Abstract:
Systems and methods for providing a self deflating cushion whereby a volume of air within the cushion is controllably released to a surface of the cushion thereby providing a cooling effect to the seated anatomy of a user. The cushion further provides a variety of internal, open cell cushioning materials that store and release air during use of the cushion.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to system and methods for providing an air cushion. Specifically, the present invention relates to an air cushion having a plurality of air chambers configured to permitted leakage of air in a controlled manner, thereby providing a cooling effect to a user. 
         [0003]    2. Background and Related Art 
         [0004]    Thermal interaction between the body and seating surfaces can result in elevated tissue temperature and moisture build-up, which may increase the risk of pressure ulcers associated with prolonged ischemia or due to macerative damage. Both the materials and geometry of current commercial seating and cushioning systems are thought to influence the body-support surface microclimate. Although much attention has been directed to the reduction of ischemia-initiated soft tissue injury through mechanical means, the influence of tissue temperature and the effect of moisture have been neglected. 
         [0005]    Support surfaces such as wheelchair cushions, other seating surfaces, and mattresses can have a major influence on the microclimate experienced by the interfacing tissues and are thought to be the result of a complex interaction between tissue physiology, environmental conditions, and the properties of the materials used in the construction of the seating system when loaded by the body and their overall geometry. The requirements of users of seating systems also vary considerably depending on levels of exertion, environmental conditions, and physiological factors, including those that may be associated with pathology, such as reflex sweating or vulnerability to hyper- or hypothermia. 
         [0006]    Thus, while techniques currently exist that relate to seating surface optimization, challenges still exist. Accordingly, it would be an improvement in the art to augment or even replace current techniques with other techniques. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention relates to system and methods for providing an air cushion. Specifically, the present invention relates to an air cushion having a plurality of air chambers configured to permitted leakage of air in a controlled manner, thereby providing a cooling effect to a user. 
         [0008]    In some implementations of the present invention, a cushion is provided having features whereby a volume of air within the cushion is controllably leaked through a top surface of the cushion to provide a cooling effect to a user. Following removal of the user, the elastic properties of the cushion causes the cushion to resume its original configuration thereby causing air to be drawn into the cushion via the top surface. In some implementations the top surface includes an opening proximate to a desired anatomy of the user such that an increased rate of air flow through the opening causes additional cooling to the targeted user anatomy. In other embodiments, the top surface includes a breathable material having a porosity configured to achieve a desired rate of air flow. 
         [0009]    Further, in some implementations of the present invention an enclosure is provided as a base for the top surface. The enclosure includes an interior lumen wherein various cushion materials are disposed. In some implementations, the enclosure further includes a non-breathable coating or covering such that air flow in and out of the cushion is restricted to the top surface. In other implementations, a one-way valve is provided between an exterior environment and the interior lumen whereby air is rapidly brought into the interior lumen via the one-way valve. The enclosure generally includes an open cell foam material that displays elastic properties following structural deformation. Still further, in some implementations an air exhaust port is provided in the coating to enable air flow between the enclosure and the interior lumen. 
         [0010]    Some implementations of the present invention further include an internal lumen having a plurality of distinct air chambers. In some implementations a barrier is provided between adjacent air chambers to permit air passage therebetween at a desired rate of flow. Air chambers are further fitted with cushioning materials to provide support, comfort and structural stability to the cushion device as needed. 
         [0011]    Some implementations of the present invention further include a gel insert disposed between the interior lumen and the top surface. The gel insert generally includes a gel or gel-like material provided to increase the user comfort associated with using the cushion. In some implementations the gel insert includes a plurality of gel pads disposed in a breathable film material. 
         [0012]    The present invention further provides a method whereby a cushion device in accordance with the present invention is manufactured. 
