Abstract:
A wound treatment device comprising an enclosed space formed from the joining of two layers of material to form a main unit is used to provide and maintain oxygen-rich or oxygen-depleted microenvironments over a wound. At least one inlet connects at one end to a source for gas and, at an opposite end, to the enclosed space to provide the main unit with gas to be delivered to a wound for treatment thereof. The plurality of delivery openings provides uniform delivery of one or more gases to the microenvironment associated with the wound. Gas is exhausted from the microenvironment associated with the wound to the external environment via the plurality of exhaust outlets such that the exhausted gases do not contaminate or otherwise interfere with the delivery of one or more gases to the microenvironment associated with the wound.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates to wound treatment devices, and more particularly to an improved device for treatment of wounds in body tissue via exposure to gases.  
       BACKGROUND  
       [0002]     The invention relates to a device for treatment of wounds in body tissue via exposure of the area of the wound to one or more gases.  
         [0003]     Treating a wound with gas (e.g., oxygen) in order to promote and expedite healing of the wound and reduce associated discomfort, such as itching, is generally known. For example, topical hyperbaric oxygen therapy (HBOT) is a technique of delivering 100% oxygen directly to an open, moist wound at a pressure slightly higher than atmospheric pressure. It is theorized that the high concentrations of oxygen diffuse directly into the wound to increase the local cellular oxygen tension, which in turn, promotes healing. Typically, such treatment is accomplished via direct application of gas to the wound area using a hose or similar delivery device aimed at the wound area. This approach requires manual attention by staff or caregivers to position and hold the hose during treatment. Additionally, application of the gas is inconsistent and can vary with each manual application, thus potentially reducing the beneficial effects of the treatment. The relative expense and lack of consistency associated with this form of treatment is therefore disfavored.  
         [0004]     Another method by which to introduce gas for the purpose of wound treatment is via systemic hyperbaric oxygen therapy (HBOT). Systemic HBOT is a technique of delivering higher pressures of oxygen internally to tissues. In systemic HBOT, the patient is entirely enclosed in a pressure chamber (e.g., hyperbaric chamber) and breathes oxygen at a pressure greater than 1 atmosphere (the pressure of oxygen at sea level). This technique relies on systemic circulation to deliver highly oxygenated blood to target tissues. Systemic HBOT is used to treat wounds as well as systemic illnesses such as air or gas embolism, carbon monoxide poisoning, and clostridial gas gangrene. Such hyperbaric chambers are substantially sealed enclosures where the inside environment of the chamber provides concentrations of various gases (e.g., oxygen). Although providing some level of consistency of treatment, the use of hyperbaric chambers and the like is relatively expensive, lacks portability, and is overly complex for the type of treatment typically needed for expedited wound healing.  
         [0005]     Additional disadvantages associated with known oxygen delivery devices include: inability to provide more than one gas source to the device without pre-mixing the gases (i.e., such devices only have one inlet for gas); non-disposability, use of inferior materials (e.g., non-biodegradable, non-hypoallergenic), no protection against multiple uses, and difficulty of use (e.g., placement/fixing of device).  
         [0006]     On balance, the controlled and consistent, topical delivery of gas(es) to a wound area is preferred for reasons associated with relative costs and complexity. The present invention provides an improved wound treatment device for such use.  
       SUMMARY  
       [0007]     An improved wound treatment device that provides and maintains oxygen-rich or oxygen-depleted microenvironments over a wound is disclosed. The present invention device is comprised of a main unit having an enclosed space therein, one or more inlets, a plurality of delivery openings, and a plurality of exhaust outlets. The one or more inlets of the main unit are connected to one or more sources of gas, and are designed to provide the enclosed space with one or more pressurized gases. As the inlets provide pressurized gas to the main unit, the enclosed space is temporarily inflated. The plurality of delivery openings allows the gas within the enclosed space to be provided directly and evenly to the wound area of the user. The plurality of exhaust outlets allows gases to escape the immediate environment of the wound area directly to the outside environment, without passing through the enclosed space.  
         [0008]     In a preferred embodiment, the device of the present invention is a single-use device and is disposable and biodegradable. This feature greatly reduces the chances of multiple uses of a treatment device on wounds by including a feature that compromises the integrity of the material of the treatment device upon removal after treatment. More than a single use of a wound treatment device, even on the same wound, much less on different wounds, or, worse, different patients, can result in the spread of microorganisms (e.g., bacteria) that may actually harm the user via additional or prolonged infection, for example.  
         [0009]     The placement and distribution of the plurality of outlets and the plurality of delivery openings over the surface of the main unit is important to the proper function of a wound treatment device. One of the improvements of the present invention device over known devices lies in the number, placement and distribution of such outlets and delivery openings. Specifically, the delivery openings of the present invention device are greater in number and are distributed over a larger area of the main unit. This feature provides several advantages to the device. First, the more widely distributed delivery openings provide a more even environment of gas delivered to the wound area, thereby increasing the consistency of the treatment. With fewer delivery openings and/or delivery openings spaced too closely together, “hot spots” of high gas concentrations can form within the field being treated. Additionally, the larger number and wider distribution of delivery openings restricts the amount of inflation of the enclosed space of the main unit. Less inflation equates to less deformation of the general shape and size of the main unit, thereby markedly decreasing the chances of disrupting the adherence of the main unit to the area surrounding the wound during treatment.  
