Patent Application
20130139321
This invention relates in general to inflatable cellular cushions and mattresses and, more particularly, to a resilient grid for use with an inflatable cellular cushion that facilitates proper positioning of an individual on the cushion, improves seating stability and positioning, protects against bottoming out and promotes air circulation around the cushion cells. The grid improves cooling and reduces moisture retention between the cushion and the user positioned on same.
Those individuals who are confined to wheelchairs or beds run the risk of tissue breakdown and the development of pressure sores which are extremely dangerous and difficult to treat and cure. Heat and humidity are additional risk factors for skin break down. Inflatable cellular cushions or mattresses provide the most uniform distribution of weight and thus provide the greatest protection from the occurrence of pressure sores. These cushions or mattresses generally comprise a base with an array of closely spaced air cells that project upwardly from a common base. The inflatable air cells are generally arranged in longitudinal and transverse rows, with a predetermined space or interstices between the cells. Each air cell exerts essentially the same restoring force against the user's body. In a sense the typical cellular cushion or mattress provides a highly displaceable surface that tends to float the user. The inflatable air cells can be interconnected and/or arranged in inflation zones.
In use, a cushion, for example, is placed on a support surface, such as a wheelchair seat or the like. The cushion is inflated and the user is seated on the cushion. The cushion is slowly deflated to allow the seated user's buttocks to sink into the cushion until the buttocks are about an inch or so above the base of the cushion. The inflation valve is closed. This position should provide an optimum uniform pressure on the tissue of the buttocks. Often this positioning is done by feel. In some situations if the individual user or care giver is not properly trained, the user is not optimally seated on the cushion. Too much or too little air is released.
In some situations the inflated cells along the periphery of the cushion flail, which decreases stability of the seated user and impairs the effectiveness of the cushion in that area of the user's anatomy. Also, in rare situations a cushion can deflate, for example, due to a puncture, faulty valve or other reason. Once the cushion, or a section thereof, deflates, the user “bottoms out”, with the buttocks or other part of the anatomy coming to rest on a support surface. Such a bottoming out situation could result in tissue damage or pressure sores.
Although the cellular cushions or mattresses work well for their intended purposes, it would be advantageous to provide a means for stabilizing the inflatable air cell cushion, to facilitate positioning of a user on the cushion and to provide some means for lessening the deleterious effects of “bottoming out.”
It also would be advantageous to reduce the temperature and humidity or moisture at the cushion/skin interface to prevent breakdown of the skin.
One aspect of the invention is a resilient grid for use with a cellular cushion or mattress, the grid comprises a plurality of structural members that define a plurality of openings, for example, like a latticework, each opening dimensioned to fit around a cell of a multi-cellular cushion, mattress or mattress overlay when the grid is positioned on the base of the cushion or mattress. When the grid is in place, each cell of a cellular cushion or mattress product protrudes through an opening of the grid. The cross members of the grid occupy the interstices between the cells to facilitate air flow among the cells. With grids constructed of certain materials movement of a user on the cushion and grid may cause the resilient grid to either compress to expel air or expand to draw in air, i.e, breathe, thereby further enhancing air flow among the cells for cooling and drying.
In another aspect of the invention the grid facilitates initial set-up and adjustment of the user on the mattress or cushion. For example, the cushion is inflated and the user is positioned on the cushion. The air in the air cells is adjusted until the user is immersed into the cells until positioned just above the resilient grid.
In another aspect of the invention the resilient grid positioned on the base of the cushion or mattress provides additional protection against bottoming out in the event the inflatable cushion or mattress leaks air. The user comes to rest against the resilient grid rather than a harder support surface such as a chair seat, conventional mattress or the like.
Further, the resilient grid provides stability to the cells that are positioned in the grid and prevents cells, particularly on or around the peripheral edges of the cushion or mattress, from flailing or moving in use.
In another aspect of the invention the grid comprises support sections for positioning under select areas of the user's anatomy, and bolsters along the edges of the grid to provide stability and positioning.
In another aspect, the grid is provided in modular units.
One aspect of a support grid of the present invention is indicated by reference number 10 in the drawings. The grid is intended to be used with a support cushion or mattress that has a base with an array of independent, upstanding cells across the base.