         [0013]    These and other features and advantages of the present invention will be set forth or will become more fully apparent in the description that follows and in the appended claims. The features and advantages may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Furthermore, the features and advantages of the invention may be learned by the practice of the invention or will be obvious from the description, as set forth hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    In order that the manner in which the above recited and other features and advantages of the present invention are obtained, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. Understanding that the drawings depict only typical embodiments of the present invention and are not, therefore, to be considered as limiting the scope of the invention, the present invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
           [0015]      FIG. 1A  is a perspective view of a cushion device in accordance with a representative embodiment of the present invention; 
           [0016]      FIG. 1B  is a cross-section view of a cushion device in accordance with a representative embodiment of the present invention; 
           [0017]      FIG. 2A  is a cross-section view of a cushion device in accordance with a representative embodiment of the present invention; 
           [0018]      FIG. 2B  is a cross-section view of a cushion device in accordance with a representative embodiment of the present invention; 
           [0019]      FIG. 3  is a perspective view of an enclosure in accordance with a representative embodiment of the present invention; 
           [0020]      FIG. 4  is a perspective view of an enclosure encased in a non-breathable coating in accordance with a representative embodiment of the present invention; and 
           [0021]      FIG. 5  is a perspective view of a gel insert in accordance with a representative embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    The present invention relates to system and methods for providing an air cushion. Specifically, the present invention relates to an air cushion having a plurality of air chambers configured to permitted leakage of air in a controlled manner, thereby providing a cooling effect to a user. 
         [0023]    As used herein, the term “open cell” refers generally to any material containing pores that are connected to each other and form an interconnected network. Some uses of the term “open cell” refer to foam materials that relatively soft. 
         [0024]    As used herein, the term “closed cell” refers generally to any material not having interconnected pores. Some uses of the term “closed cell” refer to foam materials having higher compression strength relative to open cell materials. 
         [0025]    As used herein, the term “gel” refers to a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are further defined as a substantially dilute crosslinked system, which exhibits no flow when in the steady-state. 
         [0026]    As used herein, the term “exterior surface” refers to a visible surface of a component. 
         [0027]    With reference now to  FIG. 1A , a perspective view of an air cushion  10  is shown. In some embodiments, air cushion  10  comprises an outer enclosure  20  having a top surface  30 , a bottom surface  40 , and a perimeter surface  50 . Enclosure  20  generally provides a container for housing various components of cushion  10 , as described below. 
         [0028]    In some embodiments, bottom surface  40  and perimeter surface  50  comprises a unitary structure having an opening  22 . Opening  22  may include any size and/or dimensions necessary to provide access to an interior lumen  24  of enclosure  20 . Thus, in some embodiments enclosure  20  comprises a box-like configuration having an open top. For these embodiments, top surface  30  is subsequently added to enclosure  20  thereby providing an enclosed interior lumen  24 . 
         [0029]    Some embodiments of enclosure  20  further comprise a non-breathable covering or coating  26  applied to an exterior surface  28 . Coating  26  provides a barrier to prevent or limit passage of air between interior lumen  24  and exterior environment  12  via bottom and perimeter surfaces  49  and  50 . In some embodiments, coating  26  comprises a polyvinyl chloride (PVC) material applied directly to exterior surface  28 . In other embodiments, coating  26  comprises a non-breathable material sleeve, jacket or casing (such as PVC) having an interior space into which enclosure  20  is inserted. Further, in some embodiments coating  26  comprises an air exhaust port to control air flow between interior lumen  24  and enclosure  20 . 
         [0030]    Enclosure  20  generally comprises a compressible material selected to provide adequate support to a user. For example, in some embodiments enclosure  20  comprises a semi-rigid compressible polymer material having elastic properties. Non-limiting examples of a suitable polymer material include open cell foam, reticulated foam, foam rubber, visco elastic foam, memory foam, and closed cell foam. The elastic properties of enclosure  20  cause the structure to resumes its shape following use. In some embodiments, a density of enclosure  20  is selected based on an anticipated load. For example, a cushion enclosure designed for a child may include a material having a lesser density than a cushion enclosure designed for use by an adult. 
         [0031]    Further, in some embodiments enclosure  20  includes a size and/or diameter configured for use in a specific application. For example, in some embodiments enclosure  20  is configured for use as a wheel chair cushion. In other embodiments, enclosure  20  is configured for use as a car seat cushion. Still further, in some embodiments enclosure  20  is configured for use as at least one of a chair cushion, a bicycle seat cushion, and an airplane seat cushion. 
         [0032]    Top surface  30  acts as a barrier between inner lumen  24  and an exterior environment  12 . In some embodiments, top surface  30  comprises a microporous, breathable material such as a Gore-Tex® material, a Stomatex® material, and/or a polyester microfiber. In other embodiments, top surface  30  comprises a breathable, woven or non-woven material having a waterproof coating, such as a polyurethane coating. Other non-limiting examples of suitable materials may include Membrain™, Conduit™, Hyvent™, Cloudburst Stretch EV3™, and H2NO™ materials. 
