Patent Publication Number: US-6987209-B2

Title: Flexible non-contact wound treatment device

Description:
CROSS REFERENCE TO RELATED CASES 
     This application is a continuation of U.S. patent application Ser. No. 09/547,354, filed Apr. 11, 2000 now U.S. Pat. No. 6,580,012, titled FLEXIBLE NON-CONTACT WOUND TREATMENT DEVICE, which is a continuation of U.S. patent application Ser. No. 08/838,618, filed Apr. 11, 1997, now U.S. Pat. No. 6,093,160, titled FLEXIBLE NON-CONTACT WOUND TREATMENT DEVICE, which is a Continuation-in-Part of U.S. patent application Ser. No. 08/342,741, filed Nov. 21, 1994, now U.S. Pat. No. 5,817,145, titled WOUND TREATMENT DEVICE and having common assignee. 
     This application contains material related to the following U.S. patents and pending U.S. applications and all assigned commonly with this application: 
     Ser. No. 07/900,656, filed Jun. 19, 1992 for THERMAL BODY TREATMENT AND APPARATUS, now abandoned; 
     Ser. No. 08/356,325, filed Feb. 21, 1995 for WOUND COVERING, now abandoned; 
     Ser. No. 08/785,794, filed Jan. 21, 1997 for NORMOTHERMIC HEATER WOUND COVERING now U.S. Pat. No. 5,986,163; 
     Ser. No. 08/786,713, filed Jan. 21, 1997 for NORMOTHERMIC TISSUE HEATING WOUND COVERING, now U.S. Pat. No. 5,964,723; 
     Ser. No. 08/786,714, filed Jan. 21, 1997 for NEAR HYPOTHERMIC HEATER WOUND COVERING, now U.S. Pat. No. 5,954,680; 
     Ser. No. 08/843,072, filed Apr. 11, 1997 for FLEXIBLE NON-CONTACT WOUND TREATMENT DEVICE WITH A SINGLE JOINT; and 
     Ser. No. 08/999,353, filed Dec. 29, 1997 for WOUND COVERING, now U.S. Pat. No. 5,947,914. 
    
    
     TECHNICAL FIELD 
     This invention relates to a wound treatment device and, in particular, to a wound treatment device having a substantial portion of a wound cover that is in non-contact with a wound and capable of delivering heat to the wound. More particularly, the wound treatment device includes a flexion joint that maximizes the ability of the wound treatment device to adapt to the contours and movements of a human body. 
     BACKGROUND OF THE INVENTION 
     A novel mode of wound treatment is disclosed in detail in published PCT Applications WO 94/00090 and WO 96/15745, both owned in common with this application. This new treatment employs a non-contact wound treatment device that covers a wound, forming a treatment volume about and over the wound. An embodiment of such a wound treatment device may be characterized in having a plurality of parts, three of which are useful for the purpose of description. These three parts are an attachment portion, a wound treatment portion, and a transition portion. Each portion serves a respective function. 
     The attachment portion connects and retains the wound treatment device on the skin of a person. The wound treatment portion typically includes a standoff that rises above the person&#39;s skin surface, and a wound cover that spans an open portion of the standoff. Together, the standoff and wound cover define a wound treatment volume and a wound treatment area onto which the wound treatment volume is projected. 
     The transition portion connects the attachment portion to the wound treatment portion. An important function of the transition portion is to adapt the wound treatment device to the contour of the portion of a person&#39;s body where the device is mounted and to movements of the person&#39;s body that deform the wound treatment device in situ. In this regard, an important function of the transition portion is the accommodation of patient motion by the compliance of the transition portion. 
     Achievement of this important function of the transition portion is challenged by the need to maintain the orientation of the wound cover in the wound treatment portion—both in aspect and location—with respect to the wound being treated. The orientation of the wound cover is difficult to maintain when the wound treatment device is mounted on a highly curved part of a body. While the wound treatment devices disclosed in the referenced PCT applications exhibit excellent adaptability in a surface that is parallel to the surface of the body portion where the wound treatment device is mounted, there is impairment of adaptability and disturbance of the orientation of the wound cover due to limited flexibility in the direction of a Z axis that is perpendicular to the surfaces. If the transition portion is substantially perpendicular to the attachment portion, it may buckle in response to body motion or contour and collapse the standoff in the wound treatment portion. The collapse of the standoff of course alters the orientation of the wound cover with respect to the wound, possibly reducing the effectiveness of the wound treatment device. 