         [0010]     In a preferred embodiment of the present invention device, the main unit is constructed from a hypoallergenic, biodegradable, disposable, flexible material exhibiting relatively low gas permeability. Additionally, the material includes select regions capable of removably adhering to the area surrounding the wound to be treated or is capable of be mated with material capable of providing such removable adherence. Such adherence assists in the formation of a barrier around the wound and temporarily fixes the device in place, eliminating the need for, and inconsistency of treatment inherent with, manual placement and manipulation of the device during treatment. In a preferred embodiment, the integrity of the material is compromised upon its removal to prevent multiple uses of the device. Compromising the material can be accomplished in one of any number of ways, such as select destruction of portions of the material and the like.  
         [0011]     In a preferred embodiment, the one or more inlets of the device are fitted with a connector that allows for surgical tubing of any appropriate length to be used. This feature of the device allows the device to be used at varying distances remote from the one or more gas sources (e.g., gas tank). Prior art devices are often fitted with predetermined lengths of tubing that require the user and/or the source of gas to be moved to accommodate use of the device.  
         [0012]     In another embodiment, a porous, non-adhering dressing material, such as gauze, will be used in connection with the main unit to provide additional protection to the wound.  
         [0013]     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0014]      FIG. 1  is a bottom view of one embodiment of the wound treatment device of the present invention;  
         [0015]      FIG. 2  is a top view of the embodiment of  FIG. 1  of the wound treatment device of the present invention;  
         [0016]      FIG. 3  is a top view of another embodiment of the wound treatment device of the present invention; and  
         [0017]      FIG. 4  is a cross section of an embodiment of an embodiment of the wound treatment device of the present invention positioned over a wound to be treated. 
     
    
       [0018]     Like reference symbols in the various drawings indicate like elements.  
       DETAILED DESCRIPTION  
       [0019]     Referring now to  FIG. 1 , an improved wound treatment device  100  that provides and maintains a microenvironment over a wound ( FIG. 4 ) is shown. The wound treatment device  100  comprises a main unit  110 , one or more inlets  120 , a plurality of delivery openings  130 , and a plurality of outlets  140 . As more easily seen in  FIG. 4 , the main unit  110  further includes an enclosed space  150  defined by an upper layer  160  and a lower layer  170  of the main unit  110 . When in use, the wound treatment device  100  is placed over a wound  180  to form a microenvironment  190  above the wound  180 , using zones  210  ( FIG. 1 ) for removably adhering the main unit  110  to tissue surrounding the wound  180 .  
         [0020]     Referring to  FIG. 4 , the upper layer  160  and the lower layer  170  of the main unit  110  are fused together in one or more areas to form “pillows” within the or enclosed space  150 . As will be described in greater detail below, the enclosed space  150  facilitates the delivery of the one or more gases for treatment of the wound  180 , and assists in exhausting gases from the microenvironment  190  associated with the wound  180 . Although the fusing of the upper layer  160  and the lower layer  170  is described herein to provide pillows, the mating of the upper layer  160  with the lower layer  170  of material in any suitable manner may be used with the present invention, if desired.  
         [0021]     Referring again to  FIG. 1 , the one or more inlets  120  are sized and shaped to accept and secure at one end a hose  200 , such as surgical tubing and the like, that leads to one or more sources of gas (not shown). At an opposite end, the one or more inlets  120  are in communication with the enclosed space  150  of the main unit  110 . The use of more than one inlet  120  allows for a mixture of gases to be introduced into the main unit  110  for delivery to the wound treatment area. This feature allows for wounds to be treated with a mixture of gases without the need for pre-mixing of the gases. The one or more gases to be delivered to the microenvironment  190  associated with the wound  180  may be any suitable gas, such as oxygen, air or nitrogen, and the like, and/or mixtures thereof. In a preferred embodiment, at least one of the gases is oxygen, preferably pure oxygen, as used in various hyperbaric oxygen treatment methods known in the art.  
         [0022]     Although two inlets  120  generally located on the same side of the main unit  110  of the wound treatment device  100  are shown and described herein, it is noted that any number and/or sizes and/or shapes of inlets can be used, as desired, with the improved wound treatment device  100  of the present invention. For example,  FIG. 3  illustrates an embodiment of the main unit  110  of the improved wound treatment device  100  including a single inlet  120  and a single hose  200  for delivery of gas to the microenvironment  190  associated with the wound  180 . Additionally, in a preferred embodiment, the hose  200  is of sufficient length to allow the main unit  110  to be used as remote from the source of gas as is required. The hose  200  can either be supplied in predetermined lengths with the main unit  110 , or can be common surgical tubing or the like.  