         [0033]    In some embodiments, top surface  30  is sealedly coupled to enclosure  20  to close opening  22 . The microporous structure of top surface  30  controls and/or limits passage of air, vapors and liquids from exterior environment  12  into interior lumen  24 . Conversely, the microporous structure of top surface  30  controls and/or limits passage of air from interior lumen  24  into exterior environment  12 . Thus, top surface  30  acts as a valve between interior lumen  24  and exterior environment  12 . 
         [0034]    In some embodiments, the rate of exchange between interior lumen  24  and exterior environment  12  is a function of the top surface  30  material pore-size. For example, in some embodiments top surface  30  comprises a material having a pore-size to prevent passage of vapors and fluids, yet readily permit passage of air. In other embodiments, top surface  30  comprises a material having a determined pore-size to permit passage of air at a desired rate. Still further, in some embodiments top surface  30  comprises a plurality of layers, wherein the combined porosity of the individual layers results in a desired rate of exchange between interior lumen  24  and exterior environment  12 . 
         [0035]    In some embodiments, the rate of exchange between interior lumen  24  and exterior environment  12  is a function of the top surface  30  material pore-size, and a force or load being applied to cushion  10 . For example, in some embodiments top surface  30  permits passage of air from interior lumen  24  into exterior environment  12  as a result of increased pressure within interior lumen  24 . Such increased pressure may occur due to a user sitting on the cushion  10 . Further, in some embodiments top surface  30  permits passage of air from exterior environment  12  into interior lumen  24  as a result of decreased or negative pressure within interior lumen  24 . Such negative pressure may occur as a result of excessive air loss from interior lumen  24 . Such negative pressure may also occur as enclosure  20  elastically resumes it initial shape following removal of a user. The negative pressure is neutralized as a volume of air passes through top surface  30  to refill interior lumen  24 . 
         [0036]    In some embodiments, top surface  30  further comprises an opening  32  to permit increased air flow proximate to a desired anatomy of a user. For example, in some embodiments an opening  32  is provided approximate to the perineum of a user. In other embodiments, an opening  32  is provided approximate to the buttocks of the user. Further, in some embodiments an opening  32  is provided approximate to at least one of the genitalia, legs, arms, back, head, neck and/or feet of the user. 
         [0037]    Opening  32  may include any quantity, size and configuration necessary to provide a desired air flow to a targeted anatomy of a user. For example, in some embodiments opening  32  comprises a single hole having a diameter to approximate the area of the desired user anatomy. In other embodiments, opening  32  comprises a plurality of adjacent openings having a cumulative diameter to approximate the area of the desired user anatomy. For example, in some embodiments opening  32  comprises a plurality of punctures having a controlled size and pattern to effect directed cooling relief Further, in some embodiments opening  32  comprises a region of top surface  30  having an increased pore-size relative to the remaining pore-sizes of the material. 
         [0038]    In some embodiments, interior lumen  24  further comprises a gel insert  60 . Gel insert  60  generally includes a polymeric cushioning material placed adjacent to top surface  30 . In some embodiments, gel insert  60  provides textural comfort to a user. In other embodiments, gel insert  60  provides ergonomic structure to accommodate the anatomy of a user. 
         [0039]    Some embodiments of gel insert  60  comprise a plurality of gel pads  62  arranged in a desired configuration and disposed in a matrix of breathable film material  70 . Non-limiting examples of gel pads  62  may include Ultra-Soft® blue gel, viscoelastic polymers, plastisol, silicon, an aerogel, a cationic polymer, an organogel, a xerogel, and copolymers of vinylpyrrolidone, methacrylamide, and hydrogel N-vinylimidazole. Non-limiting examples of film material  70  may include Gore-Tex®, Stomatex®, polyesther microfiber, polyurethane, Membrain™, Conduit™, Hyvent™, Cloudburst Stretch EV3™, woven materials, non-woven porous materials, and H2NO™ materials. In some embodiments, the permeability of gel insert  60  permits passage of air between interior lumen  24  and top surface  30 . In other embodiments, the permeability of gel insert  60  is combined with top surface  30  to provide a desired rate air exchange between interior lumen  24  and exterior environment  12 . 
