Abstract:
The present invention is an environmental control device for treating tissue, consisting of a chamber having a bellows configuration that is sealable to tissue around its periphery. A resealable access port is provided in order to introduce and extract fluid from the chamber. A lift tab is provided to lift the portal to an angle roughly perpendicular to the tissue, in order to minimize the risk of injury to both the patient and the caregiver.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority to U.S. provisional patent application No. 60/355,946. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The invention relates to an environmental control device for the treatment of tissue in mammals. More particularly, the invention relates to a tissue treatment system for wounds, burns, skin diseases, gene therapy, and topical treatment of tissue in a closed, localized, and controlled environment.  
         BACKGROUND OF THE INVENTION  
         [0003]    Treatment of open wounds has been accomplished in both a moist and dry environment. Wounds treated in a moist environment have been shown to accelerate the healing process. Additionally, it would be useful to be able to provide a means for maintaining a treatment in solution within a tissue region for an extended period of time.  
           [0004]    The concept of using fluid to treat the wound is generally known. Apparatuses for use in fluid treatment of wounds are also known in the prior art. For example, the system disclosed in U.S. Pat. No. 5,152,757 issued to Eriksson describes a chamber formed by a flexible sheet material having a peripheral adhesive surface. A portal is also described for introduction of treatment fluids within the chamber.  
           [0005]    Other systems, including that described in U.S. Pat. No. 3,026,874 issued to Stevens, are comprised of an annular dam that forms a seal around a wound, with a transparent and flexible “window” overlying and secured to the seal, as well as an inlet adapted for connection to a medication source and an outlet port adapted for connection to a vacuum source.  
           [0006]    However, the prior art does not address significant risks to the patient and caregiver when injecting fluids into the chamber.  
         SUMMARY OF THE INVENTION  
         [0007]    An environmental control device for the treatment of tissue according to the present invention comprises a chamber having a bellows configuration that is scalable to tissue around its periphery. A resealable access port is provided in order to introduce and extract fluid from the chamber. The access port includes a lift tab for lifting the portal to an angle roughly perpendicular to the tissue, in order to minimize the risk of injury to both the patient and the caregiver. The chamber is comprised of a transparent layer for viewing the tissue overlaid by the device.  
           [0008]    The device serves to provide a controlled environment for tissue treatment. Treatment of wounds can be accomplished by providing a wet environment over the wound site. The chamber is placed over the wound site, and a solution may be injected into the chamber through the injection port. Other elements, such as growth factors or genetically altered cells may be provided within the solution. A simple saline solution may be provided to keep the wound area wet, which has been shown to accelerate wound healing over a dry environment.  
           [0009]    An additional embodiment provides for maintenance of growth factors, cytokines, and other genetically altered cells for enhancing wound healing. It is anticipated that cellular matrices, such as that described in U.S. Pat. No. 5,824,331, issued to Usala, and assigned to Encelle, Inc., may be suspended within a gel-like medium, and injected or held within the present invention, in order to facilitate the healing of wounds.  
           [0010]    The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or by modifying the invention as will be described. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the following Detailed Description of the Invention, which includes the preferred embodiment. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    These and other features and advantages of the invention will now be described with reference to the drawings of certain preferred embodiments, which are intended to illustrate and not to limit the invention, and wherein like reference numbers refer to like components, and in which:  
         [0012]    [0012]FIG. 1 is an overhead view of an environmental control device for tissue treatment having a needle insertion port utilized in accordance with the present invention.  
         [0013]    [0013]FIG. 2 is an exploded view of the component parts of an environmental control device for tissue treatment utilized in accordance with the present invention.  
         [0014]    [0014]FIG. 3 is a cross-sectional view an environmental control device for tissue treatment utilized in accordance with the present invention.  
         [0015]    [0015]FIG. 4 is a perspective view of an access port and finger tab of an environmental control device for tissue treatment utilized in accordance with the present invention.  
         [0016]    [0016]FIG. 5 is side angle view of an environmental control device utilized in accordance with the present invention.  
         [0017]    [0017]FIG. 6 is an overhead view of an alternate embodiment of an environmental control device utilized in accordance with the present invention. 