     Z axis conformability is especially important for a wound treatment device used on a portion of a person&#39;s lower leg. The lower leg has a very tight radius of curvature. Therefore, when a three-dimensional wound treatment device is curved around a lower leg, substantial stress results that may result in deformation of the shape of the wound treatment device, in some cases even causing the wound cover to contact the wound. 
     SUMMARY OF THE INVENTION 
     The overall flexibility of a wound treatment device is enhanced by an invention based upon the inventors&#39; critical realization that provision of a membrane in the transition portion that connects the wound treatment portion to the attachment portion accommodates patient motion and contour by paying out stored material to flex the wound treatment device in all dimensions of the volume that the wound treatment device occupies. 
     In this invention, the membrane connects the wound treatment portion to the attachment portion, extending between the wound cover and the attachment portion, around the outside of an outer periphery of the standoff in the wound treatment portion. Under the standoff, the membrane attaches to the attachment portion between inner and outer peripheries of the attachment portion. 
     Preferably, the inner periphery of the attachment portion along which the membrane is attached is limited to being contained within the outer periphery of the standoff. This permits reduction of the size of the attachment portion, minimizing the total “foot print” of the wound treatment device. A smaller footprint is generally considered to be advantageous particularly when attaching the wound treatment device to a highly curved part of a person&#39;s body, such as the surface of a lower leg. 
     The membrane, its connection of the wound treatment portion with the attachment portion, and its attachment to the attachment portion along an inner periphery of the attachment portion provide a flexion joint, or a double hinge that maximizes the adaptability of the wound treatment device and maintains the orientation of the wound cover over greater ranges of body curvature and movement than previously obtainable. 
     It is, accordingly, an objective of this invention to provide a flexible, non-contact wound treatment device that adapts to body curvature and motion. 
     Another objective is the provision of a non-contact wound treatment device having a wound treatment portion, an attachment portion, and a transition portion with a membrane connecting the wound treatment and attachment portions. 
     It is a related objective in this latter regard to provide a flexion joint between the wound treatment and attachment portions in the form of a membrane in the transition portion. 
     A significant advantage of the invention is the potential reduction in size of the attachment portion, providing a smaller footprint of the wound treatment device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various figures of the drawing depict illustrative and exemplary forms of the wound treatment device. Throughout the several views, identical reference characters represent similar or equivalent structures wherein: 
         FIG. 1  is a perspective view of one embodiment of the wound treatment device; 
         FIG. 2  is a schematic view of projected areas; 
         FIG. 3  is a schematic view of projected areas; 
         FIG. 4  is a perspective view of a detachable heater in combination with the one embodiment of a wound treatment device; 
         FIG. 5  is an exploded view of the one embodiment of a wound treatment device; 
         FIG. 6  is an exploded view of another embodiment of a wound treatment device; 
         FIG. 7  is a perspective view of a heater system; 
         FIG. 8  is an electrical schematic of a pressure sensitive switch for a heater system; 
         FIG. 9A  is an exploded view of a pressure sensitive switch incorporated into a wound treatment device; 
         FIG. 9B  is a view of a portion of the pressure sensitive switch; 
         FIG. 10  is a perspective view of a passive heater embodiment of the wound treatment device; 
         FIG. 11A  is a schematic drawing depicting an alternate geometry for the transition portion; 
         FIG. 11B  is a schematic drawing depicting an alternate geometry for the transition portion; 
         FIG. 11C  is a schematic drawing depicting an alternate geometry for the transition portion; 
         FIG. 11D  is a schematic drawing depicting an alternate geometry for the transition portion; 
         FIG. 12A  is a schematic drawing depicting functional relationships between several elements of the invention; 
         FIG. 12B  is a schematic drawing depicting functional relationships between several elements of the invention; 
         FIG. 13A  is a schematic drawing depicting functional relationships between several elements of the invention; 
         FIG. 13B  is a schematic drawing depicting functional relationships between several elements of the invention; 
         FIG. 14A  is a schematic drawing depicting functional relationships between several elements of the invention; 
         FIG. 14B  is a schematic drawing depicting functional relationships between several elements of the invention; 
         FIG. 15  is a perspective view of the preferred embodiment of a flexible non-contact wound treatment device that embodies our invention; 
         FIG. 16  is a perspective view of a detachable heater in combination with our preferred embodiment; 
         FIG. 17  is an exploded view of our preferred embodiment; 
         FIG. 18A  is a cross-sectional perspective view of our preferred embodiment of the present invention; 
         FIG. 18B  is the cross-sectional perspective view of our preferred embodiment showing the operation of a membrane in adapting the wound treatment device to body motion; 
         FIG. 18C  is a magnified partial cross-sectional view of our preferred embodiment showing further operation of the membrane in accommodating body motion; 
         FIG. 19A  is a side elevational view of the cross-sectional view of  FIG. 18B  when attached to a human patient; and 
         FIG. 19B  is a side elevational view representing the cross-sectional view of FIG.  18 C. 