         [0040]    Some embodiments of cushion  10  further comprise a cushion insert  80 . Insert  80  generally comprises a cushioning material configured to provide support to a user. In some embodiments, insert  80  comprises a plurality of individual cushioning unit  82  arranged in a desired pattern or configuration. Cushioning units  82  may include any open or closed cell materials, as described above. In some embodiments, cushioning units  82  comprise a combination of cushioning materials having various densities, as shown in  FIG. 2A . 
         [0041]    In some embodiments, top surface  30  comprises a membrane  38  laminated to a fabric material  36 , as shown in  FIG. 1B . In some embodiments, membrane  38  comprises a plurality of pores  42  of controlled size and placement in a desired pattern. The size and placement of the plurality of pores  42  is generally selected so as to provide desired air flow to tissue locations of greatest risk. In some embodiments, pores  42  are provided by puncturing an air-impervious membrane  38  with a needle or blade in the appropriate locations to provide a desired pattern or shape. In other embodiments, membrane  38  comprises a grid work of holes or pores that are selectively occluded with an occlusive ink or paint to provide a desired air-flow pattern. Further, in other embodiments membrane  38  comprises a breathable material to which is added an occlusive ink or paint to selectively limit the breathability of the material so as to provide a desired air-flow pattern. By coating the membrane to create a pattern of non-occluded locations or pores  42  at the points of interest, it is possible to generate a proper discharge rate of air to cool the desired body contact areas. Further, the embodiments of the present invention provide for a slow, controlled discharge rate of air thereby providing a period of cooling relief between patient relief lifts. 
         [0042]    Referring now to  FIG. 2A , a cross-section cushion  10  is shown. In some embodiments, cushioning units  82  comprise a first cushioning material  84  forming a base portion. In some embodiments, material  84  comprises a material having a density sufficient to support the weight of a user. Material  86  generally comprises a lower density material to provide tactile or textural comfort to the user. Thus, as the user sits on top surface  30 , gel pads  62  and material  86  provide combined textural comfort while material  84  provides structural support to the cushion  10 . In some embodiments, the intermittent spacing of cushioning units  82  increases blood circulation in the user&#39;s interfacing anatomy, and further provides channels whereby air may leak though top surface  30  to interact with the user. Further, in some embodiments materials  84  and  86  are porous, resilient, elastic materials that naturally resume their shape or configuration following removal of the user. As such, following removal of the user materials  84  and  86  resume their initial shape thereby drawing in a volume of air through top surface  30  and recharging cushion  10  with usable air. 
         [0043]    In some embodiments, cushion  10  further comprises a breathable barrier  90  interposed between an upper chamber or first air chamber  100  and a lower or second air chamber  110 . In some embodiments, barrier  90  is sealedly coupled to the exterior surface  28  of interior lumen  24 . The microporous structure of barrier  90  controls and/or limits passage of air between first air chamber  100  and second air chamber  110 . Thus, barrier  90  acts as a valve between first and second air chambers  100  and  110 . In other embodiments, cushion  10  comprises a single air chamber  100 , as shown in  FIG. 2B . Further, in some embodiments cushion  10  comprises a single air chamber  100  having a porous top surface  30 . Still further, in some embodiments cushion  10  comprises a single air chamber  100  having a porous top surface  30  and a porous membrane  70 , as shown. 
         [0044]    With continued reference to  FIG. 2A , in some embodiments barrier  90  is entirely impervious to air such that air exchange between the first and second air chambers  100  and  110  does not occur. Thus, in some embodiments the function of the first air chamber  100  is independent from the function of the second air chamber  110 . For example, in some embodiments the first air chamber  100  comprises an air-exchange function with exterior environment  12 , while the second air chamber  100  functions only to retain a base cushion  94 . In other embodiments, air exchange between the first air chamber  100  and exterior environment  12  is independent from air exchange between the second air chamber  110  and exterior environment  12 . 
         [0045]    In some embodiments, the rate of exchange between first and second air chambers  100  and  110  is a function of barrier  90  material pore-size. For example, in some embodiments barrier  90  comprises a material having a pore-size to readily permit passage of air between the adjacent air chambers. In other embodiments, barrier  90  comprises a material having a determined pore-size to permit passage of air at a desired rate. Still further, in some embodiments barrier  90  comprises a material having a pore-size that is greater than the pore-size of top surface  30 , such that air passes through top surface  30  at a rate slower than the air-passage rate for barrier  90 . In some embodiments, the pore-size of barrier  90  is approximately equal to the pore-size of top surface  30 . 