         [0023]     Now referring to  FIGS. 1 and 4 , the improved wound treatment device  100  includes a plurality of delivery openings  130 . The delivery openings  130  are located only within the lower layer  170  of the main unit  110 , and are sized and shaped to allow gas to pass from the enclosed space  150  via the delivery openings  130  into the microenvironment  190  surrounding the wound  180 . Optimally, the delivery openings  130  are dispersed uniformly substantially throughout the entire surface of the lower layer  170  of the main unit  110  so that gas is delivered in a relatively uniform manner to the microenvironment  190  above the wound  180 . In a preferred embodiment, the plurality of delivery openings  130  is arranged in rows along the lower layer  170  of the main unit  110 . Although a plurality of delivery openings  130  positioned in rows within the lower layer  170  of the main unit  11   0 , spaced to provide a relatively uniform delivery of gas from the enclosed space  150  to the microenvironment  190  associated with the wound  180 , is described herein, any number and relative placement of delivery openings  130  are contemplated by the present invention and can be utilized, if desired.  
         [0024]     Now referring to  FIGS. 2 and 4 , also associated with the main unit  110  of the wound treatment device  100  is a plurality of exhaust outlets  140 . As shown in  FIG. 4 , the plurality of exhaust outlets  140  lies at the intersections of the lower layer  170  and the upper layer  160  of the main unit  110 , forming the pillows, such that they form a conduit between the microenvironment  190  associated with the wound  180  and the outside environment external to the wound treatment device  100 . The exhaust outlets  140  allow for unidirectional fluid (gas) exchange from the microenvironment  190  associated with the wound  180  to the external environment without passing through, and thereby potentially contaminating, or otherwise interfering with, the enclosed space  150 . This feature of the wound treatment device  100  of the present invention allows gases to be exhausted from the microenvironment  190  associated with the wound  180  to the external environment without impeding, contaminating, diluting or otherwise interfering with the delivery of the one or more gases via the plurality of delivery openings  130  to the wound  180 .  
         [0025]     As the one or more inlets  120  provide pressurized gas(s) to the main unit  110 , the pillows associated with the enclosed space  150  slightly inflate, providing the microenvironment  190  associated with the wound  180  with the one or more gases via the plurality of delivery openings  130 . Having a relatively large number of delivery openings  130  spaced uniformly substantially throughout the entire surface of the lower layer  160  of the main unit, prevents the enclosed space  150  from inflating to a point where the main unit  110  is substantially raised off of its preferred resting position above the wound  180 . If there exist too few number of delivery openings  130  and/or the spacing or placement of the delivery openings  130  are such that it causes over-inflation, the main unit  110  can rise away from the wound  180  ( FIG. 4 ) such that the microenvironment  190  associated with the wound  180  is comprised, thereby potentially adversely affecting treatment of the wound  180 .  
         [0026]     The positive pressure of the one or more gases being provided to the microenvironment  190  associated with the wound  180  prevents backflow of fluid (gas) from the microenvironment  190  to the enclosed space  150 , and also facilitates the exhaust of gas(es) via the plurality of outlets  140 .  
         [0027]     In a preferred embodiment, the upper layer  160  and the lower layer  170  of the main unit  110  of the wound treatment device  100  are constructed from a lightweight, flexible material, such as vapor permeable paper, which is permeable to both water vapour and oxygen, impermeable to micro-organisms, and is disposable, biodegradable and capable of being easily and removably secured to human skin, tissue and the like. Representative materials include OpSite™ wound dressings by Smith Nephew, Inc., and the like.  
         [0028]     In another embodiment, a porous, non-adhering dressing material, such as gauze, is fused to the lower layer  170  to provide added protection to the wound bed and periwound area. Representative materials to be used with the lower layer  170  include Aquaphor Gauze™ by Smith &amp; Nephew, Inc., and the like.  
         [0029]     The plurality of delivery openings  130  and the plurality of outlets  140  may be formed via selective piercing of the material forming the upper layer  160  and lower layer  170  of the main unit, or in any other manner suitable for the material.  
         [0030]     Use of the improved wound treatment device  100  of the present invention obviates the need for health care personnel or any other to position and hold the wound treatment device  100  in place for treatment. This feature is particularly advantageous where wounds require repeated, prolonged treatment regimes.  
         [0031]     Preferably, the main unit  110  of the wound treatment device  100  is sterilized and pre-packaged for a single use. Single use is preferred to avoid potential for contamination of wounds to be treated. Such contamination can occur even between wounds of the same person and should be avoided. Use of the preferred embodiment including multiple-use prevention adhesion zones is recommended to prevent such problems. In one embodiment, the zones  210  include a peel and stick adhesive strip that facilitates removable affixing of the wound treatment devices. In a preferred embodiment, the zones  210  of the main unit  110  include means to compromise the integrity of the lower layer  170  of the main unit  110  upon removal of same to prevent multiple uses of the main unit  110 . Examples of means to compromise include the use of adhesives that allow for only a single use, such that removal of the zones  210  from the tissue of the user prevents the zones  210  from adhering a second time, to the use of adhesives that require the zones  210  to be physically separated from the main unit  110  prior to being capable of removal from the tissues of the user. Any means suitable to prevent or discourage multiple uses of the main unit  110  is contemplated by the present invention.  
         [0032]     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.