that may be delivered to the treatment space  14 . Alternatively, fitting  34  may be constructed of a self-sealing material to accommodate a syringe having a hollow steel needle that is inserted through the self-sealing material to allow injection of fluids and/or withdrawal of wound fluid or air from the treatment space  14 . 
       FIG. 18  shows a fitting  54  containing an exhaust valve  55 . When this valve  55  is operational, the delivery/extraction device  51  can be operated to exhaust air from the chamber treatment space  14 . After the desired amount of air has been exhausted, the valve  55  can be set to admit the flow of liquid from the delivery/extraction device  51  into the delivery tube  31 . Other valves with various automatic, semi-automatic, and manual operations may be used to facilitate the extraction or introduction of air and liquid. 
     The length of the tube  31  may vary with the particular implementation. In an application where the tube  31  is provided to increase the distance between the delivery/extraction device  51  to protect the patient and/or chamber  12  from a needle, the tube  31  should be at least longer than the needle. In cases where the limb dressing  10  is intended to be covered with a secondary dressing, the tube  31  may be still longer. For example, the tube  31  may be between one inch and twenty-four inches in length. The tube  31  is generally flexible and may be foldable against itself depending on the specific implementation. 
     Referring to  FIGS. 19 and 20 , another embodiment is illustrated wherein the tube  31  of  FIG. 1  is a collapsible tube  61  formed of a flexible, collapsible material that normally lies flat. The delivery/extraction device  51  may be a syringe with a flexible tip  63  that is inserted into the collapsible tube  61 . The flexible tip  63  may be inserted throughout the entire length of the collapsible tube  61  such that it exits the collapsible tube  61  and extends directly into the treatment space  14 . In some embodiments, e.g., where fluids are being added, the flexible tip  63  may be shorter than the collapsible tube  61 . The collapsible tube  61  expands as necessary to allow the insertion of the flexible tip  63  and/or treatment fluids. When the flexible tip  63  is withdrawn, the collapsible tube  61  collapses and forms a watertight and airtight seal with respect to the treatment space  14 . In some embodiments, the collapsible tube  61  may have a flared end  62  where it interfaces with the chamber  12 , i.e., either terminating at the chamber  12  or extending into the chamber  12 . The flexible tip  63  may be positioned within the flared end  62 , yet not within the treatment space  14  to allow removal of fluids or air from the treatment space  14 . 
     As seen in  FIG. 21 , the tube  31  may be equipped with a portal  34  that is a fitting, such as female Luer fitting, as well as an auxiliary portal  66 , which may be made of self-sealing material for example, located on a branch tube  65 . The availability of two portals  34  and  66  increases the flexibility of the limb dressing  10  by allowing users to employ needles or needleless delivery/extraction devices  51 . 
     The tube  31  allows the portal  34  to be located a distance away from the limb  16 , the wound  18 , and the chamber  12 . Hence, if treatment fluids are be introduced into the treatment space  14  using a needle, the likelihood of inadvertently contacting the patient or health care provider or breaching the chamber  12  is reduced. Also, if the limb dressing  10  is covered by a secondary dressing (not shown), the wound  18  may still be treated through the tube  31  without requiring removal of the secondary dressing. 
     The limb dressing  10  described above has numerous applications. The tube  31  may be used to introduce a wide variety of treatment fluids and/or additives. The limb dressing  10  allows monitoring of the wound  18 , which is useful in enhancing the healing process. The chamber  12  allows visual monitoring of the wound  18  itself as well as the monitoring of fluid within the treatment space. This monitoring provides feedback to assist in the precise control of treatment variables and facilitates research. Fluid extracted from the system can be analyzed for factors that indicate wound healing status and also for the presence of deleterious factors such as microorganisms, low oxygen, high carbon dioxide and adverse pH. The fluid may be tested for the number and type of bacteria and other microorganisms per cc of fluid, the number and type of cells, the amount and type of proteins, and other factors. Clinical diagnosis of the wound physiology and the patient may also be conducted. Upon diagnosis, further treatment of the wound  18  may be commenced by introducing treatment additives and controlling treatment variables. Depending on the type of wound, the extracted fluid can be tested, e.g., for: (a) the presence of microorganisms, (b) cells, (c) amount and type of protein, (d) chemicals, (e) oxygen, (f) carbon dioxide levels, and/or (g) pH. This data may be recorded and used for wound diagnosis. Once diagnosis is complete, fluid treatment intervention may be adjusted accordingly. 
     Additional growth factors that are produced by the wound  18  may also be measured when extracted fluid is analyzed. Additional factors that may be tested for are the presence and the amounts of various inflammatory mediators and various antigens. The presence of antigens could serve an important diagnostic purpose and may be tested with specific antibodies that would be delivered through the wound chamber. This information is useful in deciding what to replace and how to treat, and would indicate improvement of the wound  18 . The limb dressing  10  establishes an environment that allows the positive factors produced by the body to be present. 
     An exemplary, but not exhaustive, list of treatment materials includes anesthetics, antibiotics, chemotherapeutics, growth factors, cell culture media, cells, oxygen, buffering agents, enzymes, and immune modulators. The cells added may include cells that have been genetically modified prior to transplantation in the wound  18  or may include other gene therapy additives such as DNA, genes, genetic material, genetic vectors, etc. 
     The limb dressing  10  also allows control of the treatment environment within the treatment space  14 . An exemplary, but not exhaustive, list of treatment variables includes temperature, colloid osmotic pressure, pH, ion concentration, glucose concentration, amino acid content, fat concentration, oxygen concentration, and carbon dioxide concentration. 
     By controlling treatment variables and by adding selected treatment additives, a variety of treatment techniques may be implemented. Those of ordinary skill in the art, in light of this disclosure, may identify numerous such treatment techniques, and the application of the present invention is not limited to any particular treatments. By way of illustration, a non-limiting sample of treatments that may be implemented in accordance with the present invention include cell treatment techniques, such as application of stem cells, gene therapy drugs, or cellular matrix gel suspension, infection treatment techniques, such as antibacterial or bacteriostatic treatments, or general treatment techniques, such as negative pressure therapy. 
     The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.