     
    
    
     DETAILED DESCRIPTION 
     For an understanding of the invention that is disclosed and claimed in this application, reference is made to  FIGS. 1-10  in which embodiments and elements of a wound treatment device are illustrated. With reference especially to  FIG. 1 , a wound treatment device  10  has a planar upper surface displaced above the skin surface of the patient or person having a wound that is being treated by application and operation of the device  10 . The wound treatment device  10  further includes an attachment surface generally held in a plane or surface that is coincident with the plane or surface of the person&#39;s skin. Together these two surfaces define an enclosed, non-contact volume over a wound treatment site. 
     The wound treatment device  10  that is illustrated in  FIG. 1  may be considered in a general way for the purpose of description. In this regard, the description of a wound treatment device is aided by considering three separate parts of the wound treatment device  10 . These parts are an attachment portion  12 , a wound treatment portion  14 , and a transition portion  16 . Each portion is designed to serve a separate function. 
     The attachment portion  12  is used to connect the wound treatment device  10  to the skin of a patient. The wound treatment portion  14  of the wound treatment device  10  defines a vertical extent or dimension of the wound treatment device  10 , and thus defines the location of the attachment surface. The transition portion  16  connects the attachment portion  12  to the wound treatment portion  14 . The transition portion  16  is provided to improve the comfort and utility of the wound treatment device  10  when the patient moves and stretches the device. 
       FIG. 1  is a perspective view of a wound treatment device  10  applied to a patient&#39;s skin surface  18 . A coordinate system  11  is depicted on the patient&#39;s skin surface  18  and it defines X, Y and Z directions. An attachment portion  12  is formed as an planar rim or flange. This attachment portion  12  is attached to the patient&#39;s skin  18  with an adhesive and it lies in a first XY plane. In this embodiment of wound treatment device  10 , a transition portion  16  is integrally formed with attachment portion  12 . Transition portion  16  rises from the skin surface in the Z direction to connect to a wound treatment portion  14 . In this embodiment, wound treatment portion  14  has a transparent planar wound cover  20  which allows one to see a wound treatment area  28 . Wound cover  20  is supported above the first XY plane by a foam ring standoff  15 . Wound cover  20  lies in a second XY plane that is vertically displaced along the Z-axis by foam ring standoff  15  from the first XY plane. Wound cover  20  and foam ring standoff  15  together form wound treatment portion  14 . The region over wound treatment area  28  is called a wound treatment volume  24 . 
     In this figure, wound treatment device  10  has been applied to a patient&#39;s skin and is in a relaxed state. In this unstressed state one can see an outer periphery  22  of attachment portion  12 . An inner periphery  23  is shown by a crease in the structure where it connects to transition portion  16 . 
     FIG.  2  and  FIG. 3  should be considered together where they show the influence of patient motion on wound treatment device  10 . Both FIG.  2  and  FIG. 3  are top views of wound treatment device  10  of  FIG. 1  with the various portions of wound treatment device  10  projected onto the first XY plane. 
     In  FIG. 2 , the wound covering is shown in a relaxed and un-stretched state having a nominal total projected area  27 . Projected wound treatment area  28  is shown at the center of the wound treatment device  10 . The outline of foam ring standoff  15  may be seen as the crosshatch area bounded by an exterior perimeter  25  of foam ring standoff  15 , and an interior perimeter  26  of foam ring standoff  15 . A transition portion projected area  17  is bounded by inner periphery  23  of attachment portion  12 ; and interior perimeter  26  of foam ring standoff  15 . An attachment portion projected area  40  is shown as that cross hatched area bounded by outer periphery  22  and inner periphery  23  of attachment portion  12 . 
       FIG. 3  shows wound treatment device  10  stretched along the X-axis by patient motion. In comparison to  FIG. 2 , the overall or total projected area  27  of wound treatment device  10  has increased. Attachment portion projected area  40  has increased slightly as attachment portion  12  moves with the underlying skin. Projected wound enclosure area  28  is essentially unchanged in area since in this embodiment foam ring standoff  15  is free move against the skin. The largest percentage area change occurs in transition portion projected area  17 . As wound treatment device  10  deforms in response to patient motion, transition portion  16  is compliant and pays out material permitting the majority of the increase in total projected area  27  to be accommodated primarily by transition portion projected area  17 . 