Grid 10 is constructed from a resilient material, for example, polyurethane foam or similar material. The foam can be closed cell or open cell. Other types of materials can be employed such as three dimensional knit spacer fabric where opposing monofilaments are vertically aligned to form a vertical support structure. The choice of material for the grid is based upon the support or air flow characteristics desired in any given grid.
Grid 10 includes a body 12 that comprising a plurality of structural members 13. The structural members may be arranged in transverse and longitudinal rows, as seen in the drawings and may be referred to as cross members. Although the width of the cross members may vary, in one aspect structural members 13 are approximately ¼ inch to ⅜ inch wide. In any event, the width of the cross members can be any width depending upon the size of the space between the cells of an inflatable air cell cushion, as will be explained.
Similarly, the height of the elements of the grid structural members can vary depending upon the material used to form the grid and the support characteristics desired. In one preferred aspect of the invention the grid is approximately ¼ inch to 1 inch in height, more preferably about ½ inch to ¾ inch in height. However, any height that meets the desired functional characteristics of the grid is encompassed by the scope of the invention. Moreover, sections of grid may be stacked to achieve desired support characteristics.
Grid 10 also comprises margins 14 which, in one embodiment, are ¾ inch in width. However, the margins can be any width and, in certain aspects to be described below, the margins comprise bolsters or the like. In some embodiments, the grid does not have peripheral margins.
The grid may be sized and configured to encompass all of the upstanding cells on a cushion or may be sized appropriately relative to the cellular cushion on which it is placed so that it only occupies a desired area of the cushion, for example, only the seated user's ischial area or the area under the thighs.
In the illustrated embodiment, the cross members extend both transversely and longitudinal to define individual openings 15 and form an array of openings which can be referred to as a grid. It will be noted that, as shown, openings 15 are rectangular and arranged in longitudinal and transverse rows. The arrangement of openings 15 can be any arrangement desired so as to be complementary to the array of cells on the cellular cushion with which it is employed. The openings can be staggered or grouped or of different sizes within the same grid.
The structural members 13 do not have to be linear. For example, the grid may employ structural members that are circular, for example, defining openings 15 that are circular in cross section. Moreover, the structural members can be oriented to form openings having other configurations such as triangular, ovals, star shapes and so forth.
Also, the number of openings 15 in any individual grid will be determined by the cellular cushion with which it is used, or the area of a cushion on which it will be used. The size of openings 15 may also vary as required. For example, in one aspect of the invention, openings 15 are 1⅜ inch by 1⅜ inch square. However, they can be any size or configuration required for its intended purpose.
In one aspect of the invention, grid 10 is intended for use on a cellular cushion, preferably on an inflatable air cell cushion 16. Although one illustrative use is with an inflatable air cell cushion, grid 10 may be employed with any cushion having an array of individual upstanding cells. And, although the detailed description refers generally to cushions for purposes of brevity and clarity, it will be understood that the same principles apply to use with cellular mattresses and mattress overlays.
In any event, as illustrated cushion 16 includes a base 18 and a plurality of individual upstanding, cells, in this case inflatable air cells 20, arranged in longitudinal and transverse rows across base 18. One preferred inflatable cellular cushion and a method of making it is described in U.S. Pat. No. 4,541,136, which is incorporated herein by reference. There are interstices 21 between the cells. The cells can be isolated or interconnected through the base or can be divided into individual inflation zones, as shown and described, or example, in U.S. Pat. No. 6,697,936, which also is incorporated herein by reference.
Cells 20 can have any cross-sectional configuration. For example, they can be finned, rectangular or any desired shape. The cross-sectional configuration of the cell, particularly at the cell base, generally is complementary to the configuration of opening 15 as defined by the structural members.
Although the illustrated embodiment shows cushion 16 having a generally rectangular configuration with longitudinal and transverse rows of upstanding inflatable cells, the grid of the present invention may be used with any configuration of inflatable air cell cushion or mattress and the construction and inflation characteristics of cushion 16 are incidental to the invention. For example, grid 10 could be used with a cellular cushion having a generally saddle-shaped configuration for use on a motorcycle seat or a substantial circular configuration for use with a stool or other seat. A grid employed on cushions of other configurations only would require that the openings 15 be complementary in configuration to the upstanding cells of the cushion.