     
    
     DESCRIPTION  
       [0018]    Although those of ordinary skill in the art will readily recognize many alternative embodiments, especially in light of the illustrations provided herein, this detailed description is exemplary of the preferred embodiment of the present invention, the scope of which is limited only by the claims that may be drawn hereto.  
         [0019]    The present invention is an environmental control device for treatment of tissue. The treatment of tissue may include treatment of wounds, including burns, incisional wounds, excisional wounds, ulcers, traumatic wounds, and chronic open wounds. Additionally, tissue treatment may include treatment of skin disorders, hair follicle treatment or stimulation, skin grafting, and introduction of genetically altered or synthetically developed cells or matrices. The term “wet environment” as used herein refers to fluids (in both liquid and/or gaseous form) or gel-like solutions or suspensions. The above referenced treatment modalities and definitions are meant to be exemplary and are not intended to limit the scope of the present invention.  
         [0020]    Referring now to FIGS. 1 and 2 in particular, there is illustrated the primary components of a device that operates in accordance with the present invention. The present invention is a device  10  that includes an expandable liquid impermeable membrane  12  that may be pleated or otherwise formed into a bellows chamber.  
         [0021]    The bellows membrane  12  may be formed by sealing, such as by a weld, the outer perimeter of a flat sheet of membrane  12   a  to the outer perimeter of a first annular membrane  12   b , which may be ring shaped, to form an outer bond  13   a . The inner perimeter of the first annular membrane  12   b  is fused to the inner perimeter of a similarly shaped second annular membrane  12   c  to form an inner bond  13   b . The second annular membrane  12   c  serves as an attachment ring  14  of the bellows membrane  12  to provide a surface for attachment of the bellows membrane  12  to tissue  17 . Positioning tabs  19   a  are provided at convenient positions, such as at opposing ends of the attachment ring  14 , to allow for ease of manipulation of the bellows membrane  12  during attachment to the tissue  17 . The bellows shaped membrane  12  is preferably made of a transparent polyurethane material, in order to create a liquid impermeable seal, while allowing visual inspection of the tissue covered by the device  10 .  
         [0022]    An adhesive  15  is bonded to the attachment ring  14  to allow the device  10  to be adhered to an area of tissue  17  that requires a controlled environment, such as an open wound  16 . The adhesive  15  is comprised of a material that allows it to be easily removable from a laminate, such as the release liner  22 , but that also provides for a fluid tight seal to the tissue  17 , for an extended period of time. The adhesive  15  is such that it will maintain a fluid tight seal between the attachment ring  14  and the tissue  17 , despite the shear and pressure forces that may be applied to the area of the tissue  17  being treated by the device  10  during everyday activities. For example, the adhesive material must be able to maintain a fluid tight seal should the present invention  10  be applied to tissue located on the abdominal region of a patient who is still able to maintain normal daily activities. It is contemplated that an acrylate adhesive may be used, such as that sold by Entrotek Corporation under part number ECA- 134 . Alternate adhesives may also include polyisobutylene, such as that sold by Corium under the Cor-tak X trademark designation. Silicone adhesives, such as that sold by Nusil Technologies under part number Med 1356, may also be used. Similarly, a styrene adhesive, such as that sold by National Starch Corporation under part number Durotak-87-6173 may also be utilized. The above referenced adhesives are provided by way of example and are not intended to limit the type of adhesive utilized in the present invention. It is to be understood that other adhesives may be utilized that are capable of maintaining a fluid tight seal between the attachment ring  14  and the tissue  17  for up to approximately five to seven days, or longer if necessary, without the necessity of reapplying the adhesive  15  to the device  10 .  
         [0023]    A stabilizer layer  18  is provided for support of the bellows membrane  12 , and is removably attached along the upper portion  14   a  of the attachment ring  14  prior to adhesion to the tissue  17 . The stabilizer layer  18  is a semi-rigid piece of material, such as a stiff paper or thin cardboard material, having a shape and size substantially similar to the attachment ring  14 . The stabilizer layer  18  is coated with a laminate like material or otherwise treated, to allow the stabilizer layer  18  to be easily removed from the attachment ring  14  with minimal force, and without damage to the attachment ring  14  or the stabilizer layer  18 . An incision, or slit  20 , may be may be cut through one or both opposing ends of the stabilizer layer  18  to aid in the removal of the stabilizer layer  18  without disruption to the bellows membrane  12 . Positioning tabs  19   b  are provided at convenient positions, such as at opposing ends of the stabilizer layer  18 , to further aid in the removal of the stabilizer layer  18  when desired by the user.  