       FIG. 4  shows a detachable heater  32  positioned for insertion into a pocket formed by pocket cover  21 . Pocket cover  21  is bonded to wound cover  20  and is sized to retain heater  32 . Foam ring standoff  15  and wound cover  20  serve to stabilize the shape of wound treatment device  10  while transition portion  16  accommodates patient motion. Consequently, heater  32  is reliably and comfortably positioned above the wound surface. In general, it is desirable to use a planar heater as heater  32  which has a prescribed heat output per unit area. This form of heater results in a more uniform flux of radiant energy applied to the wound. The amount of heat supplied to the wound area is largely independent of the height of heater  32  above the wound surface within the range of functional heights of this device. In some cases, non-uniform wound area heating might be desirable and therefore the watt density of the heater may be non-uniform across its surface. 
       FIG. 5  is an exploded view of the first embodiment of wound treatment device  10 . Attachment portion  12  and transition portion membrane  36  are formed as a unitary composite shell  38 . Composite shell  38  may be vacuum formed from closed cell polyolefin foams such as Volara-6AS, which is a polyethylene material as sold by Illbruck Inc., of Minneapolis, Minn. It should be apparent that many other materials may be substituted within the scope of the invention. Foam ring standoff  15  may be die cut from foam sheeting of a reticulated polyurethane foam. The absorbency of the foam as well as its mechanical properties can be tailored to the particular wound treatment application. For example, the foam standoff may be impregnated with a medicament such as an antibiotic, antifungal, or antimicrobial material. It may also be desirable to supply a deodorant material or nitric oxide releasing material from the foam standoff. Wound cover  20  and wound pocket  21  may be made from a thin film of polyethylene. In general, the composite shell should be sufficiently self supporting so that when wound treatment device  10  is removed from its release liner, wound treatment portion  14  is held up or supported by the shaped flexion joint of transition portion membrane  36 , and some effort is required to evert composite shell  38  and turn it inside out. This behavior defines the self supporting feature which causes foam ring standoff  15  to lie gently against the skin even when wound treatment device  10  is upside down. For larger wound coverings it may be desirable to apply a tacky adhesive to the patient contact surface of the standoff. 
       FIG. 6  is an exploded view of another embodiment of wound treatment device  10 . Attachment portion  12  and transition portion membrane  36  are formed as a unitary composite shell  38 . In this embodiment, the wound treatment volume is defined by a serrated cup standoff  34 . Standoff  34  may be made from a more rigid polymeric material, such as polyethylene, or the like. The serrations typified by a plurality of serrations  44  permit serrated cup standoff  34  to flex and accommodate patient motion. This embodiment shows a release liner  42  coupled to attachment portion  12  of composite shell  38  with an adhesive  46 . In this embodiment, pocket cover  21  is bonded to composite shell  38 . 
       FIG. 7  depicts a portable power supply  48  to provide for the ambulatory use of the heated versions of the wound treatment device. A collection of battery cells may be wired together to form power supply  48  which may be conveniently attached to a belt  49 . A suitable cable  50  may be used to conduct power to heater  32 . In many instances, it may be desirable to cut off power to heater  32  if wound treatment device  10  is collapsed against the wound so as to prevent overheating of the wound surface. 
       FIG. 8  shows a schematic representation of a touch switch  52  which may be incorporated directly into detachable heater  32 . Heater  32  includes a continuous resistive heating coil  51 . A conductive membrane makes up touch switch  52  and is arranged near heating coil  51  so that it may “short out” segments or portions of coil  51  it touches. In use, all power to heating coil  51  is completely turned off by pressure applied to an entire touch sensor  53 . 
       FIG. 9A  shows an exploded version of heater  32  incorporating a touch switch  52  of the type described schematically in  FIG. 8. A  switch cover  45  has a conductive membrane which is located over the conductive pattern of heating coil  51 . It is held in position with an adhesive band  54 .  FIG. 9B  shows the underside of switch cover  45  showing a plurality of discrete insulation bumps typified by a bump  47  which serve to space and support touch switch  52  above heating coil pattern  51 . Pressure supplied to switch cover  45  inactivates heater coil  51 . 