         [0046]    Some embodiments of cushion  10  further comprise a base cushion  94 . Base cushion  94  generally comprises an open or closed cell material, as discussed above. In some embodiments, base cushion  94  comprises a reticulated foam, such as a Dry-Fast™ open cell foam. In some embodiments, base cushion  94  comprises a material having a density greater than cushion insert  80  thereby providing additional structural stability to the cushion  10 . In other embodiments, the porosity of cushion  94  provides storage of air that will be ultimately dispersed to a user via top surface  30 . Further, cushion  94  generally comprises an elastic material such that upon removal of the user, cushion  94  resumes it initial shape thereby drawing in a volume of air through top surface  30  and barrier  90 . 
         [0047]    In some embodiments, enclosure  20  further comprises a one-way valve  46 . Valve  46  is generally disposed on a perimeter surface  50  of enclosure  20  and provides one-way fluid communication between exterior environment  12  and at least one of first and second air chambers  100  and  110 , respectively. In some embodiments, one-way valve  46  is provided as a means for rapidly recharging or refilling air chambers  100  and  110  following removal of the user from top surface  30 , such as a pressure relief lift. Thus, valve  46  generally limits air flow to passage of air from exterior environment  12  into air chambers  100  and/or  110 . 
         [0048]    In some embodiments, enclosure  20  further comprises an air pump  66 . Air pump  66  provides air flow for rapidly recharging or refilling air chambers  100  and  110 . Air pump  66  may be useful for either refilling air chambers  100  and  110  during a pressure relief lift or for filling air chambers  100  and  110  while the patient remains seated, such as for a quadriplegic patient. In some embodiments, air pump  66  is battery powered. In other embodiments, air pump  66  is powered by the power source of a wheel chair or patient bed. 
         [0049]    Referring now to  FIG. 3 , a perspective view of enclosure  20  is shown without coating  26 . Of particular note is exterior surface  28 . In some embodiments, exterior surface  28  comprises an exposed, outer surface of enclosure  20 . Thus, exterior surface  28  refers to the visible outer surface of enclosure  20 . In some embodiments, exterior surface  28  is covered with non-breathable coating  26 , as shown in  FIG. 4 . In other embodiments, a plurality of air exhaust ports  34  is provided in coating  26 . Ports  34  provide fluid communication between enclosure  20  and interior lumen  24 , such that air within the material of enclosure  20  is exchanged between the enclosure  20  and interior lumen  24  during use. Further, following removal of the user air is drawn into the interior lumen  24  via top surface  30  and subsequently passed into enclosure  20  via air exhaust ports  34 . 
         [0050]    With reference to  FIG. 5 , gel insert  60  is shown. As previously discussed, some embodiments of insert  60  comprise a plurality of gel pads  62  suspended in a matrix of a breathable film material  70 . Insert  60  may include any size or shape as required by a desired application. In some embodiments, insert  60  is configured to dimensionally correspond to top surface  30  of cushion  10 . In other embodiments, insert  60  is configured to correspond only to those areas of top surface  30  anticipated to contact the user. 
         [0051]    In some embodiments of the present invention, a method for manufacturing a self deflating cushion device includes: (i) providing an enclosure having a top surface, a bottom surface, and a perimeter surface; (ii) disposing a lumen within an interior of the enclosure; (iii) forming a first air chamber within a first portion of the lumen, the first air chamber being positioned adjacent to the top surface; (iv) forming a second air chamber within a second portion of the lumen; (v) interposing a first valve, such as barrier  90 , between the first and second air chambers; and (vi) interposing a second valve, such as a breathable material, between the first air chamber and the top surface. In some embodiments, the method further includes providing an air exhaust port between the enclosure and at least one of the first and second air chambers. Further, in some embodiments a non-breathable covering or coating is applied to an outer surface of the enclosure. Still further, in some embodiments a gel insert is inserted between the first air chamber and the top surface. 
         [0052]    Thus, as discussed herein, embodiments of the present invention embrace system and methods for providing a cushion. Specifically, embodiments of the present invention relates to an air cushion having a plurality of air chambers configured to permitted leakage of air in a controlled manner and to provide a cooling effect to a user. 
         [0053]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Thus, the described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.