         [0024]    The release liner  22  is removably attached to the adhesive  15  to allow the device  10  to be handled without exposing the adhesive  15  to surfaces not intended for application of the device, and otherwise aid in the handling of the device  10 . The release liner  22  is treated, or is comprised of a material that lends itself to easy removal from the adhesive layer  15  without damage or reducing the adhesive properties of the adhesive layer  15 . In practice, the release liner  22  is removed just prior to attachment of the device  10  to the area to tissue  17  to be treated.  
         [0025]    The amount of time required for the device  10  to be applied to the tissue  17  is dependent upon the type of treatment to be used, and the anatomical location of the affected tissue. For example, utilization of the device  10  to decontaminate a wound will likely require a relatively short-term treatment protocol of 1-3 days. However, utilization of the device  10  for bacteriostatic treatment of a wound, in order to limit or prevent the bacterial count in a wound, may require a longer term of approximately 5-7 days of treatment. Other anticipated uses of the device  10 , including gene therapy or epithelial cell seeding, may require treatment durations in excess of 7 days.  
         [0026]    Referring back to FIGS. 1 and 2, the device  10  also includes a resealable access port  24  for introduction or extraction of fluid material within the bellows membrane  12 . The access port  24  is formed from an elastic, latex-like material that is capable of maintaining a fluid tight seal despite repeated penetrations, such as by a hypodermic needle  28  shown in FIG. 5, utilized to introduce material within membrane  12  of the device  10 . An exemplary material for use of the access port  24  may include isoprene.  
         [0027]    The access port  24  is preferably bonded to a finger tab  26 , which in turn is bonded to the membrane  12 , preferably positioned 0.5-2.0 centimeters from the outer bond  13   a  of the device  10 . The finger tab  26 , as illustrated in FIGS. 4 and 5, provides a means for lifting the access port  24  away from the tissue  17  in order to reduce the risk of injury to the patient during insertion of the needle  28 . The finger tab  26  is of a size ideally suited to be easily grasped between the thumb and forefinger of a user, as depicted in FIG. 4. A reinforcing weld  27 , which may be “T” shaped, is provided to prevent the access port  24  from being lifted to an angle that may risk puncturing the membrane  12  during insertion of a needle  28  through the access port  24 . The distance  27   a  between the access port  24  and distal portion  27   b  of the reinforcing weld  27  is of a measurement sufficient enough to prevent the access port  24  from being positioned at an angle that allows the access port  24  to touch the inside portion of the membrane  12 , or otherwise risk puncture of the membrane  12  during insertion of a needle  28 , and is preferably between about 1.0-2.0 centimeters. The reinforcing weld  27  also serves to reduce the risk of injury to the user when inserting a needle  28  through the access port  24 . The risk of injury is reduced by preventing the user from grasping or holding the finger tab  26  less than about 1.0-2.0 centimeters from the access port  24 .  
         [0028]    The distance  27   c  between the distal portion  27   b  of the reinforcing weld and the distal edge  26   a  of the finger tab  26  is of a measurement sufficient enough to allow an average sized thumb and forefinger to comfortably grasp and hold the finger tab  26 , and yet not long enough to allow the user to grasp the finger tab  26  without lifting the access port  24  to a sufficient distance away from the tissue  17 . The distance  27   c  is preferably between about 1.5-2.5 centimeters.  
         [0029]    Turning now to FIG. 6, there is illustrated an alternative embodiment of the present invention, in which the device  10  is in an elongated, or elliptical form. It is anticipated that the preferred embodiment of the present invention will be a circular shape, as depicted in FIG. 1, and having an approximate diameter of about 10-14 centimeters. However, it is to be understood that the actual size and shape of the device  10  is only to be limited by the nearly infinite size and shape of wounds or tissue areas to be treated by the present invention.  
         [0030]    While the invention has been described herein with reference to certain preferred embodiments, these embodiments have been presented by way of example only, and not to limit the scope of the invention. Accordingly, the scope of the invention should be identified only in accordance with the claims that will follow.