       FIG. 10  shows an accessory device  55  or cover. This may take the form of a passive heater (or insulator) with a reflective surface facing the wound. Accessory device  55  may also take the form of a mapping grid where a grid work of lines is positioned on a transparent card to permit tracking of the wound healing process. 
     FIG.  11 A through  FIG. 11D  should be considered together. These drawings facilitate a description of the connection of the various structures of the invention and represent several alternative connection geometries. In general, to accommodate patient motion, the transition portion pays out stored material to increase the projected area of the transition portion. Each of these drawings represents a mechanical schematic cross section of a wound treatment device  10  in the XZ plane. In each Figure, the wound covering is in the relaxed state. 
       FIG. 11A  shows a schematic view of a ring standoff  15  extending from a first plane  56  to a second plane  58 . Transition portion  16  has a transition portion membrane  60  which is coupled to attachment portion  12  by a first flexible connection  62  formed at the intersection of attachment portion  12  and transition portion  16 . Transition portion membrane  60  is connected to treatment portion  14  at a second flexible connection  64  which is formed at the intersection of transition portion  16  and wound treatment portion  14 . Wound treatment portion  14  is generally a cylindrical cup-shaped structure defining a wound treatment area on the patient skin surface. A minimum interconnection distance  66  is depicted as a dashed line extending from first flexible connection  62  to second flexible connection  64 . The length of minimum interconnection distance  66  can be used to characterize the “length” of transition portion membrane  60 . For many embodiments of the invention, the length of transition portion  16  between first flexible connection  62  and second flexible connection  64  is greater than the length of the straight line drawn between these points. This relationship is true for many embodiments of the wound treatment device when they are in the relaxed or unstressed position. It should be noted that the vertical distance between first plane  56  and second plane  58  represents a minimum value for minimum interconnection distance  66 . In the XY plane, first flexible connection  62  forms a first perimeter  61  and a second perimeter  63 . In the embodiment depicted in  FIG. 11A , first perimeter  61  is larger than second perimeter  63 . 
       FIG. 11B  is a mechanical schematic diagram which represents a cross section of another embodiment of the wound treatment device  10  with an alternate connection geometry. In this drawing, wound cover  20  extends radially beyond wound treatment volume  24  so that a second perimeter  68  is greater than a first perimeter  71 . This generates a reflex transition portion  74  construction which may be adopted to increase the “length” and amount of material in the reflex transition portion  74 . 
       FIG. 11C  shows a construction where a first perimeter  76  and a second perimeter  78  have approximately the same value and are both concentric with an axis  90 . This construction can produce an undulated transition portion  77 . Once again, the length of undulated transition portion  77  exceeds the length of a line  65  between first perimeter  76  and second perimeter  78 . 
       FIG. 11D  shows a hemispheric shell  70  as wound treatment portion  14 . In this embodiment a second perimeter  80  is a single line of attachment that is generally concentric with axis  90 . In this embodiment, a first perimeter  81  has a length which greatly exceeds the length of second perimeter  80 . This construction forms a hemispheric transition portion  79  which has a length which exceeds the linear distance between second perimeter  80  and first perimeter  81  along a line  85 . 
     Although the various geometries vary in detail, it is preferable to form transition portion  16  from a resilient material which is generally self-supporting, yet sufficiently flexible so that it acts as a compliant hinge mechanism. This flexibility substantially limits the transfer of shearing force from wound treatment portion  14  to attachment portion  12  of the wound treatment device  10 , and visa versa. With the geometries set forth in FIG.  11 A through  FIG. 11D , transition portion  16  of wound treatment device  10  forms a shaped flexion joint or formed expansion joint which stores “material” in a pleat, convolution, bellows, or the like. This type of structure provides a means for expanding the size of transition portion  16  resulting in minimizing the transfer of forces from attachment portion  12  to wound treatment portion  14 . 
     FIG.  12 A through  FIG. 14B  should be considered together. In these embodiments of the invention, the standoff structure reduces in height resulting in increased transition portion projected area  17  during the stretching of the wound treatment device. 
       FIG. 12A  shows a part of a wound treatment device having foam ring standoff  15  in the unstressed or relaxed state. In this instance, transition portion projected area  17  is proportional to a dimension  88 . In  FIG. 12B , the wound treatment device has been stretched and the height of foam ring standoff  15  is reduced in the Z direction which has increased transition portion projected area  17  as represented by dimension  91 . 