As illustrated, body 12 of grid 10 is positioned on base 18 of the cushion. Each individual inflatable cell 20 is positioned within an opening 15 and the cross members 13 surround the exterior of the cell, generally adjacent the base of the cell, creating air flow paths 22 between the cells. The cross members 13 of grid 10 fit around the bottom or base of the inflatable cell such that the upper portion of the inflated cell can expand and form a contiguous support surface. Cross members 13 preserve the integrity of interstices 21 when the cells are inflated creating patent air flow paths and thereby enhancing airflow between the cells.
In use, cushion 16 is placed on a support surface, such as a wheelchair seat with grid 10 positioned on a cushion as explained. Grid 10 may extend over the entire expanse of cushion 16 or may be positioned only on selected areas of the cushion, as explained above. The inflatable cells 20 then are inflated through a valve as understood in the art. The user is positioned on the cushion and air is released from the cells until the user's body, for example the buttocks and ischial area, are properly immersed in the cellular cushion and positioned just above grid 10. The valve is closed to secure the cells in their desired inflated condition. If the cushion 16 is a zoned cellular cushion, the user is positioned on the cushion and it is adjusted as disclosed in U.S. Pat. No. 6,687,936, which is incorporated herein by reference.
In one aspect of the invention, grid 10 can help prevent bottoming-out if the inflatable cellular cushion loses air. The seated user would only sink down until his buttocks came to rest on the resilient grid and hence would not come to rest on a hard support surface that could cause pressure sores or other harm. Hence, the grid can be constructed from an appropriate resilient, yet supportive material that can provide adequate support to a seated user if the air cell cushion bottoms out help prevent the formation of pressure sores, particularly if the bottoming out is temporary or limited in time.
As stated above, in another aspect of the invention, cross members 13 maintain the integrity or patency of the interstices between the cells, which allows more air flow among the cells for cooling and prevent fluid retention.
Moreover, depending upon the material the grid may be compressed and released by movements of the seated user. This alternating compression and release can increase air flow between the cells by a breathing or bellows action to help cool the areas between the i cells and hence cool the user's buttocks and ischial area.
The presence of grid 10 provides for optimum positioning. In cushions without the novel grid, the cushion is placed on a support surface and the user is seated on a cushion, the cushion is inflated. Air is released from the cushion until the user is immersed in the cushion to the optimum depth, generally an inch or so above the support surface. With grid 10 in place, the cushion can be deflated until the user's buttocks are positioned right at the surface of the grid, thereby assuring correct positioning and immersion.
Furthermore, in one aspect of the invention, grid 10 improves stability of the seated user. With cross members 13 surrounding the base of an individual cell, each cell seated in an opening 15 is stabilized to prevent shifting for flailing, particularly cells on the edges of the cushion. Moreover, relatively small grids that fit over only the cells along the edges of the cushions may be employed to prevent flailing of the cells. A smaller grid could be placed under the thigh of a person who had a leg amputated to offset loading and position the seated user more symmetrically. Furthermore, sections of grid may be stacked to vary the support characteristics.
It will be noted that although grid 10 can be a simple, flat rectangular grid, it also can be constructed with other elements to enhance seating stability. As seen in
Furthermore, various elements of a grid may include a first side bolster 26 on one side of the main body and a second side bolster 28 on the opposite side of the main body. The bolsters 26, 28 angle forward and ramp up the downwardly angled wall 24 of front support 23. Front support 23 provides a contoured or rearward angled, raised seating surface for better positioning. Each of the components includes cross members 13 which define openings 15 that fit around cells of the cellular cushion. Grid 10 with bolsters and supports can be a unitary apparatus or provided as modular units with several elements or components. Each of the elements can be constructed of a material that provides for optimal support characteristics. They can be harder or softer. They can be provided as modular elements of varying height. Moreover, they can be stacked to provide customized support.
It will be understood that various changes and modifications may be made in the illustrated embodiments without departing from the scope of the invention. Hence, the description and drawings are intended to be illustrative only and should not be viewed in a limiting sense.
This application claims the benefit of provisional application Ser. No. 61/359,990, filed Jun. 30, 2010, which is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2011/036061 | 5/11/2011 | WO | 00 | 2/8/2013 |
| Number | Date | Country | |
|---|---|---|---|
| 61359990 | Jun 2010 | US |