       FIG. 13A  shows a part of a wound treatment device having serrated cup standoff  34  in the unstressed or relaxed state. In this instance, transition portion projected area  17  is proportional to a dimension  98 . In  FIG. 13B , the wound treatment device has been stretched, and the height of serrated cup standoff  34  is reduced in the Z direction. The serrated wall sections splay out to permit the height reduction which increases transition portion projected area  17  as represented by a dimension  99 . 
       FIG. 14A  shows a part of a wound treatment device having foam ring standoff  15  in the unstressed or relaxed state. However, in this construction attachment portion  12  and a transition portion membrane  96  lie entirely in first plane  56 . In this instance, transition portion projected area  17  is proportional to a dimension  94 . In  FIG. 14B , the wound treatment device has been stretched and the height of the foam ring standoff  15  is reduced in the Z direction. This height reduction increases transition portion projected area  17  represented by a dimension  92 . 
     The Invention 
     Our flexible, non-contact wound treatment device is illustrated in  FIGS. 15-19B  where the same reference numerals specify identical parts throughout the drawings. 
       FIG. 15  is a perspective view of a flexible, non-contact wound treatment device  100  for application to a patient&#39;s skin surface. An attachment portion  102  is formed as a collar or flange. This attachment portion  102  is for attachment around a wound through an adhesive layer on the underside of the attachment portion. Our preferred embodiment of wound treatment device  100  also embraces a wound treatment portion  104  that includes a wound cover  105 , described below, supported by a support member in the form of a standoff  106 . A transition portion  108  connects the wound treatment portion  104  to the attachment portion  102  and preferably includes a membrane  110  that extends around an outer periphery of the support member  106  and is attached to the attachment portion  102  between inner and outer peripheries thereof. 
     Referring now to  FIGS. 15 and 17 , in the wound treatment device  100 , the attachment portion  102  is an integrated, unitary assembly preferably having three sections: a foam layer  111 , an adhesive film layer  112  on a bottom surface of the foam layer  111 , and a release liner  113  covering the adhesive film layer  112 . One or more lines of weakness or perforation  114  are provided on the release liner  113  so that its parts may be separated and selectably peeled off of the adhesive film layer  112 , thereby to expose the adhesive film layer  112  a section at a time for application to a person&#39;s skin. The foam layer  111  may comprise a naturally open-celled polyurethane foam. The foam layer  111  is preferably approximately ⅛″ thick. The adhesive film layer  112  may comprise a high MVTR thin film, pressure sensitive adhesive (PSA) laminate available as a package under the trade name Mediderm from Bertek. The foam layer  111  is heat bonded to the adhesive film layer  112 . The material of which the adhesive film layer  112  is comprised is selected for a combination of adhesion level, permeability, and conformability (stretching and flexing with the skin) to allow prolonged skin contact, without complications. The release liner  113  is a white release paper coated with a release agent that is provided on the Mediderm 3701 product. The perforations or slits  114  are made during assembly to aid in the removal of the release liner  113  prior to attachment of a wound treatment device to a person. 
     When  111 ,  112  and  113  are assembled, the attachment portion  102  is a flexible collar shaped part with an inner periphery portion  111   i  on an upper surface  111   s  of the foam layer  111  around an inner perimeter, or edge,  111   e.  The upper surface  111   s  faces, and is therefore disposed under, or beneath, the support member  106 . The attachment portion  102  further includes an outer perimeter, or edge,  111   o.    
     The wound treatment portion  104  includes the support member  106 , which is preferably a ring of absorbent foam such as a naturally open-celled polyurethane foam that is selected to have favorable characteristics of absorbency, leaking and resevoiring. Such material is available as a product sold under the trade name Aquazone from Foamex. The support member  106  has an upper surface  107 , a lower surface ( 109  in FIGS.  18 B- 19 B), an outer perimeter, or edge,  118  and an inner perimeter, or edge,  119 . The thickness of the support member  106  is preferably in a range extending from ½″ to ⅝″, with the exact dimension being selected to maintain non-contact at wound sites whereby, during use, the foam ring can compress and conform without the wound cover contacting the wound. The wound cover  105  in the preferred embodiment includes a layer  120  preferably of 4 mil.-thick clear, flexible polyurethane film with favorable characteristics selected, but not limited, to include moisture vapor transfer, oxygen permeability, and transmission of infrared radiation. Such material is available as a product sold under the trade name Deerfield 6100S. The layer  120  is attached to the upper surface  107  of the support member  106  by a ring  124  of adhesive comprising a synthetic rubber-base adhesive such the product sold under the trade name HL-2306-X by H. B. Fuller Adhesive. When the layer  120  is attached to the upper surface  107  of the support member  106 , a perimeter portion  121  of the layer  120  extends out beyond the outer perimeter  118  of the support member  106 . The wound cover  105  further includes a stretcher layer  125  attached to the layer  120  so that the layer  120  is sandwiched between the stretcher layer  125  and the upper surface  107  of the support member  106 . The stretcher layer  125  is a 5 mil-thick planar sheet of (preferably) clear, somewhat flexible polyester film having enough stiffness to aid in maintaining planarity of the wound treatment portion  104 . The function of the stretcher layer  125  is to hold the layer  120  taut, much as a “stretcher frame” tautens an artist&#39;s canvas. The stretcher layer  125  is attached to the layer  120  by a layer  126  of adhesive comprising a clear flexible polyester carrier film coated on both sides with an aggressive adhesive. The adhesive layer  126  is oriented over the support member  106 . A film carrier allows for the adhesive to be run in a web process and die cut during manufacturing of the stretcher layer  125 . The stretcher layer  125  further includes a pair of slits  128  that receive a detachable heater. With the provision of the slits  128 , a pocket is formed between the stretcher layer  125  and the layer  120 . 
     The transition portion  108  includes a lower collar  130  that is preferably formed from the same material as the layer  120 . The transition portion  108  also includes the outer perimeter portion  121  of the layer  120  that extends out beyond the support member  106  when assembled thereto. When the wound treatment device  100  is assembled, a circumferential edge  122  of the layer  120  is joined to a corresponding circumferential edge  132  of the lower collar  130 . Preferably, the edges  122  and  132  are sealed or welded together by a heat process. When so joined, the outer perimeter portion  121  of the layer  120  and the lower collar  130  form the membrane  110 , which extends over the outside of the outer perimeter  118  of the support member  106 . The lower collar has a ring-like shape that includes an inner periphery  131 . An inner periphery portion  133  comprises an annular portion of the lower collar material on a surface of the lower collar that faces away from the lower surface  109  of the support member  106 . The lower surface  109  is not shown in  FIG. 17 , but may be seen in  FIGS. 19A and 19B . 
     The membrane  110  of the transition portion  108  is attached to the attachment portion  102  by heat-bonding or otherwise connecting the inner periphery portion  133  of the lower collar  130  at or near the opposing inner periphery portion  111   i  of the attachment portion  102 . 
     Many variations of the assembly illustrated in  FIGS. 15 and 17  are possible. For example, the support member  106  could be contained within the structure formed by the layer  120 , lower collar  130 , and attachment portion  102 , unattached to any portion of the structure. 
       FIG. 16  shows a detachable heater  140  positioned on the wound cover  105  within a pocket formed between the layer  120  and the stretcher layer  125 , with the opening to the pocket provided by one of the slits  128 . The wound cover  105 , with the heater  140  contained within the pocket, is supported substantially in a plane or surface above a wound by the support member  106 . The heater  140  is generally planar and may be connected to and powered by a portable power supply such as that illustrated in FIG.  7 . 
     Refer now to  FIGS. 18A-18C  in which  FIGS. 18A and 18B  show details of the wound treatment device  100  when assembled and put in use.  FIG. 18A  illustrates the relationship of the attachment portion  102  with respect to the support member  106  of the wound treatment portion  104 . In this regard, when the wound treatment device is assembled and placed on a flat surface, the attachment portion  102  and wound treatment portion  104  substantially align along the inner perimeters  119  and  111   e.    
     The seal between the inner periphery portion  133  of the lower collar  130  and the inner periphery portion  111   i  of the attachment portion  102  lies beneath the lower surface of the support member  106 . This is the surface that is indicated by reference numeral  109  in  FIGS. 19A and 19B . Preferably, the seal joining the inner periphery portions  133  and  111   i  is a continuous, closed-loop seal. Although, for reasons explained below, this is the preferred location of the seal between the lower collar  130  and attachment portion  102 , the inventors contemplate that the seal could comprise a substantially continuous, closed-loop trace anywhere between the outer perimeter  111   o  and inner perimeter  111   e  of the attachment member  102 . 
     In  FIGS. 17 and 18A , the seal between the edges  122  and  132  of the layer  120  and lower collar  130  is exaggerated as a flange. In practice, the shape of the membrane  110  extending from an upper outer edge  107   ue  of the upper surface  107  to a lower outer edge  118   be  of the outer perimeter  118  is rather elongated, with the flange much less pronounced than shown in FIG.  18 A. Of course, the membrane  110  in the extent from the edge  107   ue  all the way down to the seal that joins the inner periphery portions  133  and  111   i  is not attached, and is therefore free from, although in close proximity to, the outer perimeter  118 , lower edge  118   be  and lower surface  109  of the support member  106 . 
     Referring now to  FIGS. 18B-19B , the flexible, non-contact wound treatment device  100  of this invention is suitable for placement onto a skin surface  150  of a patient or person so as to include a selected wound area  152  that abuts a treatment volume  156  within the wound treatment device  100 . This attachment may be directly to the skin surface  150 , or on another member such as an ostomy ring that is, in turn, mounted or attached to the skin surface  150 . As  FIGS. 18B-19B  demonstrate, the flexible, non-contact wound treatment device  100  of this invention satisfies the objective previously stated by a capability of being conformably attached to an uneven, changing surface supporting a wound treatment portion  104  that remains reasonably or substantially planar in its shape, regardless of body contour or movements. In this regard, as  FIGS. 18B and 19B  illustrate, the attachment portion  102  operates as a hinge or flexion joint that pivots at the seal between the inner periphery portions  133  and  111   i.  Relatedly, the attachment portion  102  is free to conform to the shape of the skin surface by flexibly deforming between the inner and outer perimeters  111   e  and  111   o.  At the same time, the wound treatment portion  104  is relatively undeformed so that the support member  106  is able to support the layer  120  and stretcher layer  125  in a relatively planar orientation with respect to the wound area  152 . In the meantime, the wound treatment device  100  forms a barrier between the wound treatment volume  156  and the ambient atmosphere by virtue of the seal between the edges  122  and  132  of the layer  120  and lower collar  130 , and the seal between the inner periphery portions  133  and  111   i.  The bottom of the wound treatment device  100  is sealed to the skin  150  when the release layer  113  is peeled off so that the adhesive film layer  112  seals to the skin surface  150 . 
       FIGS. 18C and 19B  illustrate the conformability of the wound treatment device  100  provided by flexion of the membrane  110  in the transition portion  108 .  FIGS. 18C and 19B  are “snap shots” of the flexible, non-contact wound treatment device  100  after placement as described above with reference to  FIGS. 18B and 19A  and after movement of a body part on which the device  100  is placed. In these figures, movement is accommodated by excess length in the membrane  110 . In  FIGS. 18C and 19B , the membrane  110  has tensioned along the perimeter  118  to provide strain relief between the lower edge  118   be  of the support member  106  and the seal between the inner periphery portions  133  and  111   i.  In addition, the flexibility of the membrane  110  and its freedom from the outer perimeter  118  and lower surface  109  permit a play out of excess length of the membrane  110  that abuts the outer perimeter  118  of the support member  106 . This moves the membrane  110  into close touching engagement with the outer perimeter  118 , while lengthening the amount of membrane  110  available between the lower edge  118   be  and the inner periphery portion  111   i.    
     In another aspect, as  FIGS. 18C and 19B  show, the membrane  110  acts as a double hinge or a double pleat between the lower edge  118   be  of the support member  106  and the attachment portion  102 . A first hinge pivot or pleat is at the seal between  133  and  111   i.  This hinge permits the attachment portion to pivot toward and away from the wound treatment portion. The second hinge—at edge  118   be —allows the wound treatment portion to move toward and away from the attachment portion. Manifestly, the same effect could be achieved by attachment of the membrane  110  to the lower surface  109  inside of the edge  118   be.    
     Three significant advantages result from placement of the attachment portion  102  beneath the support member  106  of the wound treatment portion. 
     First, in plan, the shapes and extents of the bottom surface  109  and the attachment portion  102  align and largely overlap, thereby reducing the “foot print” of the wound treatment device  100  to a single, substantially annular shape from the two concentric shapes of  FIGS. 2 and 3 . 
     Next, the double hinge (or pleat) provided by the membrane  110  increases the conformability of the wound treatment device to shape and movement, while maintaining the planarity of the wound cover and preventing its contact with a wound. 
     Last, the lower collar  130 , in extending substantially to the inner perimeter  111   e  of the attachment portion  102  forms a barrier to moisture and wound exudate which may be absorbed by the support member  106 , thereby reducing maceration of skin underneath the attachment portion  102 . 
     While the invention has been illustrated by means of specific embodiments and examples of use, it will be evident to those skilled in the art that many variations and modifications may be made therein without deviating from the scope and spirit of the invention. However, it is to be understood that the scope of the present invention is to be limited only by the appended claims.